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+======================================================================+ | Imagine Mailing List | | FREQUENTLY ASKED QUESTIONS | |----------------------------------------------------------------------| | Compiled By | | Michael B. Comet | | Steve Mund | | Mark Oldfield | | Dave Wickard | +======================================================================+ This is the Frequently Asked Questions posting for the Imagine Mailing list. This posting is sent every so often to answer general questions that users of the 3D rendering software, Imagine by Impulse Inc. may have. It is aimed toward all users, especially newcomers to the program. If you find any errors or have answers to other frequently asked questions that you would like to have included in this posting, please send e-mail to: imlfaq@flip.sp.paramax.com (FAQ List). - Mike C. ======================================================================== Last Update : April 18, 1994 Monday Issue Number : 5 What's New : Section 1, No 1. Added more magazines and archive info Section 5, No 1. Postscript problems in Spline Editor Section 7, No 12. Help with FOG Section 7, No 13. Widescreen rendering Section 7, No 14. Rendering particle Spheres Section 8, No 4. Soap Bubble Attribute Section 8, No 5. Spaceship Panel attribute Section 8, No 6. Using the wrinkle texture Section 9, No 4. Hex edit for high res video change Section 9, No 5. What are particles? ------------------------------------------------------------------------ CONTENTS: ========= SECTION 1 - Support Products/Sites 1] Imagine related: References/Help Books/Magzines/ftp sites. 2] How do I reach Impulse? 3] What is the Imagine Mailing List and how to get it? SECTION 2 - Modeling and Detail Editor 1] How do I brushmap a ground plane? 2] How do I make glass? 3] The Slice command doesn't work or gives me errors. 4] How can I make a room so that the walls don't have cracks? 5] When I select a group of points in the DETAIL editor, all I can do is drag them...not ROTATE or SCALE interactively. 6] List of common Index of Refractions 7] How do you make mirrors? 8] How do I make "metals" and what are some good gold attributes? 9] Is there a quick way to add faces to my object without using the Slice command? SECTION 3 - Forms Editor 1] After a Forms Editor object is loaded into the Detail Editor and manipulated, it won't reload into the Forms Editor. SECTION 4 - Cycle Editor 1] I made this animation sequence in the Cycle editor, but when I set it up in the stage/action editors, the motion of the overall object isn't there! SECTION 5 - Spline Editor 1] I tried to import a Postscript font but I got a "Vector not found" error. What does this mean? SECTION 6 - Animation, Stage Editor and Action Editor 1] Even though I move an Object/Camera/Light to a new POSITION/ALIGNMENT/SIZE in the STAGE editor, Imagine seems to 'forget' what I did! 2] How do I use the Grow Effect? 3] How do I use the Tumble Effect? 4] How do you get something to roll (at the right speed!) while following a path? 5] When I move a Tracked Camera in the STAGE editor, it doesn't realign and draw the Perspective view correctly! 6] When I increase the number of frames in an animation I find my scene gets mangled in the first frame. Why? SECTION 7 - Rendering and the Project Editor 1] Why do objects render fine in Scanline, but disappear in Trace? 2] I have a problem with Filtered objects/fog and the Global Backdrop! 3] My animation frames look fine, but when animated, they have the "crawly" effect. 4] What situations, parameters, attribute values, etc. require the most trace rendering time? 5] How do I get rid of the "Jaggies?" 6] How can I figure out pixel aspect for a given resolution? 7] When making a disco ball effect, will a SPHERICAL light set at 255 be bright enough to cause visible spots on the surfaces in a scene? 8] How long should it take to do a full trace picture with perhaps one transparent glass on a Amiga 3000/25? Is 4.5 hrs too much? 9] Is there any particular format that Imagine prefers? Ham? 32 Color? EHB? 24 bit 1000 x 1000? 10] I would like to use conical light sources with my rendering, is there anyway "see" in wireframe where the light will fall? 11] How important is lighting for a rendering, and is there any "preset" method used to get good results? 12] Help with Fog, How do I use it and how does it work? 13] How can I render in Widescreen/Letterbox format? 14] I selected Spheres for my particle object, but all I get is a polygonal shape! SECTION 8 - Essence Settings and Other Attributes 1] Electrical Arc (Essence) 2] Veined Marble (Essence) 3] Rough marble/rock (Essence) 4] Soap Bubble (Imagine 2.0 and higher) 5] Spaceship Panels (Imagine 2.9 and higher) 6] Bark, mountain, stone effects (Imagine 2.9 and higher) SECTION 9 - Miscellaneous 1] What the heck is BTW, IMO and other weird abbreviations... 2] Rendering and refresh times are MUCH too slow, even with an accelerator. Are there any Basic tricks or hints to help? 3] How long will before my renderings aren't ugly anymore? 4] Hex edit for Imagine - High Res video mode change Amiga only 5] What are Particles? CLOSING - Closing statements and Disclaimer ======================================================================== SECTION 1 - Support Products/Sites ======================================================================== 1] Imagine related: References/Help Books/Magzines/ftp sites. REFERENCES AND HELP BOOKS: "Imagine 2.0 User Manual", Impulse Inc, 1992. (Yes....read the manual!) "The Imagine Companion", David Duberman, Motion Blur Publishing, 1991 "Understanding Imagine 2.0", Steven Worley, Apex Software Publishing, 1992. MAGAZINES: These are some good graphics magazines, most of which focus on the Amiga computer. If anyone has some other suggestions please post them to the FAQ list! "Amazing Computing for the Commodore Amiga" aka "Amazing Amiga" P.O. Box 2140 Fall River, MA 02722-9969 USA (508) 678 - 4200 (800) 345 - 3360 (508) 675 - 6002 (FAX) (A general Amiga computer magazine, focusing more on how to, hints and tips, programming, reviews of software and hardware(less ads and more meat than AW)) "Amiga Video/Graphics Magazine" (formerly AVID) 365 Victor Street Suite "H" Salinas, CA 93907 (408) 758 - 9386 (408) 758 - 1744 (FAX) (A general Amiga computer magazine, focusing on both hardware, software, utilities and graphics) "Amiga World" P.O Box 595 Mt Morris, IL 61054-7900 (800) 827 - 0877 (815) 734 - 1109 (A general Amiga computer magazine, focusing on both hardware, software, utilities and graphics) "AV Video" 701 Westchester Ave White Plains, NY 10604 (800) 800 - 5474 (914) 328 - 9157 (914) 328 - 9093 (FAX) (An audio/video and computer magazine. Has articles about all types of video and graphics applications including the Amiga and Video Toaster) "Computer Artists" P.O. Box 2649 Tulsa, OK 74101-9632 (A magazine specifically for