Hi,
Thanks for reading.
In this tutorial, I’ll be going through the results of my testing on how to create anime style impact damage on hard surfaces. I should also note, I`m using blender 2.8 Eevee only.
To be honest, there are countless ways this could be done, so I’ll just be detailing the following ways I tried.
1, Procedural, with Dynamic paint and boolean.
2, Hand drawn, or generated texture with displacement.
3, Custom mesh with shape keys.
1, Procedural, with Dynamic paint and boolean.
There are 2 ways you can do this, The first, allows you to create a hole with cracks around anywhere on your surface, but it doesn’t look as good as 2. 2 is where we will use a material that references the world center or vector 0,0,0 and allows you to create a better looking crack material, but is limited to only working at those coordinates.
1,1 Cracks and/or holes anywhere.
So for this one, first you will need to decide if you just want to make a dent in the object or a full hole, as the workflow will be slightly different. Which I’ll explain later.
For now you’ll need to add 2 objects, one to represent the surface to be cracked, and one to represent the object impacting it. I used a cube scaled like a wall, and a sphere.
What we are going to do is use dynamic paint to set the wall as the canvas and the impact object as the brush with volume and proximity. The scale at which we set the proximity will determine how far the cracks radiate out from the hole.
So now we have our canvas and brush objects, we need to have the material assigned to the wall/canvas visually represent the interaction. So enable the paint map in the dynamic paint canvas settings. Then if we use the attribute node and enter the name of the Paint map. Which is by default Paintmap_DL, we will be able to see the interaction. So continue to build the material until it look like this:
It’s at this point you’ll have to decide if you want a dent or hole.
If you want a dent. Then you will need to add another canvas to your wall, and set it to displacement,
This will displace the wall around the sphere and create a dent wherever you move the sphere to.
If you want a hole, then add the boolean modifier like this 
, but don’t use the second dynamic paint canvas.
1,2 Better looking cracks, but only at 0,0,0.
So for this one we need to make sure the center of our wall/canvas, is at 0,0,0.
And change the material to this . As you can see the cracks look much better. The rest works the same as above.
2, Hand drawn, or generated texture with displacement.
Ok, for this method, we will need 2 textures. You can either hand draw a color and displacement texture,
or one generate them using the above 0,0,0 method and save it as an image however you like.
Once you have your textures, you’ll need to add an object to act as a surface to be impacted, and add the texture like you normally would. The use the displacement texture you created as the texture in the displacement modifier.
Then all that left to do is key frame the texture switch and displacement to happen at the moment of impact. Simple.
I’m my example I also used the texture to act as a map for the particles of rock emitted.
To make the particles, I first added an icosphere and used a displacement modifier on it. Then I added an empty and set that to be the location for the displacement. Then when you duplicate the rock, the second one will have a slightly different shape, I made about 10 different little rocks like this, then applied the displacement modifier and deleted the empty. Select all the rocks and press CTRL+G to add them to a collection. Then in the particle system select collection and chose your group. Then you`ll need to set the particle system frames to only appear at the moment of impact.
3, Custom mesh with shape keys.
This one requires you to model your cracks by hand, what I did was I dropped in a picture of some real life cracks in glass and modeled my shapes around that.
Keep it flat for now. Once its made add a shape key, this will be your start point for the animation. Now add another shape key, this will be the end point. With the second shape key now selected, you can begin to model again and scale your effect outwards and rotate some of the pieces to give a splinted fractured look. Once your happy with the effect, your pretty much done. As you slide the 2nd shape key you’ll see your cracks grow outwards from the surface. You can use this animated crack in your scene. If you want to make a hole in it, just use the boolean modifier like earlier in the tutorial.
And that’ll do it. Thanks for reading. If you have any questions feel free to get in touch here or on twitter https://twitter.com/IdentyTee. I’ll help if I can.