Hi Oskar, well hmmm I think that maybe your earlier method of painting a displacement texture would be actually be a good way to go, since you'll be able to use just regular geometry instead of anything especially dense. But you'll want to use some automatic UV unwrapping tool to get the UVs prepared for you.

- Michael

Hi Michael!

Well in this case I find it very hard to do good UV mapping, since it is two cylinders meeting. I try to minimise the seams. (I know this is a general problem, and not related to MOI) Otherwise I agree that a displacement workflow seems most approriate.

/Oskar

How many welds? One thing you could do is a simple fillet on the join, then grab the seam edge that is created from the fillet with copy, then delete the fillet surfcae and past that seam edge back in, then rotate it with the edit fram widget to be "reversed" and sweep it with the 2 rails left from the fillet surface gap. Instant welds...Actual geometry.

Hi Oskar,

I'm just curious why you would want such detailed welds in your model.

-

Hi!

Well the welds are just an example of a detail you might want to ad afterwards. For higher realism. Since welds are not perfect shapes they are not perfect for nurbs. But a simple fillet would do most of the time.

I'm really searching for a way to improve models after exporting from MOI. Not only in Modo but whatever way is clever. It could be welds or seams in some leather seat. Details that you don't want to ad in nurbs.

Burrman: I actually tried something similar, but I'm having a hard time getting does cylinders to fillet. I will try your method later.

Danny: I want detailed welds for closeups. But I only want them if I can find a fast workflow to get them :)
But in my opinion that kind of details ads alot of realism.

/Oskar

Hi Oskar, you could also try 3D-Coat or ZBrush for altering the geometry instead of doing UV textures, if you have an area that is difficult to set up good UVs for.

Here's an example from a while ago where MoI was used to do some basic shapes and then ZBrush was used to add detailing like knurling on the sword handle and embossing on the shield:
http://moi3d.com/forum/index.php?webtag=MOI&msg=1045.1

But definitely 3D-Coat and ZBrush come to mind if you're looking for a general way to add detailed lumps and bumps to a model.

- Michael

>>>>but I'm having a hard time getting does cylinders to fillet. I will try your method later.>>>>

Be sure to make one of the cylinders just a bit smaller than the other. 2 cylinders exactly the same size like that may give problems.

Hi Oskar,

This joint was done in Modo using procedural displacement. I added a noise layer to the material and made the effect displacement.
In the noise properties I used a Fractal type and played with the values, frequencies & amplitude.






The benefit is you don't need to add alot of extra geometry manually.

Quick and on a budget :)

MoI



Sculptris


Simlab


Cheers

Ok, thanks!

Michael: Of course ZBrush has come to my mind as well. But I dont have any expeience from it. Will it actually differ from using modos sculpting tools? I will get a dense mesh or I will need a clean UV to apply the generated displacement to? Or is there any particualr differnce in the way zbrush handles the exported mesh? I'm thinking of the vertex normals? And should i be terrified about loosing the vertex normals in modo?

Burrman: I thought I did that. Will look in to it.

Danperk: That is a trick. Did you apply the displacement to a fillet? I think that could be a good way to handle welds. Use a fillet in moi and the ad a displacement in modo and use a vertex texture to make it bulge.

Danny: This looks like fun! I will have to try sculptris. But other than that, I guess this workflow is the same as zbrush?

/Oskar

Hi Oskar, well ZBrush is much more completely focused on that kind of a thing, I'm not personally familiar with Modo's sculpting tools so I can't give you a very good answer myself but I don't recall hearing very much about sculpting being a particularly big area of focus in Modo.


> I will get a dense mesh or I will need a clean UV to apply the
> generated displacement to?

Well, if you're having difficulty with UVing, then you would probably want to make a dense mesh and then save the altered geometry rather than doing it by texturing.

If you are able to get good UVs, then it sounds like you can already use Modo to do what you need, is that correct?


> And should i be terrified about loosing the vertex
> normals in modo?

Well, it depends on what you are trying to do. Since you are trying to actually add imperfections it may not be so important for you to get the super accurate smoothness of the original vertex normals.

If you want things to look completely perfectly smooth and pristine, that could be more of a factor. But it seems like you are actually trying to avoid that kind of a look.


