A quick test of V-Ray Next‘s PBR workflow,
Namely designing materials while previewing them using V-Ray,
Defining the material properties using the new (to V-Ray) Metalness attribute, and using Roughness rather than Glossiness, shows good results IMO.
Results are generally consistent through Blender & Cycles, Maya & Arnold, and UE4.
Software: 3ds max 2019 | V-Ray Next | V-Ray next GPU
In V-Ray Next (4) for 3ds max, a new Metalness parameter has been added to the Reflect parameters of the VRayMtl material.
This allows for easy creation of realistic metal materials and also effectively enables a PBR workflow with V-Ray.
When the Metalness parameter is set to 1.0, the material becomes completely reflective, the Diffuse color controls the general reflection color, and the Reflect color (which should generally be set to white) controls the reflection color at grazing incidence angle.
The IOR parameter still controls how fast will the main reflection color (set by the Diffuse color) blend into the Reflection color, and I don’t know whether some form of complex Fresnel has been implemented or if it’s just a dielectric simple Fresnel blended over a reflective surface.
Use the Map Scaler (MapScalar) Object Space Modifier to make UV coordinates conform to a uniform map real-world size.
Create effective UV coordinates for angular geometrical meshes quickly by applying an Unwrap UVW modifier, and in the UV Editor, selecting all the mesh, and choosing Mapping > Flatten Mapping, and than applying a Map Scaler modifier and setting its Scale parameter to the wanted texture size..
When applying the Map Scaler modifier to an object with deformed UV’s, it will break the UV’s in order to force consistent scale.
If the Scale parameter matches the file’s system unit definition in Customize > Units Setup > System Units Setup, than it will effectively work as real world map scale, and allow you to set a real world texture size in the Coordinates rollout of the texture in the Material Editor.
Render a test with White Balance set to Custom with pure white color.
Let the rendering go on at least until the pixel values stabilize (the Denoiser works at lieast once..).
set the white balance custom color to a color sampled from the VFB at a point that you know should be appearing completely neutral (neither warm or cold)
* Each time you want to test different sample locations you need to sample the pixels from the test rendered with custom pure white.
The procedure in Maya is identicle, Add V-Ray Physical Camera attributes to the camera and enable them,
Create a test render with pure white White-Balance Color,
Sample the white/grey surface color in the V-Ray VFB (Render Window) to the White-Balance color, and render again.