|
Author
|
Topic: A real solution to skybox seams!
|
rgoer
btw cocks
 Posts: 2147
Registered: Aug 2003 |
posted 06-26-2004 01:11 AM 
I am ****ing sick of skybox problems...I've got a gf4-era nvidia quadro card, so the only way I can get any idea of how my skies look on ati hardware is with the "enable comformant clamping behavior" driver setting... but I'm not sure if it's giving me an accurate representation. I rendered six images out of Cinema4D that form a seamless cubemap. Cool. I set that as my sky. Cool. Somebody with ati hardware checks out my map and tells me my sky ****s out on an ati board. Great. Since then, I've re-painted my skybox images to have a four pixel seamless border on all four sides of all six images, as per Sock's and Speedy's informative instructions, but I still get some pretty blatant seams when I set my nvidia card to "ati mode." Then I recompile with -skyfix, and the seams are noticably better in "ati mode" (although still pretty visible), so I switch back to normal "nvidia mode" and check out my -skyfix version and see that I now have the same slight seam behavior (seems usually don't show up at all, ever, when I'm running in "nvidia mode"). I guess what I'm curious about is: is there an actual solution (besides converting my six-image cubemap to a one-image angular map) to this situation? Is it even worth ****ing about? I'm ready to give up, but if somebody knows something I'd still love to hear it. [This message has been edited by obsidian : 07-23-2004.]
|
MegaMan44
The Afflicted
 Posts: 539
Registered: Jun 2001 |
posted 06-26-2004 01:21 AM  
Actually as an ati user (which i am since half a year) you dont notice those seams too much anymore... :]would be nice to have a real solution tho.
|
Hipshot
Gaze into the face of Fear
 Posts: 551
Registered: Jan 2002 |
posted 06-26-2004 01:23 AM  
I have problems with that too, well; when I compile with skyfix, _I_ get black borders, when I compile without, peeps with ATI get them. As I see it, its ATIs fault, and therefore I won't compile with skyfix, I wan't a good solution (that works good on both cards) for this too.
|
seremtan
smile medicine
 Posts: 2492
Registered: Nov 2003 |
posted 06-26-2004 05:29 AM 
I'm with Hipshot on this one. nVidia is the dominant architecture, so it makes sense for mappers to focus on what works for that. Perhaps it's down to Radeon users to submit bug reports, and see if a future driver update fixes it? Whatever causes it, it can't just effect Q3A skyboxes and nothing else. That would be too weird.
|
seremtan
smile medicine
Posts: 2492
Registered: Nov 2003 |
posted 06-26-2004 06:31 AM
Oh, and is Bryce 3D a free download (if so where?) or not? I can't seem to find it anywhere via Google, just tutes.
|
Kat
"...mostly harmless?!"
 Posts: 3219
Registered: Nov 2000 |
posted 06-26-2004 06:37 AM 
Bryce is now owned by our software buddies Corel. Go to thier site and see what you can find.I need to be corrected on this but I think either ydnar or digibob suggested that ATI actually impliments the OpenGL code 'correctly' and that seems were the fault of Quake3. My memory is hazy on this though... [This message has been edited by Kat : 06-26-2004.]
|
digibob
coding junky
 Posts: 3676
Registered: Feb 2000 |
posted 06-26-2004 08:45 AM 
quote:
Originally posted by Hipshot:
As I see it, its ATIs fault |
It's not, it's id's fault ( and many other games companies ). ATI's rendering is how it should be, NVIDIA are the non standard compliant ones ( hence why they have a tickbox to make it compliant ).
|
rgoer
btw cocks
Posts: 2147
Registered: Aug 2003 |
posted 06-26-2004 10:47 AM
but is there anything to do about it?
|
rgoer
btw cocks
Posts: 2147
Registered: Aug 2003 |
posted 06-26-2004 10:53 AM
And what is nvidia doing wrong that prevents visible seams?
|
Hipshot
Gaze into the face of Fear
Posts: 551
Registered: Jan 2002 |
posted 06-26-2004 11:20 AM
Yea, how can it be nVidias fault, and why is carmack so keen on OGL and nV then, I still say nV is the better OGl player...  But I guess its just a matter of drivers, and that ATI then are to afraid to be called cheaters if they optimize the ogl code for Quake III E based games... [This message has been edited by Hipshot : 06-26-2004.]
