Problem with retopo tool


I want to cut some holes in a mesh with help of the retopo tool, so I retopo a circle onto an object, but whatever I do (probably something wrong!!) the retopo’d circle does not “touch” the surface of that object but it offsets slightly.

I have attached the blend file of an example I made to illustrate this: a circle retopo’d onto a 32*32 UVsphere.

If you rotate the view you will see that the circle does not touch the sphere but has a slight inwards offset.

Am I doing something wrong, or is this normal?



RetopoProblem.blend (193 KB)

Yeah, an unfortunate side-effect of the way retopo works is that it is only as accurate as your graphics card’s depth buffer. So if you have any SLIGHTLY glitches or steps in it, your projection will take the same knocks. A handy alternative to the retopo tool, though, is the Shrinkwrap modifier. I think it might be what you’re looking for, I hooked it up and the projection lined up instantly. :smiley:

Thanks, ZombieJohn!

The shrinkwrap modifier did the job!

Pitty about the depth buffer issue on my GFX card though!
Does this mean that, if I wanted to solve this problem, I would have to buy a “better” card (present card = NVIDIA GeForce 8500 GT) or is it something that could be solved via settings?


I don’t think many cards invest a lot of time in high-detail depth buffers, so I don’t think upgrading your card would provide much of a noticeable difference. Although one way you CAN improve your resolution is by shrinking the start and end clipping planes of your viewport camera, so the information in the z-buffer can be condensed to give more information over a smaller space.

OK, Thanks!