You can assign Blender materials to different face selections or assign normals to groups of faces to retain existing edge loops. There’s no tool yet in the current version to indicate a custom edge flow.
Alternatively or additionally, you can use vertex paint to assign more polygon detail to areas, such as the mouth.
In general I can recommend the ZBrush ZRemesher workflow for QuadRemesher in Blender:
- Set desired settings (e.g. symmetry).
- Run QuadRemesher with a relatively low Quad Count value. The default value of 5000 is okay in many cases. Increase the Quad Count for highly detailed meshes. I usually don’t go beyond 12000.
- A copy of your source mesh will be made automatically, and made invisible.
- Add a Shrinkwrap modifier to the QuadRemeshed object, and assign the hidden source mesh to it. Sometimes it works better to change the Shrinkwrap projection method to Project and check both the Negative and Positive checkboxes.
- Add a Subdivision modifier with one subdivision iteration.
- If necessary, repeat steps 4 and 5 to increase the level of detail derived from the source mesh.
This workflow is actually even better than ZBrush Project All, because it’s non-destructive. If you change something to the source mesh, it will automatically be reprojected to the QuadRemeshed mesh, then subdivided.
People who are not familiar with ZBrush ZRemesher usually increase the polygon count a lot, thinking there should be enough polygons to capture all the details, but the best workflow is the above-mentioned approach, where QuadRemesher can capture the global mesh flow / curvature, and details can be added by Shrinkwrapping (similar to Project All in ZBrush) and Subdividing. This approach keeps the base QuadRemeshed mesh editable, UV mappable, riggable, etcetera.
The progressive subdivision workflow is also ideal for a Multiresolution modifier (although some work needs to be done on the Multiresolution modifier in Blender 2.81 at the time of writing).