by Rebecca Zoldan

Project to avoid high draw calls

Ideally best VFX particles for an XR project would be simple and short lived particles, with simple and small textures(256x256). It should avoid collisions, light and spawning too many particles. The shaders should be unlit, and you should prefer articles with little transparency, since it is very costly.

Also another technique for particles, would be ATLAs system for the texture, considering the max size for each particle texture should be 256x256, using a 1024x1024 texture mapping 16 squares of different particles:

| 16 particles • 16 different 256×256 textures • Likely 16 materials • = 16 draw calls (or more) | 16 particles sharing one texture atlas • 1 texture • 1 material • Different UV regions • = 1 draw call (if batched properly) | | --- | --- |

Best practices:

• Simulation Space: World (more stable in AR)xx

• Disable Collision unless absolutely needed

• Disable Lights module

• Disable Noise unless very subtle

• Keep Start Size small

• Keep max particles low (50–200)

• Use Unlit shader

• Reduce overdraw

• Use GPU instancing if available

• Use small texture sizes

  

Avoid: