performance cost of several lightEnvProbes

[romain.janil]

Hi, I'm testing a setup with one LightEnvProbe for ambient and reflections disabled (at least set to 0), att distance are inf for this one, and several lightEnvironmentProbes wisely spanned at various places, to get more credible reflections on high-rises across vast urban vistas . These ones don't affect ambient, only reflections with a finite attenuation distance (~500m), baking is dynamic, only 1 face/frame, and low res (256), no supersampling. I'm noticing a performance drop from 60fps more to circa 40fps. Does this make sense ?  Tested with 1+ 8 LEP. Thanks for pointing me to an optimization.

R

[silent]

Hi Romain,

Each dynamic reflection adds additional camera and all the objects that should be reflected are rendered one more time each frame. So adding 8 probes with dynamic reflections you need to render scene (or only part of it depending on reflection settings) 8 additional times.

The resulting framerate depends on many factors, so it's hard to tell if there is any room for improvement without seeing the actual test scene. If you can share your scene with us - we can tell more precisely what else can be done here.

Additionally you can try to find the most heavy spots using the Microprofile tool and try to optimize them as well:

• https://developer.unigine.com/en/docs/2.11/videotutorials/essentials/microprofile
• https://developer.unigine.com/en/docs/2.11/videotutorials/advanced/microprofile_for_artists

Thanks!

[romain.janil]

Hi Silent,

I can't share the world but here's a typical situation, highrises and helipads everywhere, so use case is  to get realistic (not accurate I don't talk about raytracing) reflected buildings on the tallest one, in order for a building not to reflect itself or reflect some buildings which are too far away (which is the case if I use only I lightprobe, or some generic reflection sphere or box).

 

[silent]

In that case microprofile should be your best friend :) You also can try to switch LightEnvironemntProbe (using the WorldSwitcher) when it's far away and replace it with regular probe without dynamic reflection. Maybe that will also help a bit.

 

[romain.janil]

Thanks I'll try the switch trick,and off course micro-profile everything.