computer artists. Articles on software and methods from Amigas, PC's and MAC's) "Computer Graphics World" P.O Box 122 Tulsa, OK 74101-9845 (800) 443 - 6632 (918) 835 - 3161 ext. 400 (918) 831 - 9497 (FAX) (A general computer graphics magazine focusing on the latest technology from PC's to SGI's) "Video Toaster User" 21611 Stevens Creek Blvd. Cupertino, CA 95014 (800) 322 - 2834 (A magazine focusing specifically on NewTeks Video Toaster device. Nothing related to Imagine, but some more neat pictures to look at!) FTP SITES: There is now a new ftp site set up for Imagine related items including pictures, animations, tutorials, objects, and help files such as previous postings from the list, and this FAQ at: wuarchive.wustl.edu in the /systems/amiga/boing/video/imagine Under this directory are the following sub-directories: art archive anims objects Note: New files cannot be sent directly here. Instead send any new files you wish to upload into the same directory: /systems/amiga/boing/incoming/imagine Files here will/should eventually get moved to the proper location by the ftp site administrator. Don't forget to send a text file explaining the data you uploaded, and where it should be placed. The archives are kept by Nik Vukovljak. They can be found in the archive subdirectory listed above, and in the incoming/imagine directory. New archives may also be posted to aminet. Aminet can be reached on the same FTP site (wuarchive.wustl.edu) under /systems/amiga/aminet. Numerous other sites also have the aminet directories. ------------------------------------------------------------------------ 2] How do I reach Impulse? Impulse Inc. 8416 Xerxes ave. North Brooklyn Park, Minnesota 55444 USA (612) 425-0557 (800) 328-0184 FAX: (612) 425-0701 ------------------------------------------------------------------------ 3] What is the Imagine Mailing List and how to get it (From the Imagine Mailing List Sysop, Dave Wickard) The Imagine Mailing List is a wide variety of Amiga computer artists sharing friendship and knowledge. The main thrust of the List is the Imagine renderer. Subjects discussed though have varied widely. There are discussions of Imagine and it's competitors, Imagine wish lists for future versions, 3D rendering principles in general, single frame recording techniques and many more. With first day users thru battled scarred veterans :-) there is someone at your level of knowledge on the List. We are always glad to see questions from every level of user. So often a simple and seemingly embarrassingly easy question will lead to an interesting comment on a related topic. New products, both hardware AND software, are discussed as to their relationship with Imagine and Amiga 3D rendering. Names of Amiga luminaries dot the list, and often join in to lend their insights without the usual "noise" of a USENET newsgroup. There are over 300 individual sites receiving the Imagine Mailing List, and they include many networks, BBS systems, user groups, and individual computer artists from literally around the globe. We share one thing. Interest in each other's work with Imagine. YOU can get the Imagine Mailing List. All you need is access to Internet mail. Simply mail to the following address: imagine-request@email.sp.paramax.com and in your subject line, enter the word "subscribe". If you are reading this from a Commercial System, ask the Amiga Coordinator to set up an Imagine Mailing List area that everyone can read. ======================================================================== SECTION 2 - Modeling and Detail Editor ======================================================================== 1] How do I brushmap a ground plane? The problem with brushmapping a ground plane is that the ground itself is off 90 degrees in relation to its' axis for proper brush placement. (Add a primitive plane, a ground and compare them). The following will properly set a ground wrap: 1) Add a ground object, select it, go into attributes, select a brush to use. 2) You will now be in a requestor for the type of brushmap and placement etc... 3) Select TRANSFORM AXIS 4) Click on ALIGNMENT and set X = -90. Leave Y and Z at 0 5) Click on SIZE and leave X = +640. Set Y = +2, Z = +400 6) Click on POSITION and Leave X = -320, Y = -200. Set Z = +1 7) Click on PERFORM. 8) If you want the brushmap to repeat forever click REPEAT. 9) Click OKAY. Your brushmap will now be placed correctly. You can of course resize it on the X/Z axis if you wish for scaling purposes. Basically step 4 re-rotated the brush axis properly and 5 and 6 fixed the size and position which Imagine screws up since it thinks it's brushmapping on the other axis. ------------------------------------------------------------------------ 2] How do I make glass? You can use the following Attribute setting for a default glass: RED GREEN BLUE VALUE COLOR 0 0 0 * REFLECT 0 0 0 * FILTER 255 255 255 * SPECULAR 255 255 255 * DITHERING * * * 255 HARDNESS * * * 255 ROUGHNESS * * * 0 SHININESS * * * 0 (Very important see below!) PHONG = ON INDEX = 1.50 FOG LENGTH = 0.00 This should give you glass. One thing many people get confused by is: 1) Shininess must be set to ZERO. If you set this to anything but 0, the FILTER setting will not work. This is just the way Imagine works since FILTER usage assumes shininess automatically. 2) No background. To get glass, you need surroundings. If you render a glass cup on a pure black screen, you'll probably just see the highlights. Adding global colors for Scanline and Ray Trace will give your object something to refract. 3) Ray Trace. To get refraction of surrounding objects exactly, you need to Trace, though scanline WILL approximate refractivity. ------------------------------------------------------------------------ 3] The Slice command doesn't work or gives me errors. Due to the complexity of doing a 3D slice, sometimes Imagine gives errors, or actually crashes during this operation. Things to do if you plan on using this function are: 1) Save _ALL_ currently loaded object BEFORE trying to slice. 2) If you get an error, move one of the objects slightly and try again. Moving one of them may yield a working slice. ------------------------------------------------------------------------ 4] I'm making a house which has many rooms and thus many walls, what is the best way of adding walls to the house so that they leave no cracks in the corners ? Three possible methods --- 1. You can design your walls to be nice dimensions like 100 or 1024 instead of 383.38. Place your axis at the corner of each wall. Then, to get seamless joints, use "snap to grid" in the project editor which will instantly adjust your walls to a perfect fit (If wall lengths are multiples of the grid line spacing). 2. Create a 2D outline of the floorplan and extrude it up. Then simply pop a ceiling and floor on it. The floorplan could be created either in Imagine or even a paint program and then auto-traced. This means you will have to bust up a few polygons to add the windows and doors, but that is a minor task if you have a complex floorplan. 