I’ve been trying to work with sculpting lately to help give my meshes a bit of life after creating initial structure. I’ve been using the method Ben Simonds talks about in his Master Blender Class book; I avoid triangles, give it a fairly clean structure with rows and columns of rectangles, and use my concept in the background to build around.
When I add the multires modifier for sculpting (CC, and Simple), I sometimes get small black tears, and after switching to Wireframe, I still cannot see the cause. At one point I found a face inside the structure that seemed to cause this, but that was only one of 2-3 tears. Also, I noticed adding edges inside a 3D mesh binding each side of the mesh is not a good idea, since I seem to create pits, and filling them just causes more issues, as well as tearing.
So my question is what are causes for these tears, and are there other things to watch for when preparing a mesh for sculpting?
I see something like that when sculpting with dynamic topology on but with out using that i’m not sure what would cause them, in dyn topo I think its a mixture of detail size of one area conflicting with a neighboring area and usually just have to touch the area with the problem with a smooth brush to fix it up.
Ahhh ok. That makes sense. I’ve been running without dynamic on, and my last mesh was probably not basic enough. I created another mesh with the same shape, but much less detail prior to the multires, and haven’t seen the issue at all so far. On the last mesh, I tried using the smooth brush, and I think a lot of the verts were just too close making the tears worse. I could make a bit better by using the “fill” deepen, but wasn’t a realistic solution. Per your explanation, it would make sense if there was a lot of geo clumped together.
Thank you for the explanation.
Is the Enabling Dynamic option fairly beneficial? I have dealt with it some, but I need to read up on it more to really grasp the concept behind it all.
make sure you don’t have overlapping faces/edges, it’s very bad
make sure you do not have internal faces/edges, it’s very bad again
make sure you have no doubled or tripled or more vertices and do not have inverted normals or you’ll get odd results (Select All, press W -> Remove Doubles then press CTRL+N), if you have overlapping or internal faces, the normal recalculation will go bad, so check previous problems first
check what is non manifold in Edit Mode -> Select -> Non Manifold, intentional openings in a mesh can be detected as non manifold but most of the time and should’nt be a problem if intentional, but non manifold nasty areas are detected too, often related to overlapping or internal face/edges
blender precision tend to go very bad for extremely small objects, it will reflect on sculpting them, so if you need a 1 millimeter big object to be fully sculpted, scale it up by 10 or 100 before sculpting it , even if you have to rescale it down after.
if you scaled or rotated your base mesh in Object Mode, press CTRL+A in Object Mode to apply those transformation, or you’ll have brushes doing odd results
if you’re going Multires , make sure the base mesh is NOT high poly, multires require a low poly base if you want to go high poly sculpting with the multires subdivision, it’s a known problem, as if you start with a mesh that is not low poly, you’ll have performance being impacted badly once you increase the multires by a few levels, while starting with a low poly will allow you to go much higher in final polycount without performance being crippled.
if you’re going Dyntopo , you don’t have to care about the base mesh polycount, but try to not go with a cube, because too big faces can be a problem, if you want to start with a cube, just subdivide it once or twice and it will be good to go.
do not use Dyntopo and Multires at the same time, you’re going into trouble.
Multires has a nasty problem that can ruin definitively your sculpt (spikes appearing on your sculpt that you fix by smoothing in a multires level, will re-appear in another, and after fixing there will be back in the levels you already repaired…) that are known but not identified in the code , so save regularly and often so if the spike bug occurs for you, you can load a previous blend and resume sculpting.
Wow, thanks Sanctuary! Exactly what I was looking for.
Multires has a nasty problem that can ruin definitively your sculpt (spikes appearing on your sculpt that you fix by smoothing in a multires level, will re-appear in another, and after fixing there will be back in the levels you already repaired…)
This is what happened to me when I tried filling those pits, due to the internal edges. :spin:
Absolutely great information, and thank you again!
