Skin Painting Bug with Turn To gPoly

[lightcube]

I've discovered a bug that is rather annoying. I have a skinned mesh that was too laggy in my viewport... so I added a Turn To gPoly modifier to the mesh below the skin. This does help somewhat with playback. But now when I go to modify the skin weights with the Paint Weights, the Paint Blend Weights checkbox cannot be changed. I tested on another object with the same basic setup and the bug continues.

So if the Modifier Stack looks like this:

Skin

Turn To gPoly

Mesh

You can no longer change the Paint Blend Weights checkbox.

[EDIT] This is in Max 2015 SP2. Not sure about other versions.

[spacefrog_]

Using gPoly and skin might be dangerous IMHO as gPoly changes the vertex order. So some changes below it might trigger that and make your skin weights go bust... I think gPoly was only a temporary solution for performance bottlenecks..

Do you really see much viewport performaance gain using it in Max 2015SP2 ?

[lightcube]

Well, a couple things. No, there was not a dramatic improvement, but there was some improvement. Since it was still skipping frames during playback, it wasn't really worth it in the end.

That being said, the vert ordering didn't seem to change from what I saw. And, the documentation on GPoly specifically gives this scenario. So since this is how the documentation explains the use, it's certainly a bug. You can keep skinning... you just can't change the blend paint mode.

[aon.914858227]

There are are a couple of things that can help with performance of skinned characters:

(Likely you are already aware of this.)

1) Avoid anything that turns the mesh into a polymesh in the stack. Poly select,editpoly-mod or editablePoly as base.

2) Turn Turbosmooth completely OFF.(RightKlick->Off in Viewport.) Turbosmooth turns the input mesh to polyMesh even if

    viewport iterations are set to zero.

At my system a character with 250k polys and 15 objects-> 12fps playback.

[lightcube]

Yeah, in the particular case that I'm working on, there is no Turbosmooth mod, etc. It should be optimized. I was trying to take a shortcut in this case by using gPoly because it serves the case of what gPoly seems to be made for (I never used it until last week). I don't think it will really help here anyway... but it was while attempting this that I discovered this apparent bug.

[jonathan.matthews]

Hello-

Please report your findings here:

http://download.autodesk.com/us/support/report_a_bug.html?SelProduct=3dsMax

When reporting your findings please be as specific as possible.  

Please report the development case number you get back to this thread so that I can track it internally.

Thank you.

[lightcube]

I submitted this last week, and it was filed under: BSPR-15785 Cannot change Paint Blend Weights if Turn to gPoly in stack

[jonathan.matthews]

Thank you.  I will track it internally and will let you know of any developments.