You might try 3D-Coat first, it could possibly be easier to get into initially than ZBrush.

- Michael

Hi Michael!

I guess Zbrush is the king when it comes to sculpting, but modo has a toolset that allows you to sculpt both real geometry and displacement maps. One big difference is that modo can't push as many polys as Zbrush. But for my needs it seems that i can get by with modo. Altough it does bother me that i have to delete the vertex normals :) At least if I go with the dense mesh workflow.

But wouldn't I loose the vertex normals in any app when I start to modify the mesh?

/Oskar

Hi Oskar,

> But wouldn't I loose the vertex normals in any app
> when I start to modify the mesh?

Yes, you will - the vertex normals are tied to the particular shape so once you modify the shape you also need to have new vertex normals to go along with the new shape.

But like I mentioned, the original vertex normals are more useful if you want a super smooth and non-perturbed shading that looks exactly like the original NURBS model, which tends to be what people are usually more focused on with "hard surface" type mechanical models.

You seem to be talking about making bumps and imperfections on your shapes, so maintaining super smooth precision shading and uniform reflections does not seem like it would be as much of a priority for you.

Just as a general tip, if you do need to work on output generated from MoI without preserving vertex normals, it tends to help if you generate a more evenly diced up mesh instead of having a mix of large polygons (from stuff like planes) right next to small polygons for more curved areas. Meshes that are made up of more evenly sized polygons tend to work better when they are edited and have new vertex normals created just based off of the polygons.

- Michael

Well, my most important reason for using Moi is that it is fast and easy for hard surface modelling. I guess I have to choose between super smooth and extra details from time to time.

Anyway, I feel alot more comfortable deleting those vertex normals now.

And thank you for the tip!

/Oskar

>Did you apply the displacement to a fillet?<

Yes, and applied a red style in Moi where I wanted to use the weld material/displacement in Modo.

Hi Oskar,

> I guess I have to choose between super smooth and
> extra details from time to time.

Yeah, sometimes you will need to make this choice.

But if you can keep the geometry in place (with vertex normals), and only paint a displacement texture map on it to add detail, that's the case that gives you the best of both worlds.

Can you maybe describe a bit more about why you were unable to do that with your original case? Does Modo have a problem dealing with UV seams making it hard to make a good looking displacement in an area where there are seams?

Maybe in the future Modo could use the Ptex system to make that work better - it's a system that can be used instead of UV mapping, it instead makes a kind of separate mini texture for every little individual polygon but then also has a filtering mechanism that is supposed to make things work better across borders.

I think Ptex was particularly designed to make painting on stuff easier without having to set up UV mapping.

- Michael

Hi Michael,

I agree that a displacement map is the best compromise. Modo is pretty good with UVs so that is not the issue. Although I'm no expert on displacement maps, I think they are very sensitive to UV-seams. In this particular case with two cylinders I think it is very hard to get a good UV without seams. To make things even worse there is no fillet between my cylinders. If I manage to add fillets I think it is going to be ok.

If Ptex gets widely adopted it is gonna make life alot easier for alot of people, me included.

Thanks for your help!

/Oskar

Hi Oskar,

> Although I'm no expert on displacement maps, I think they
> are very sensitive to UV-seams.

I'm not sure if that absolutely has to be the case though...

The Ptex stuff for example basically has the equivalent of seams at every polygon edge, but apparently it also incorporates some mechanisms to make the transitions work better.

So I'd think it would be possible to have something similar applied to regular UV map displacement painting.

You may want to try ZBrush or 3D-Coat to see if they handle doing displacement map painting across regular UV seams better than what you are seeing in Modo.

- Michael

Hi Oskar, I did a bit of digging, and there appears to be plenty of complaints about displacement map painting in Modo not really working as well as it should across seams, here is a discussion thread:

http://forums.luxology.com/discussion/topic.aspx?id=37566


So based on that discussion, I would say you should definitely try 3D-Coat at least and see if you can paint a displacement map better in there, and then just assign that map in Modo instead of doing the actual painting in Modo for displacements.

If that eliminates the issue you ran into with seam displacement artifacts, then you would have a workable general solution set up.


All kinds of models can have UV seams in them, so I don't think just trying to avoid seams is really feasible.

- Michael

3D Coat has Ptex now.
Brian