Why do corners in walls look not perfectly joined sometimes?

[i30817]

You know, sometimes in a mission you look at a corner in a room and you can see yellow in dots there, probably light from the other room. I was wondering if this is a floating point error, mapping error, and i was also wondering if there wasn't a easy way for mappers to avoid it in the editor (not that i'm a mapper).

Edited May 8, 2011 by i30817

[Springheel]

Huh? Do you have a screenshot?

[Komag]

I think it's called "sparklies", I think I know what you mean. I don't know the cause, and it's a problem I despise. I don't know of a reliable way to avoid the problem. After noticing an area where these show up, just moving things a bit or rebuilding in some slightly different way can sometimes make it go away, so that's about all we can do (I think).

[Baddcog]

I think it's probably more a graphics card issue or driver issue. I've never noticed it in TDM myself.

[Tels]

I think it's probably more a graphics card issue or driver issue. I've never noticed it in TDM myself.

 

I occasionally have this problema and it usually happens along "seams" of triangles. If you turn on "r_showTris" you see the yelow sparkles follow the edges.

 

No idea what causes it, as some missions are prone to it, others not. I think it is indeed caused by light spill which is then "hidden" by the all in front of it painted over, but not exactly, leaving the sparkles. Might vanish with antialising?

[Sotha]

I occasionally have this problema and it usually happens along "seams" of triangles. If you turn on "r_showTris" you see the yelow sparkles follow the edges.

 

No idea what causes it, as some missions are prone to it, others not. I think it is indeed caused by light spill which is then "hidden" by the all in front of it painted over, but not exactly, leaving the sparkles. Might vanish with antialising?

 

I've seen these too and I think it has something to do with situations where you have

location A | visportal | location B

Location A is very brightly lit, then pitch black location B may show these strange sparklies. The geometry is flawless, so it must be some kind of engine/video card thing.

[rich_is_bored]

Sparklies are the mapping term. T-junctions are the cause. Here's an example where caulk is used to improve visibility...

 

 

See the "T" formed where the edges meet? The problem here is that the edges of the primitives line up but not the vertices. For the vertices to line up the long brush must be split into two. Fortunately the compiler does just that but only if the member that needs split is a brush and part of the same entity. If you mix brushes, patches, and entities you need to be mindful of how they meet. A general rule to follow would be "vertices touch vertices and edges touch edges".

 

Also this is also something to consider with regards to the subdivision level of a patch because each level introduces new vertices you have to account for.

[Sotha]

A general rule to follow would be "vertices touch vertices and edges touch edges".

 

I'm confused, as usual.

 

So this does not apply to worldspawn brushes? They do not need to be cut? In the problem region I only have worldspawn things. (Plus a few decorative func_statics.)

 

But if I mix patches and worldspawn, I would need to make verts touch verts and edges touch edges. But that doesn't sound feasable at all: think about a patch end cap, which is a vault. That touches the edge of a worldspawn brush. According to the general rule here the brush should be cut into multiple brushes that touch the endcap verts with their verts.

 

That does not make sense and I've never seen any sparkling issues due to such vaults touching a brush edge. And I've done tens/hundreds of those so far in my mapping career.

 

Yep, definately misunderstood something here...

[rich_is_bored]

Nothing needs to be cut unless you see sparklies. When I said "general rule" I was referring to the way in which you fix it, not something you needed to do globally.

[Sotha]

I cut all the worldspawn brushes in the location in question so that verts should be against verts.

I still see the artifacts. I even managed to get a few screenies out of them:

 

Here, have a look:

 

 

I don't know what they are. I see a yellow/orange line which sparkles. It is never a full line, but shows only a few pixels at a time. When I move and look around they few pixels blink and form the line.

 

The lines seem to form a constant shape. They seem to somehow go through the visportal in the wooden doorway frame. The yellow sparkling line does NOT co-incide with any tris if I turn r_showtris 4 on. When I walk so that I see through the doorframe, the lines disappear as I see the geometry through the visportal. The world just behind the doorway is very well lit.

