[3ds Max] Seperate all elements to objects while keeping normals?

Davision3D · Nov 2017

I found several Max scripts that seperate all elements to objects but none of those keep the mesh normals.

The only workflow that keeps the normals seems to be this:
-Clone the whole object
-Edit mesh, delete everything but one of the elements
-Repeat

This is for Destructible chunks that I need to import in UE4 seperated as objects. Now this can be 500-2000 chunks per asset so doing this manually like that would be kinda crazy.

If there is no solution for that Plan B could be to somehow project the old mesh normals on to all the seperated objects at once. But the steal normals scripts I found can't do that.

Any ideas?

Justo · Nov 2017

Have you tried Soulburn's free ObjectDetacher script? I don't know if that keeps the mesh normals, but if I recall correctly, it does.

Eric Chadwick · Nov 2017

I put some of my experimental results here on the wiki, might help you.
http://wiki.polycount.com/wiki/Vertex_normal#3ds_Max

Speciifically:

If you add an Edit Normals modifier and make the normals Explicit, then go below it in the modifier stack and Detach as an Element, the normals will be preserved. This works with Editable Mesh, Edit Mesh, Editable Poly, and Edit Poly.

Noors · Nov 2017

Looks like Soulburn is using detach function, so it probably breaks normals aswell.

I do the same as you : copy the object and delete faces. Dealing with normals is painfuly slow.

Works only for editable mesh. I did test on a simple object, so, if it does nothing, it's because it crashed



fn getElements obj=
(
	f = obj.numfaces
	elements = #()
	done = #()
	for i = 1 to f do
	(
		if (finditem done i) == 0 then 
		(
			faces = meshop.getElementsUsingFace obj #(i) as array
			append elements faces
			join done faces
		)
	)
	return elements
)

try
(
	obj = selection[1]
	objFaces = #{1..obj.numfaces}
	elements = getElements obj

	for i=1 to elements.count do
	(
		keepFaces = elements[i] as bitarray
		delFaces = objFaces - keepFaces
		newObj =  copy obj
		meshop.deleteFaces newObj delfaces delIsoVerts:true
		
		--uncomment next line to center pivot 
		--newObj.pivot = newObj.center
	)
)
catch()

<br>

Davision3D · Nov 2017

Noors said:
Looks like Soulburn is using detach function, so it probably breaks normals aswell.

I do the same as you : copy the object and delete faces. Dealing with normals is painfuly slow.

Works only for editable mesh. I did test on a simple object, so, if it does nothing, it's because it crashed


fn getElements obj=
(
	f = obj.numfaces
	elements = #()
	done = #()
	for i = 1 to f do
	(
		if (finditem done i) == 0 then 
		(
			faces = meshop.getElementsUsingFace obj #(i) as array
			append elements faces
			join done faces
		)
	)
	return elements
)

try
(
	obj = selection[1]
	objFaces = #{1..obj.numfaces}
	elements = getElements obj

	for i=1 to elements.count do
	(
		keepFaces = elements[i] as bitarray
		delFaces = objFaces - keepFaces
		newObj =  copy obj
		meshop.deleteFaces newObj delfaces delIsoVerts:true
		
		--uncomment next line to center pivot 
		--newObj.pivot = newObj.center
	)
)
catch()

<br>

Thanks a lot, that works great!

Eric Chadwick said:

I put some of my experimental results here on the wiki, might help you.
http://wiki.polycount.com/wiki/Vertex_normal#3ds_Max

Speciifically:
If you add an Edit Normals modifier and make the normals Explicit, then go below it in the modifier stack and Detach as an Element, the normals will be preserved. This works with Editable Mesh, Edit Mesh, Editable Poly, and Edit Poly.

Yea, that wiki page was really helpful but making normals Explicit does not help in this case.

Justo said:

Have you tried Soulburn's free ObjectDetacher script? I don't know if that keeps the mesh normals, but if I recall correctly, it does.

Same problem with that script.

Larry · Dec 2017

Have you tried face weighted normals script after you split them? In the end it's a pile of broken junk, does it look that bad in the engine with materlsa on them? I mean, nobody is going to notice

gandhics · Dec 2017

Could u give me a small sample file for testing?

[3ds Max] Seperate all elements to objects while keeping normals?

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