Particle collision in games can be limited when relying on Scene Depth, which can only use what is within the camera view for collision. Scene Depth isn't very accurate at some angles for
particles that have longer lifetimes or that are used over a large area. If you're project is using Mesh Distance Fields for your project,
the particle's Collision Mode can use the whole-scene for collision instead of Scene Depth.
The Distance Field Collision Mode offers more reliable collision than the one for Scene Depth. However, because the Global Distance Fieldis used to represent a lower resolution of the whole scene, you may find that particles will pass through thin objects or that sharp corners are rounded when using the Distance Field Collision Mode. In
return for the lower resolution, collision with Distance Fields runs very efficiently. Its performance cost is about the same as Scene Depth collision and it works without camera view restriction. The
Distance Field collision mode is a Shader Model 5 (SM5) feature. On hardware that doesn't support SM5, the particles collision will automatically fall back to using Scene Depth collision instead.
In this guide, you'll learn how to enable the Collision Mode for Distance Fields in your Particle System.