Interesting and fun thread!
So here is how would I do this system.
- Tree : A Static Mesh with dynamic material.
- Matching Cut Angles: On Hit animation, depending how you set the interaction cut angle be automatised or you get the hit results of axe to apply a mask on specific part of the mesh uv. Another way is to use a shader that you spawn a mesh over there that have a stencil . Stencil cuts would be an easy option there or cross section since we will need to fill it anyway
- OnCut: After a specific number is reached etc. Copy mesh to dynamic->Boolen slice cut with a specific angle->Copy Mesh back to static meshes->Lower is placed, upper is physics enabled with a force toward cut side.-> Upperside has a new parameter that dissolves tree, makes it go away (or some more crazy design over here to save the cut tree state and decay over days )
Here is some design problems to think about.
- If trees can be cut from any angle and angle of interaction then determining the full cut can be problematic. Its recommended to have a certain hits from divided cardinal angles. If any section receives total of N cuts is considered done. N can be depending on tree age,size.
- What to do if player cuts from a side a bit then goes other side and cuts a bit from there. Is tree cut or not.
- Since we are making realism and realisation on this interaction; we will need some kind of animation during the cutting process on the tree. Rather than having skeletal meshes every where think it can be done by a simple shake scripts and some slight rotations to achive the weight of these impacts.
- Since we are making realism and realisation on this interaction; we will need a very nice sound design (I particaulary like the sound design of NewWorld cutting trees)