billboardsFaceCameraPosition - On or off?

Unity Engine
1

In quality setting is there a performance hit if we set billboardsFaceCameraPosition to on?

Im on IOS but im interested in the performance implications in general for all platforms.

2

The short answer is having billboardsFaceCameraPosition set to on negatively impacts performance, which is usually small, but increases with how many billboarded sprites/quads/particles you have

Here’s why:

  • When billboards do not have to face the camera, they can have their own rotation set to the camera rotation, spun around so it faces the opposite direction (and therefore the billboard and camera generally face each other). If the camera is not pointed at the billboard, the billboard will not look directly at the camera, thus the slightly reduced quality over billboardsFaceCameraPosition.
  • When billboards do face the camera, each billboard has to calculate a vector between their world-space position and the camera world-space position and normalize the vector to find the direction they’re facing. Normalizing a vector involves division, which is one of the slower math operations, then consider how many billboards have to do that every frame! (A TON if you’re using billboarded particles!) It’s not enormous overhead, but it’s worth disabling if you need better performance, especially on weaker hardware like smartphones.
1 Like
3

Wow thank you Gambit - that’s exactly the kind of information i was looking for. I really appreciate your help:)

Im adding extensive quality options to my game update and this will help a lot to fine tune performance.

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