[Closed] vray MultiMatteElement from Layer

If several Classes falls into the same Superclass and you need to filter them, one way I can think of is to have either a “whitelist” or a “blacklist” of Classes, the shortest or the safest one, depending on what information of the scene you have. It might not be elegant but could work.

This function uses a blacklist to filter out the default Particles Systems:

(
 fn GetSceneNodes =
 (
 	blacklist =
 	#(
 		pf_source,
 		particlegroup,
 		snow,
 		blizzard,
 		pcloud,
 		spray,
 		superspray,
 		parray
 	)
 	
 	layernodes = #()
 	for o in objects where iskindof o node do
 	(
 		if superclassof o == geometryclass do
 		(
 			if finditem blacklist (classof o) == 0 do append layernodes o
 		)
 	)
 	return layernodes
 )
 nodes = GetSceneNodes()
 )

This other function uses a whitelist to collect some of the Geometry Classes and Shapes:

(
 fn GetSceneNodes =
 (
 	whitelist =
 	#(
 		polymeshobject,
 		editable_mesh,
 		editable_poly
 	)
 	
 	layernodes = #()
 	for o in objects where iskindof o node do
 	(
 		if finditem whitelist (classof o) != 0 or superclassof o == shape do append layernodes o
 	)
 	return layernodes
 )
 nodes = GetSceneNodes()
 )

Thank you PolyTools3D,
just abit stuck as, were to put that into the script?

Im not very proficient with maxscripting

Good question!
I am not entirely sure of how the function works nor do I have a proper scene to fully test it, but I guess that for Meshes, Polys and Shapes the following code should work:

clearlistener()
 
 fn keepChars str pass: = (
 	local killChars = case pass of
 	(
 		1: "abcdefghijklmnopqrstuvwxyz0123456789_ABCDEFGHIJKLM  NOPQRSTUVWXYZ!()*- /@" 
 		2: "abcdefghijklmnopqrstuvwxyz0123456789_ABCDEFGHIJKLM  NOPQRSTUVWXYZ!()*- /@"
 		3: "abcdefghijklmnopqrstuvwxyz0123456789_ABCDEFGHIJKLM  NOPQRSTUVWXYZ!()*- /@"
 	)
 	for i = str.count to 1 by -1 where (local index = findString killChars str[i]) == undefined do str = replace str i 1 ""
 	str
 )
 
 fn cropString str charMax = (
 	if str.count > charMax then
 	(
 		str = keepChars str pass:1
 		if str.count >charMax then
 		(
 			str = keepChars str pass:2
 			if str.count > charMax then
 			(
 				str = keepChars str pass:3
 				if str.count > charMax then
 				(
 					str = substring str 1 charMax
 				)
 				else str
 			)
 			else str
 		)
 		else str
 	)
 	str
 )
 
 fn removeElementByPrefix pref = (
 	
 	clearlistener()
 	local re = maxOps.GetCurRenderElementMgr() 
 
 	for i = re.numrenderelements()-1 to 0 by -1 do
 	(
 		x = (re.GetRenderElement i)
 		elName = x.elementName
 
 		prefix = substring elName 1 pref.count
 
 		if prefix == pref do
 		(
 			format "Removing element %

" elName
 			re.REmoveRenderElement x
 		)
 	)
 )
 
 
 
 (
 	
 	local re = maxOps.GetCurRenderElementMgr() 
 	local el = multimatteelement
 	local groupsSoFar = 0 
 	--starting ID's number
 	local startID = 00
 	--MultiMatteElement name remove
 		
 	local whitelist =
 	#(
 		polymeshobject,
 		editable_mesh,
 		editable_poly
 	)
 
 	removeElementByPrefix "matte_"
 
 	for el = 1 to re.numrenderelements() do
 	(
 		re.GetRenderElement el
 	)
 
 	while groupsSoFar*3 < layerManager.count-1 do 
 	(
 		layerGroup = ""
 		idGroup = #()
 		
 		for i = 1 to 3 while (x = i+groupsSoFar*3) <= layerManager.count-1 do
 		(
 			layer = ILayerManager.getLayerObject x
 			layerRefs = refs.dependents layer
 			layerName = (cropString ((layerManager.getLayer x).name) 9)
 			layerNodes = #()
 
 			layerGroup += layerName
 			append idGroup (startID + x)
 
 -- 			for o in layerRefs where classof (superClassOf o) == node and superclassof o == GeometryClass do
 -- 			(
 -- 				append layerNodes o 
 -- 			)
 
 			for o in layerRefs where iskindof o node do
 			(
 				if finditem whitelist (classof o) != 0 or superclassof o == shape do append layerNodes o
 			)
 			
 			----help????
 			for obj = 1 to layerNodes.count do
 			(
 				if layerNodes[obj] != "shapes" do 
 				(
 					layerNodes[obj].gbufferChannel = x
 				)
 			)
 			format "LayerRefs: %
" layerRefs
 			format "Layer: %
" layerName
 			format "Objects: %
" layerNodes
 			format "ObjectID: %
" x
 		)
 
 		if idGroup.count < 3 do
 		(
 			append idGroup (idGroup[idGroup.count] + 1)
 			if idGroup.count < 3 then 
 			(
 				append idGroup (idGroup[idGroup.count] + 1)
 			)
 			else()
 		)
 		
 		---Name_Pass
 		layerGroup = "matte_" + layerGroup
 		format "MultiMatte name: % is % characters.
" layerGroup layerGroup.count
 		format "IDs in MM: %

" idGroup
 		format "--------------------

"
 
 		if groupsSoFar*3 < layerManager.count-1 do
 		(
 			re.addrenderelement (el elementname:layerGroup R_gbufID:idGroup[1] R_gbufIDOn:(on) G_gbufID:idGroup[2] G_gbufIDOn:(on) B_gbufID:idGroup[3] B_gbufIDOn:(on) )	
 		)
 		
 		groupsSoFar +=1 --increment the groups counter
 		
 	)
 	
 )

Of course. The OP can add as many things as needed, depending on what the scenes contains and what needs to be excluded. That’s why my suggestion of blacklisting or whitelisting. I would believe that most scenes would use polys or meshes, but that’s far away from been accurate, as I have no idea of what other artists/developers have in their scenes.

They could use a load of custom or commercial plugins that I we are not aware of. For example, as I don’t have Forest Pack to test it, I have no idea of what you can build with it or if everything you can build with it will fall into the #Itoo_Software category.