Merge Geografts

The idea is to remove the body vertices hidden by the piece of anatomy, and to merge common vertices at the boundary and create a single seamless mesh from the two original meshes. Note that merging anatomy changes vertex numbers. Hence will not be possible to import morphs afterwards, neither to the geograft nor to the body mesh. It is a good idea to save the blend file before merging geografts. More on Geografts and Shells.

It is possible to merge multiple geografts, but only if all of them are merged at once. Select all geografts to merge, make the body the active mesh. Again, this is because merging relies on vertex numbers. If the body mesh has been changed in some way, either by merging other geografts or by some other kind of editing, vertex numbers have changed and the body vertices can no longer be identified.

Here the three geografts are selected, and the character mesh is the active one. Press Merge Geografts. This tool has two options.

• Geometry Nodes (Experimental): Merge geografts with geometry nodes instead of destructively changing the mesh.
• Add Vertex Table: Add extra information that makes it possible to load morphs even after geografts have been merged, cf. this blog post. This feature can be disabled because it may lead to performance issues.
• Fix UV Tiles: Move geograft UVs to tiles based on texture names.
• Merge UV Layers: Combine the geograft render UV layer with the body render UV layer.
• Allow Overlap: Also merge overlapping UV layers.\nCan destroy UV assignment.
• SubD Displacement: Add SubD Displacement to the merged mesh if some geograft has it. May slow down rendering.

The geografts disappear from the outliner, and the vertices are merged with the body. The body vertices beneath the geografts are deleted, and the common boundaries are glued together, making the body with geografts a seamless mesh. We see in edit mode that new high-density regions have been created.

And the geograft materials have been added to the materials of the body mesh.

Fix UV Tiles

The UV coordinates for the Genesis characters are arranged in tiles: face on the first tile (1001), torso on the second tile (1002), legs on the third, etc. Many geografts are placed on the first layer, even if they are to be merged with the torso and therefore should be placed on the second. This does not normally affect rendering because textures are repeated to the next tiles, but will be a problem if we make UDIM materials.

If Fix UV Tiles is enabled the geograft UV coordinates are automatically moved to the right tile before merging. The tool determines the correct tool by examining the texture names. If a geograft uses torso textures which end with _1002, the geograft UV vertices are moved to the second (1002) tile.

Merge UV Layers

Many geografts have two UV layers, one for the geograft shell and one for the background torso textures. UV layers with the same name are automatically combined, but not so if they have different names.

The base mesh has an UV layer called Base Female, but the background UV layers of the geografts are called Default UVs. Those layers will thus only be combined if the Merge UV Layers option is enabled.

After merging all geografts with Merge UV Layers enabled there is a single UV layer for the body textures and two layers for the shells. If the option was disabled, we can eliminate the extra UV layer manually with the Merge UV Layers tool.

Geometry Nodes

Geometry nodes were introduced in Blender 3.0 and can be used to merge geografts in a non-destructive way. This makes it possible to import new morphs after geografts have been merged. However, it appears that some glitches remain so this option must be considered experimental. Using geometry nodes is of course Blender specific, it is not possible to export them to other application such as game engines.

The geografts are now hidden, but must remain in the scene.

The character mesh acquires a nodes modifier.

In the geometry nodes editor a node tree is generated.