HIgh Poly Corner Problem
Hey everyone,
I've been trying to figure out how to do corners well in high poly. I've used bevel with some success but sometimes it does weird things..
The topology is exactly the same in both corners, but when I subD one produces a nug and the other does not. Does anyone have a time-efficient solution? I have about 8 of these to fix.
Thank you!
I've been trying to figure out how to do corners well in high poly. I've used bevel with some success but sometimes it does weird things..
The topology is exactly the same in both corners, but when I subD one produces a nug and the other does not. Does anyone have a time-efficient solution? I have about 8 of these to fix.
Thank you!
Replies
Check this thread: http://www.polycount.com/forum/showthread.php?t=56014
Also, post a shot with more of the mesh, so we can see the surrounding geometry, and your reference, so we can see what you're trying to accomplish.
Here's a full shot of the piece:
SubD:
This is how I'm trying to solve it:
All I'm trying to do is sharpen certain edges and corners.
Is there maybe a way to do this without splitting polys and pushing verts in a haphazard way? Are there any general rules for corners that I need to learn?
modify into desired shape
add supporting loops
remove loops around the sides, this causes a small bit of pinching but should be fine when you bake.
Alternatively, add an extra set of edge loops, and then carry those control edges down the side a little further, you'll still get some pinching but maybe this is a more clean result, again shouldn't be noticeable when you bake.
Alternatively alternatively, just use a shitload of sides, like 128 or more. This will be harder to work with, but you can do some creative stuff like creating the bits that merge into this as floaters.
Another method would be to create the zigzag shape as a straight section with a lot of edges and then use a FFD or some kind of bend deformer to make it go in a circle
I would model it flat and then put a bend of 360 degrees on it. And put a shell on it in the end
Why don't you just use two edges at each peak and valley instead of one central edge with support edges? Wouldn't that eliminate the pinching? I think the reason it's pinching is that the geometry is just too sharp.
Anyway, I think this was the route of all my subsequent problems, but I have a few more questions.
Here is the final sculpt:
I baked an occlusion map (which made my material turn grey, does anyone know how to turn it back?) with mudbox 2011 and this is what I got:
Some of the UV's got messed up as you can see, so I was wondering if that's normal. Which brings me to my next point:
Also done by mudbox.... Should I just use Xnormal? or Did I mess up with my settings? It took my comp an hour to bake 1.5 mil polys with a fairly new computer.
Can you elaborate on what that means? Was I supposed to use edge loops for consistency and keep my mesh symmetrical all around?
Isn't it better to fix the base mesh so that as little pinching occurs as possible? I thought if I left the pinches there, the sculpt would have been even more f'ed up. Is that kind of stuff easily fixable by subdividing and sculpting manually?
What Mighty Pea means is you need have your model topology divided so its as even as possible like a grid. The goal is to avoid a lot of thin polygons and have areas of large polygons because of how subdivision works. When you subdivide a model in Zbrush for example it will place most of new polygons where the smaller polygons are and the larger areas get less polygons. The problem with this is that the large areas is where you normally need the most detail and you won't get it if you don't divide those areas evenly. Try it if you don't understand.
Yeah pinching can be an issue if you need to sculpt but it depends. You make your model and deal with it on a case by case basis. If pinching is a problem you deal with it.
So you mean instead of subdividing the mesh, i just manually put edge loops all over the place? I believe I get it now. I thought going from low poly to high was just about hardening certain edges with edge loops. Oh boy.
Thanks for explaining it, man. I learnt a ton on this model, so the next one is gonna kick ass.
Generally, its done the other way around, first creating the highpoly, and then building a simplified low around high. Its a mess to do it low->high.
Yep.
So, as simplest and generally put as it can possibly be (This is how I go about it, anyways...), it's LIKE this...
1) Build your low poly base mesh to match the general SHAPE of what your goal is. It's up to YOU to keep in mind what the high poly will have to somewhat conform to when baking to the low poly. By this, I mean, you can't have a low poly cube and try to bake a normal map off a high poly model that is a sphere, and try to make that work on a LP cube. Get what I'm saying?
2) Make sure this base mesh has evenly distributed quads / topology. This is because you want subdivision to be even across the entire mesh. If you do not have an evenly distributed topology, resolution will differ when subdividing in ZBrush, Mudbox, etc, causing strokes and details to differentiate in resolution when sculpting, which when noticeable, is terrible.
3) Sculpt the crap out of this mesh...
4) Export a decimated / lower poly count mesh, from the high poly sculpted mesh in ZBrush / Mudbox etc., to use for re-topologization purposes in Topogun, 3D Coat, Maya, Max, whatever.
5) Retopo this mesh.
6) Assuming you have saved iterations of your high poly model, use the one you feel is most appropriate (has the highest detail) for baking normals, Ambient Occlusion, etc., and the new, retopo'ed mesh you just made to bake TO. You can do this using xNormal, ZBrush, Maya, etc.
This is one workflow in a pool of millions, that you will never understand completely. I am NOT saying your stupid - I'm saying that every artist's workflow is different, with different habits, different paths of doing things, etc. You'll one day have your absolute own workflow for doing things, and it will be yours alone. So, by all means, you don't have to follow this workflow to a T. It's whatever works for you....I tried being as general as I could.
I hope you know the rest lol...
Max you can get loops evenly placed in your model with connect for example.
The advantage to sculpting is also that you can just subdivide something a few times without smoothing, then subdivide once with smoothing and you'll have those smooth edges you were trying to get, without pinching. I noticed you use Mudbox so I quickly googled how to do this in there: "Go and look under the optoins box next to subdivide and uncheck smooth."
As for going low>high, I agree with EQ that it's messy. On the other hand, I generally make the broad shape first, then add supporting edges (the ones that tighten certain edges for subdivision, basically) in a seperate edit poly layer. This gives me an easy way to get rid of them later to have a simplified mesh for the lowpoly. It still requires tweaking ofcourse, but I find this to be a nice way to work for mechanical objects.
edit: here are some links to the wiki that might prove useful:
http://wiki.polycount.com/CharacterSculpting
http://wiki.polycount.com/BaseMesh
http://wiki.polycount.com/ReTopologyModeling
Eric Chadwick's (and co.)done an amazing job on these pages.
Yeah, but this is blockout -> high -> low, which is still very different from low -> high, which is just a huge mess as you're trying to build a usable high from an optimized lowpoly model.
Thank you so much for all the info, everyone. You have no idea how helpful your replies have been, and I'm actually about to show you when I post up my final screens of the scene this model is from in UDK.
But first, I have a question about X-Normal. Does anyone know how to get the normal maps to only take into account the closest mesh to the low poly? To show you what I mean, there are various objects overlapping each other, and the normal map seems to reproduce the overlaps instead of being baked individually for each object. So you get this:
I think the farthest high poly mesh overrides whatever the rays hit before it, so I was wondering if there is a setting in X-Normal that makes sure each object gets its respective normals, instead of "being blocked" by adjacent ones... Because so far I've been forced to bake each object one by one.