Connecting edge loops of incompatible vertex count (16 vs 5 sides)


I’m doing the Hydrant tutorial by Blackheart Films.

I’ve noticed he made the bolt in his hudrant 8-sided, while the reference has a 5-sided bolt. The test of the mesh is based on a 16-sided cylinder.

16 and 5 don’t have an integer common divisor.

I’ve thought about a way to connect the 16 and 5-edged loops without creating hideous shading problems and bad topology.

This is what I’ve come up with:

Is this a good solution? There’s a bunch of poles here, but after applying subsurf it looks decent.

I’ve first added extra loop cuts on my 5-sided part to bring the vertex counts a bit closer, then I’ve added an inset from the 16-sided part to make the problematic area smaller and bridged the two loops trying to have as little stretching in the quads and triangles as possible. I’ve then rotated some edges, and rearranged quads and triangles to have them flow the in a most natural way I could find here.

Here’s my .blend file, if anyone wants to use it (maybe for showing me a better solution?):
Fire Hydrant 02.blend (180.5 KB)

I’m not sure if that’s of any importance, but I’m focusing on modelling with video games in mind.

Yours is just fine and there are different ways of connecting. I changed your mesh and just got rid of the triangles and made it all quads… the end result is the same as far as I see except you lose the edge loops by doing so.,

and you could even remove the edges in the pentagon for all quads if you wish…

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Wow! Thank you!

It didn’t occur to me I could get rid of all the triangles to make it quad-only.

I’ve went on and did so following your example:

Also on another part of the model:

In the second instance some of the quads became concave, which I was afraid would cause problems after subsurf - they seem to look fine there, but I am not sure about this.

Is is better to have concave quads than triangles instead?

Here’s the final .blend file so far:

Fire Hydrant 08.blend (279.7 KB)

I treat this as an exercise in topology (and also a test project to learn Substance with).

I think most would say NO, but in this case it has no effect on the out come, I see NO bad faces, giving weird texture issues…and in parts I think it enhances some of the edge flow ( the indents on the side connectors for example).
I think this turned out very well, and should texture up nicely in Substance!

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Thank you very much for your help!

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I wouldn’t worry too much about topology for a static object like that. And a lot can be fixed using some normal modifiers. If it ain’t deforming from animation, don’t lose too much sleep over it!

Here’s some quick tips I made that might interest you: (some topology tips, like how to go from one number of edges to another) (weighted normals - a modifier that can often fix shading issues caused by imperfect topology).

Thanks! I want to learn the proper topology way regardless, because so far I’ve been making it a bit messily, and I need to step up my game. Once I can make it perfect, I can choose not to if it’s not.worth the time, but so far so just wasn’t able to make it right :slight_smile:

I’ve finished texturing the model in Substance Painter:

That was a nice exercise, though I won’t be putting this into my portfolio for obvious reasons :smiley: