As of v1.1.0, one can only assign an unique material to an Rhino Object.
That's realy a pain
We try to keep the material list as "clean" and accurate as possible, by incorporating any material.
Consider 2 cases :
A) Composite multilayer construction :
Solution a) v1.1 : Compute the actual total weight /m2 with all the discreet materials, assign the value through a specific material
Solution b) v1.1 : Create as much Rhino Objects (surfaces, volumes) as you will have, and assign each a material.
Solution x) : Assign to the object (surface, volume) as many materials it must represent : fiber fabrics+bounding, core, ..., even paint or Teck decking !
B) Tank holder (water, fuel, ...) : materials : Stainless steel 316L 8030 kg/m3, fuel 850 kg/m3
Solution a) v1.1 : Compute the mean weight /m3 with the 2 materials, assign the value through a specific material
Solution b) v1.1 : Create both Rhino Objects (outer volume or surface for SSteel, inner volume for fuel) and assign each a material.
Solution x) : Assign to the object both surface and volume material
Could you please consider this feature soon ?