This guide should is designed to export your PBR Metallic/Roughness textures from 3dsmax to blender.
We will take our PBR textures, place them into a standard material and export to FBX. FBX settings are based on your preference and dont affect the material. Just be sure to check your units scale factor if you work in units other than meters.
Dielectric:
Notes:
Specular Level: 0.25 = Specular 0.5 in Blender
Reflection = Checked On, but 0% which turns off Metallic on import
Normal Map: DirectX texture in 3dsmax, I swap this to OpenGL texture for export to blender.
Roughness texture in Glossiness slot.
Comparison Renders
Conductor
Notes:
Same as above except swap the Reflection channel to 100% for Metallic objects (or place the Metallic map here)
Comparison Renders
Specular Control
If you want to control the Specular yourself using a 0/1 Map then place this into Specular Level (3dsmax). This will transfer this to the Specular Channel (blender).
This is a reference chart for those who want a quick way to set up your PBR materials in 3dsmax to get the correct look. Sometimes you will buy a model and it comes with many textures, ill clarify these below.
Dialectric
Vray Roughness/Metalness Workflow
Reflection is always white (same as having a white bitmap).
Set the IOR value for the dialectic in Fresnel reflections > Frensel IOR.
Set BRDF > Use roughness.
Vray Glossiness Workflow
Notes:
Similar notes as Metallic Workflow however change these properties below.
Change the BRDF >Use glossiness.
Replace the Roughness bitmap with Glossiness.
Corona Workflow
Notes:
This method is the same as Vray Glossiness workflow.
Comparison Renders
Conductor (Metal)
Vray Roughness/Metalness Workflow:
Notes:
This is a Conductor the Metalness input is set to 1.0 (same as having a white bitmap).
Reflection is always white (same as having a white bitmap).
Fresnel has no effect as its using the Metalness control, as long as you enable the Fresnel reflections checkbox.
Set BRDF > Use roughness.
Vray Glossiness Workflow
Notes:
Change the BRDF >Use glossiness.
Replace the Roughness bitmap with Glossiness.
Disable Fresnel Reflections checkbox.
We now have color in our Reflection bitmap, which means the grazing angle will not look correct without some help from an additional falloff. Refer to Vray’s Guide for more information. Specifically this quote: “The Reflection should be set to white so as to get the proper reflectivity and preservation of energy; without this, the glancing angle will never be 100% reflective — which it should be.”
Place your Reflection bitmap into a Falloff node (Map 1) in the Reflect channel. Set the settings as below:
Corona Workflow
Notes:
This method is the same as Vray Glossiness workflow except we simply change the Fresnel value to 999 (which is equivalent to unchecked in Vray).
Comparison Renders
Bitmap Import sRGB/Linear
Make sure you import your bitmaps with the correct gamma. This is a reference below to help you with that.
sRGB – Bitmap Gamma 2.2 (or default import):
Diffuse
Base Color
Reflection
Opacity
Specular Color (if required)
Ambient Occlusion (if required)
Linear – Bitmap Gamma 1.0 (override):
Metallic
Roughness
Glossiness
Normal
Height
IOR (If required)
Ambient Occlusion
If you have a material from the internet that looks like the Ambient Occlusion is in the material preview make sure you Composite > Multiply these in 3dsmax so you get the same outcome as the Preview.
Height Maps
These go in the displacement for your material.
Normal Maps
If you know the normal map is authored as DirectX you can leave the default settings on import.
If you know its OpenGL then you need to flip the green channel, otherwise inspect the map visually to see if it looks inverted.
Other Maps
You will often see other maps such as IOR, Specular, etc, these are not required in the above workflows unless you want them ofcourse and understand how they affect the material. For more information on these you can read my other post which goes into the use of these maps and when you need to use them – which is more often when you have a material with mixed dialectrics and conductors.
Cinema 4D
There is a great guide to do the same technique in Cinema4D here.
James Vella 