3. A cheesy option is to make your walls too big. Then INTERSECT them. You get a mess BEHIND the wall, but if you don't look there, you'll never see it. wall 1 | ------------------+-- \|/ | bug-eyed O.O | wall 2 monster v | | camera X ------------------------------------------------------------------------ 5] When I select a group of points in the DETAIL editor, all I can do is drag them... it doesn't let me ROTATE or SCALE that clump of selected points. Imagine will let you move selected points, as well as rotate and scale them. The limitation is that you cannot do this interactively in Version 1.1 or earlier by using the mouse: The Transform command does the manipulation. The picked points can be translated, scaled, rotated, and positioned INDEPENDENTLY of the rest of the object. Rotations and scalings all use the object's axis a reference point. Absolute positioning will move the FIRST point you pick to the location you choose, and the rest of the picked points will be translated an equal amount. Interactive dragging is accomplished using the "drag points" mode. Note: Versions 2.0 and later support interactive point editing. ------------------------------------------------------------------------ 6] List of common Index of Refractions (and not so common too!) (All items except Vacuum are in alphabetical order) (STP = Standard Temperature and Pressure) MATERIAL Index ------------------------------------- Vacuum ...................... 1.00000 (exactly) Air (STP).................... 1.00029 Acetone ..................... 1.36 Alcohol ..................... 1.329 Amorphous Selenium .......... 2.92 Calspar1 .................... 1.66 Calspar2 .................... 1.486 Carbon Disulfide ............ 1.63 Chromium Oxide .............. 2.705 Copper Oxide ................ 2.705 Crown Glass ................. 1.52 Crystal ..................... 2.00 Diamond ..................... 2.417 Emerald ..................... 1.57 Ethyl Alcohol ............... 1.36 Flourite .................... 1.434 Fused Quartz ................ 1.46 Heaviest Flint Glass ........ 1.89 Heavy Flint Glass ........... 1.65 Glass ....................... 1.5 Ice ......................... 1.309 Iodine Crystal .............. 3.34 Lapis Lazuli ................ 1.61 Light Flint Glass ........... 1.575 Liquid Carbon Dioxide ....... 1.20 Polystyrene ................. 1.55 Quartz 1 .................... 1.644 Quartz 2 .................... 1.553 Ruby ........................ 1.77 Sapphire .................... 1.77 Sodium Chloride (Salt) 1 .... 1.544 Sodium Chloride (Salt) 2 .... 1.644 Sugar Solution (30%) ........ 1.38 Sugar Solution (80%) ........ 1.49 Topaz ....................... 1.61 Water (20 C) ................ 1.333 Zinc Crown Glass ............ 1.517 ------------------------------------------------------------------------ 7] How do you make mirrors? The trick with mirrors (or especially chrome-like objects) is not setting the attributes of the mirror correctly, but making sure that the environment is set up so something will be reflected into the camera. If a mirror is TOO reflective, the mirror can actually become invisible! This is because the mirror's own flat glass/metal flat coloring is overwhelmed by all the reflected light. You see a PERFECT reflected image, so the object itself isn't shown. This is especially true with flat mirrors. Some attributes that give a nice mirror polish: RED GREEN BLUE VALUE COLOR 150 150 150 * REFLECT 200 200 210 * (a bit of a blue tint) FILTER 0 0 0 * SPECULAR 255 255 255 * DITHERING * * * 255 HARDNESS * * * 255 ROUGHNESS * * * 0 SHININESS * * * 0 PHONG = ON INDEX = 1.00 FOG LENGTH = 0.00 ------------------------------------------------------------------------ 8] How do I make "metals" and what are some good gold attributes? One thing you can do to make your objects look more like metal is to give them a specular setting close to the main color of the object, but higher in intensity. One mistake is to often make the specular a pure white. This makes objects look more like plastic than metal. For example, if you are trying to make gold, don't make the specular pure white, but try a bright yellow or yellow/orange creame color. Another problem is that many metals reflect the world. For example a chrome ball is pretty much just a shiny mirror. Thus, if you want to make realistic metals you will need to at least simulate reflection. This can be done by adding a global reflect map, doing a true ray trace or even just setting sky colors in the stage editor. You can use the following Attribute setting for a default gold: RED GREEN BLUE VALUE COLOR 205 205 80 * REFLECT 180 160 125 * FILTER 0 0 0 * SPECULAR 255 255 160 * DITHERING * * * 255 HARDNESS * * * 255 ROUGHNESS * * * 0 SHININESS * * * 0 PHONG = ON INDEX = 1.00 FOG LENGTH = 0.00 This should give you something close to gold. Note that the reflect values are fairly high. You may wish to lower them to see how it would look if you don't have anything to reflect etc... ------------------------------------------------------------------------ 9] Is there a quick way to add faces to my object without using the Slice command? Here is a neat trick to add faces. This method works best with an object that is basially concave (such as a circle). 1] Make the outline of your object, i.e.: points and edges. 2] Extrude the object a distance away. 3] Pick all the points that were just made...i.e.: The ones that now comprise the back face. Using Bounding box selection would probably be helpful. 4] Choose Join! 5] Translate the now 1 pt back on the Y axis by the distance you extruded from, and position the point somewhere in the center of the object. The object is now a solid faced object with all faces connected to one point on the center, just like the primitive disk object. ======================================================================== SECTION 3 - Forms Editor ======================================================================== 1] I was working in the forms editor on an object, and loaded it into the detail editor for modification. However, I can't seem to be able to get it back into the forms editor! Help! Simply put, you cannot load objects saved from the detail editor back into the forms editor. The reason is the forms editor requires a specified object structure which the detail does not. Thus, saving an object in the detail editor loses that information. When you work with the forms editor is recommended that you keep a spare copy of the FORMS OBJECT saved separately from any detail object. In this way you can then go back and make modifications in the forms editor. ======================================================================== SECTION 4 - Cycle Editor ======================================================================== 1] I made this really