Competing or complimentary to occlusion culling (and Gaia player culling)?

[Bil Simser]

Hi guys,

Just wondering about how SECTR fits in with Unity's built-in occlusion culling and Gaia's player culling?

Should I be baking the scene for occlusion culling *and* then use SECTR, or is that just creating redundant opimizations?

Also there's a camera culling part you add for SECTR but the Gaia player also has a culling component to it (when you use the toolbox to combine meshes then use the small, medium, and large layers). I'm not using the Gaia player control as I have my own but should I be adding this component to my player and setting it up for layer culling as well as what you need to do with SECTR or again, is this just making it more complicated than it should be and won't have any effect?

Finally in the "game ready" tutorials you guys export the terrain as a mesh. I'm assuming if you're using SECTR you wouldn't do this and let SECTR handle the terrain directly?

Thanks

[Tikal]

I'm also curious in this and it seems like this question never got answered. @Adam

[Peter]

@Bil Simser @Tikal Sorry, it looks like we missed this question.
 

On 2/15/2022 at 4:58 PM, Bil Simser said:

Should I be baking the scene for occlusion culling *and* then use SECTR, or is that just creating redundant opimizations?

You can do both, but it is going more in the direction of redundant optimizations because it is questionable if you gain performance by the additional few objects being filtered out that one single culling would not catch vs. the extra overhead of running another culling system.
I think it is more important to determine if you need dynamic or baked occlusion culling and choose the appropiate culling tech: Sectr works by evaluating the visible areas through portals (doorways, windows) during runtime, and you can add new areas or even shift entire rooms around.
The baked occlusion culling works by evaluating "is this area visible from this other area?" during design time, which is fast during runtime but requires that all the relevant content remains static.
If you do not need this dynamic part, and / or there are no portals that restrict the viewport, you will get better results with the baked occlusion culling, if you have dynamic levels (procedural level generation, moving architecture, etc.) then the SECTR culling will allow you to dynamically cull that.
 

On 2/15/2022 at 4:58 PM, Bil Simser said:

Also there's a camera culling part you add for SECTR but the Gaia player also has a culling component to it (when you use the toolbox to combine meshes then use the small, medium, and large layers). I'm not using the Gaia player control as I have my own but should I be adding this component to my player and setting it up for layer culling as well as what you need to do with SECTR or again, is this just making it more complicated than it should be and won't have any effect?

It is a bit difficult to answer in so far as that the "tech" for the layer based culling lies in the unity camera object, it is a feature of the unity camera that (strangely) is not exposed anywhere in the regular camera component. We are not doing any calculations for the distances ourselves, and I assume you will have this overhead anyways if you use it or not (where all the layers would have the same culling distance). I would therefore assume you will only get an advantage if you use it on top of your other culling method and it can shave off a few extra objects from being rendered by the layer distance.
 

On 2/15/2022 at 4:58 PM, Bil Simser said:

Finally in the "game ready" tutorials you guys export the terrain as a mesh. I'm assuming if you're using SECTR you wouldn't do this and let SECTR handle the terrain directly?

Meshes are normally faster than unity terrains, if you do not need features of the unity terrain object (e.g. grass rendering, splatmap based texturing etc.) It should also be faster to replace all the terrains in a sectr loaded scene with meshes.