Photogrammetry retopology/projection like Zbrush

Question

I am doing some photogrammetry scans using Agisoft Photoscan and importing the scans to Blender. The problem is that the UV maps are a mess, the meshes have too many polygons.

The most common workflow is to transform the untextured mesh from tris to quads using Zbrush, create a lower resolution clone, divide it in polygroups to get a better UV map and then generate displacement and normal maps by projecting the high-resolution mesh onto the lower resolution mesh.

What I want to do is to have this same workflow in Blender, but I haven't found any specific tutorial, especially for the latter of the mentioned steps.

Thank you in advance!

Answer 1

Retopology and Baking of 3D Scans/Photogrammetry with Blender and Free Software

Purpose: Determine if you need to 3D print, create static renders, or animations. For animations, texture baking is necessary.

Step 0: Cleaning Raw Scan Data

Free: MeshLab - fix floating objects, non-manifold issues, and holes. Paid: 3D Coat - voxel sculpting, repairs, auto-retopo, UV tools. Step 1: Retopology

Manual Retopology:

Use Blender AddOns for detailed edge flow. Free: F2 AddOn Paid: RetopoFlow AddOn Tutorial: Retopo Tutorial Auto-Retopology:

For non-detailed animation, use auto-retopology. Free: Instant Meshes - Instant Meshes Step 2: Baking Maps

Bake normal and color maps from high-poly to low-poly meshes. General Workflow in Blender:

Clean raw scan data. Use Instant Meshes for auto-retopology. Import into Blender and create UV layout. Place high and low-poly objects in the same location. Create a texture in the low-poly mesh's material node. Select high-poly first, then low-poly. In Cycles render menu, select bake type and settings: Enable "selected to active" Set appropriate ray distance Set margin for UV edges Bake the texture. Save the baked image and load it into the image node. Connect the baked texture to the shader.