great animation sequence in the cycle editor, but when I set it up in the stage/action editors, the motion of the overall object isn't there! When using the cycle editor, Imagine only remembers changes in size, position, and so on in relation to the main parent. Thus, if you make a change to the parent object, it gets forgotten. What this means is if you make a nifty robot jumping cycle, and make it in the cycle editor so the robot actually move up etc... all that will be remembered is the changes to the legs, arms and anything OFF of the PARENT. The overall rotations and movements to the main object will be gone. Two solutions exist. One is to simply make those changes in the stage editor each time you need to. The second is to group a plain axis before you start to your object. (ie: Make the parent have a Null link). Then, you can rotate everything by rotating the main child grouped right under this null axis. This way you aren't moving the "parent", and everything will be remembered. ======================================================================== SECTION 5 - Spline Editor ======================================================================== 1] I tried to import a Postscript font but I got a "Vector not found" error. What does this mean? There are a couple of different formats of Postscript files. If Imagine doesn't like one, it will pop up this or other errors. In that case you will either have to use another Postscript file, or find a software package that will convert it from that format to one Imagine will load. ======================================================================== SECTION 6 - Animation, Stage Editor and Action Editor ======================================================================== 1] Even though I move an Object/Camera/Light to a new POSITION/ALIGNMENT/SIZE in the STAGE editor, Imagine seems to 'forget' what I did! All objects must have timelines split wherever there is a change in position, alignment or size. If you do not set this up, Imagine will forget the changes no matter what. Rather than going back and forth to the ACTION editor and adding timelines, you can have Imagine automatically create the timelines properly so everything tweens as normal. There are the "Position Bar", "Alignment Bar" and "Size Bar" commands under the OBJECT menu in the STAGE editor. So, if you have just gone to a frame and are making a new POSITION, ALIGNMENT or SIZE for an object (or camera or light) to tween to, press RIGHT AMIGA and 7/8/9 respectively. Or use the respective bar commands from the OBJECT menu. This will extend or put a 'split' in the timeline for you (you can check this in the ACTION editor). Also, don't forget to "Save Changes"if you want to keep the motion! ------------------------------------------------------------------------ 2] How do I use the Grow Effect? To use the grow effect, create an object in the DETAIL editor that you wish to have 'extrude' over time. Create a spline path as normal in the detail editor. This will be the path the object extrudes along during the animation. GROUP (not join) the object with the PATH AS THE PARENT. If you do not make the path the parent, it will not work. To do this, select the path, then hold shift and select the object, then select group. Save your GROUP for loading in the animation. Finally, add the effect in the ACTION editor for the grouped object. ------------------------------------------------------------------------ 3] How do I use the Tumble Effect? The tumble effect is used to tumble 1 or more objects during an animation. To tumble an object, create your object or objects in the DETAIL editor. Still in the detail editor add an axis. Group (not join) the AXIS to all the objects you want to tumble with the AXIS AS THE PARENT. Then load the GROUP into the STAGE/ACTION editor and add the effect as normal. NOTE: The reason for the null object (axis) as parent is that Imagine does not TUMBLE the PARENT, just the children. ------------------------------------------------------------------------ 4] How do you get something to roll (at the right speed!) while following a path? Getting an object to spin (like a plane doing a barrel roll) is easy- you align to path, then set Y rotation to be from 0 to 360 and it will do a complete spin. This is not in the right direction for a rolling ball, though. [Annoying feature- you can't say from 0 to 720 for two spins, or 0 to 3600 for ten.] To get it to roll I created a second path, which was basically a larger copy of the first, so the first path was just inside of the second path. I had an axis (a track) follow this new, outside path, then used "align to object" to make the sphere point to the axis. Thus, as the ball moved along its path, one end (the positive Y axis direction) was always pointed at right angles to the direction of motion. Is this clear? Now using the "initial Y angle" and "final Y angle" I set them to 0 and 360 and it rotated as it rolled. As a special effect, I raised the "track path" a little in the Z direction so the sphere looks a little bit like a top rolling around, since the spin axis was not horizontal anymore. An alternative would be to make a cycle object, rolling around the X axis. This is equally valid, but I did it this way first. ------------------------------------------------------------------------ 5] When I move a tracked Camera in the STAGE editor, it doesn't realign and draw the Perspective view correctly! If you have Imagine 2.0 or higher, press RIGHT AMIGA and the K key together, or select "Camera (Re)track" from the OBJECT menu. This will make the camera repoint to the track from the new position and will redraw the perspective view. If you have an older version of Imagine (or if you just want to) you can press RIGHT AMIGA and the C key or select "Goto" from the FRAME menu. Go to the current frame you are already on which will cause imagine to redraw everything. ------------------------------------------------------------------------ 6] I have found that after creating a scene in the Stage editor, and then deciding that I want an animation and adjusting the highest frame count, my scene gets mangled in the first frame. Why? Well, it seems to me that this will happen if you don't split your channel bar from the first frame (where you want stuff to be exactly) to the second frame. I usually setup my scenes so that I have the first frame all set as it should be and then I do my transformation from frames 2-whatever. In this way, the first frame is ALWAYS where it's suppose to be no matter what changes I make in the remaining animation. If you look at your channel it should have a break between frames 1 and 2 and then be continuous (if that's the way your animation works out) from 2 on. ======================================================================== SECTION 7 - Rendering and the Project Editor ======================================================================== 