Posting some ideas/implementations for UE4.13’s draw to render targets.
These are mostly made by expanding upon the Content Examples project, the underlying stuff is explained in the Blueprint Drawing to Render Targets Training stream
https://youtube.com/watch?v=VJGdq3hQAs8
- The material which does the painting (ForceSplat in the Content Examples) has an added ‘Direction’ vector parameter which gets multiplied into the result. This lets you feed in the bullet direction to get directional holes
- Slight randomisation in the strength and size of each impact
- The depth component of the height field is plugged into the opacity (Masked) so at a certain depth, a hole forms
- The depth is also subtracted from the color input, resulting in darkened holes & impacts
https://youtube.com/watch?v=7KO5LB3eOVI
- Each snowball traces downwards and paints the canvas as it rolls. This is fed into the material which pushes the floor down to leave a trailing indent, as well as to change the colour a bit
- They grow based on their speed and how much they touch the ground, which increases the size and depth of the effect
http://www.mediafire.com/convkey/229a/37nmn3wtnq95nvczg.jpg
- Each sphere checks for nearby neighbours with an overlap sphere
- Traces to them and paints their material to extend the surface
- Black spheres follow a spline and are immune to painting
- The paint is very strong, but the material is min/max limited to get the cut-off edges near the black spheres
Hopefully my vague bullet points & the tutorial video are enough to help, any specific questions are welcome.