Projecting high poly on low poly

Cirmius

Hello,

I made a head with a lot of details in Zbrush and then I did the whole retopology using Blender. The thing is I used the lower subdivided high poly mesh, because my computer couldn't handle a long retopology session with such geometry.

When I bake this model on my lowpoly – it's ok, but of course details are kinda blurry. When I'm trying to do the same thing with the max subdivided high poly mesh I have, the normal map is a bit moved up. Moving along the Z axis in Marmoset takes a long time because of the polycount (: And even then after "repairing" high poly coordinates by moving more or less along the axis I don't see a difference.

Is there any option to "reproject" the high poly on my retopologized low poly model?

Alex_J

you can decimate the hi poly in zbrush using zplugins>decimation master. should be able to reduce it probably 5-10x without losing noticeable detail.

in toolbag if you accidentally moved one model away from the other, you can check box for ignore transforms (so long as you hadn't froze transformations before export)

also double check your UVs and UV sets. Some actions in zbrush will create an alternate UV set.

if moving high poly objects around is necessary and its slow, do that in zbrush instead. Export your models, move them around in zbrush because it handles huge polycount well, then export from zbrush. Don't overwrite files - give each descriptive name.

Research if it's possible to do something like an alembic cache in blender for faster retopo. A simple more mechanical alternative is to export your high poly in pieces and retopo one at a time. And of course if it is symmetrical, you only need half.

kanga

To get a lowpoly with all the details of a highpoly (except the profile):

1/ Duplicate the high resolution tool in zBrush.

2/ Set the duplicate to its highest subd level.

3/ Decimate the duplicate in stages: 20%, 10%, 5% finally 2%. Its good to have a bit of resolution for retopology in Blender.

4/ Export the decimated duplicate from zBrush as an fbx.

5/ Import the fbx into Blender. It should be too small.

6/ Adjust the scale under the export settings in zBrush, from memory it should be set at 100. Im not sure it has been a while. In any case adjust the scale of the exported fbx in zBush till it is the perfect size in Blender. Then save the tool and the export scale setting will be saved with it.

7/ Build the lowpoly in Blender using the imported decimated fbx as a base. These are the retopology settings in Blender: https://www.youtube.com/watch?v=CuQzPDs99yM

8/ uv the lowpoly in Blender and export the result as an fbx.

9/ Export the highpoly from zBrush as an fbx.

10/ Import the uved lowpoly fbx into your baking app and point the baker to the exported highpoly from zBrush.

11/ Bake your textures and the included normal map should work fine.

12/ Have fun!