I have modeled a T-rex, and everything has gone well so far. The problem now is how when I zoom out in material mode, the gums are seen slightly outside of the mouth, where they should clearly be inside, so the faces are intersecting one another. The gums are inside the mouth yet the faces intersect when I view the dinosaur from far away. But I really don’t want to delete the whole thing and restart the whole mesh from scratch, as it took nearly an entire week to do, and I want to get rid of intersecting faces without having to delete and restart my model. How can I delete intersecting faces on my complex T-rex model? It is normal in Solid mode and Wireframe mode until I place materials on it, then the gums intersect with the lips of the T-rex. Why is it doing this? This also happens in Render mode. I have used 1 Subsurface modifier and 1 Mirror modifier and I then did 1 Decimate modifier to unsubdivide the model. What the heck is going on?
Without seeing the model, it’s hard to say. If I am correctly understanding what you’ve done, probably best to add an extra loop around the lips and then around the gums. Use the first loop to give the lips some thickness by scaling it in towards the inside of the mouth. Then use the gum loop to maintain the gum shape, and pull the gums in towards the inside of the mouth.
In edit mode you might want to enable Viewport Overlays (top right circle/disc icon) → Mesh Analysis: Intersect… then you can see what faces does overlap and then… do some corrections…
or:
This is might be just a clipping issue… check your N-panel → View → Clip: Stat/End values…
When I view the T-rex up close and from a medium range, it does not have any intersecting faces in the gums/lips unless I zoom out very far. It seems like a clipping issue with Blender itself. This seems to be normal for 3d modelling software if I’m not mistaken. I think what I might be experiencing is known as “z-fighting”, or something like that. Blender seems to try and calculate the vertex distances when drawing in the 3d viewport, and if it can’t, the whole mesh starts to have intersecting issues like here. In some cases, two different materials can cause z-fighting or intersecting despite the mesh being perfectly fine and no transparency in the materials.
Z-fighting is ovelapping geometry on the same place… i guess you should show a screenshot ?!
This is likely caused by the depth buffer. The depthbuffer is nonlinear. Distant values have less precision. Thats why it starts there. They are not really intersecting but too close. Increase the distance between these two mesh parts or decrease the frustum ranges of the camera along the z axis. For the viewport you can do this in the npanel on the right side under View ( Clip End). Decrease that value.
The solution was to set the Clip Start to any value greater than 4, which made the material intersection go away. It was indeed a depth-buffer problem, the value was not high enough, causing the faces to intersect due to lack of tolerance.