|
Black Dog
Insane Quaker
 Posts: 491
Registered: Oct 2003 |
posted 06-26-2004 11:32 AM
http://home.planet.nl/~monstrous/skybox.html
|
seremtan
smile medicine
Posts: 2492
Registered: Nov 2003 |
posted 06-26-2004 01:22 PM
Informative stuff BD. Looks like the angular mapping method is only foolproof way to make non-tiling skies without glitches. [This message has been edited by seremtan : 06-26-2004.]
|
obsidian
Meridanox Duodecim
 Posts: 1419
Registered: Feb 2002 |
posted 06-26-2004 04:07 PM 
It's not a matter of being bugs or anything with Q3 or any of the videocard drivers, just different times in which Gl-Texture-Clamp behaviour was implemented. Quake3 was released before it was implemented, which is why skyboxes turn foobar when running with it on - because the game was coded in a time before this feature even existed.The -skybox switch is a hack that ydnar added in an attempt to fudge the same results on both ATI and nVidia cards with or without clamp behaviour enabled. ATI hasn't supplied us with an easy way to turn it off, nVidia has - but the idea is that it should be turned on for newer games. Would be nice if the videocard drivers could autodetect the game or something... hmm... Anyway, there is no easy way to compensate, though I have seen a few skyboxes created by ydnar and compiled with -skyfix that seem to work quite nicely with or without clamping, not sure what he did exactly to get those results, I've been meaning to ask him but it keeps slipping my mind. y might be able to give you some pointers. IMO, if you're pulling your hair out over this, then the issue isn't really worth the stress. Just create the skybox and leave it as is. It's not that noticable anyway. ------------------
Q3Map2 Shader Manual
|
Shallow[BAP]
The Illuminated
 Posts: 1237
Registered: Dec 2000 |
posted 06-26-2004 04:27 PM
Something I've been meaning to try since ydnar put the skyportal stuff in q3map2 is to essentially build a standard environment skybox manually. This would mean making a little cube in Max (or whatever) and UVing it nicely with a set of six properly edged skybox textures, exporting (probably to ASE so that a functional cube could be easily retooled by anyone with notepad for their own use), then slapping it in the map scaled up to taste with the skyportal stuff.Obviously you'd need to do some fiddling about in shaders so it wasn't mipmapped, was unlit etc. And "UVing it nicely" means having the UVs extend one texel beyond the edge of each surface, to eliminate texture bleeding. Has anyone tried anything like this?
|
Hipshot
Gaze into the face of Fear
Posts: 551
Registered: Jan 2002 |
posted 06-26-2004 06:41 PM
thought about that too, the unreal way...
|
Black Dog
Insane Quaker
Posts: 491
Registered: Oct 2003 |
posted 06-26-2004 10:51 PM
Wouldn't the texture resolution reduce as you moved away if it was just a texture painted on the inside of a box?I thought the entire point of a skybox was that it's a special texture which displays at the same scale/resolution/parallax no matter where you view it from.
|
rgoer
btw cocks
Posts: 2147
Registered: Aug 2003 |
posted 06-26-2004 11:31 PM
All of ydnar's seamless skies are clampmapped angular maps, like in that tutorial about bryce and hdrshop etc (but I'm pretty sure he paints his in photoshop by hand from photo sources rather than using those tools).One thing I am playing with is using a hex-sphere in a portal sky (a sphere divided into six "cubic" sides) rather than a cube, I'll let you know if it works.
|
rgoer
btw cocks
Posts: 2147
Registered: Aug 2003 |
posted 06-26-2004 11:35 PM
if you scale the _skybox entity up to factor 256 or so, you really can't tell it from a "real" skybox...
|
The5thHorsemen
The Afflicted
Posts: 539
Registered: Jan 2003 |
posted 06-26-2004 11:47 PM
I cant belive this question keeps poping up.when is sombody going to hack out a UI menue for ATI to turn the texture clamping on and off .
|
obsidian
Meridanox Duodecim
Posts: 1419
Registered: Feb 2002 |
posted 06-27-2004 06:21 AM
rgoer: try adding nomipmaps to your skybox shader and see if it helps.I have seen an actual skybox by ydnar somewhere using the 6 skybox images and the -skyfix switch (unless I'm going crazy). I'll see if I can find it...
