marveloustut

There are a lot of Marvelous Designer workflows. They all have their benefits, but this is one that I use most often when I’m working.

The workflow has a couple of advantages: its fast (can be done in minutes) and all done in zbrush so not a bunch of program hopping, it produces nice meshes for sculpting, it maintains UVs, it maintains polygroup borders for easier retopo and detailing, and it maintains fabric thickness (and assigns the thickness edges its own UV space, so no edge UV seam on tiling patterns).


This guide assumes you have a working knowledge of zbrush and marvelous designer, and the concepts of each. If I leave you hanging without a specific explanation, there are a number of tutorials available for any of these topics, which can be found with a google search.


Step 1 – Exporting from Marvelous

These are the completed pants in Marvelous Designer.

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Typically I finalize my export with these settings. The “add’l thickness” depends on the thickness of individual pieces, but the particle distance is fairly high. Marvelous Designer is more of a basemesh exporting program, it creates great starting points that need work in zbrush. This method works just fine with lower Particle Distances, so feel to use whatever is needed.

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The main consideration is that we have to export the pieces so that they dont overlap. In the example below, no exported piece maintains a border with any other piece.

We have to do this to avoid welding inappropriate vertices at a later step. So to do this, we will export in batches. Export the pieces in any combination, but they cannot share a border. 

It is typically okay for them to share a corner, as like below, because the verts do not generally line up at the corners 100% when something is exported with thickness (it seems to calculate thickness from the middle, so unless both pieces have the same exact normal tangent, you should be fine). Still, I avoid exporting corners together when I can. Even the most complicated patterns in Marvelous can usually be exported in 5 or fewer groups.

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Export each group using these settings. This will give us unwelded panels with thickness.

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Step 2 – Import into Zbrush

Import all pieces into zbrush. When exporting, I typically name mine whatever_x, to avoid confusion. I also suggest importing the avatar first, into the top slot, to make sure that zbrush will maintain scale if you need to go back and import/export anything, or when you go to merge the tool with your main sculpt later.

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Step 3 – Doing the Remesh.

Everything in step 3 must be done to each subtool individually. These steps are pretty quick, so even if it feels slow at first, it should only take 1-2 minutes to get all the subtools done.

Start the process with the top subtool. First, go to Polygroups->Auto Groups.

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Because the vertices aren’t welded, auto-grouping the mesh will split the mesh into panels, typically front, back, and the edge border.

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The one problem this creates with some meshes is internal lines – for instance the fly and pocket on the jeans above. If we re-mesh with these lines in place we can get sub-optimal results. To get rid of them, isolate the panels that should be connected, then hit Polygroups->group visible. This will combine it into a single panel (like below, on the right). Then un-hide the hidden parts.

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Below is what it should look like, with panels around all the appropriate areas, including the thickness border. Its okay if the thickness border has multiple polygroups along the edge, as seen below.
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With everything ready, press Geometry->Weld Points. This will weld all of the appropriate verts, and make the mesh a single piece.

Now we are ready for the remesh. Using these settings (below) in the Geometry tab to keep the topology clean. Use “Keep Groups”, with the “Smooth Groups” slider set to .5. This forces Zbrush to preserve the polygroups in its retopo, so it holds the edges and shapes better.

For the “Target PolyCount”, use a number that will keep the mesh fidelity, without being too dense. Also, as you repeat these steps for each subtool, try to keep topology similarly dense.
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 Zremesh should give you the below results.

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So now the fabric is properly remeshed, and the verts are welded.

Lastly, we need to re-group the polygroups so that the mesh is divided into two parts – interior and exterior. This is a crucial step for proper UV mapping.

Its important to group the external side of the mesh together with the border, this way we avoid a UV seam at the clothing edges.  To do this, just hide the interior panels (as show on the left below), then hit “polygroups->merge visible”. Invert the visibility, and repeat, so that you end up with two groups: interior and exterior.

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Now repeat step 3 for each subtool.


Step 4 – Combining Meshes. 

Once each of the subtools has been dealt with, and has proper polygroups in place, you can combine all of the subtools down into a single subtool. I usually save a copy at this point, just to be safe.

This is what the mesh should look like. Notice that the exterior mesh is one polygroup(green), and the interior mesh is another(purple).
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Step 5 – Automated UV Unwrapping

So now the mesh is ready for UVs. Because the mesh is divided into panels, and the interior panels are a separate polygroup, using the zbrush automated UV unwrap will produce UV’s that are naturally very close to the Marvelous Designer patterns we imported.

Hit UV-Master->Work on Clone, then

Turn on “symmetry” and “Polygroups”. 

Then hit “Unwrap.”
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After unrwap, use UVmaster->flatten to see the result. It should look similar to this. Notice that the patterns are divided by polygroups into interior and exterior, and that the UV’s fairly closely match the Marvelous Designer patterns.

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Use polygroups to select the interior islands. The interior islands dont matter much in most cases, because they will never be seen or baked down. So drag them off to the side so you can work on the main, external, UVs, in this case the green UV’s.

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Below are the finished UVs.

The useless interior UVs are scaled down and jammed into the bottom. The main UV’s are straightened and organized at the top. Always arrange these UV’s in the correct direction, so that if you use zbrush surface noise or something similar, the patterns or tiling maps will flow in the correct direction. For instance if you are going to apply stripes, you would want them to run down the length of the leg, so arrange the UV’s in that direction.

A tip: If you have many UV’s to organize, use polygroups->autogroups, so you can use the polygroup selection tools. If you want to quick select a UV island with transpose on, press CTRL+SHIFT and click, and it will auto-mask that island off.

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When UV’s are ready, hit UVmaster->Unflatten.

Copy the UV’s, and paste them back onto your main mesh.
Check the UV’s by going into the noise plug and using ‘stripes’ to make sure everything is lined up correctly.

Below is result from the above UV’s.

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Step 6 – Finalizing the Mesh for sculpting.

The final step is to separate the panels of the mesh into polygroups to make them easier to work with. Just hit Polygroups->AutoGroups. Now as you sculpt, you can hide or show whichever panels you need. Its particularly helpful at retopo. For instance if you need to get into the crotch or armpit, you can simply hide the panels of one side and continue on unobstructed.

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And that’s pretty much it. 

It does seem like there are a number of steps, maybe too many especially because they have to be done in batches, but its actually quite a quick workflow. It takes a couple minutes to work through all the subtools and setup the UV’s, about 5 minutes for these pants total. The resulting panels made sculpting and detailing quicker and easier, and the UV’s allow the use of tiling surface noise.


Using polygroups to hide and mask meshes helps detailing, especially with seams and dirt/damage. 

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Problems with this Method

There is one main problem to this method, which can be fixed if you look out for it.

We cannot import meshes which share a border, because on the third step, when we hit the ‘weld verts’ button, it will randomly weld verts along that border, and destroy the mesh along that part. To get around this, we import and remesh the marvelous output in groups. However there are situation where a border is unavoidable, such as when you have a single piece of cloth wrapped around the avatar and sewn to itself, for instance on a sleeve.

To solve this, for instance on a sleeve, its possible to hide 1/2 of the sleeve and use the move tool with a large size to move the border off of its opposite side. This way the verts are clear of each other when we vert weld them in zbrush.

An alternate solution is to just live with it. On the sleeve, for instance, the ruined seam is hidden at the bottom side of the arm where it will rarely be seen, and using the inflate brush will hide any of the bad geometry anyways.


The finalized, sculpt ready mesh on the left, and the finished, sculpted mesh on the right. MARV_23

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