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Rendering Architecture and Performance?

Hello,

Is there a post or article or answerhub question somewhere on what we should be able to expect from the Lighting pipeline?

  1. Are dynamic lights shaded in a deferred manner? If I want a lot of dynamic lights, what do I have to give up to keep performance up?

  2. Are stationary lights really stationary? if it is placed on a mesh that animates and moves around, then it isn’t stationary?

Over the course of the next month I am going to start replacing the programmer art of our prototype game with actual art, and hopefully not kill performance when doing it.

Our initial concepts call for a lot of dynamic lights (sirens, signal lights, “stadium” lights, etc). I want to leverage the strengths of Ue4 lighting and not exploit weaknesses and thus kill our game’s performance.

Thanks!

Found a couple of things, but not much. Going to add them here.

On Instancing meshes:
https://answers.unrealengine.com/questions/1481/no-performance-benefit-from-instanced-meshes.html

Seems like there are two themes here. If you want lots of dynamic lights, sacrifice dynamic shadows. If you want lots of meshes, instance them.

There’s some high level documentation on the renderer here

>1) Are dynamic lights shaded in a deferred manner? If I want a lot of dynamic lights, what do I have to give up to keep performance up?

UE4 uses deferred shading so dynamic lighting is efficient, shadowing is another matter. Dynamic shadows from Movable lights are the biggest rendering cost typically. A shadow casting light can cost 100x more than an unshadowed light.

>2) Are stationary lights really stationary? if it is placed on a mesh that animates and moves around, then it isn’t stationary?

Stationary light means its lighting will only be correct if not moved. We generally try to prevent invalid edits on Stationary lights (like moving it in game), but it is possible to get around that sometimes. It will just result in incorrect lighting, or unbuilt lighting (shows up in an on-screen message).

Thanks Daniel!

That link is awesome, don’t know how i missed it.