Hi!

I wonder if anyone has a good workflow for adding extra detail to your exported MOI meshes?

For example, I need to add some welding creases to a T from joined cylinders. First I tried to use the paint tool in modo to make a displacement texture. This didn't produce very good results. It was ok in some areas and bad in others. I guess you have to add some time to straighten out the UV's for this to work.

Then I exported a much more dense mesh from MOI to modo, still using the LWO format. Now I tried to use the sculpt tools to produce the extra details. But when deforming the mesh the normals messed up. I kind of expected that. Now I deleted the vertex normal map and everything looks good. So I guess I can use it in this case.

But can I expect this workflow to work for other more complex meshes? Reading this post, http://forums.luxology.com/discussion/topic.aspx?id=44399&page=1, the vertex normal map seems crucial to get corrct surface smoothing.

Any suggestions is deeply appreciated!

/Oskar

Hi Oskar, getting the original NURBS vertex normals through does tend to help a lot with making the rendered surface preserve all the shading characteristics of the original NURBS model.

But if you want to edit the model to change it, then you're going to be in a different category because that means you're trying to make something that looks different from the NURBS model instead of something that looks exactly like it.

In that kind of situation, your best bet is to use the "Divide larger than" setting in MoI to make polygons diced up into small regular sizes, that should help reduce shading glitches, and also at the same time you'll probably need that in order to do decent deformation of the objects as well.

See these previous posts for some examples of how you would want to have the mesh look:
http://moi3d.com/forum/index.php?webtag=MOI&msg=2833.5
http://moi3d.com/forum/index.php?webtag=MOI&msg=1084.2
http://moi3d.com/forum/index.php?webtag=MOI&msg=1549.4
http://moi3d.com/forum/index.php?webtag=MOI&msg=804.26


I'm not entirely sure if I understand the kind of thing you're trying to do though, if you only want to modify just one region of your model instead of modifying most of it, you might want to separate your model into some different chunks or something so that the majority of it can have the proper vertex normals and get the nice extra smooth and accurate shading on it and only do the editing on certain regions.

Maybe if you could post an example of one of your sample results it would help to illustrate.

- Michael

Hi Oskar,

> First I tried to use the paint tool in modo to make a
> displacement texture. This didn't produce very good
> results. It was ok in some areas and bad in others.
> I guess you have to add some time to straighten out
> the UV's for this to work.

Actually it seems like this would be a pretty good route to go, but yes with an additional UV unwrapping tool used to set up the UV mapping for you, the default mapping saved from MoI is not set up for painting.

I think PaQ has had good results using UVLayout for this purpose: http://www.uvlayout.com/

- Michael

Hi Michael!

Here is an image of what I am going for. I think this looks good. But it is a very dense mesh. I used the "divide larger than" option when i exported. You might be right about splitting the model into smaller parts. Using a dense mesh where it is needed. But I'm worried that this might cause glitches between lowres and highres areas of the mesh.



Thank you for the links, I look into them.

/Oskar

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