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hrgiger
12-31-2015, 02:06 PM
Wondered if anyone who uses LW and Zbrush have a way to keep any creasing they do in Zbrush to carry across to LightWave? In simple cases where its a single loop, I can simply add an edge loop or two for a similar effect but in a lot of cases, only creasing will give you the same results.

hrgiger
01-02-2016, 09:44 AM
Talked to Lino some about this on skype and he suggested a couple of things..thank you Lino for your help!

One would be to export the mesh at a higher subdivision level so that it retains the creased mesh shape better. Thats an ok solution although you really have to export a pretty dense mesh to exactly match the object in zbrush but it will probably be what I do for now.

The other suggestion would be to export the low poly mesh from zbrush and then use cc subdivision and use edge weighting where youd had creases in zbrush. This would be my preferred solution but im finding that some edges are showing different levels of hardness even though they are using the same edge weight. I will post an example later.

Surrealist.
01-02-2016, 04:40 PM
Well if you use the second solution I would assume it to be different. And it would take experimentation.

The third solution I would suggest is just going old school and using edge loops. Until LightWave has proper CC's using that as a solution will end in roadblocks down the line.

jeric_synergy
01-02-2016, 06:11 PM
again, not that I've ever used them but: isn't this the kinda thing normal maps excel at? That zipper JoePoe (??) posted was pretty convincing.

hrgiger
01-03-2016, 03:09 AM
Well if you use the second solution I would assume it to be different. And it would take experimentation.

The third solution I would suggest is just going old school and using edge loops. Until LightWave has proper CC's using that as a solution will end in roadblocks down the line.

Edge loops work when its just a single edge loop. But for areas where you have loops coming together and then going off in differing directions, you end up with ugly poles which don't keep a consistent creasing. Here is a shot of what it should look like with creasing in zbrush, the other is adding edge loops and the resulting mesh in LightWave.

Eric I haven't tested with the various maps but creasing is a geometric property only which is what I was after.

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DogBoy
01-03-2016, 03:58 AM
Here is a shot of what it should look like with creasing in zbrush, the other is adding edge loops and the resulting mesh in LightWave.

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That is wierd and looks like it's edge loop alg is different than LWs: in LW i'd expect the loops to look like the attached.

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Surely you could just use SubPatch Weight on the 2 poles to fix it.

djwaterman
01-03-2016, 05:03 AM
What exactly is this creasing in ZBrush, is it really some sort of edge weighting? I was rather hoping it could be converted into tight edge loops inside of ZBrush before exporting but apparently no.

hrgiger
01-03-2016, 05:58 AM
That is wierd and looks like it's edge loop alg is different than LWs: in LW i'd expect the loops to look like the attached.

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Surely you could just use SubPatch Weight on the 2 poles to fix it.

True and in this case it works but that's a very simple case. There are other situations where simply adding an edge loop isn't enough to define an area.

And by the way, SubPatch Weight is not really useful as it sharpens all edges going into a vertex where in this case I only want to sharpen in one direction. Which is what edge weighting does in cc subdivision but there are other issues associated with that.

gerry_g
01-03-2016, 06:01 AM
did old tutorial when first learning ZBrush which warned me off using creasing, what it does is use a brush type that when stroked on the object surface draws multiple loops closer together to create an effect similar to edge looping, trouble is it is only visible it the high resolution object and not the low one and if you freeze out the high one the crease is likely to be so dense it will give you problems, I would learn to use other methods such as building an edge up then polishing it to get the same result, or mask along an edge then flatiron one side

hrgiger
01-03-2016, 07:10 AM
Sorry I'm away from the computer at the moment. When I get home later, I will post a part of a model which cannot be duplicated simply with edge loops. The example I posted earlier was not a good example because as dogboy showed earlier that can be done with loops (and yes by the way, zbrush adds edge loop by hiding parts/polygroups then adding a loop inside so it's different then running bandsaw in lw. To run a edge loop in zb like in lw, I would use zmodeler which I didn't do above).

wolfiboy
01-03-2016, 07:27 AM
I suppose you got your object by zremeshing a dynamesh-boolean tool? Well, I tried to re-produce your object by this way.
For the ZRemesh-process I used the opportunity to use the polypaint to increase the density on the wanted edges. So I got more geometrie on the the wanted sharp edges only. Of course I need to play with the density a little bit more to get the best result.

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lino.grandi
01-03-2016, 07:35 AM
Maybe it is possible to "read" the crease information from ZBrush through GoZ and import the object as weighted CC. I'll ask our developers.

Deep Purple
01-03-2016, 08:54 AM
I do not see edge sharpness available in the GoZ mesh data structure.
Cross-checking shows the same problem in Maya 2016 (screenshot attached).

Cheers,
DavidF

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Surrealist.
01-03-2016, 09:15 AM
Well I was talking about old school modeling techniques. I have never seen a shape anywhere I could not create with the correct edge flow. All I am saying is that it is an option, going old school. I am not saying there aren't shapes I would not enjoy creating that were done with creases, lol... I am not here to make a challenge. :) But I have yet to be stumped by anything I could not do. And that is over quite a few years and modeling quite a lot. So just as a solution, it could be a viable option.

