Hello,
After countless experiments with basic shapes using Cell Fracture addon, I tried to brake few more complicated objects. I’ve imported a human object from Makehuman and tried to brake different parts, but the result I get is some blocky objects remaining after applying cell fracture (see attached pictures).
I’ve tried many things - applying subsurface and solidify modifiers, as well as removing armature modifier, removing doubles from mesh, etc. with no luck. Every time I get these blocks, like from incomplete addon execution.
Anyone encountered these?
I’m using Blender v2.65a
I’ve also had a few issues with the cell fracture, and one I found gave constant trouble was the material index function. Have you got that enabled at all? Otherwise try changing the method from particle system to own verts and see if you get the same results.
It is still a very beta version of it the addon at the moment aswell, so some bugs just might not be fixed yet.
this is a common problem. It is usually caused by non-manifold or “bad” meshes. Here’s two things you can do that will help:
Make your mesh watertight before you run cell fracture. As far as I know the addon does some behind-the scene-boolean-magic , and one of the quirks of boolean operations is that it does not like non-manifold meshes.
Select all non-manifold edges with “ctrl+shift+alt+m”, then fill with “f”. You can also triangulate with “ctrl+t” and do a tri-to-quad with “alt+j” to convert the ngons (cell fracture probably works with ngons, but it can be nice to convert them).
Use zero recursion level. Unfortunately more than 0 recursion levels means that it is much more likely to produce errors.
Thanks Enigma246 for your input - yes, I have material indexes - there are several materials applied to different parts of the mesh.
Thanks ktysdal, your guidelines helped a lot - after ‘cleaning up’ the mesh following your instructions, I had only two artifacts. Applying solidify modifier helped too. I left the recursion level at default 0 value.
So I figured there are two ways of dealing with those artifacts - you can hide them from view/render and this way you don’t loose your original mesh. The culprit is that those extra pieces create some kind of tension and your mesh explodes violently into pieces without any control. It’s fine for my current animation, but for more sophisticated animation it won’t do.
The other way is to delete the artifacts, but this way you loose connected pieces from original mesh. It could be resolved by just using camera angle to hide the missing pieces. Or create duplicates of missing pieces from the original, nonfractured mesh, fill the missing holes and animate those pieces ‘by hand’.
Another thing that has helped me immensely is to scale up the mesh as much as possible. I’ll even make it as large as the grid plane most of the time. Then once the pieces have been fractured, I can scale them all back down. I rarely (if ever) end up with errors this way. The smaller the object you’re fracturing, the harder it will be for Blender to break it up precisely.
I got the same problem first time I launched the add-on with simple monkey mesh, and still can’t force it to work properly. I didn’t use any transformations or modifiers. But it’s ok with torus, cube and icosphere. Really cool.
I have also seen Cell Fracture leave junk in the viewport as you show.
You can add a REMesh modifier to your mesh, turn it up to 8 then apply it. You will get a heavy mesh for your output, but remesh can fix some modeling problems. Run Cell Fracture again on the remesh output.
Im having a problem with the materials index as it dosent apply the colour i specify before i run cell fracture.
Im using Blender 2.67b.
Anyone else having this problem
In addition to setting the material index in the Cell fracture popup, your object must also have a material in that given index before you attempt to fracture. Try adding a second material to your object, then increase the material index to 1 to get shards with an inside and outside material.
