Footprint Decals and Normal Rotation

Hi, I’m trying an experiment with physical footprints: footprints that appear to behave appropriately with light and sound and are as physically correct as possible.

But for some reason, I can’t get decal actors to spawn in my setup. Particle effects work just fine, and I’ve been using a mesh particle to get away with this, but for some reason all the particles (regardless if they’re mesh, sprites, or GPU sprites) disappear at the same time after about a minute of working properly, and they don’t map appropriately to the ground. It would be nice if I could rotate the particle/decal according to the hit normal, but I’m having difficulty with that. It just seems to rotate wherever the heck it wants to rotate. And for some reason, mesh particles don’t light properly because even though it spawns at a different angle, the normal never changes.

If I can get decals to work, spawning at the right rotation angle, and get the lit normals to function appropriately, that would be fantastic!


I seem to be taking one step forward, but 10 steps back with this thing. For some reason, the decals not appearing is a problem with the way it’s rotated. I managed to fix the rotation so decals get shot vertical from the ground surface, but now they don’t rotate with the actor at all. Help!

OK, I managed to blend the rotation offset with the hit normal vector. It works as expected. I’ll just use this thread to keep updating on things I’m trying to do, as there is a lot I still need to learn.

I want to make a completely physical footprint system: if your feet touch the water, they get wet and leave wet footprints, which dry up the more you step down. You can put footprints in the sand at any time. These systems can overlap. A different VFX occurs for different surfaces, and surfaces have the ability to opt out of decals.

At the moment, I want to make sure each footprint is laid down with its own material variable to fade out, but I’m not entirely sure how to do this. I think it has something to do with parameters and timelines. I’ll post the results when I get it working better.

Ugh, everything I want to do is difficult for some reason. There are no timelines in the anim blueprints :expressionless: