Help with Normals
 

Hello everyone - I am working on the head of a character which I have just created blend shapes for and bound to the skeleton.

When I rotate the neck joint, dark patches appear on the head, yet disappear when the character goes back to the bind pose.

I adjusted the normals of the head before creating the blend shapes and binding it to the skeleton.

The first picture shows the character in the bind pose.

And here is the head after rotating the neck - see the dark pathes around the ear. Why would the angle of the normals in certain areas change after rotating the neck?

Any ideas?

I dont know the answer...but doesnt it have something to do with paint weights? I know in one of my tutorials you have to adjust for things like this once a character is textured.../shrugs

there are tools in maya to fix this. use the vert normal edit tool,
or set vert to normal.

Thanks for taking a look esion and vladimirjp - I am a bit confused though - I used the vertex normal edit tool to edit the normals before building the blend shapes and binding the head to the skeleton.

Does that mean that I have to edit the normals after binding the head to the skeleton?

The only difference between the two pictures above, is that I have rotated the neck joint and then these dark patches appeared. I thought that you had to edit the normals before binding geometry?

I am pretty sure that it doesn't have anything to do with painting weights.

Thanks again for taking a look.:beer:

This person seems to be having the same problem -

http://www.3dbuzz.com/vbforum/showth...98#post1072898

though, I am not sure what the solution is - do you fix the normals before or after binding?

Ok - I think I've got it - I didn't realise you could edit normals after you bind to the skeleton, so I set the normals to face and then I used the edit tool to correct any problem areas.

Thanks again. :beer:

ok - still having some problems - I tried setting the normals to face after binding and that did sort out most of the problems - when I rotate the head the normals stay the same - but I still have some dark patches on the ears and eye and if I use the edit normals tool to correct these areas, they look fine in bind pose, but not when I start rotating the neck joint...

What am I doing wrong?

guess I shouldn't give up the day job just yet...

Ok, think I have sorted it out. I used the set to face tool on the problem areas and then used the soften normals tool to soften the geometry. Now when I rotate the head everything seems to look fine....

a question i've got for ya, arran... using esion's advice, what happens if you instead of rotating the head tilt it extreme left and right? there's a part of me that thinks you've got a paint weights problem, and that there's a vertex in there that's stuck to another bone as well, causing it to not move as much as the others and deforming the head itself, causing the change in the way the normals look...

Hey Neostrider - thanks for taking a look. Actually I think I managed to sort this problem out. I am pretty sure that it was a problem with the normals - when I tilted the head the same thing happened. In the end, I used the set to face tool to make sure the normal was facing the correct way (this 'hardened' the geometry) and then used the soften normals tool to balance the areas out...if that makes sense.

I am still not sure what was going on though. It was as if the normals from certain areas were not rotating with the rest of the head. I am pretty sure it wasn't anything to do with painting weights as I spent quite a bit of time playing with that tool and it did not seem to have any effect on the dark patches. In fact the areas that were giving me problems were areas that I had tried to fix earlier using the edit vertex notrmal tool, so now I am wondering if it had something to do with deleting history or the way objects were grouped - it was almost as if certain areas were reverting to a previous state...anyway, is it time for beer?

Thanks again mate.:beer:

well figured arran, glad you sorted it.
as a rule I generally delete the history (only if you know its ok to!) and then do a soften or harden and then set the normals to face as sometimes it can work ok and other times you get problems where it hasn't done what it said on the tin...

Thanks T1ck - I'll give that a go.