Model Lighting/Shading Advice Needed

[STALKERGB 6]

Hey guys,

Just a quick question,

On my infantry models the section where the arm connects to the main body seems to cause the lighting to be different on the upper arm to the lighting on the shoulder, so at certain angles when one is dark the other appears as though it is in the light. Is there a way to fix this so that the lighting/shading seems continuous rather than completely different? I wondered if it was to do with the fact that the arm and the body are not part of the same UV section, by that I mean the UV of the arm isn't attatched to the UV of the should although they both use the same texture.

As you can see there is a clear divide between the shoulder and arm, the images below show this in game. Is there a way to fix this so it doesn't look divided (as an example like the BIS delta or US infantry)

Is there a way in O2 to fix this or do I need to re-UV bits of the model?

Any help much appreciated.

STALKERGB

[max power 21]

It the first screenshot it looks like the crease is caused by a lot of geo density in that area, and in the in game shots it looks like a hard edge problem. It also looks like the lighting is on the wrong angle.

To fix it, try selecting the affected area (or everything), and press f5. That will 'recalculate' the normals.

If that doesn't fix it, see if there is a hard edge there. Select the vertexes around that joint and press 'i' to smooth the edges.

If the above doesn't work, and if there is a cluster of edgeloops there, you may have to downmodel the joint in order to get rid of the crease.

[STALKERGB 6]

I had a look at the edges and they are all smooth (changed it to hard edge then back to smooth to be sure). I had a go at recalculating the normals incase I'd forgotten but it didn't seem to change anything (see image below).

Could you explain the edgeloops thing a bit more as well as the downmodelling? It could well be that.

EDIT, it may also be worth noting that, the area causing the problem used to be the end of the body armour on the ARMA1 units and the start of the arm.

Cheers for the help Max Power

[max power 21]

http://www.lightwiki.com/images/9/99/GridMeshExample.gif

This model is composed of quads. Each quad is formed by a pattern of edges more or less like the latitude and longitudinal lines on a globe. That pattern of concentric rings of edges are called edge loops.

Notice on the model (such as it is), the areas with greater detal have edges that are close together. Look around the eyes, nose, and mouth. Notice that these edge loops that are close together form 'creases' in the vertex shading. Edge loops that are close together can give the appearance of creases depending on the shape of the surface.

To downmodel those edge loops, what you want to do is decrease the detail in that area. Hopefully that will smooth out the lighting. So, if there are three edge loops in that area, you can try getting rid of one or two of them by merging the vertices. You can also try spreading them out. Tighter geo = more severe crease.

edit: after doing that normal stuff (recalculate, hard soft edge), see if the problem still exists in the same severity in a renderer that encorperates your pixel shaders.

Edited July 28, 2010 by Max Power

[STALKERGB 6]

Cheers Max Power, I'll have a look at my model and see what I can do, thanks for all the info :)

[max power 21]

I should say that these crease happen only around soft edges, usually where the geometry is forming a corner or a curve. Thinking about it, making a hard edge where the vest meets the shoulder should probably get rid of most of that distortion.