Caulk vs nothing (another optimization thread)

[Boothand]

I'm not mapping much these days, but there's something I sometimes think of.

In GtkRadiant you make brushes, as usual, and they often have more sides than you really need. We caulk these sides so that they don't get rendered, but the collision detection will still be calculated. So for a map with lots of brushes, where 90% of all collision is actually hid under the ground or inside walls... wouldn't that start to impact something?

 

Ideally, wouldn't it be better with a map consisting only of planes and models, and an equally flat single plane for every collision surface, instead of a four-sided brush that won't play any part?

 

If so, wouldn't using a material like no-draw be more suitable than caulking unless the character is actually supposed to collide with it?

[Xycaleth]

Ideally, wouldn't it be better with a map consisting only of planes and models, and an equally flat single plane for every collision surface, instead of a four-sided brush that won't play any part?

 

If so, wouldn't using a material like no-draw be more suitable than caulking unless the character is actually supposed to collide with it?

I believe engines these days use maps which are essentially a collection of models, with a separate collision mesh (usually a simplified version of the map). This has benefits for collision and rendering - you don't have unnecessary collision data, and your rendering can potentially be faster. Where models are used more than once, GPUs nowadays can draw them in one go, even if they are in different positions, different sizes, etc. So yes, it probably is better

 

After a quick talk with @@Didz, caulk is still necessary for calculating vis. nodraw doesn't block visibility (from the vis stage's point of view), nor is it solid (so no collision data is generated for it). There's also nodraw_solid apparently, which is solid, but it still doesn't block visibility.

[mrwonko]

The nice thing about convex brushes is that collision detection against them is pretty fast. Yes, it's theoretically faster with less sides, but I wouldn't start optimizing that before finding out how much performance it costs.

 

Now patches on the other side are pretty expensive. I believe it's the collision, although it might be the rendering; at one point I converted a round room from patches to an ase model and gained quite a lot of performance.

[Oobah]

Caulk just removes things that will be rendered.  More or less the older variation of modern day models which people model to only show the specific things people will see in a level.