how to use multimat material?

[aurumgallente]

Many X4 models have multimat material and it is a big mystery for all modmakers how to use it.
Any information how to work with this tool?

[linolafett]

The multimaterial is a feature, which enables us to package a large amount of tileable textures into a single material, thus saving drawcalls.
It uses vertex colour (vertex illum channel in Max) to get the needed data on which texture in the array should be used and how it should be modified (metalness/smoothness/dirt).

Dump from our internal docu:

This shader enables artists to create a broad range of surfaces in a single material.

The shader uses the Vertex illum channel to control its properties.
Vertex illum red channel = smoothness
Vertex illum green channel = metalness
Vertex illum blue channel = Texture ID for the texture array

Vertex Alpha for the dirt layer.

[BrummBear02]

its not a mystery. its just a pain to use without a proper tool for it.
you need to extract the material with gimp or some other image program thats able to open it so you can see what each layer looks like.
and then the blue channel has an offset of one. blue 0 is layer 1 if im not mistaken. could be the other way around.
if you dont intend to use a wide range of the multimat material in one ship its simplet to extract the layer you want and create a seperate material for it.
or avoid it completely.

[aurumgallente]

I was thinking to make a mod for S solar poweplant. If you to open .dae file of solar powerplant, you will see it uses extensively multimal material.