How do I access materials in maxscript without material editor?

Question

There appear to be two options to access materials in maxscript, through the compact Material Editor and the Slate material editor. The problems is that a scrip that attempts to access/modify materials via the compact editor (currentMaterialLibrary , sceneMaterials, meditMaterials) fail if max is set to use the Slate editor and vice versa.

Is there a way to access the materials directly in maxscript, irrespective of which editor is used?

Once I have the material, I would like to:

1. Purge unassigned materials from the scene so that missing textures on unused materials don't throw error's on scene open/network rendering.
2. Check certain material properties (i.e. Glossy subdivision) so purchased models with "unnecessarily high values" don't ruin render times.

Answer 1

If you want to find all existing materials (in the scene or not), the following snippet will do that for you

for aMtlType in material.classes do 
(
    for aMtl in (getClassInstances aMtlType processAllAnimatables:true) do
    (
        print aMtl
        -- Does this material exist in the scene or not?
        if (findItem sceneMaterials aMtl) == 0 do (print "This material does not exist in the scene")
    )
)

I'm not quite sure how to purge it from the scene. You could get dependents (refs.dependents aMtl) then replace any references to this material to a new default material. That should work, although I haven't tried it (or even tried to run it). So... test it well and use with care :-).

defMtl = ...
for d in refs.dependents aMtl do (
    refIdx = 0
    for i = 1 to refs.getNumRefs d do ( if (refs.getreference d i) == aMtl ) do ( refIdx = i )
    refs.replaceReference aMtl refIdx defMtl
)

For your second question - checking properties - you can check if it has the apropriate property and set the value as necessary

if (hasProperty aMtl "diffuse") do ( aMtl.diffuse = 0 )