Retopologizing MD meshes with folds/wrinkles
( turn on English subtitles )
- Blender ( method 1 ) - best for garments made of geometrically simple, straight-edged patterns;
- Blender ( method 2 ) - best for garments made of symmetrical, geometrically complex patterns;
- Blender ( method 3 ) - universal, but is best for garments with folds/wrinkles;
- Blender ( method 4 ) - universal, but is best for people whose version of MD precedes 4.
Hello. In this tutorial, I will explain how to retopologize MD meshes with folds/wrinkles in Blender.
WRITTEN TUTORIAL:
PLEASE DO NOT REPOST
If internal lines generated based on the shapes of patterns ( as shown in Method 1 and 2 ) would not go along folds created in the process of cloth simulation, they have to be drawn manually. Fortunately, you can get away with creating only a few of them and do the rest in Blender.
Let’s start by selecting patterns and solidifying them ( RMB - Solidify ) ( 1 ).
There are 2 ways in which you can draw lines:
- Line ( 3D pattern ) ( 2 ). This tool was introduced in MD 7. Select Line ( 3D Pattern ), LMB-click on the mesh to start, double-click to finish.
- Internal Polygon/Line ( 3 ) . in 3D window LMB-click on the mesh where you would want to start a line, choose Internal Polygon / Line tool, click on 2D pattern to start, double-click to finish.
Draw lines in places where you would want vertical edge loops to be, in this case along or around folds. Once done, switch to Edit Line ( 3D pattern ) tool ( 4 ), Shift-select all of them, RMB-click on one and choose Convert to Internal Shape ( 5 ).
Choose Edit pattern tool ( 6 ), RMB-click on one line, choose Extend / Trim to Pattern Outline ( 7 ). Adjust the ends and remove unwanted points, if needed.
Select the patterns and export them ( File - Export / Export ( Selected ) ). Enable Single object, Unweld, Thin, Unified UV coordinates, m ( for The Sims 4 ). Disable Include Internal Shapes.
Then use Reset 2D Arrangement ( 1 ) and export the patterns again as a second file, this time with Include Internal Shapes enabled.
Import both files in the same order. Shift-click on patterns to deselect them, then double-Shift-click on any curve to make it active. Combine all curves with Ctrl J. Convert curves to mesh with Alt C - Mesh from Curve/Meta/Surf/Text ( 1 ).
Select patterns, switch to Edit Mode ( TAB ), with everything selected ( A ) go to Select - Select Boundary Loop ( 2 ), separate these edge loops with P - Selection ( 3 ). Combine ( Ctr J ) this mesh with the one that was made from curves. Use remove doubles ( 4 ) to connect everything. Select one unwanted vertex, Select - Select Similar - Amount of connecting edges ( 5 ) to select the rest. Deselect all corner vertices with Ctrl Shift RMB. Remove all selected vertices with RMB - Dissolve Vertices. Select everything again, press F to create a surface. Split faces with vertical edges using Ctrl R ( MMB to increase or decrease the number of edges, LMB to slide them, LMB again to finish ).
Once done, apply Shrinkwrap modifier. Choose the pattern mesh as Target ( 1 ), enable Adjust edit cage to modifier result ( 2 ), ( optionally ) Keep above surface ( 3 ), and set offset ( 4 ). Select one vertex at the corner, Ctrl-Shift-RMB-click on another one on the opposite side, RMB-click on the blue handle or press G Z and move vertices down. Repeat on every curved side. You can select all vertices at the bottom of all patterns and move them simultaneously, but it doesn’t always work well.
Select all vertical edges and Subdivide them ( 5 ). Set number of cuts ( 6 ). To save yourself some time, use Subdivision Surface modifier to increase the density instead of doing it manually. Set subdivision type to Simple ( 7 ) and subdivision number to 1 or 2 ( 8 ), apply.
Let’s transfer UVs. Start by creating a UV map in Object Data tab with + ( 1 ). Then add Data transfer modifier ( 2 ). Choose the pattern mesh as Source object, Nearest Face Interpolated in Face Data Transfer drop-down menu, UVs in Data layers to transfer, apply.
The skirt and the patterns are basically the same mesh but with vertices in different positions, meaning we can morph one into another using Shape Keys. Since the newly created mesh has a completely different topology, we cannot make it a shape key for the skirt on its own. Fortunately, we can bind it to the original pattern mesh with Mesh Deform ( Or Surface Deform ) modifier and it will follow its transformation.
Sometimes when binding one mesh to another, you may get a “Target contains concave polygons” warning, even after using Mesh - Clean up - Split concave faces. Instead just apply Triangulate modifier ( 1 ) to the target mesh and bind again ( 2 ).
Hide the retopologized pattern mesh and select the original one. In Object Data tab unfold Shape Keys. Hit + to create Basis ( 1 ). Select the skirt mesh, Shift-select the original pattern mesh, in the special menu choose Join as Shapes ( 2 ). Select the added option and drag Value to 1 ( 3 ). Unhide the retopologized pattern mesh. As you see, it followed. Apply Mesh Deform modifier to save the result.
For the surface to look smoother either raise an angle in Auto smooth ( 1 ) or disable it. If you still have shading issues, select everything and click on Smooth button in Shading/ UVs - Faces ( 2 ).
I’m going to append the top part of my dress to use it as a reference in the process of editing the mesh. I will set Maximum Draw Type found in Object tab to Wire ( 3 ) to see the wireframe.
If in certain areas the resulting topology is unnecessary dense, you can manually reduce it. Start with isolating one part of the mesh by selecting one face, Select - Select linked ( 1 ) and pressing Alt H to hide unwanted geometry. Select horizontal edge loops at the bottom with Alt Shift RMB, delete them with Delete key - Dissolve edges. Select one horizontal edge loop where topology starts to get unnecessary dense. Use Select - Checker deselect ( 2 ). To preserve smoothness where folds are, manually deselect ( Shift RMB ) edges in these areas and collapse them ( Alt M - Collapse ) with UVs checked. Further edit topology with loop ( Shift Alt RMB ) or ring ( Shift Ctrl Alt RMB ) selection, Merge ( Alt M ) and Delete menus, Knife ( K ) or Connect ( J ), G ( move ) with Snapping on ( Shift TAB ), until it looks similar to this ( 3 ).
THANK YOU FOR READING.
If you have any questions or suggestions to improve this workflow, please leave them under the video / in replies to this post / in the ask box or message them privately on tumblr / via e-mail ( [email protected] ).