LINEAR WORKFLOW SETUP
1) check "convert image to sRGB for renderview " in VRay common render settings
2) setup LWF in VRay render settings:
PASSES (VRay render element)
lighting- diffuse*color
GI- indirect
diffuse-color
materialID- material MASKS (add VRay materialID attribute to Shading Group)
multiMatte-object MASKS (add VRay objectID attribute to transform, shape or group node)