Level Optimization

[Skred]

Is there a good Level optimization tutorial?

I remember a long time ago before UE3 was publically released hearing that there are no anti-portals and that there are no ZonePortals. As well that meshes will occulude other things.

Is this all true? and where can I find a simple guide to level optimization techniques in UE3? I read some of the UDN page but that's like WAYYY technical. I just need to know if I can zone stuiff off, AP it, etc etc...how to approach it.

[urgrund]

from what I understand, UE3 uses occlusion queries which at least scales to any sort of level of any size.
http://udn.epicgames.com/Three/LevelOptimization.html
http://udn.epicgames.com/Three/VisibilityCulling.html

Another powerful (and sometimes overlooked) feature is LOD's. They are great because you can drastially reduce polycount (even down to billboard imposters) and reduce fill-rate by applying extremely cheap materials to LOD's - in fact, a complex building with 5 materials could get baked down to a boxy imposter mesh using a single render-to-texture version of the close-up LOD.

[Skred]

from what I understand, UE3 uses occlusion queries which at least scales to any sort of level of any size.
http://udn.epicgames.com/Three/LevelOptimization.html
http://udn.epicgames.com/Three/VisibilityCulling.html

Another powerful (and sometimes overlooked) feature is LOD's. They are great because you can drastially reduce polycount (even down to billboard imposters) and reduce fill-rate by applying extremely cheap materials to LOD's - in fact, a complex building with 5 materials could get baked down to a boxy imposter mesh using a single render-to-texture version of the close-up LOD.

Is this kinda like the low poly mesh vs High poly mesh on character models?

[Bah_Mee]

Lod

LOD or Level of Detail is the optimizing of a 3D models poly count as it gets further in the distance, You can set the model, at a certain distance, to switch to a lower poly version of the model.

[urgrund]

Is this kinda like the low poly mesh vs High poly mesh on character models?

Hmm, not really
LOD's are revisions of the same mesh that are progressively faster to render through a combination of material reduction, fill-rate reduction (cheaper shaders) and vertex processing reduction (fewer triangles).

A good is example is AssassinsCreed2, you can see the LOD transitions fade in as you move closer to a building... clever and careful construction of the LOD static meshes make it less apparent that anythign happened.

But, what was once a 10'000tris building structure with numerous wall/trim and door materials can devolve literally into a 12tris box with a single low res (128x128) texture on it! That's how they render entire cities at good frame rates

So in the end, if you're making levels that have expansive outdoor envronments, LODs are something you should really consider!

[Skred]

NICEEEEE.....lol

Well then how do ya do it? Tutorial maybe? That sounds like the cornerstone of optimization to me

Can you do it to stock assets etc? Sorry... I'm a nubface

[urgrund]

pretty basic... read over this:
http://udn.epicgames.com/Three/Stati...uide.html#LODs

as a first test, just make 1 Box and 1 Sphere in 3dsMax and export them both as .ase files. Then follow the tutorial above, just so that you get a workign sample to see the Box switch over to the Sphere.

From there, it will be entirely your choice how much you want to reduce each LOD stage.

[Skred]

pretty basic... read over this:
http://udn.epicgames.com/Three/Stati...uide.html#LODs

as a first test, just make 1 Box and 1 Sphere in 3dsMax and export them both as .ase files. Then follow the tutorial above, just so that you get a workign sample to see the Box switch over to the Sphere.

From there, it will be entirely your choice how much you want to reduce each LOD stage.

Thank you sir!