Quake3World

The other day I discovered something about building a Caulk Hull that made me wonder, if I had been doing the caulk hull "abstraction" (simplification of geometry) correctly. And that in fact I could have optimized even more aggressively.


In a nutshell: Using the Caulk Hull the way the Player Clip Hull is set up.


What I found in AEtour, a map based on concentric circles using patches for more than 90% of the geometry is this. The problem with a layout and using patches in such a way obviously is visibility. Since patches do not block visibility you see everything in the map all the time (i.e. the typical box map). So I started to rebuild the thickened patches that constitute walls with structural caulk brushes. Carefully placing the brushes inside the thickened patch mesh walls. And that worked fine.

But at one point I had mad a mistake, and the caulk brushes were actually sticking out of the rounded patches (they were *not* in the same plane). I would have guessed this would cause a hall of mirrors effect or something as evil. But as it turns out, the caulk brushes simply were invisible, and obviously restricting the movement along that wall slightly (much like player clip, simplifying geometry would).

This really surprised me, because if this indeed works, you could simplify the *inside* of a 90 degree bevel with a straight line (looked at in top down view). The *outside* could be well approximated with 2 or 3 angled brush faces.

Another example of this way of using caulk brushes, could be applied to walls, that have niches (indents / ledges). I would normally have tried to place a caulk hull brush in such a way to only *share* faces of that textured wall, but never actually stick out. Now I could actually place a caulk brush, exactly the way I would place a player clip brush, i.e. covering the niches to avoid getting snagged. Thus greatly simplifying the caulk hull, and making my like easier mapping.


Question is, is this indeed the way to go?


On Hint Brushes, and sticking out Caulk Hull brushes
If you place caulk hull brushes in such a way that the stick out of walls etc. too much you would be messing up visibility potentially, right? E.g. the engine would think that a caulk hull brush is in the way of the line of sight, where in fact the geometry (detail brushes + patches) would actually let you look past that corner. Thus you could create these ugly "missing" geometry areas?


Did I get all this right?


If I did, I could technically turn AEdm7 into detail, and build a very abstract (simplified) caulk hull, even though many walls show geometry "indents", also optimizing AEtour would be greatly simplified.

(Not sure if the above requires some screenshots, to help explain what I mean?)

sounds like id went hammer-style with their caulk (hammer's nodraw is the same). mostly i think these different shaders exist merely to tell one kind of geometry from another in the editor

for instance, hammer has

* nodraw - solid, invisible, blocks VIS
* invisible - solid, invisible, doesn't block VIS
* clip - solid, invisible, doesn't block VIS

i'd say using caulk as clip could result in some strange VISing anomalies on occasion

I should have said the above less provocatively.

Obviously there are many situations for player clip that you would *not* want to use as part of the caulk hull (thus structural). E.g. some of the angled off corners or wedges around boxes to avoid the player getting stuck. Mainly - I just noted - on non-void connected detail brush geometry, like deco crates.

I was thinking of clipping happening to simplify walls being similar to what you want to do with a caulk hull.

Noted: Walls with niches, would react differently to covering it with caulk, e.g. rockets would impact sooner. So there is a trade off.

The main reason I never used caulk this aggressively, is in-editor visually. Caulk would cover all my walls, making it a pest to see textures. Filtering Caulk (only recently used that) could make is possible though.

The unexpected results you saw came because patch meshes aren't clipped up in the same manner as regular brushes would.

Since parts of your patch mesh are visible outside the caulk, the entirity of the patch mesh is visible no matter how much of it you obscured by caulk. This is because patches have no interaction with brushes (beyond seaming along the edges where appropriate).

Hope this makes sense, and hope I understood what you described correctly.

Keep in mind that if you have too much caulk poking out it will effect the lightmaps and shadows that get compiled/shown in game. You can have a little poke but not a big poke. Patch meshes tend not to behave the same way as poked brushes though (as Foo pointed out).

Ah... good points.

Will test this a bit... I always had the feeling I was doing the right thing, and the lighting issue mentioned would be a hefty price to pay.

I'll try this out in AEdm7 and post some shots.