Theanine3D
Member
Hi guys!
This is my first post in here. I'm very proud of the work you guys do, so that's why I started to work on something on my own.
I'm using UE4 as my engine, and 3DS Max for modeling, but now I have a problem with collisions.
I have the following object
I want my main character to walk around the spiral.
When I import it into UE4, the collisions aren't that precise, even if I regenate them with the highest parameters.
Is there a right and easy way to get that result?
Pieces of collision need to be convex, with no concave parts. That means, no dents. Read this:
https://docs.unrealengine.com/latest/INT/Engine/Content/FBX/StaticMeshes/#collision
For models that are concave, you'll have to make a copy of this model (follow the UCX naming conventions described in the URL above), and split the copy into separate parts, ideally none of them intersecting, and all of them 100% convex. There are scripts that can do the latter for you automatically. Like this one. http://www.scriptspot.com/3ds-max/scripts/convex-hull
Here's an example from my own game Lolly Joe. The top is the original house model that you see in-game. The bottom is the simplified collision mesh I made manually.
I took the original house model and split it into separate parts. None of them intersect or overlap. Every single piece is disconnected from each other, and is also 100% convex. The chimney had to be split into 2 parts to make that possible.
There's a lazier, less performance-friendly alternative to all of this. Just open up the mesh in UE4, scroll down in the settings until you see "Collision Complexity." Choose "Use Complex Collision as Simple." This enables per-poly collision, which means every single face/triangle on the original mesh is used as collision instead of a more optimized, simpler collision mesh. This is not the ideal method, but you can get away with it if the model is low-poly enough. I've seen some indies do this to save time, but you should avoid it whenever you can because it can lead to bugs like falling through the floor. The engine has to work a lot harder to calculate collision with this method, and anything moving very very fast will often just go straight through the collision instead of being blocked by it.
Also, protip: never use the collision auto-generated by the engine. Making collision manually is always the way to go. The auto-generated collision only works OK for anything that is inherently already convex in shape. Like a tennis ball - perfectly smooth with no holes or dents. Your mountain is too ridged to ever work with auto-generated collision.