Rectangular shapes in cylinders with subdivision surface

Question

What can you do to get clean rectangular shapes in a cylinder while using the subdivision surface modifier?

For the time being I've been trying to extrude them in the model and adding creases or support edge loops, but the end result looks weird even with an edge split modifier. The problem with support edge loops is that they affect other parts of the model that don't really need them and if I add some triangles to stop the flow things start to look bad.

After those problems, I added the rectangles separately by duplicating parts of the edge loop and adjusting them to the smooth form of the cylinder, but I was wondering how someone with more experience would tackle this.

score 3 · Answer 1 · edited Mar 14 '17 at 09:17

3

Adding the rectangles separately is probably easiest. If you are stuck on adding it into the topology, here is what I got by using mark sharp, edge creases, and the cast modifier with a vertex group. (the base topology is simple enough to be self-explanatory)

If you want to remove all n-gons, you can add two loops and line them up with the top and bottom of the box. Then knife cut between them to get this:

One more trick...use the data transfer modifier to fix normals:

edited Mar 14 '17 at 09:17

Community

1

answered Aug 29 '16 at 16:59

JakeD

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Very interesting method with cast modifier but I can't reproduce it with full loop cuts (to not to have ngons). Could you elaborate more about it? You could check out my older question about it: http://blender.stackexchange.com/questions/60710/hard-surface-modeling-on-cylinder in this case working Cast modifier could be a savior. – cgslav Aug 29 '16 at 20:00
Ok, so it will not work with making loop cuts and then extrude shape? – cgslav Aug 29 '16 at 20:11
Check this blend: http://blend-exchange.giantcowfilms.com/b/1859/ I'm also using AutoSmooth. – cgslav Aug 29 '16 at 20:40
What's wrong with the blend you posted? – JakeD Aug 29 '16 at 20:44
Under and over the extruded shape there are some 'glitches'. – cgslav Aug 29 '16 at 20:45
Let us continue this discussion in chat. – JakeD Aug 29 '16 at 20:46

Rectangular shapes in cylinders with subdivision surface

1 Answers1