Shrinkwrap not only for holes?

The shrinkwrap modifier is good when you need holes in a body of a car or other vehicle, but it’s not working if you just do an extrude inwards and leave the bottom faces! If the bottom faces are removed, then it works because then it’s a hole. Is there a way to overcome this?

Without shrinkwrap:

With shrinkwrap:

Set up a vertex group for parts you wish to be influenced, or indeed not influenced by the shrink wrap, and then assign that vertex group in the modifier. Alternatively, you can wait to extrude anything inwards until after you’re done with shrink wrap and have applied it.

Thanks for your answer! When I select all faces, except the extruded faces, and create a group and then add that group to the shrink wrap modifier, then the mesh looks like it does without a shrin kwrap modifier! I have tried this before and it didn’t work.

How do I assign a group to not influence the shrink wrap?

You set of up a vertex group that will be affected by the shrnkwrap. You can either manually assign (using assign button in vertex groups) or you can weight paint the mesh. In the skrinkwrap modiifer theres a dropdown for vertex groups. So just exclude the verts you don’t want affected and assign them.

You might try and activate the little toggle next to the vertex group in the modifier. (two arrows pointing left and right from memory) Also make sure you’ve got your normals all calculated properly, and applying scale/rotation can’t hurt.