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Thumbnail Image Lists the name of a still image that is associated with the
select preset. This gives you a visual idea of how the render settings will affect
the rendered image.
Click [...] to open the Specify An Image dialog box (a standard file selection
dialog box) where you can browse to and select a thumbnail image for presets
you create.
Materials
Apply Materials Applies the surface materials that you define and apply to
an object. If Apply Materials is not selected, all objects in the drawing assume
the color, ambient, diffuse, reflection, roughness, transparency, refraction,
and bump map attribute values defined for the GLOBAL material. For more
information, see
MATERIALS on page 1118.
Texture Filtering Specifies if texture maps are filtered.
Force 2-Sided Controls if both sides of faces are rendered.
Sampling
Controls how the renderer performs sampling.
Min Samples Sets the minimum sample rate. The value represents the number
of samples per pixel. A value greater than or equal to 1 indicates that one or
more samples are computed per pixel. A fractional value indicates that one
sample is computed for every N pixels (for example, 1/4 computes a minimum
of one sample for every four pixels). Default=1/4.
Max Samples Sets the maximum sample rate. If neighboring samples find a
difference in contrast that exceeds the contrast limit, the area containing the
contrast is subdivided to the depth specified. Default=1.
The values of the Min Samples and Max Samples lists are "locked" together so
that the value of Min Samples can't exceed the value of Max Samples. An error
dialog box is displayed if the Min Samples value is greater than the Max
Samples value.
Filter Type Determines how multiple samples are combined into a single pixel
value. The filter types are:
■ Box. Sums all samples in the filter area with equal weight. This is the
quickest sampling method.
■ Gauss. Weights the samples using a Gauss (bell) curve centered on the
pixel.
■ Triangle. Weights the samples using a pyramid centered on the pixel.
1648 | Chapter 18 R Commands