 

The geometry looks flawless, the visportal seems to be in order. I have several such doorways like this in the map, but none of them show this behavior.

 

A grand mystery, eh? A subtle ugliness, but still I'd like to get rid of it.

[Springheel]

I've never seen that.

[rich_is_bored]

Can you select that region and make a prefab out of it? I'd like to have a look at it.

[PranQster]

I was thinking this was about the sometimes transparent areas that appear when working with very small brushwork and patches with detail at the .25 and .125 unit level.

After seeing the screenshots I realize I have never seen this.

Using nvidia drivers with linux... various releases over the last couple years.

[Sotha]

Can you select that region and make a prefab out of it? I'd like to have a look at it.

 

Sure, I'll isolate a testmap at my next fragment of free time.

[Sotha]

Sure, I'll isolate a testmap at my next fragment of free time.

 

Ok, over heres:

http://www.mediafire.com/?0v2rardoczwa0b8

 

The sparklies occur in the dark room, just in front of the map start position. They are seen only at the doorway which is farthest from the starting position. The doorway nearer the starting position does not show the strange lines.

 

Please let me know if you figure out what is going on. And thanks for looking into this!

[stumpy]

I was told those lights along edges of triangles were caused by a maths rounding error in the graphics drivers for your video card. eg length of one edge 40.0000, length of other edge 40.0000, graphics driver seeing lengths as 39.9999 and 40.0001 because the graphics card sees them as two different lengths, it fills the gap with a default fill.

[rich_is_bored]

What a weird glitch. It's not sparklies as the shape does not appear to correspond with edges anywhere in the map. But it clearly has depth and form. It seems to be just outside the bounds of the map but there's nothing there.

 

I removed everything non-essential. I remade the entire wall where this problem occurs. I tried toggling lights, visportals, and a host of other things. I need a young priest and an old priest.

[New Horizon]

Does it happen with both the normal and enhanced interaction shader? What about ambient methods?

[Tels]

What a weird glitch. It's not sparklies as the shape does not appear to correspond with edges anywhere in the map. But it clearly has depth and form. It seems to be just outside the bounds of the map but there's nothing there.

 

I removed everything non-essential. I remade the entire wall where this problem occurs. I tried toggling lights, visportals, and a host of other things. I need a young priest and an old priest.

 

Not a young priestess?

 

Anyway, I *think* it might be the portal sky that "leaks" from "behind". I am seeing the sparklies (on Linux, Nvidia), but so far it is very hard to spot and does not appear to correlate with tris or visportals or light scissors.

 

However, it looked to me like it might be the portal sky behind the scenery, so I added 2 more visportals to the first door the player walks through (because I thought only one wouldn't help and there would be none there).

 

And lo and behold, sparklies gone. However, while in game, I noticed that there are 3 visportals in the first door (because there was already one I overlooked), so I deleted one of these. And sparklies there were, again.

 

So it seem replacing the first visportal by 3 visportals removes the sparklies.

 

Maybe it is because the sky is then rendered only once?

[Hit Deity]

I've heard it's either heat or driver issues...

 

I doubt it's heat, really, because the same sparklies show up pretty consistently from place to place, regardless of temps in PC or GPU, on my system at least. They happen at the same areas, same junctions, and with the same regularity, regardless of drivers, temps, or anything else that I can think of that might introduce "random" factors.

 

I think it's a rendering problem, specific to certain cards. I've played the same games on different cards, and some do it and some don't. It might be a design problem. Wish I knew. I would think it has something to do with the way different cards "overlay" textures onto surfaces. For some strange reason, they chose a highly visible effect to put there at the problem areas, probably as a debugging tool. It would be interesting to know if it is fixable or not, and they just leave them in sometimes because it's not worth the trouble to fix, or if it's a graphics card limitation that you can't get around. (I have a feeling it's the latter, or more would get fixed.)

 

What about putting (a) different texture(s) on those surfaces...does that change the sparklie effect any?