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Assertion failed on skin object

by Paul Fassett · in Artist Corner · 07/04/2004 (3:11 pm) · 6 replies

Ugh I keep getting this strange error when I export my model from 3ds saying assertion failed on skin object. I went and looked for a dump file but found none. The exporter was downloaded from the tools site so it's not a bad compile. I also check to make sure all vertices have weights and they do. I only get this error when I use the biped with the skin modifier. I checked the forums and it seems that this happens when you collapse mesh smooth which I did my question is, if this is the problem how do I get mesh smooth uncollapsed, or how do I otherwise fix this problem. Thanks ahead of time for any input.
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Torque Owner Paul Fassett
#1
07/04/2004 (5:56 pm)
I just realized what it was and when I first started patching the model together the meshsmoothing got collapsed when I attached the arm mesh to the body. And it seems this is irreversible. What am I gonna do? If I loose this model I will loose almost two months worth of work. Please god help :) So question is, am I gonna have this problem with bones as well or is this just some kind of funky error with bipeds.

If it's just with bipeds I can save the model.

Torque Owner Joe Maruschak
#2
07/04/2004 (6:33 pm)
Did you save an uncollapsed version of the mesh (incremetal saves?)

check for double faces or unwelded vertices. Use the STL check modifier to check for these. Also make sure that nothing is selected in the modifier below the skin modifier.

Torque Owner Paul Fassett
#3
07/04/2004 (7:01 pm)
No I didn't save an extra copy because it was done before the first save. I was still constructing the head. I managed to get rid of the error by converting the model to editable mesh from poly, and the model seems to export great but after export the mesh in 3ds shrinks to the size of a peanut and becomes see through. When I add the mesh to the game as a static object it looks fin untill you get close and if you are looking at the mesh from the front you can see through the skin to the back and visa versa with the back. What could be causing that?

Torque Owner Joe Maruschak
#4
07/04/2004 (7:04 pm)
What you are explaining sounds like flipped normals. CHeck your scale and make sure that the scale on all the axes are positive.

Torque Owner Paul Fassett
#5
07/04/2004 (7:10 pm)
Stupid question, but how do you check axes to see if their scales are positive. Which I'm sure is probably in a FAQ or resource somewhere.

EDIT: Ok it does seem to be the normals being flipped but I dont know what is causing it to happen. I use the edit normals modifier and select all the normals and hit unify and that doesn't work, then I wrapped the model in a box changed the box to editable mesh, attached it to the model then deleted the box as an element and that didn't work either.

Torque Owner Paul Fassett
#6
07/04/2004 (8:07 pm)
Joe thank you for letting me know about the normals. I finally got the model exporting right.

I'm going to share what happened with everyone as I read about the problem in the max 5 documentation.

The documentation says that Editable polys do not support normals and if you use polys when editing the model the normals get flipped because they get stripped of the normals coordinates or something of the sort. So if you collapse the poly into a mesh, thats when the normals get flipped. The way to fix this is add a normal modifier and click the unify and flip normals check boxes then export away.

I saw a few posts about this and saw no resolution so I hope this helps some people. Thank you again Joe for your help.