1] Why do objects render fine in Scanline, but disappear in Trace? There are 2 possible causes for this. 1) You are running out of RAM 2) You objects are outside of the World Boundary To check #1 (for the Amiga), pull down The Project editor after you start a render during the initialization phase. Click once on the Workbench backdrop and you should see how much RAM you have on the top of the screen. As Imagine starts to render, this will decrease. If it becomes close to 0, chances are, that's your problem. To solve that, buy more RAM. The other possibility is that the objects are outside of the world boundary. The world boundary is basically a box in which your objects are placed. When you enter the STAGE editor, you are placing objects in this "virtual box" whose center is 0,0,0. When you Trace, Imagine clips ALL objects that fall outside of the box. The size of the world boundary is set in the ACTION editor. In this editor, there should be an item named GLOBALS. Whatever numbers are set in the SIZE timeline becomes the size of the box so that it lies from +/- Value for X,Y and Z. The default is no information present, which Imagine assumes is +/- 1024 units for all 3 coordinates. Thus to fix this problem you can: 1) Scale your entire scene to fit inside the +/- 1024 size boundary 2) Add a size line and set the X,Y,Z to the values you need (This can be found by using "coordinates" in the STAGE editor and moving the cursor around to find the values) 3) Add a size line and set the X,Y,Z sizes to 0,0,0. This will force Imagine to calculate the world size for ALL frames based on where objects are for the FIRST frame. This is important since if your objects move farther out during subsequent frames, you will have to set the size manually (see 2 above) since it will now be outside the computed boundary, and thus clipped. Note: The world boundary has no effect in Scanline rendering. Note: Setting the World Size to 0,0,0 regardless of problems will usually DECREASE Trace times! ------------------------------------------------------------------------ 2] I have a problem with Filtered objects and the Global Backdrop! For some reason, clear or glass like objects will not be clear when used with a backdrop. To get around this render with "genlock sky" and then use an image processing program to composite the rendered image onto the background pic for each frame. Fog objects have a similar problem. ------------------------------------------------------------------------ 3] I have created an animation (Hurrah!) and when I look at each of the individual frames, they look just as I thought they might. However, when I animate them, anywhere I have applied the "roughness" parameter, surfaces look animated...with lots of "crawling" effect on them. What gives? Roughness should NOT be used on objects that will be animated. (Unless of course, the "crawley" effect is what you're after). This is caused by a bug in the roughness algorithm. One of the main work-arounds suggested, is by using a very small or fine bump-map. Another work- around is to create a DPaint (or for that matter ANY IFF) multi-gray shaded screen and apply it as an altitude map. ------------------------------------------------------------------------ 4] What situations, parameters, attribute values, etc. require the most trace rendering time? The list is long: reflections and refractions increase rendering time significantly, anti-aliasing (0 longest)-BTW this you must edit in the .config file and resolve depth (also in .config file), number of polygons, camera position (obliqueness), size of brush maps and even the numerical entries of solid textures, resolution, display and render modes etc etc. The big ones are refraction, edge level(antialiasing, reflection (along with "depth") and #of polygons. Pretty well in that order too. Remember that a higher refraction index is longer rendering time also. And yes the scale of the object means a LOT. Imagine uses something called an *Octree* to calculate the scene. This is related to the world size setting which is also discussed here in article number 1 above. The difference can go from *hours* to minutes, so scale your scene by the size you make your world. You can select everything in the scene (including camera and lights) and scale it interactively. ------------------------------------------------------------------------ 5] How do I get rid of the "Jaggies?" The .config file for anti-aliasing defaults to 30. This is ok, but not great. The best is 0 and final rendering should always be 0. So you must edit this file every so often (before opening Im) or build a front end on the work bench (requires programming knowledge, though). BTW, the anti-aliasing is EDLE in .config file. {for those unfamiliar with the term jaggies - they refer to the way lines drawn by computers tend to haved a jagged or stair stepped appearance, instead of a smooth continuous line. This is usually found more in low resolution images.} ------------------------------------------------------------------------ 6] How do I figure out the pixel aspect for a certain resolution display? I am rendering a picture to be displayed on a macII at 1024x768. Does anyone know the formula or is it device dependent? Pixel aspect ratio depends both on the aspect ratio of the display device (your monitor) and the resolution that fits onto that screen. Most monitors use a 4 x 3 aspect ratio so that to achieve square 1:1 pixels, the resolution must also be 4:3. 1024 x 768 will achieve this as well as 640 x 480. The Amiga typically uses a non-square aspect ratio of about 1.2:1 such as 320 x 200, 640 x 400, 768 x 480, etc. So the pixel ratio can be found using... (horiz res. / horiz display size) : (vert res. / vert display size) If your monitor has a 4:3 aspect, you should have 1:1 pixels. ------------------------------------------------------------------------ 7] When making a disco ball effect, will a SPHERICAL light set at 255 be bright enough to cause visible spots on the surfaces in a scene? No, I bet that a light of 255 won't work too well. So crank it up to 2000! Lights are not limited to 255 (It is logical that lights can be as bright as they want). Values above 500 or so are pretty severe; they cast strong shadows, like a very sunny day. Above 3000 or so and it looks like you're world is lit by nuclear weapons. ------------------------------------------------------------------------ 8] I have a Amiga 3000/25. How long should it take to do a full trace picture with perhaps one transparent (nearly) glass? Does 4.5 hours sound reasonable to you? I am running the floating Point version of Imagine. The floating point version of Imagine uses inline floating point code for maximum speed. It does not use the libraries. I suspect that the non-FP version uses the libraries, just in case. You can probably SPEED UP your trace time SIGNIFICANTLY by scaling up the whole scene