Polyray Revision History Version 1.7 Released: 17 March 1994 o Added parametric surfaces. Now possible to define a mesh object (surface) where each point in th emesh is a function of u and v. o Added bump maps o Added noeval to definitions to cure a particle system bug o Added support for JPEG images in textures, etc. o Added support for system calls in 386 version. Can now call an external program from within Polyray. o The default shading flags for raytracing is now set to: SHADOW_CHECK + REFLECT_CHECK + TRANSMIT_CHECK + CAST_SHADOW + UV_CHECK The difference is that it is no longer assumed that surfaces should be lit on both sides (normal correction), this boosts rendering speed at the cost of funny shading once in a while. UV_CHECK was added to allow turning off checking of u/v bounds on objects (also a speedup). o Changed u_steps, v_steps back to the way it was in v1.5. Now for all objects it is uniformly subdivided by exactly the value of u_steps/v_steps. o Significantly enhanced the "function" object. Polyray will now accept any predefined function as part of the function definition. o Added NURBS objects. (Sorry, no trim curves yet.) o Displacement functions are now possible on CSG objects. They also work in raytracing now (although you may need to really boost the u_steps and v_steps values to get good results). o Now supports /* ... */ comments (C style). No you can't nest them. You can nest the single line "//" comments within them. o Internal modifications made that should result in less memory usage by objects. Your mileage may vary. o Modified numeric input to allow numbers like "1.", ".1" - mostly cause a user had some BASIC programs that were brain dead about putting a 0 in front of the decimal place. o Fixed up bug in polygon tracing that caused them to drop out if they were oriented in just the right way. o Added a second raw triangle output format - only outputs the vertex coordinates. This makes it more compatible with RAW2POV. Previous style with normals and u/v still available. o Removed BSP tree bounding. It wasn't any faster than slabs and locked up every once in a while. o Added a glyph object to support TrueType style extruded surfaces. Glyphs are always closed at the top and bottom, they may have both straight and curved sides in the same shape. A program to extract TrueType information and write into Polyray glyph format is included with the documentation archive. o Support for simple particle systems. Can define birth and death conditions, # of objects to generate, and ability to bounce off other objects. o Added many more VESA display modes. There are now 5 SVGA 256 color modes, 5 Hicolor modes, and 5 truecolor modes supported. If your board doesn't support a selected mode, Polyray tries a lower res one having the same # of bytes per pixel. Version 1.6a (Crud, stuff was still broken...) Released: 23 April 1993 o Problems in writing Targa images! Uncompressed/RLE was being set improperly in the image file. o Allocation/Deallocation of static variables had some problems. Mostly fixed, however: DONT use a non-static texture in a static object. o Added some code to "special" surface to make use of an alpha value in a color map. If you use "color xxx_map[foo_fn]", it will grab the alpha value and use it for the transmission scale. (This overrides any transmission scale you might put in later, so beware.) Version 1.6 (beta) Released: o Added opacity values to 16 and 32 bit Targa output. Just a single bit in the 16 bit files. In the 32 bit files the extra channel holds the percentage of the background that contributed to the pixel. o Added static (last from frame to frame) variables o Added indexed and summed textures. o Added RLE compressed 8 bit Targa files. o Added VESA Hicolor display in 640x480 (still a bit buggy). Don't use anything but "-t 0" or "-t 1" for status displays or the screen will go wierd after about 50 lines. o Added texture maps (similar to color maps), indexed image files (for use with texture maps) o Added output of raw triangle information. Render type 3 will render the image as triangles, in ASCII form. Each line of the output has the form: v1 v2 v3 n1 n2 n3 uv1 uv2 uv3. Where vx is a 3D vertex, nx is the normal at the corresponding vertex, and uv1 is a pair of u,v values for each vertex. (This means there are 24 floating point values per line.) o Fixed bug involving conditional include files. If an include directive was inside a conditional, the file was read regardless of the value of the conditional. o Smoothed out Bezier surfaces. A patch (smooth) triangle is now used instead of a flat one when performing final intersection tests. o Fixed view bug in scan conversion - if the direction of view was along the y-axis & the up was along the z-axis, the image came out upside down. o Added displacement to scan converted surfaces o Added u-v mapping to most primitives. The variables u and v work in all expressions. This is especially useful for image mapping. o Added u-v limits to several primitives. This allows for creation of sections of a primitive. o Changed scan conversion to be adaptive to the on-screen pixel size. Unless limited by u_steps or v_steps, the subdivision of a primitive continues until a polygon about the size of a pixel is created. This is then drawn. The biggest drawback is the appearance of cracks when the adaptive subdivision is different for adjacent parts of a surface. o Changed the meaning of u_steps and v_steps for most primitives. They now mean the number of binary subdivisions that are performed rather than the number of steps. Therefore "u_steps 4" in this version is equivalent to "u_steps 16" in previous versions. (Unaffected primitives: blobs, sweeps, lathes. These still work the old way.) o Fixed dot product of vectors in expressions. o Added Legendre polynomials as an expression. Pretty cool for doing spherical harmonics. o Added depth mapped lights. Useful if you need to do shadows of things that can only be scan converted (like displacement surfaces). o Fixed problems with using a torus in CSG. (Only appeared in some versions of v1.5) Version 1.5 Released: 8 November 1992 o Added textured lights o Added directional lights o Added haze o Found the missing top line in scan converted images - Polyray was using the background color for the entire top line. o Added layered textures. o Expression processing code improved - bugs removed, memory used diminished. o Plugged memory leaks. Extensive debugging of memory allocations and frees performed. Animations should be