Hi guys! I’ve been detail-sculpting this model for about a month in Zbrush, but only now I discovered that it can’t export any of the detail that I have sculpted. I’m pretty sure that this error is associated with when I first imported the model to Zbrush, the model had already enough polygons that when I divided the model (in the “Geometry palette”) Zbrush would crash, so I used HD Geometry instead. After a month of using HD Geometry (which the day this thread was posted), it was time to bake/export the normal and displacement maps, so I turned the HD Geometry subdivision levels down to 1 (the minimum) and when I hit the “Create Normal Map” button Zbrush gives me an error message saying that I should lower the subdivision levels.Anyway… Here are some images that might help you understand what’s going on:
Oh, I see. Seems like the model needs to be divided from the “Geometry” palette. So is there a way to transport HDGeometry details from one mesh to another?
when I first imported the model to Zbrush, the model had already enough polygons that when I divided the model (in the “Geometry palette”) Zbrush would crash
Could you be more specific?
Was it a multires / apply modifier mesh?
If so, under geometry panel, try to rebuild subdivisions. ZBrush magic.
I did use the multires modifier, but I applied it before I exported the model. It ended up with 7865060 verts before I exported it. After importing the model in Zbrush, if I would divide the model (in the “Geometry palette”) zbrush would crash. Which meant, I had to use HDGeometry instead.
There are several options here. All basically giving you a new mesh that you then transfer the details to in Zbrush.
If could be you have way too much geometry than you need.
But a better workflow would be to export two versions of the mesh. One highest and then one lowest from Blender.
Then in Zbrush simply import the two meshes into one tool as subtools. From here you can then subdivide the low poly mesh and then “project all” the details from the high to the low.
See the Zbrush docs about this.
In the event you don’t have a low version, then you can simply duplicate the subtool and reduce it down to the lowest level. Then take that new mesh and delete all of the higher levels. Use something like Zremesher to bring it down to a low poly level, then subdivide (not necessarily as high as the original) and project the detail to the low res version.
This is the basic workflow if you want to bring a new mesh in with UVs for baking.
Another alternative is to retopo the mesh by hand and you have the same workflow.
Either way you then bake the mesh from the highest level down to the lowest level which has UVs.
This is probably why you are getting the error message. Because you really don’t have a low res mesh at the base level.
In the event you don’t have a low version, then you can simply duplicate the subtool and reduce it down to the lowest level. Then take that new mesh and delete all of the higher levels. Use something like Zremesher to bring it down to a low poly level, then subdivide (not necessarily as high as the original) and project the detail to the low res version.
I don’t believe you can project HD geometry.
If you don’t do at least one normal subdivsion you don’t have a lowest subd level to go to to allow you to bake a normal map. If you’d reduced the poly count at the start to allow you to make that first subdivision, you’d be good to go.
Ask on the zbrushcentral forums if there is a solution or cut your losses and redo with a method you know you can bake.
@Richard Marklew
Yeah, it seems like Zbrush does need a lowest subdivision level to be able to bake the normal maps. I just tested it and it didn’t show the error message anymore and didn’t crash, however it was VERY slow. But time is something I need to handle in this case.
I believe the only way (maybe) to get the normal and displacement maps done, would be by starting the hi-res sculpting process from scratch. We learn from our mistakes anyway.
And in this case I learned from all your advice, guys. Thank you!
Cool, yeah, I was not aware - as I have never tried - that transferring HD would not work. Seems kinda strange through, as it is a feature and should fit within the normal workflow. I would think at the very least there would be some way to bake that higher detail down to normal subdivisions where you’d loose some detail but keep the sculpting you did.
But anyway now you know the workflow in Zbrush. Good luck with the rest of your projects!
Again, I don’t believe that will work in this case since you’d need to make the HD geometry normal geometry first and you have to assume the original mesh can be reconstructed. I’ve not looked but not sure if reconstruct subdivisions is even available if you have HD geometry. I thought I’d looked at this as an option to originally answer the problem but ruled it out because it wasn’t possible (could be wrong)
Edit: Reconstruct Subdivision not available when you have HD Geometry
Yes and no Richard.
I mean, we may assume that neon15 applied a multires modifier before exporting. In this case reconstruct will work.
He entered HD because he couldn’t subdivide more.
HD… right, we can’t handle it this way.
HD produces high freq details. IMO, such details better be baked as B&W bump map (16-32 bit). Tangent normal maps aren’t the best for such fine details. A tangent normal map baked from reconstructed subdivisions + a bump map for HD derails only. This is what I would try.
I’m actually encountering a nother problem. Zbrush keeps crashing after I get out of the HDSculpting mode. The model has two HDGeometry subdivision levels and geometry subdiv levels for me to be able to bake the normalmap.
I’m using HDGeometry too because after I subdivided the model up to two levels in the geometry palette and I needed to subdivide one more time, but Zbrush gave me an error message that said “Subdividing the current mesh will produce a mesh with polygons count larger than specified in PREFERENCES:MEM options”.
So I had to use both, basic subdivisions and HD geometry. As I said before, the problem that i’m encountering occures when I apply the HD sculpted geometry to the mesh, and Zbrush ends up crashing.
Any suggestions to avoid this problem? Is there a way to split the mesh into separate subtools?
