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3Delight introduces the concept of AOV forwarding to solve a classical problem with reflection, refraction and transmission AOVs. For example, a diffuse surface reflected by a mirror will usually appear in the reflection AOV. In some cases it is much more practical to see that diffuse surfaces in the diffuse AOV, leaving the reflection AOV black for that surface. This feature is not part of OSL language but is an attribute that users can set on a per-object basis. This means that there is no need to change your shaders in order to benefit from this feature.
Follows a visual Here is an example of some commong common AOVs with and without forwarding:
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In 3Delight, any parameter with no incoming connection will be optimize optimised out (folded). In order to read any primitive variable from the geometry, the OSL network must contain a reader node that calls the getattribute() function and outputs output it to the input parameter. This clearly states the behaviour of the network.
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