Command Line Options

Any options you give the renderer on the command line override internal variables in the SDL file. These options allow you to change the behavior of the renderer without having to edit the SDL file.

Usage

To use the command line options

1. Use the cd command to move to your project directory (for example, cd user_data/demo).
2. Enter the command for the renderer, followed by any options (see below), and the name of the SDL file (for example, renderer -s10 sdl/animation_1).

Options

renderer|raytracer [-H] [-an] [-bn] [-en] [-f script] [-gn][-hn] [-m filename] [-p filename] [-d filename] [-C color_map_filename] [-c quantized_output_file] [-j] [-k] [-Kn] [-on] [-O][-qn][-P][- sn] [-Sn] [-Bn] [-En] [-rn] [-tn] [-wn] [-Wn] [-xn] [-yn] [-Yn] [-zn] [-Zn] [filename]
-an	Use the integer n as the aalevel.
-tn	Use the integer n as the aathreshold.
-sn	Use the float n as the starting frame number.
-bn	Use the float n as the by frame number.
-en	Use the float n as the ending frame number.
-Sn	Use the integer n as the start extension.
-Bn	Use the integer n as the by extension.
-En	Use the integer n as the size extension.
-fstring	invoke the program string after each frame.
-gn	Use the float n as the gamma correction value.
-mstring	Produce a matte file and Use string as the filename.
-pstring	Use string as the pix filename.
-dstring	Use string as the depth file name.
-C string	Use the SGI imagelib image format file to quantize to after each frame.
-c string	Output the quantized image to the file string after each frame.
-j	Raytrace transparent objects without attenutation (Beere's law ignored).
-k	Keep depth maps in memory after reading (read them once). If used, a depth map file will be read ONCE, or if depth map saving is not turned on, the map will be created ONCE and used for all subsequent frames.
-Kn	Turn depth maps on disk usage to n. 0=off, non-zero =on. If used, a depth map file named the same as the light will be created if it doesn't exist, and used if it does exist.
-O	Use byframe of 1.0 as applied to motion-blur.
-on	Use byframe of n as applied to motion-blur.
-P	Preserve the non-glowed image.
-qn	Set the quiet flag to n (0 or 1).
-Tn	Use the integer n as the number of Y pixels in a tile.
-hn	Use the integer n as the image height.
-wn	Use the integer n as the image width.
-Wn	Use the integer n as the ylow for backgrounds.
-xn	Use the integer n as the xleft.
-yn	Use the integer n as the ylow.
-Yn	Use the integer n as the yhigh for backgrounds.
-rn	Use the float n as the aspect ratio. If more than one camera is defined in the SDL file, this option only affects the first camera.
-Gn	Turn saved geometry on (non-zero n) or off (0).
filename	Use filename as the SDL filename. If no filename is present standard input will be used.
-zn	Make camera depth output respect transparency, if transparency is greater or equal to n. This allows transparency mapped objects to affect the camera depth output files. If the flag is set to 1, anything that is at least 1% transparent will not show up in the depth file. If the flag is set to 50, anything that is more than 50% transparent will not show up in the depth file. If it is set to 99, only things that are totally transparent will not show up in the camera depth file.
-Zn	Set fast_shading to n (0 or 1).
-H	Print a usage message.

Reducing the Color Depth of the Output Image

Quantizing reduces the number of colors used in an image (usually to prepare it for display on a lower-resolution platform, such as games hardware). Typically this means reducing the number of bits per pixel from 24 (8 bits for each of R, G, and B) down to 8 bits per pixel. The quantize process tries to reduce the color errors introduced by the color space reduction.

To quantize output images to use a pre-made color map:

1. Use the aquant stand-alone utility to create a color map file.
2. Use the -C option to specify the color map file to quantize to.
3. Use the -c option to specify the filename of the output quantized file. Make sure to specify a different name than the main output file. This way, if you do not like the results of the quantization, you can requantize the file.

The stand-alone utility aquant creates color map files in SGI Imagelib image format which can then be fed to the renderers to quantize images as they are rendered. (See the documentation for aquant in the Stand-alone Utilities Guide)

PowerCaster and PowerTracer Options

The multi-processor renderers have a few extra options for controlling how they use multiple CPUs.]

powertracer|powercaster [-H] [-an] [-bn] [-en] [-f script] [-gn][- hn] [-m filename] [-p filename] [-d filename] [-C color_map_filename] [-c quantized_output_file] [-qn] [-sn] [-Sn] [-Bn] [-En] [-rn] [-Wn] [-Yn] [-k] [-Kn] [-on] [-O] [-P][-tn] [- wn] [-xn] [-yn] [-nn] [-I] [-Tn] [-U] [-zn] [-Zn] [filename]
-nn	Use the integer n as the number of processors to PowerTrace on.
-I	Print out statistics at the end of the PowerTrace.
-Tn	Use the integer n as the number of Y pixels in a tile.
-U	Leave output pix file uncompressed (not Run Length Encoded).
All other options are identical to the single processor commands.

Examples

Example 1

To render every other frame ("by frame" of 2) of frames 4 through 8 of an animation, but numbwe the output files 10,11 and 12, enter:

renderer -s 4 -e 8 -b 2 -S 10 -B 1 sdl/animation_scene_1

This produces the following pix files:

pix/animation_scene1.10 (which is frame 4)
pix/animation_scene1.11 (which is frame 6)
pix/animation_scene1.12 (which is frame 8)

Example 2

To test a few frames of an animation (say, frames 1 to 5) without overwriting existing pix files, enter:

renderer -e 5 -p pix/test_anim -m mask/test_anim 
sdl/animation_scene_1

This produces the following pix and mask files:

pix/test_anim.1
pix/test_anim.2
pix/test_anim.3
pix/test_anim.4
pix/test_anim.5
mask/test_anim.1
mask/test_anim.2
mask/test_anim.3
mask/test_anim.4
mask/test_anim.5