in the stage editor (see question 4 above!). A trace time of 4.5 hours on a 3000/25 definitely a "wee bit" on the high side for a scene as simple as you describe. ------------------------------------------------------------------------ 9] Is there any particular format that Imagine prefers? Ham? 32 Color? EHB? 24 bit 1000 x 1000? The best is a 24-bit image, of course. Anything works, but the color range of a 24-bit will beat the tar out of a 16 color any day. Exceptions would be objects with a few discrete colors, like a red, white, and blue flag. Then a 24-bit and a 4 color image are equal in quality. Note that Imagine converts them all to 24-bit internally, though- the memory goes down equally for a 100 by 100 4-color as it does for a 100 by 100 24-bit. ------------------------------------------------------------------------ 10] I would like to use conical light sources with my rendering, is there anyway "see" in wireframe where the light will fall? Note: In imagine 2.9, the ability to turn on 'Light Lines' was added in the Stage editor. The following describes another way to 'see' the light in the Stage editor before this feature was implemented. Of course you can still use this in 2.9 and above. For conical lights, the X-axis size determines the radius of the light beam at the distance set at the Y-axis. This if a light has a X size of 50, and a Y-size of 200, the light would have a circle with the diameter of 100 units at a distance of 200 units from the light's axis itself. You can use this information to create a conical light object in the detail editor. By creating a wireframe light, you can then load the light in and actually "see" and resize it to get an idea for the lights size. Add a primitive cone object. Then position the axis of the cone such that it is at the exact tip op the cone object. Finally rotate and resize the cone's axis so the Y axis extendes to the end of the cone and the x-axis (which should allready be set okay) has the diameter of the cone. The above can be done in 4 steps using the transformation requestor, make sure that the "transform axis only" box is checked in steps 2,3 and 4: 1] Add a primitive cone with default values. 2] Set the Position on the axis -100 on the Z-axis. 3] Set the axis alignment to -90 on the X-axis. 4] Set the axis size to X=50, Y=100, Z=50. Front or side view of cone: Z---X /|\ / | \ / | \ / | \ / | \ +-----|-----+ Y Once this is done you will now have a cone object with the axis set correctly to be a light. It is not yet however a light source. Go into the attributes requestor for the object and click on the box labeled "light". In here is a standard light box just like those in the action editor. Click on conical, and set the color and other options as you wish. At this point you must remove any faces from the object. If you do not do this, when you render the object will will have a white cone. Simply go into "Pick Faces" mode and then "Select All" of the faces and finally "Delete" or "Cut" them. You will now have a wireframe cone light. Save this object. From now on, you can load this as a normal object into you renderings and resize, scale and move the light around as you wish. The only drawback to this method is that to change light parameters such as color or shadows, you must re-edit the object in the detail editor and then resave it. ------------------------------------------------------------------------ 11] How important is lighting for a rendering, and is there any "preset" method used to get good results? Lighting in computer graphics is a very important element in creating images. It takes a while of experimenting with different types of lights and settings to get good results, but there is one basic setup that can also be used as a starting point. The basic approach is one used for lighting real world video scenes. It is known as a "3 point" light setup since it involves 3 light sources. The first light source named the "key" light is the main light for the scene. It is usually placed about 45 degress above and to the side of the camera. This provides overall light so you can see your objects etc... The second light is known as the "back" or "top" light. Place this light above and slightly behind the center of your scene. In video this is used to show highlights on a persons hair so you can tell where the back of their head is. In this case, it provides a similar function so that you can see the back parts of objects. This is typically set at about 2 times the key lights intensity, though for computer graphics a setting equal to or less than that of the key is usually enough. The final light is the "fill" light. This is usually placed at a 45 degress angle below and to the side of the camera so that it is on the opposite side of the "key" light. This light should be dim and possible colored and diffused to give some illumination to any part of the scene not covered fromt the other lights. For rendering this means lowering the intensity and or making the light "diminish in intensity". With this setup there should be an improvement over any rendering using just one light. As a test setup a ground and a stationary object. (The typical chrome ball with cool highlights on a checkered ground works well here) Render once scene with just one light (the key light only). Then add the other 2 or more fill lights and re- render it. There should be a big difference. Also, don't forget that lights can be colored, can cast shadows and can be "conical spotlights". All this can be used to give greater value to your scene. ------------------------------------------------------------------------ 12] Help with Fog, By J. Koszarsky Fog isn't too bad once you get the hang of it. There are a couple problems to be aware of though. Overlapping fogs will cancel each other out wherever they overlap. Fog objects should be closed objects. If you have a tube be sure to close the ends up. And when you scale your object up or down you should be aware that the fog length will not scale with your object, I found this very annoying. Imagine you have a 100x100x100 cube and you make it a fog object. What does the fog length mean? If you make your fog length 50 units and then move a non-fog object into the fog, once it goes beyond 50 units you won't be able to see it anymore. 