much happier now. o No longer need to define maximum number of primitives. o Added support for greyscale Targa (type 3) files. These can be used as the output format, as imagemaps, and as height fields. o Buggy SVGA support removed. Only standard VGA mode (320x200) supported. o Gridded objects added. o Arrays added o Components of CSG objects are now properly sorted by bounding slabs o User defined bounding slabs removed. Polyray will always use bounding slabs aligned with the x, y, and z-axes. o Clipping and bounding objects removed. Clipping is now performed in CSG, bounding is specified using a "bounding_box" declaration. o Added wireframe display mode. o Added planar blob types. (Also added toroidal blob types, but they only appear in scan conversion images due to the extreme numerical precision needed to raytrace them.) o Added smooth height fields. o Fixed shading bug involving transparent objects & multiple light sources. o Fixed diffuse lighting from colored lights. o Changed RLE Targa output so that line boundaries are not crossed. Version 1.4 Released: 11 April 1992 o Support for many SVGA boards at 640x480 resolution in 256 colors. See documentation for the -V flag. (Note: SVGA displays only work on the 286 versions.) o Changed the way the status output is managed. Now requires a number following the -t flag. Note that line and pixel status will screw up SVGA displays - drawing goes to the wrong place starting around line 100. If using SVGA display then either use no status, or "totals". o Added cylindrical blob components. Changed the syntax for blobs to accommodate the new type. o Added lathe surfaces made from either line segments or quadratic splines. o Added sweep surfaces made from quadratic splines. o Height field syntax changed slightly. Non-square height fields now handled correctly. o Added adaptive antialiasing. o Squashed bug in shading routines that affected almost all primitives. This bug was most noticeable for objects that were scaled using different values for x, y, and z. o Added transparency values to color maps. o Added new keywords to the file "polyray.ini": shadow_tolerance, antialias, alias_threshold, max_samples. Lines that begin with "// " in polyray.ini are now treated as comments. o Short document called "texture.txt" is now included in "plydoc.zip". This describes in a little more detail how to go about developing solid textures using Polyray. o Added command line argument "-z start_line". This allows the user to start a trace somewhere in the middle of an image. Note that an image that was started this way cannot be correctly resumed & completed. (You may be able to use image cut and paste utilities though.) Version 1.3 (not released) o Added support for scan converting implicit functions and polynomial surfaces using the marching cubes algorithm. This technique can be slow, and is restricted to objects that have user defined bounding shapes, but now Polyray is able to scan convert any primitive. o A global shading flag has been added in order to selectively turn on/off some of the more time consuming shading options. This option will also allow for the use of raytracing as a way of determining shadows, reflectivity, and transparency during scan conversion. o Added new keywords to the file "polyray.ini": pixel_size, pixel_encoding, shade_flags. o Improved refraction code to (mostly) handle transparent surfaces that are defined by CSG intersection. o Fixed discoloring of shadows that receive some light through a transparent object. o Jittered antialiasing was not being called when the option was selected, this has been fixed. o Fixed parsing of blobs and polygons that had large numbers of entries. Previously the parser would fail after 50-60 elements in a blob and the same number of vertices of a polygon. o In keeping with the format used by POV-Ray and Vivid, comments may now start with "//" as well as "#". The use of the pound symbol for comments may be phased out in future versions. Version 1.2 Released: 16 February 1992 o Scan conversion of many primitives, using Z-Buffer techniques. o New primitives: sweep surface, torus o Support for the standard 320x200 VGA display in 256 colors. o An initialization file ("polyray.ini") is read before processing. This allows greater flexibility in tuning many of the default values used by Polyray. o User defined bounding slabs added. This greatly improves speed of rendering on data files with many small objects. o Noise surface added. o Symbol table routines completely reworked. Improved speed for data files containing many definitions. o Bug in the texturing of height fields corrected. Version 1.1 (not released) o Added parabola primitive o Dithering of rays, and objects o Blob code improved, shading corrected, intersection code is faster and returns fewer incorrect results. Version 1.0 Released: 27 December 1991 o Several changes in input syntax were made, the most notable result being that commas are required in many more places. The reason for this is that due to the very flexible nature of expressions possible, a certain amount of syntactic sugar is required to remove ambiguities from the parser. o Several new primitives were added: boxes, cones, cylinders, discs, height fields, and Bezier patches. o A new way of doing textures was added - each component of the lighting model can be specified by an implicit function that is evaluated at run time. Using this feature leads to slower textures, however because the textures are defined in the data file instead of within Polyray, development of mathematical texturing can be developed without making alterations to Polyray. o File flush commands in the data file and at the command line were added. o Several new Targa variants were added. o Image mapping added. o Numerous bug fixes have occurred. Version 0.3 (beta) Released: 14 October 1991 o This release added Constructive Solid Geometry, functional surfaces defined in terms of transcendental functions, a checker texture, and compressed Targa output. o Polyray no longer accepted a list of bounding/clipping objects, only a single object is allowed. since CSG can be used to define complex shapes, this is not a limitation, and even better makes for cleaner data files. Version 0.2 (beta) (not released) o This release added animation support, defined objects, arithmetic expression parsing, and blobs. Version 0.1 (beta) (not released) o First incarnation of Polyray. This version had code for polynomial equations and some of the basic surface types contained in "mtv".