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- GUIBlobs. By Chris Underwood, with optimisation and GUI by Ben Wyatt.
-
- email: csuwz@csv.warwick.ac.uk
- www: http://www.csv.warwick.ac.uk/~csuwz
-
- GUIBlobs is a program for creating splodge effects, like water dropletts on
- a plate of glass. Here's how:
-
- Run the program - double click it's WB icon.
-
- Play with the program - put the threshold slider bar to about half, then click
- the 'add blobject' button. Place a blobject on the screen that appears. Place
- another couple near and overlapping it. When you're satisfied, click the
- render frame button and wait a few seconds (not a few minutes, like it was
- before Ben Wyatt got his hands on the source - cheers Ben) while it draws
- you a pretty blobby picture.
-
- Explaination of the buttons:
-
- Load/Save blobscape
- Load or save the definition of the current blobs.
-
- New blobject
- Place a new blobject on the blobscape.
-
- Delete Blobject
- Remove a blobject from the blobscape.
-
- Delete all
- Remove all blobjects from the blobscape.
-
- View blobscape
- Show the blobject screen.
-
- Linear move
- Set up linear movement for a blobject. This is for animation purposes.
-
- Radial move
- Set up the end size for a blobject in the animation.
-
- Preview anim
- Show a near-realtime rendition of the animation.
-
- Render frame
- Draws a blobject frame. If you have more than one frame, you will be prompted
- for the frame number to be drawn.
-
- Render Anim
- If you have more than one frame, you will be asked for a base save name. Enter
- something like ram:frame, and the anim will be rendered to files ram:frame001,
- ram:frame002 etc.
-
- Frames
- Sets the number of frames to animate over.
-
- Render quility
- Sets the quility of the blob drawings. Fully left is slowest, but best
- quality. Moving the slider to the right changes to a lower quility that draws
- faster.
-
- Colour mapping
- Sets the style of the colour mapping. There are three choices, explained in
- more detail later.
-
- Differential
- Set to sine to make the animation slow down towards it's ends, such that it
- can be ping-ponged smoothly. Set to linear for a constant change between
- frames.
-
- Grid
- On - grid on
- Off - grid off
- Simple, huh?
-
- Density range
- On: Do print the colour range in the top-left.
- Off: Don't do the above!
-
- Threshold
- Sets the threshold of blobbyness. The slider ranges from 1 (far left) to 0
- (far right). More on this later.
-
- The theory of blobbyness:
-
- The blobs that you play with are just like the blob object in POV-Ray (an
- excellent PD ray-tracer for almost all platforms, including Amiga, PC, RiscPC,
- Unix X machines and Macs). The blobs in GUIBlobs are simpler because they
- have no field strength specifier - they are all assumed to be equal field
- contributors. My blobs are also 2D, not 3D. Anyway, how are they drawn?
-
- Well, it's like this: Each blob emits a magic field that becomes weaker the
- further you go from the centre of the blob. What you do is set a threshold
- that the field must be greater than for a blob to exist. All my program does
- is wonder about figuring where this threshold is exceeded. Where it is, a
- pixel is drawn. The colour of the pixel represents how much greater than the
- threshold the field is at that point. Simple, huh? If you didn't get any of
- that it really doesn't matter. Just remember this: Smaller thresholds will
- produce smaller blobs that take longer to render, but they'll look so much
- better that you'll not mind the extra render time. Smaller thresholds tend to
- make the blobs more attractive to each other and you get a lovely effect
- when two are close, but not quite touhing: a small protusion extends from
- each blob towards the other. Spot this with an anim of two blobs slowly
- moving towards each other.
-
- Right - that's about as much as I feel like writing on GUIBlobs. I have other
- progs to document too you know! If you're in the mood for more graphical
- stuff after this, look for DGraph 4D and Sim Water on the Aminet very soon
- (possibly already by the time this gets uploaded). DGraph 4D is another prog
- written by me (Chris Underwood) and optimised by Ben Wyatt. He also gave it
- a pretty WB interface too.
-
- DGraph 4D is a graph renderer. It is a 4D graph renderer though - it will
- create frames for an animation of a changing 3D surface. It will also light
- source the surface so it looks good. Try it.
-
- Sim Water is my newest program. I expect if Ben gets to see it he'll want
- to optimise it because it ain't too quick at the moment. It does create
- rather nice animations of water running down through an IFF picture though,
- so you'll probably like it if you've got enough HD space free to make the
- anims up.
-
- E-Mail me for whatever reason,
-
- CMU
-