50 units is the point at which an object inside the fog will be totally obscured by that fog. If you shorten the length to say 25 then the fog will become more dense. Making the length larger creates a less dense fog. If the length is greater than 100 then you will be able to see objects on the other side of the cube. Using global fog in the Stage/Action editors is similar but it is applied everywhere, like an infinite plane. You can however control the heights(Z) where the fog begins & ends. So if you wanted fog in a grave yard you could tell it to start at the ground level and end as high as you want, depending upon what your are looking for in your scene. The fog length works the same as with objects. If it is set to 100 units then any object in your scene that is beyond 100 units will be hidden in the fog. For a very subtle fog I sometimes set my length to 2048 or greater, this is very thin. There is another annoying feature of fogs. It looks great when used for making atmosphere on a planet but it will illuminate the entire planet, no matter where the light source is placed. So you can't get a dark side if you have the fog around the entire planet. You can get around this by using a half sphere fog for the atmosphere and aligning it to your lightsource. ------------------------------------------------------------------------ 13] How can I render in Widescreen/Letterbox format? Besides making for some neat looking animations, this will also lower rendering times. For a render that would normally be 768x482 or so, make it 768x380. Leave the ratio just as it is (6:7). Any where from 380-330 or so will look pretty good. Remember though that Imagine will still show the entire normal view of the animation in the Stage editor's preview window. This means that while you can see objects at the top of the screen here, they might actually be cropped in the final rendering. ------------------------------------------------------------------------ 14] I selected Spheres for my particle object, but all I get is a polygonal shape! In order for you to get spheres in the particle object you will have to render in Ray Trace, not Scanline. Otherwise you end up with a faceted sphere of only a few polygons. ======================================================================== SECTION 8 - Essence Settings and Other Attributes ======================================================================== 1] Electrical Arc (Essence) Here's how to make an electrical arc between two rods, like something out of Frankenstien's lab. 1] Start with a plane with 255 R,G,B on Color and a light blue (or whatever color you want the arc to be) in Filter. 2] Use Ringfract as follows: Set the Z axis to point out of the plane, (rotate 90 on X) Low Trans Start=30 Low Trans Width=5 Hi Trans Start =40 Hi Trans Width =5 Set the color to 0,0,0 for RGB. Leave other settings at defaults Place the axis of Ringfract in the middle of the bottom edge of the plane. 3] Now use Swapcrf to swap the color and filter values. Do this by setting all parameters to 0, and then setting the following values to 1: Filt -> N Color = 1 Refl -> N Refl = 1 Color -> N Filt = 1 Now when rendered, there should be something similar to an electrical arc (or maybe some sort of plasma). To have the arc grow, rotate the Ringfract axis on X up or down so that the plane and cylinder do not intersect at 90 degrees. If you animate this it looks like the arc gets taller until the arc breaks (i.e. the plane no longer intersects Ringfract's cylinder in a curve, but instead in two lines). Also setting the plane to bright will make it look correct in dim scenes. ------------------------------------------------------------------------ 2] Veined Marble (Essence) The veinedmarble texture is used twice, once for large, widely spaced veins. The second use is for finer, closely spaced veins. For veined green marble set the object color to 40,80,40 for Red Green and Blue respectively. The texture veins are a gray-green color. Text#1 Text#2 Parameter Text#1 Text#2 Parameter 800.0 300.0 Initial Scale 4.0 5.0 Turbidity 7.0 7.0 # of Scales 0.9 0.98 Color Level 0.4 0.4 Scale Ratio 120.0 120.0 Color Red 0.6 0.6 Amp Ratio 150.0 150.0 Color Green 0.4 0.4 Time Ratio 120.0 120.0 Color Blue 0.0 0.0 Time 0.0 0.0 Fade 0..1 1.0 1.0 Sharpness 0.0 0.0 20.0 10.0 Vein Spacing 0.0 0.0 Rotate the second texture 45 degrees around the X and Y axes with respect to the first texture. You may want to rotate the first texture as well. ------------------------------------------------------------------------ 3] Rough marble/rock (Essence) This uses 2 textures, one for a main color variation, and the other for the bump/roughness. This is very effective for creating stone surfaces. Try these settings on a primitive plane. Object Attribs R G B Value Color = 136 118 128 Specular = 153 134 132 Dithering = 255 Phong = On All others at 0. Texture 1: fractalcolor Texture 2: bump Parameter Value Parameter Value Initial Scale 15 Initial Scale 5 # of scales 5 # of scales 4 Scale Ratio 0.4 Scale Ratio 0.5 Amplitude Ratio 0.4 Amplitude Ratio 0.5 Time Ratio 0.4 Alt. Adjust 3 Time 0 Fade 0..1 0 Base->1 Trans 0.3 Axis placement left at default 1->2 Trans 0.6 Color 1 End 1 Color 1 Red 70 Color 1 Green 60 Color 1 Blue 60 Color 2 Red 255 Color 2 Green 240 Color 2 Blue 240 Fade 0..1 0 Axis placement left at default When rendered an off gray stone will be created. Great for caverns, dungeons and so on. Just slap it onto the walls or columns to give it good-ol' natural look. ------------------------------------------------------------------------ 4] Soap Bubble (Imagine 2.0 and higher) COLOR REFLECT FILTER SPECULAR R 250 10 192 255 G 215 10 162 245 B 225 10 133 238 Dithering Hardness Roughness Shiniess Index of refraction 0 245 (Or less) 0 0 1.08 Then Add a Pastella Texture with the following data in each column: 102.333374 100.00 0.0 0.0 255.0 255 0.0 180 100.0 80 0.0 110 255.0 0.0 100.0 0.0 Now, try render it, and remember to put a object behind, and try to make several copies, and make a complete bubble bath! ------------------------------------------------------------------------ 5] Spaceship Panels (Imagine 2.9 and higher) This uses the RADWIND, TUBEWIND, or RECTWIND textures to create multicolored spaceship panels: - Add a primitive sphere with it's default values. - Apply the RADWIND texture (or other 2 textures depending on the shape of your object) - Make these adjustments to the texture variables: Column One Two ____ ____ 1 210 *These params will will give you panels that 3 210 are randomly colored from the two color ranges 60 210 defined in column two. 0 190 *Play around with some of the variables to get 1 190 the effect right for you. 0 190 0 -1 0 0 ------------------------------------------------------------------------ 6] Bark, mountain, stone effects (Imagine 2.9 and higher) This uses the WRINKLE texture. - Add default cylinder and CLOSE the TOP - Select the top edges of the cylinder and MAKE SHARP - Apply the WRINKLE texture and render. This will look like bark around the cylinder....play with the noise functions to adjust the look of the bark. Now make these changes to the Texture: Column One Two ___ ___ 0.5 150 * This will look like the sides of a mountain 0.5 150 around the Cylinder. On the top of the 10.0 150 cylinder it will look like granite. 