old GTR energy compensation and V-Ray 7

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In the article, the old gtr_energy_compensation (gtr_energy_compensation=0) material from V-Ray 7 has also been changed to be rendered with the new GTR energy.
As a result, if the old gtr_energy_conservation material contains color in Diffuse, the color will change significantly when rendered with V-Ray 7.

When loading a scene in V-Ray 7, materials with gtr_energy_compensation=0 flag should have their Diffuse color changed to white.

Or does the scene converter do this?

[hermit.crab]

Mind if you attach a scene? ̶F̶r̶o̶m̶ ̶w̶h̶a̶t̶ ̶I̶ ̶t̶e̶s̶t̶e̶d̶ ̶i̶m̶p̶o̶r̶t̶i̶n̶g̶ ̶a̶ ̶s̶h̶a̶d̶e̶r̶ ̶(̶a̶l̶u̶m̶i̶n̶u̶m̶ ̶b̶r̶u̶s̶h̶e̶d̶ ̶p̶r̶e̶s̶e̶t̶)̶ ̶f̶r̶o̶m̶ ̶V̶-̶R̶a̶y̶ ̶5̶,̶ ̶r̶e̶n̶d̶e̶r̶s̶ ̶s̶i̶m̶i̶l̶a̶r̶l̶y̶ ̶(̶w̶i̶t̶h̶o̶u̶t̶ ̶t̶h̶e̶ ̶F̶r̶e̶s̶n̶e̶l̶)̶ ̶i̶n̶ ̶V̶-̶R̶a̶y̶ ̶7̶,̶ ̶u̶n̶l̶e̶s̶s̶ ̶y̶o̶u̶ ̶m̶a̶n̶u̶a̶l̶l̶y̶ ̶c̶h̶a̶n̶g̶e̶ ̶t̶h̶e̶ ̶G̶T̶R̶ ̶e̶n̶e̶r̶g̶y̶ ̶c̶o̶m̶p̶e̶n̶s̶a̶t̶i̶o̶n̶ ̶m̶o̶d̶e̶.̶

EDIT: Never mind, I must have tested wrong. With V-Ray 7, we always have Fresnel (as it should).

When loading a scene in V-Ray 7, materials with gtr_energy_compensation=0 flag should have their Diffuse color changed to white.

I doubt that this will solve anything.

EDIT: You probably mean Reflection color, right? Either way, that won't do anything different as old the old behaviour is not supported in V-Ray 7. The only way is to adjust the shader (to something desired) manually.

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This problem occurs with materials with Metalness of 1.0.

Until V-Ray 6, old gtr_energy_compensation (gtr_energy_compensation=0) Metalness 1.0 materials were ignored even if the Diffuse had color.

Now everything is handled with the new gtr_energy_compensation, i.e., in V-Ray 7, if a Metalness 1.0 material has a color in the Diffuse, it will affect the reflected color.

Here is a comparison of the attached scene rendered with V-Ray 6 and V-Ray 7.

[hermit.crab]

This problem occurs with materials with Metalness of 1.0.
Until V-Ray 6, old gtr_energy_compensation (gtr_energy_compensation=0) Metalness 1.0 materials were ignored even if the Diffuse had color.
Now everything is handled with the new gtr_energy_compensation, i.e., in V-Ray 7, if a Metalness 1.0 material has a color in the Diffuse, it will affect the reflected color.

That's right. However,

When loading a scene in V-Ray 7, materials with gtr_energy_compensation=0 flag should have their Diffuse color changed to white.

This works on the attached scene, but it won't if f.e. the shader has Anisotropy enabled, hence why I said shaders must be adjusted manually.

Otherwise, you can use the following script to set a white diffuse to all scene shaders without the gtr energy compensation option:

for i in sceneMaterials where (classof i == VRayMtl) and (i.option_gtrEnergyCompensation == 0) do i.diffuse = color 255 255 255

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This works on the attached scene, but it won't if f.e. the shader has Anisotropy enabled, hence why I said shaders must be adjusted manually.

That's certainly true.

In any case, I will say that finding the cause of this problem is very tedious.
Support personnel will have a hard time.