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4.1.1 Image and Camera Options

All the standard options are supported and are listed in the table below along with their default values. Some of those options have an extended behaviour in 3Delight:

Display
You can open more than one display at once by giving Display a file name that begins with a "+". For example, the following two commands will write the image to `image.tif' and to the framebuffer.
 
Display "image.tif" "file" "rgb"
Display "+window" "framebuffer" "rgb"
Since the renderer uses floating point numbers internally, the colors are exposed and quantized using the values specified with the Exposure and Quantize commands. However, you may want to expose and quantize values differently for each Display. This is made possible by specifying exposure, quantization and dithering values directly on the Display line. An extended Display command would look like:
 
Display "file" "driver" "variable"
    "exposure" [gain gamma]
    "quantize" [zero one min max]
    "dither" [amplitude]
Note that there are four values given to the quantize token, compared to three for the Quantize command. This extended syntax allows to specify a value for zero (black), whereas the Quantize command assumes this value to be `0'. Using this fourth parameter, colors are quantized using the following formula:
 
value = round(zero + value * (one - zero) + dithervalue)
value = clamp(value, min, max)

Hider
Hider only supports the `hidden' hider. It takes one optional parameter, `jitter', to tell 3Delight what sampling pattern to use. Valid values for this parameter are `0' (regular sampling grid), `1' (jittered grid) or `2' (quasi Monte-Carlo sampling). For example:
 
Hider "hidden" "jitter" 0
tells 3Delight to sample the scene using a regular grid pattern. The default sampling pattern is the jittered grid.

Hider "depthfilter" "filter name"
Sets a filter type for depth values filtering. The following filters are recognized:

`min'
The renderer will take the minimum z value of all the subsamples in a given pixel;
`max'
The renderer will take the maximum z value of all the subsamples in a given pixel;
`average'
The renderer will average all subsamples z values in a given pixel;
`midpoint'
For each subsample in a pixel, the renderer takes the average z value of the two closest surfaces. Depth associated with the pixel is then computed using a min filter of these averages. Note that midpoint filtering may slowdown your renders slightly.

Option Default Value Comments
Format 640 480 1 --
FrameAspectRatio 1.0 Square pixels
ScreenWindow -1.3333 1.3333 -1 1 Computed using Format (640/480 = 1.333...)
CropWindow 0 1 0 1 No croping, the entire screen is visible;
Projection "orthographic" --
Clipping 0 1e30 --
PixelSamples 2 2 Enough for a preview. If motion-blur or depth of field is used increase those values to at least 4 4;
PixelFilter "box" 2 2 Enough for a preview. A high quality setting would be "sinc" 6 6;
Exposure 1.0 1.0 Gain = 1, Gamma = 1;
Display "default.tif" "tiff" "rgb" Create a RGB TIFF named `default.tif'.

Standard options and their default values.


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This document was generated by Aghiles Kheffache on July, 31 2003 using texi2html
3Delight 1.0.0. Copyright 2000-2003 The 3Delight Team. All Rights Reserved.