Creasing is good if you have an end to end solution. And if the devs can do that, then great. But I think they'd have to fix CC's first.

I use creases from time to time in Maya, but that is because I have an end to end solution right there. I would think it would take some experimentation to export crease data correctly.

So anyways, back on topic, I think the solution is to simply recreate it for better or for worse in LightWave with CCs. But I would not count on CC's until they are fixed. And if it was my production I would not bother. I'd just model it traditionally. (if in LightWave that is)

My 2C

hrgiger
01-03-2016, 09:23 AM
I do not see edge sharpness available in the GoZ mesh data structure.
Cross-checking shows the same problem in Maya 2016 (screenshot attached).

Cheers,
DavidF

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Apparently, using Maya ascii file keeps the creases.

jeric_synergy
01-03-2016, 09:37 AM
But I would not count on CC's until they are fixed. And if it was my production I would not bother. I'd just model it traditionally. (if in LightWave that is)
My 2C
When LWG finally fixes CC modeling, I hope they present it with a bunch of "Before/After" screen grabs and sample meshes so we can prove to ourselves that it actually will work in our own productions.

Surrealist.
01-03-2016, 09:56 AM
Well I think the modeling part is not as bad. Maybe creases don't come over perhaps exactly from Zbrush and perhaps it is not as good as creases in other implementations.... but

I prefer to model with CC's. But I revert over to subpatch once I get to quads because of all of the other non-modeling issues they create. UVs for one, Useless. Can't use subpatch interpolation which kills CCs right there for image maps with UVs. There have been other issues reported similar to mine that I linked related to displacements and so on. Some others I have seen reported but can not remember. But the UV part kills it for me. I use image Uvs for pretty much everything these days. Your image maps don't map properly with subdivision surfaces on and set to linear. Freezing is an option but that kind of kills the advantage of using SDS in the first place.

oops should clarify the modeling aspect. I don't model in LightWave currently. But when I was, so this should have been past tense... I would always model with CCs untill I have quads. Since the other apps I model in use proper CCs and since I am exporting anyway, the base mesh, to Lightwave, it is a non issue.

But once back in Modeler and setting up textures, I use Subpatch and Uv interpolation to Subpatch.

hrgiger
01-03-2016, 03:17 PM
Ok, here is another example which isn't as easy to do with merely adding edge loops. Also shows an issue I have with CC weighting in that even edges you set at 100% hardness still are pretty 'murky' as in pretty soft looking. Yes, it tightens up and gets pretty close to the shape I want but it doesn't do well enough to reproduce the effect of creasing from Zbrush. I've attached a piece of the current object I'm working on if anyone is interested in having a play with it.

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The pictures are a shot of the base model in Modeler, another in zbrush showing the model with creasing and subdivided, and then a closeup in modeler with CC subdivision and edge weighting applied at 100%.

jasonwestmas
01-03-2016, 03:33 PM
I didn't read everything here but if you cut and paste (in modeler) to break the welding where you want the crease to happen, you can create poly groups real easy with Polygroups auto create. Next weld your verts together in Zbrush with a single click and then use the crease by polygroup feature. I realize that this isn't a one fix for all situations however.

jwiede
01-03-2016, 07:05 PM
Ok, here is another example which isn't as easy to do with merely adding edge loops. Also shows an issue I have with CC weighting in that even edges you set at 100% hardness still are pretty 'murky' as in pretty soft looking. Yes, it tightens up and gets pretty close to the shape I want but it doesn't do well enough to reproduce the effect of creasing from Zbrush.

See Gerry's reply above. Crease is _old_, and its known issues are part of why Pixo added explicit new hard-surface brushes and tools during ZB4. Try using polish and/or flatiron brushes instead in producing your hard edges, the export geometry produced should be much better.

hrgiger
01-03-2016, 07:38 PM
How the geometry is produced in Zbrush has little to do with its geometry upon export. Because either way, you're either retopologizing the mesh after the modeling is done, or you're using Zmodeler which makes extensive use of creasing with the new Dynamic subdivision in producing hard surface models.

If you watch most any tutorial in hard surface modeling in the last year or two during the latter part of the current Zbrush 4 cycle, almost all of them use creasing (including those directly from Pixologic themselves). So creasing may have been around a while, but I see no indication that it is in any way, an antiquated method of defining hard edges in Zbrush.

I've sent some questions off to a few people who have done some of the tutorials and hope to get a sense of how they deal with creases outside of ZB. It may just be a displacement issue so Jeric might have the right idea in this case(although I would think more then a normal map would be needed as normal don't actually displace the geometry). Will check it out.

Oedo 808
01-03-2016, 08:56 PM
I don't know how I'd get by without using Crease.

hr, are you sure that the CC edges aren't giving you what you want, just that subpatch smoothing blurs even sharp corners, with no way that I know to tell it not to, or have I missed the point? This is what I get if I freeze the CC SubDs:

http://forums.newtek.com/attachment.php?attachmentid=131750&d=1451879484

hrgiger
01-03-2016, 09:21 PM
Yeah that's possible Matthew. Looking at it again, it may be an OGL issue as the results are more consistent in VPR.