Overlapping rooms geometry produces visual artefacts

[vvs-]

This is visible over certain angles only, e.g. setgamef(1,7) setEntityPos(player,38335,45407,4352,275,0,0) or setgamef(5,1) setEntityPos(player,52875,42308,3584,65,0,0). By rotating the camera the artifacts disappear. It may be related to #40.

Here's a link to screen shots.

[TeslaRus]

It is overlapping rooms conflict... I though about these bugs too and I have one idea, how to fix it, but will it be enough good solution: to add stencil test to room rendering?

[vvs-]

You mean that it's caused by Z-fighting? Although, I'm not a specialist in CG.

[TeslaRus]

In TR different rooms (not alternative) may have some shared space, it is not Z-fighting... In engine uses VBO and if room has only one active frustum, the whole room mesh will be rendered. If both overlapped rooms has active frustums than we can see described bugs.

[vvs-]

Thank you for your explanation. So, it wasn't the primary reason here. Though, the fix could be quite similar I suppose.

[TeslaRus]

I add stencil frustum test in commit 3be9b71 + add some information to TR forum; TR3, map 13 (Area 51 map) looks better, but some glitches still exists (described in forum... but I found easy solution... heh...)

[vvs-]

It was also on All Hallows level. Now all these artifacts seems to be fixed. I don't see any bad side effects except it's slower.

[vvs-]

I was speaking too soon. Yes, there are problems now with frustums in Old Mill level and some others.

[TeslaRus]

I test new system - it is really slow (fps drops to 30 on my old PC). I had add condition to use frustum test only with overlapped rooms. It reduce stencil test calls (fps increase).

[vvs-]

Much faster and better now. But still a problem remains. At setgamef(5,10) setEntityPos(player,78222,46130,-5376,84,0,0) rotating camera to the left makes a pillar to disappear from view.

[TeslaRus]

I check setgamef(5, 10) and setEntityPos(player,78222,46130,-5376,84,0,0) and must say one: why pillar are located in room 18 (where other pillars located, in left of Lara) instead room 86 where is pillar's really position!? Engine can't correctly render things that are located pretty incorrectly... It can be fixed only by new scripts functions and some level scripting. Level design surprise me... hehe...

[vvs-]

Here's another: setgamef(1,1) setEntityPos(player,33909,74149,-2048,0,0,0), then rotate to the left. This one appeared after @cochrane recent VAO code merged in. I'm commenting here because it seems reasonable but may open separate bug if necessary.

[vvs-]

Seems that original bug is fixed now.

[vvs-]

Related to #367. It's arguable that OT frustums should work like this in Old Mill. There are incompatibilities in portals code.