Map-based isotropic BSDF¶
Description¶
This BSDF model uses hemispheric maps representing BRDF values over all reflected directions. Each map corresponds to an incident light direction, and uses equidistant hemispherical projection. Currently, only isotropic BRDFs are supported (the incident light direction only depends on theta).
Any kind of image maps is supported, including high dynamic range images in HDR or EXR format. Spectral EXR are fully supported.
These maps may be generated, or measured directly with a system designed by Eldim SA, which provided the data used for rendering the example, measured on a pink metallic paint sample.
Note
Using this feature requires an Advanced Edition license
Children Nodes¶
This node is an image list. It may have a variable number of image children representing the reflected light at several indident angles.
user-defined | First incident angle |
user-defined | Second incident angle |
user-defined | ... |
Parameters¶
name | type | description |
---|---|---|
thetas | table(real) | List of incident angles for each child image, in degrees |
Ocean XML 4.0 example¶
<bsdf type="isomap" name="brdf">
<param name="thetas" type="list">
<row theta="10"/>
<row theta="20"/>
<row theta="30"/>
<row theta="40"/>
<row theta="50"/>
<row theta="60"/>
<row theta="70"/>
<row theta="80"/>
</param>
<image name="1" path="RedPaint_10deg_BRDF.exr"/>
<image name="2" path="RedPaint_20deg_BRDF.exr"/>
<image name="3" path="RedPaint_30deg_BRDF.exr"/>
<image name="4" path="RedPaint_40deg_BRDF.exr"/>
<image name="5" path="RedPaint_50deg_BRDF.exr"/>
<image name="6" path="RedPaint_60deg_BRDF.exr"/>
<image name="7" path="RedPaint_70deg_BRDF.exr"/>
<image name="8" path="RedPaint_80deg_BRDF.exr"/>
</bsdf>