Building with a USD Export

Before You Begin

You need the following:

• USD export

• bodyShapeG_CombinedSkelMesh (from the Creating Your MetaHuman step)

Create a Cloth Asset

1. To create a cloth asset, inside your working folder, right-click in the Content Browser and select Physics > Cloth Asset.

   Name your new cloth asset CA_techwearOutfit_bodyShapeG, and hit enter to save.

   

2. The Dataflow Graph window will appear, giving you the option to select your preferred template.

   For the purpose of this tutorial, select USD Cloth.

   

3. Double-click your cloth asset to open it in the Dataflow Editor.

   

4. In the Graph panel, delete all but the following nodes:

   • USDimport

   • TransferSkinWeights

   • Remesh

   • Remesh_LOD2

   • ClothAssetTerminal

   Your graph should now look like this:

   

Set Up Your Meshes in Dataflow Editor

1. In the Graph panel, select the USDImport node. In the Node Details panel, import your USD by clicking the three dots next to USD File.

   

   Once imported, your asset should be visible in the Construction Viewport in the Dataflow Editor.

   A new folder containing your USD file, materials, static meshes, and textures will appear in your working folder in the Content Browser.

2. Connect the Collection pin on the USDImport node to the Collection (in) pin on the TransferSkinWeights node.

   

3. Select the TransferSkinWeights node. In the Node Details panel, under Skeletal Mesh, select bodyShapeG_CombinedSkelMesh.

4. In the Graph panel, connect the Collection (out) pin on the TransferSkinWeights node to the Collection LOD[0] pin on the ClothAssetTerminal node.

   Your graph should now look like this:

   

If you do not wish to add or generate any LODs, right-click on the ClothAssetTerminal select Remove Option Pin to remove the remaining pins (so it does not expect any more LODs). You can then continue to Create an Outfit Asset.

Set Up LODs

1. In the Graph tab, right-click and search for Remesh. Drag the Remesh node to the graph.

2. In the Graph tab, connect the Collection (out) pin on the TransferSkinWeights node to the Collection (in) pin of the Remesh node. Don’t disconnect TransferSkinWeights from ClothAssetTerminal.

   

3. You can visualize changes made in the settings of the Remesh node by enabling the Construction Viewport. In the Construction Viewport tab of the Dataflow Editor, click the Display View dropdown in the top-right corner (default 3DView) and select Render.

   

   You can also change the Construction Viewport display from Lit to Wireframe and many other options.

   If you do not see your asset in the Construction Viewport, always check whether Render is selected. This option can become deselected easily.

4. Connect the Remesh node’s Collection (out) pin to the ClothAssetTerminal.

5. Repeat steps 1, 2, and 4 for each LOD. For this tutorial, you will adjust each Remesh node's Target Percent Render in the Node Details panel:

   • Remesh node for LOD[1]: Set Target Percent Render to 50.

   • Remesh node for LOD[2]: Set Target Percent Render to 30.

   • Remesh node for LOD[3]: Set Target Percent Render to 10.

   

Painting Weight Maps (Optional)

Due to the limitations of skin weight transfer from the body, you may occasionally encounter strange looking artifacts, such as tearing in areas like armpits and upper thigh regions. If you notice these during animation sequences, this means you need to pre-paint maps that control skinning operations. You can paint maps on your garment which can control the following operations: Relax, Prune, Hammer, Clamp, and Normalize.

To see and paint the weight map, follow these steps:

1. Double-click the Cloth Asset to open it in the Dataflow Editor.

   

2. Click on your static mesh import node and then click the Paint Weight Map button in the General tab.

   

3. To paint on the sim mesh, start by changing the Vertex Group to SimVertices3d.

   When painting maps on a sim mesh to relax them, the mesh MUST BE MERGED. Otherwise, relaxing it will cause it to pull apart at the seams.

   If you are unable to achieve the desired results, we recommend trying a render mesh instead.

4. Double-click the PaintWeightMap and it should appear in the construction viewport. If it doesn’t, check to see if 3dSim is selected.

   Name it something informative. In this example, the map is for an LOD_0 mesh which would control “relax” so we named it LOD0_relaxMap.

5. Paint the areas you would want affected by your operation of choice in white, and leave everything else black. When you are done, click Accept.

   

6. Now, the static mesh is ready to have a map attached. Right-click in the dataflow graph, type SetSkinningSelection, and select it when it pops up.

   • Connect the Collection pin of the PaintWeightMap to the Collection pin of the SetSkinningSelection node.

   • Connect the Attribute Key pin on PaintWeightMap to the Selection Map pin on the Set Skinning selection node.

   • Connect the Collection out pin on the SetSkinningSelection node to the Collection pin in the TransferSkinWeights node.

   

7. Click on the SetSkinningSelection node and in the Node Details panel. Change Vertex Group to SimVertices3D.

   Set Correction Type to whichever type you want to use.

   You can leave the Selection Map blank, as it is connected to the Paint Weight Map node already via the Attribute Key or Selection Map connection.

   You can connect the same map to more than one SetSkinningSelection node if you wish to use the same map.

8. Now repeat for every asset you want to make maps for. If you hand made LODS, you need to paint maps for those as well.

   Once you’ve done this, you must re-evaluate your cloth asset and save it. Then go into your outfit asset (if you’ve already made one), re-evaluate, and save that too.

Next Step

• 

  Create an Outfit Asset

  Create an Outfit Asset for use in Unreal Engine or to publish on Fab.