Material transparency in OptiX version 4

Gaming and Visualization Technologies Visualization OptiX
1

Hello,
in the old OptiX versions (until 4.0) in file glm.h the structure GLMMaterial includes field alpha - transparency. It is value of ‘d’ in MTL-file.
But in new versions (4.0) in file Mesh.h structure MaterialParams not includes this parameter. Tiny_obj_loader get transparency as ‘d’ value, and i see this value in m_materials[i].dissolve field by debugging in loadMeshOBJ(), but this value will be not set into MaterialParams structure, so will be lost. Is this an error?

PS: in old OptiX versions (until 4.0) i have found a small error: in glm.cpp in _glmReadMTL() at the end of function the MTL-file will not be closed: no string “fclose(file);”

2

Hi. The SDK samples do not use material transparency, so we ignore the ‘dissolve’ field as you noted. However, you could add support for it and pass it to an OptiX material pretty easily. The default phong material from optixMeshViewer does not handle transparency, so you would also need to write a new material.

Did you have an application in mind?

3

Thank you very much for answer, dlacewell.
I have done this already - have extended the MaterialParams structure.