Documentation:ZBrush Optimization Workflow

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ZBRUSH OPTIMIZATION

Note: If you are using this application because you are having trouble filling holes in Maya or Blender, you can use the ‘Close Holes’ function under Geometry > Modify Topology and then export the tool to be reimported back into Maya or Blender.

1. Go to lightbox > projects and double click DynameshSphere128.zpr. This opens up a preexisting sphere template
2. On the right side, load tool and load photoscan model
   1. If model is loaded without the texture try one of the following:
      1. Restart ZBrush and repeat steps
      2. Import and apply texture
         1. At the top, go to Texture > Import and locate the texture file
         2. Then click the large empty box, opening the loaded texture files, and open the texture file you imported.
         3. Underneath,click ‘FlipV’
         4. On the right side, scroll down to Texture Map, and click the empty box to load the texture
3. Go to Subtool and click duplicate. Keeping an original will be handy if there are mistakes
4. Hide 1st subtool by clicking the eyeball next to it and then select second subtool
5. Use transpose tool to rotate and move model so it is easier to clean
6. Use select tools to trim and delete artifacts or unnecessary parts
   1. You can do this by holding CTRL+SHIFT and click dragging over the parts
   2. The highlighted part will be isolated and surrounding areas will disappear
   3. Hold CTRL+SHIFT and click drag an area NOT on the model. This will invert the display, hiding the unnecessary part and revealing the model
   4. On the right, go to Geometry > Modify Topology > ‘Del Hidden’
   5. Continue and repeat to trim the model
7. Go to Geometry > Modify Topology and click on ‘Weld Points’ and ‘Close Holes’
8. Then open ‘Mesh Integrity’ and click ‘Fix Mesh’ and then ‘Check Mesh Integrity’
   1. If a window pops up, it will tell you if there are still issues with the model
9. If the model is single sided, extrude the model so it has thickness
   1. You can do this by either by masking the closed hole polygroup and using the transpose tool to move it OR:
   2. Holding CTRL and painting the ‘outside’ of the model you want to keep and then using the transpose tool to move the unmasked areas ‘in’
10. Rename subtool model in the Subtool menu on the right to “O_clean” (‘O’ for original)
11. Duplicate subtool
12. At the top, go to Zplugin > Decimation Master and click ‘Pre-Process Current’
13. When done, change Decimation % to ‘20%’ and hit ‘Decimate Current’
    1. If after decimation model loses too much detail, Undo and raise the percentage number, and decimate again. Repeat until it reaches lowest polycount while still retaining details
14. While your new decimated model is selected in the Subtool menu and “O_clean” is visible, go to Subtool > Project and toggle on Geometry and Color click ‘Project All’
    1. If after hiding “O_clean” there is a large difference in detail that is loss, Undo and lower ‘PA Blur’ or ‘Mean’
    2. If polygons are being stretched like shards, lower ‘Dist’
15. Export tool as .obj and label as [label]_optimizedModel_[version##]
    1. Ie. FlaskScan_optimizedModel_01
16. Now, open your file explorer/finder and open the .mtl file in a word doc or notepad
17. Make sure the bottom line is “map_Kd [originalTextureFile+extension]”
18. Save doc and upload all materials to the respective folders
    1. Ie. optimization_output > tests > FlaskScan

Note: You can further optimize the model for use in Unity, however, it is a little bit longer and more complicated process to get it manageable in polycount and will have to adjust/fix your textures by hand

TIPS & TRICKS FOR ZBRUSH

1. By default the dynamic perspective camera is toggled on. You can toggle this off for a more accurate view of the model
2. If it is annoying for the faces of your model to disappear as you rotate around, on the right go to Display Properties > Double Sided. This will make your normals double sided
3. While rotating, you can lock the camera in 90 degree increments by holding shift as you rotate
4. If you want certain details to pop, you can use a combination of masking and adjusting the deformation sliders
   1. I like to use masking by color and then adjust the inflate deformation
5. You can also sculpt certain details if you so wish but be careful it doesn’t stray too far from what the client wants