1.0 20 * When applied to organic objects the vertical 0.5 50 faces will have the rivulets, the horizontal 0.0 20 faces will be granite-like. 0.0 0 * Try changing the first three variables in 1.0 0 Column one to 10,10,1 respectively. The resulting look will make the cylinder look like a core sample around the cylinder, while the top of the cylinder will have a marble like quality. ======================================================================== SECTION 9 - Miscellaneous ======================================================================== 1] What the heck is BTW, IMO and other weird abbreviations... BTW is an abbreviation for "By The Way". IMO is an abbreviation for "In My Opinion" IMHO is an abbreviation for "In My Humble Opinion" IML is an abbreviation for "Imagine Mailing List" :) is a sideways smiley face :( is a sideways frowny face ;) is a winking-eye face etc... ------------------------------------------------------------------------ 2] My rendering times and even my refresh times in the editors are much MUCH too slow, even with an accelerator. Is there any basic tricks or hints that are often overlooked that might help me out?" Always be sure to MERGE your objects. This eliminates multiple faces, points and lines. Some objects have a VERY large number of these and it can slow your times down by up to 1/2! ------------------------------------------------------------------------ 3] When does one get good enough so that they don't render ugly pictures! Practice with a simple objects (to cut down trace time) over and over and over. Varying lighting & color etc. This will allow you to get the effect you want which is only a technical problem. ------------------------------------------------------------------------ 4] Hires Video modification for Amiga Imagine From James R. Walker ***Note: The following explains how to modify the actual executable file of Imagine. Do this at your own risk! If you have any problems or end up trashing your copy of the program it is your own fault. It is highly recommended that you make a backup copy of the program before you mess with it. Ok, here's how it works... (If you don't have an Amiga, don't do this!) Get a filezapper type program. (NewZap DPU FileZap Hex etc...) Look up your version of Imagine on the chart below. Edit the executable at the bytes indicated in the chart. The block #s and byte #s are shown in decimal. The hex numbers in parenthesis are the hex versions of the block numbers. The bytes to modify are, of course, in hex. Replace the resolution you find there with the resolution you want. Then save the new file. (I don't have to remind you to keep a backup of Imagine on hand!) Notice that Imagine automaticly doubles the vertical resolution for use in interlace mode. So, if you want vertical resolution of 462 then you must tell it to give you 231. (231 = 00E7 in hex) Imagine Version # Horizontal Vertical FP 1.1 Block 393 ($189) Block 83 ($053) Bytes 220 & 221 Bytes 162 & 163 From 02 80 From 00 C8 (Example: To 02 BC = 700 in dec)(To 00 E7 = 231 dec) FP 2.0 Block 497 ($1F1) Block 95 ($05F) Bytes 328 & 329 Bytes 250 & 251 From 02 80 From 00 C8 INT PAL 2.0 Block 500 ($1F4) Block 94 ($05E) Bytes 124 & 125 Bytes 42 & 43 From 02 80 From 01 00 FP PAL 2.0 Block 497 ($1F1) Block 95 ($05F) Bytes 388 & 389 Bytes 244 & 245 From 02 80 From 01 0 INT 2.9 Block 1561 ($619) Block 119 ($077) Bytes 486 & 487 Bytes 480 & 481 From 02 80 From 00 C8 FP 2.9 Block 1529 ($5F9) Block 95 ($05F) Bytes 82 & 83 Bytes 168 & 169 From 02 80 From 00 C8 FP PAL 2.9 Block 1529 ($5F9) Block 95 ($05F) Bytes 146 & 147 Bytes 162 & 163 From 02 80 From 01 00 Impulse told me, in the past, that Imagine is made to run ONLY on a 640 x 400 screen. I was told that if I changed it, I would do so at my own peril. I pass this information on to you. One Final Note: Imagine PC users have a whole different program than Amiga users. This modification will not work on the PC version. I would guess that a simmilar modification for the PC version would be more complicated, given that VGA modes are more complicated than Amiga modes. ------------------------------------------------------------------------ 5] What are particles? (Note: Particles were add in Imagine 2.9) There are a couple of different meanings and interpretations of what particles and particle animation software should do. In general, a particle is an object, or point in 3D space that is then controled by parameters mimicking real world physics. For example, take a point in 3D and apply motion to it as if it were under gravity. The result would be it would move downward increasing in speed. So you can use particles to simulate wind, exploding, melting and other things that move points in different ways. Particles can also be objects or simple polygonal shapes rather than just points. In imagine, you can make a 'particle object' by modeling a normal object with faces. Then, using the particle requestor in the Detail Editor, specifiy that all faces/polygons of the object be replaced by cubes, spheres, tetrahedrons and so on...or even other objects. When you go to render the object, each face will be replaced with the particle you have chosen. This means in Imagine, you can make objects created out of many 'particles' even though you don't use any particle type of motion. This is true since you could now take that object, and just animate it normally using standard key frame techniques and so on. However, Imagine does have a new method for applying the motion control over these particle objects, (or even normal objects, since it will simply affect the faces). In the Action Editor you can now use the particle effect. This lets you specify how the particle/faces of the object will be affected over the course of an animation. In general, particle systems allow one to simulate complex motion easily. They allow one to create many particle objects and to have their motion defined by mathmatical properties. ======================================================================== CLOSING - Closing statements and Disclaimer ======================================================================== Hopefully this document is useful to people out there. Once again, if there is anything you want added/changed/deleted, please e-mail as listed at the top of the document. What follows is a small disclaimer so no one gets sued for information that is harmful or accidentally incorrect or misleading. (If you find a mistake...please send e-mail so it can be fixed!). Disclaimer: There is no guarantee regarding any information presented in this document. The information may not be correct, useful or helpful. The reader accepts ALL responsibility for actions pertaining to reading this document regardless of consequence. ======================================================================== END OF IML-FAQ -- +--------------------------------------------------------------------------+ | Michael Comet, mbc@po.CWRU.Edu - CWRU, Software Engineer/Graphics Artist | | Computer Graphics/Animation! - Liquid Vision SIG (go liquid), Freenet | +--------------------------------------------------------------------------+