Level Design Static Mesh Culling?

[jeffduquette]

Letz say I set a static mesh wall to cull at whatever distance -- 4096UUs or whatever. ANd I know I should be checking every vantage point to make sure that this can't occur during game play, but lets say -- just for the sake of disscussion -- that a Player actually has a direct line of sight through the culled mesh from a distance beyond the 4096UUs cull setting. Now lets say that same player spots a bad guy and shoots at him. The projectile trajectory in theory has to pass through the space occupied by the culled mesh. What happens?

Does the projectile "sense" the culled mesh and a collision occurs between mesh and projectile. Or does the projectile not "sense" the culled mesh and thus proceeeds along its merry way to the intended target?

Does "culled" mean "culled" fropm the perspective of both what is being rendered as well as culled from projectile collision. Or is cull strictly a visual rendering thing?

 

[Shurek]

Jeff,

You could try an experiment to figure this out (as I don't know the answer off the top of my head). Put a static of a tank in one of your maps. Set the cull distance to 512uu - about 8 meters - and then fire off a clip from an MP40 or something. See if the bullets spark off of the invisible tanks or pass through to hit the ground on the other side.

 

[jeffduquette]

Good idea. I did just that. Got a bit of serendipity.

First: The mesh isn’t culled from the perspective of projectile collision. I But a PzkwIV behind an uber tall wall and set cull to 512UUs. Drove a Sherman 76mm up to the wall until the wall finally popped into view. Than I backed-up until the wall pooped back out of view. Shot the main gun, the coax, and a Thompson SMG at the MkIV and all the shots bounced off the invisible\culled mesh.

Serendipity:

1) The point at which the mesh disappears when sitting in the drivers position – head up – is different from the location that the Mesh disappears while gazing through the gunner’s telescope. You have to drive further away – I’d guesstimate another 300UUs to 500UUs from the wall before the mesh disappears from the gunner’s sight picture.
2) Same deal with the TC position when looking through Binos – but its even further removed from the gunners position. The mesh finally disappers from the TC bino view maybe another 300 to 500 UUs further back from the position at which the mesh disappears from the Gunners sight picture.

I didn’t try the perisciscope views at either the radio\hull MG position, nor the drivers head defilade position, nor the TCs periscopes.

So the gist was that cull settings do not affect projectile collision. The projectile "sees" the wall and collides with it regardless if the gunner sees the wall. And; cull distance isn’t absolute. It varies between “naked” eye view and optic enhanced view.

 

[SchutzeSepp]

wtf, i posted an answer here yesterday saying culled meshes still stop projectiles right after shureks post. or am i dreaming?

 

[worluk]

Culling happens on the client, projectile collision on the server. Server doesnt cull.

 

[jeffduquette]

Culling happens on the client, projectile collision on the server. Server doesnt cull.

I want to make sure I understand the ramifications of what you are saying. Am I getting any advantage in terms of online map performance\map optimization for online play by using static mesh culling? Or should I just leave it set to zero.

 

[[TW]DrGuppy]

Ideally, every single static mesh should use a cull distance. This takes a lot of work so you can leave some of the lower poly object at 0 if you'd like. Another time saving technique is to select all the static meshes in a house or room and set them all at once to something standard like 2000. There is essentially no downside to using cull distances, other than the time it takes to go through and punch in the numbers and make sure they're not popping out of view too soon.

 

[jeffduquette]

Thanks Guppy.

 

[Akyo]

Yes culling is important on every map. Im using culling on outdoor meshes, and set it near the fog blending. So popping in stuff is not seen.

But when it comes to meshes, that are inside a house, like furnitures, example:
Anyway, you dont see through buildings, so you dont see it popping up. Rooms are mostly 5-10 metres, and then comes a wall. So you can use a low culling number like 2000.