Cell Fracture

The Cell Fracture addon allows you to make fractures of a mesh in Blender 2.8. This add-on is build in Blender and while in development already working. Since there is not much documentation, here a video with some tips worth mentioning.

How to activate the Cell Fracture addon?

In latest builds, Blender 2.8 RC and later, you can find Cell Fracture by selecting the object and then go to Object in the menu of the 3D viewport and click Quick Effect > Cell Fracture.

For older builds: In Blender you go to Edit > Preferences > Addons. And in the searchfield you type: frac. Then activate the addon, save preferences and refresh. You can then find the addon in the N-Panel under the Transform Tab.

The User Interface

The Cell Fracture addon for Blender 2.8 is working but still in development. So I give just a brief overview because it might work differently later.

Fracture From

Here you can define where to fracture the mesh from. This can be verts, particles, ~~random~~, annotation pencil. In case you use the annotation pencil, which is a good idea, don’t forget to go to the Active Tool settings in the properties panel. There, you can set it on Surfaces in which case you can make strokes on the surface.

Transform

With Simplify Base Mesh we can simplify the mesh. With that you simplify not the fractures, but the copy of the original mesh right before making fractures.

Noise is more like a seed of the fractures. So if you don’t like the result try another “seed”. No matter what you press, next or previous and back, it’s always random it seems.

Margin makes a gap between the fractures. Try a value of 0.03 which you might like.

With Scale you can make fractures aligned to the X, Y or Z axis. Maybe handy when you want to make a pile of logs. For example give the first scale option the value 0.

Recursive Scatter pulls the fractures apart. It seems to be a it CPU intensive.

Interior Meshes has the options: Copy original data, Vertex Group, Smooth Faces, Mark Sharp Edges. The first option matched the original mesh materials and data layers. And vertex group will make a vertex group of the inner vertices,

Custom Properties gave an error in my case. Info will follow when fixed.

In Scene Management there is an option to hide the original mesh. (Otherwise the fractures and the original mesh will be on top of each other). Another option is to place the fractures next to the original mesh. We can also define if we want to use collection, new collection and give that a name.

Video: Cell Fracture addon – Blender 2.8

In case you cannot watch the video, here some notes discussed in the video.

To prepare the scene, place your mesh and make some annotation strokes on the mesh. You can press Shift+Spacebar, and click annotation. Be sure that you make strokes on the surface. To do that, go in the properties panel and then the Tab called Active Tool and Workspace Settings. There is an option to make strokes on surface.

Once prepared, select the object. Then in the menu of 3D view: Object > Quick Effect > Cell Fracture. ~~It doesn’t matter much what you do in the user interface, because later you will get a pop-up on the bottom left that is interactive~~ (Not anymore in latest builds). Play with the settings to your liking.

Once you have fractures, these fractures doesn’t look good for rendering because they have sharp edges etc. To make them more usable we make a modifier stack. Start with a Decimate modifier and use Collapse, Ratio 0.3. Then add a Bevel Modifier and use the options Angle 50, Clamp overlap on, put width quite high and Segments 1. Later you will play with the settings to your liking.

Now to apply this modifier stack to all fractures. Make sure that the fracture that has the modifier stack is the active one. (Selected vs Active). Then press Ctrl+L and select: modifiers. Now all the fractures have the same modifier stack and the same settings. Then, when you change a value in the modifier stack, press first Alt. That way all the fractures will be affected.

The same for material. Give one fracture a material and then selected all other materials as well. Press Ctrl+L and select: Materials.

Then finally select all fractures and go in the top menu in the view port and click Object. Go to Rigid body and click: add active. Make a plane under the fractures, and give the plane a rigid body to but then a passive one. Then play the timeline and enjoy.