|
rgoer
btw cocks
Posts: 2147
Registered: Aug 2003 |
posted 06-27-2004 07:11 AM
-skyfix can work if your edges are pretty uniform, but I just wasn't interested in simplifying my sky... ;^)I did, however, hack together a model with carefully mapped uv coordinates that, when placed in a portal sky, works perfectly with six-image skies. I'll post the model and the .shader in a bit, here are some shots: A normal skyparms sky in "ati mode": 
****ing pwnt! The model, still in "ati mode": 
It's got fewer tris than a normal sky, too ;^) Edit: the exact same images are used in both of those screenshots... the only difference is that the top shot renders the six images via skyparms and in the bottom shot they are uv mapped to the hex-sphere model. [This message has been edited by obsidian : 07-23-2004.]
|
rgoer
btw cocks
Posts: 2147
Registered: Aug 2003 |
posted 06-27-2004 07:13 AM
btw this model's uv mapping only works correctly to remove seams if you have prepared your skybox images with a two pixel border as in sock's or speedy's instructions...
|
obsidian
Meridanox Duodecim
Posts: 1419
Registered: Feb 2002 |
posted 06-27-2004 04:33 PM
Interesting workaround... and I assume the hex-sphere method works in "non-ATI" mode?Could you post a r_showtris 1 mode screenshot too?
|
rgoer
btw cocks
Posts: 2147
Registered: Aug 2003 |
posted 06-27-2004 05:43 PM
Normal skyparms:
My sky sphere: 
|
rgoer
btw cocks
Posts: 2147
Registered: Aug 2003 |
posted 06-27-2004 05:44 PM
This is what the sphere itself looks like, btw:
|
Neotic
The Afflicted
Posts: 643
Registered: Feb 2000 |
posted 06-27-2004 05:47 PM 
rgoer the version you passed to me, i dont think i have that problem. then again i'm using it in ET and not q3. so maybe thats the reason it seems fine. i am on a radeon 9500.
|
rgoer
btw cocks
Posts: 2147
Registered: Aug 2003 |
posted 06-27-2004 06:16 PM
Yeah Q3 is full of buggy behaviors that were fixed in ET ;^)
|
Hipshot
Gaze into the face of Fear
Posts: 551
Registered: Jan 2002 |
posted 06-28-2004 01:14 AM
That is great rgoer, can we download this somehwere? Hey, I see that you also are using a flare in front of the sun, that owns! [This message has been edited by Hipshot : 06-28-2004.]
|
rgoer
btw cocks
Posts: 2147
Registered: Aug 2003 |
posted 06-28-2004 05:11 AM
Yeah I packaged it up and it is available here. The sky-sphere .ase model is included in the archive, just edit it in a text editor to link it to your own sky assets and rename the file, feel free to use it etc etc just give me a shout-out or something ;^)
//Obsidian: edited download link
[This message has been edited by obsidian : 07-23-2004.]
|
Shallow[BAP]
The Illuminated
Posts: 1237
Registered: Dec 2000 |
posted 06-28-2004 05:32 AM
That's cool man - it never would have occured to me to spherify the cube.
|
wis
Insane Quaker
Posts: 313
Registered: Apr 2002 |
posted 06-28-2004 05:34 AM
thats great rgoer! Ever wondered why skyfix isnt working for me, always thought i'm doing something wrong no i know it isnt my fault One question: Why aren't you using a cube instead a sphere in your model?
|
rgoer
btw cocks
Posts: 2147
Registered: Aug 2003 |
posted 06-28-2004 05:36 AM
I've messed around with giant cubes in the _skybox area before, but the view gets distorted when the player moves away from the _skybox entity's origin... the sphere prevents that from happening
|
obsidian
Meridanox Duodecim
Posts: 1419
Registered: Feb 2002 |
posted 06-28-2004 07:23 AM
Just one suggestion:
To reduce the number of tris even more while maintaining the same LOD, you may want to use a geosphere instead of the normal sphere object.
|
rgoer
btw cocks
Posts: 2147
Registered: Aug 2003 |
posted 06-28-2004 07:31 AM
The six cubic sides is the important thing about the hex sphere, and the reason I didn't use a geodesicEdit: I guess I mean "important" as in "really easy to uv map" [This message has been edited by rgoer : 06-28-2004.]
|
obsidian
Meridanox Duodecim
Posts: 1419
Registered: Feb 2002 |
posted 07-23-2004 06:57 AM
Prepared thread for archival:-fixed rgoer_mars.zip download link
-removed second page
-edited subject title
-washed rgoer's mouth with soap 
|
Quake3World.com Forums
