Best program/tricks for correct topology holes in hard surface

dlots

There are a few discussions on how to do holes (circular, polygonal) into a single quad. However, the workflow gets quite manual and requires quite a bit of planning and edge loops if you are completing the following specific objective:

Repeating instances of a polygon hole into a surface that consists of multiple arbitrary quads.

I have attached a file that illustrates specifically what I mean:

I know how to accomplish this manually with a planned out approach by:

http://blenderartists.org/forum/attachment.php?attachmentid=416778

1. modeling the polygonal holes and extruding their edges to create the surrounding hard surface
2. adding edge loops to the instance so that the repeating instances can have their edges bridged easily
3. aligning it to the bridged repeated instances to the target mesh's existing surface
4. adding edge loops to the 2 meshes (the repeating hole mesh and the target mesh) so that they can be easily bridged/merged

My problems with this workflow is that it is quite slow and one cannot easily preview if they are satisfied with the result before embarking on the long and well planned journey (hence I suppose the evangelization of the workflow of sculpting and then retopology in Zbrush for hard surface).

(It is also destructive to the mesh in that it adds a lot of edge loops if you want to maintain quad topology but that is expected regardless of any sort of automation presumably.)

The faster alternative is to use a sculpting program and hope that an automated remesher results in a sufficient accurate solution, but I cannot imagine that this works 100% for game engine production quality models.

In the instances where presumably ZRemesher doesn't output something useable, what is the best program (namely the one that has tools beyond basic vertex operations) with the best tricks,shortcuts,features for accomplishing this?

2bytes

If you want to learn Nurbs, then Moi3d is an easy one to pick up and excellent for hard surfaces.  The workflow is with booleans, and solid modeling. It outputs polygons, but its not a subdivision surface. You would need to output the final resolution mesh with this workflow.

This introduces a lot more possiblilties because you are not just limited to circles,  but could create an array of elipses or any other shape and punch holes as you want.

JedTheKrampus

Well, there's a bit of a problem with the way you did it here, and that is that it subdivides really poorly.



Here's how I'd make such a brake disk for baking-down purposes.



I have a "create hole" script that deletes each region of selected faces, extrudes the edges in, morphs it to sphere, and extrudes in again. It's part of Wazou's scripts which can be found here: https://github.com/pitiwazou/Scripts-Blender

I created a circle with 64 cuts, extruded it and scaled it down 0.5x, did four loopcuts, subdivided once with a modifier, used circle select to select relatively quickly most of the places where I needed holes, set the pivot point to individual origins so each selected region would have its own hole, ran the hole script with Wazou's pie menu, selected all the other regions with circle select, ran the hole script again, then adjusted the holes so that they'd all be roughly the same size and followed the correct curve. I had to scale down the innermost holes that originated from six faces and the outermost holes, and rotate the innermost holes a bit around the 3d cursor. Then, I solidified it, added some support loops, popped on a subsurf modifier and called it a day. Here's how it looks with no wires.

JedTheKrampus

You could also probably do a shape like this pretty fast with 3d Coat voxels, although it would take more system power during the creation process than traditional SDS modeling.

dlots

Thanks so much Jed, that is really informative. I was aware that particular file was not correctly done with the holes, trying illustrate the difference with incorrect topology for subdivion vs correct. Thank you!

That workflow and those tools look really good, but I'm always interested in any other tricks across all programs. I am interested in knowing the complete state of the art for making hard surface paneling to know the right tool for the right job.