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Very basic question about liquids and cylinders

Posted: Tue Sep 22, 2015 9:27 pm
by AndyW
I would like to know what you think is the best way to do that stuff:

3 Brushes 4 Cylinders VS 3 Brushes 2 Cylinders:
A or B?
[lvlshot]http://i.imgur.com/My6UcDY.jpg[/lvlshot]

1 Lava Brush VS 9 Lava Brushes:
A or B?
[lvlshot]http://i.imgur.com/cmdJJaX.jpg[/lvlshot]

Can it cause an error pushing stairs into a bevel like this?
[lvlshot]http://i.imgur.com/9A1ZAfp.jpg[/lvlshot]

Ingame i cannot see any difference but im not sure if if there are real "Pros and Contras"
Anyway i would do the "clean" way with more Brushes or Curves but im really not sure if its that important!
:confused:

Re: Very basic question about liquids and cylinders

Posted: Wed Sep 23, 2015 12:01 am
by Martinus
1. Depends on the platforms heights. If the platforms are too low, and had one big lava brush over under it, that can cause light problems on them.
2. No, maybe (stairs).

Re: Very basic question about liquids and cylinders

Posted: Wed Sep 23, 2015 1:07 am
by Silicone_Milk
Liquids, from what I remember, were usually one brush where you were able to do so but in cases where you had to use multiple brushes (to prevent liquids being in rooms that should be dry but appear on the same z-level), a nodraw shader is used on the faces where the liquid brushes meet.

Re: Very basic question about liquids and cylinders

Posted: Wed Sep 23, 2015 7:01 am
by AEon
1. Interestingly, whereas patches usually needs to be perfectly vertex aligned with surrounding brushwork to avoid sparklies, this does not seem to be the case for the circular bottom of cylinders. E.g. you can just place them flush on the ground and there will not be any sparklies. So in this case you can just use two patch cylinders to traverse through the central brush. (IIRC)

2. Liquids... traditionally one would case (A) since that is much easier to manipulate and you do not have issues with several liquid brushes connecting... since at connections you would have to manually place a nodraw brush to avoid visual artefacts. I am not completely certain, if q3map2 actually cuts the liquid brushes apart or not. But sticking with A is usually the good move.

3. I never really used stairs like that... but the 90° patch should not cut into your brush steps, so there should not be any sparklies. Your stairs seem to be very cleanly created, i.e. there are no gaps between the brush steps AFAICT also with the wall... so your stairs should also be "watertight". So all that is all good.

3. (2nd thought)... so in principle pushing your brushes into such a patch is not the problem. BUT... the vertical edge of the first (lowest) step touches the tip of the vertical edge of the much higher patch (the tip of the patch bend), and this is also the case for the last step. Since these edge pairs (brush/patch) do not match up in height there will be sparklies there. At least I am pretty sure there will be. This might not be visible, if you are lucky, and there is no void behind your stairs, but if there is, sparklies are likely to become visible. Hope I could explain it in an understandable manner. If not, if you upload your test stairs (.map and .bsp), I could give it a go in Radiant, take screenshots, and mark the areas I mean in it. Though, I am not really sure how to cleanly avoid sparklies in this compact case.

Note: In Radiant you will not see such sparklies, they only show up after a map compile using q3map2 in the a bsp file you load into Q3A.

Re: Very basic question about liquids and cylinders

Posted: Wed Sep 23, 2015 11:25 pm
by obsidian
Overdraw typically results in a higher performance hit than vertex counts. In addition, over long distance and especially if running the game in 16-bit mode, z-fighting artifacts can appear. For this reason, your option A is generally the better bet.



With your lava, definitely NOT B, your example given is full of T-junctions and will result in a LOT of unnecessary polygons. Mitre edges to reduce T-juncs, use LavaCaulk shader on surfaces between lava brushes, and that will be the best solution. If in a pinch, solution A will work but you face the same overdraw issue as your first example. If the lava shader emits light, you could end up with some weird lighting artifacts and that would be the big deal breaker.

Image



Curved stairs with a bevel, I guess there's no real "clean" solution to something like this unless you rebuild the curve surface with very careful use of brushes and phong shade the curved side, or go with a model, but that's a hell of a lot of work. I would clip those brushes relatively close to the curve bevel to minimize overdraw and call it a day. Make sure unseen sides are caulked.

Re: Very basic question about liquids and cylinders

Posted: Thu Sep 24, 2015 10:37 am
by AndyW
Thank you Guys, very interesting stuff here!
:up: