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loden
04-19-2004, 12:51 PM
Hi,
when I turn on final gather those quad artifacts come out, I tried different settings of min/max radius, falloff stop, increasing ray etc, but those artifacts still reamain there. No strange settings for render globals, I tried also with higher sampling but nothing works :(
Anyone can help me?
Thanks!

loden
04-19-2004, 12:55 PM
ops, forgot the image....

loden
04-19-2004, 12:55 PM
ops, forgot the image....

loden
04-19-2004, 12:55 PM
sorry, I've got problem with connection, really sorry!

poly enslaver
04-20-2004, 04:55 AM
Hi. I really like the artifacts but these are really strange!!! Never seen before... If scene is not so big you may post or give the direct link I'll check it. At this point try just to look thru your settings in MR for Maya... may be you'll find something. And set FG radiuses all to 0.

loden
04-21-2004, 07:17 PM
Thanks for your answer! I couldn't post that scene right now but I can tell you that I try several time to export all the geometry camera and lights and import it in a new file but nothing change...I checked all the settings for lights also, nothing strange...Min/max radius and falloffs zeroed out....I don't know, I couldn't imagine what' the problem could be...Have u ever had problem of those quad artifacts like mine?
Thanks again

Jackdeth
04-21-2004, 09:02 PM
Ahhhh. Here's a hint.... I bet your object doesn't have UVs....

loden
04-21-2004, 11:36 PM
In these scene I have both object with uvs and without, but anyway the problem start when I start up FG so I don't think it could be a mapping problem! And those artifacts aren't "3d" ( i.e. they're not "inside" the 3d world like the noise that appears on the wall with a low FG rays value) they're in "2d",like the artifacts that happen with a movie with a bad divx compression! Really I couldn't explain better than this, maybe tomorrow at work I redo this render with an high resolution to explain better!
Thanks

loden
04-21-2004, 11:45 PM
that's what I mean when I say "2d".....hope this could help in the meanwhile!
http://lodenfactory.altervista.org/img2.jpg

gmask
04-21-2004, 11:46 PM
Originally posted by loden
In these scene I have both object with uvs and without, but anyway the problem start when I start up FG so I don't think it could be a mapping problem!

I have seen this before and it is not because of the UV's .. it's been a while but it has to do with your settings in your render globals. What FG settings are you using and give your machine specs while you are at it.

loden
04-21-2004, 11:59 PM
We tried this scene on several pc, all AMD 2.4 Ghz someone with Nvidia card and some with Matrox card, win 2000/xp.
My FG settings where changed maybe 20 time, from very low to very high, but the pics I posted had 50 rays, min/max 0,036/0,36; 1 for filter, 0 falloff start and 5 falloff stop. The only relevant thing is that if I decrease the min/max value to ridiculous number like 0,00036/0,0036 I could reduce the size of those artifacts (and increase drammatically my rendertime....).

gmask
04-22-2004, 12:05 AM
Originally posted by loden
We tried this scene on several pc, all AMD 2.4 Ghz someone with Nvidia card and some with Matrox card, win 2000/xp.
My FG settings where changed maybe 20 time, from very low to very high, but the pics I posted had 50 rays, min/max 0,036/0,36; 1 for filter, 0 falloff start and 5 falloff stop. The only relevant thing is that if I decrease the min/max value to ridiculous number like 0,00036/0,0036 I could reduce the size of those artifacts (and increase drammatically my rendertime....).

50 rays sounds like way too few.. try 100 or 1000 and I think yiou min max should be more around 3.6 / .36 unless the overall size of your scene is very small which could be a problem in itself.

Also try importing the scene into a new scene file and re-entering the settings for render globals.

loden
04-23-2004, 02:35 PM
Ok, here u can find 2 renders: the large one is with 100 of FG rays sampling on 1/3 gauss; the small one has 500 FG rays. As u can see, nothing change but the quality of the rendering, but those artifacts still remain there! I also scaled the scene and reimported, now is 15/20 units total, large enough for me!
http://lodenfactory.altervista.org/cgtalk.jpg
http://lodenfactory.altervista.org/cgtalk2.jpg
Thanks in advance!

poly enslaver
04-23-2004, 03:33 PM
HI. yesterday I've got these artifacts too. I can clearly say it's because of FG. For me the solution was just to import the geometry and create another light. But than I've noticed that happens if you change the setting of GI (number of photons) and do not rebuild the FG, also using big FG radiuses can be useful. Howver that can be just a coincidence.

loden
04-23-2004, 05:56 PM
Ok, after a full revision of my scene I undestood...believe it or not it was the camera!!! I had my camera out of the wall and I used near clip plane to adjust my shot; during the render, everything well until I turn on FG...I don't know why but If the camera is outside the wall and u use near clip plane to view inside and u use FG those artifacts come out! I couldn't believe it because with GI and without FG the render is perfect! Please, test it by yourselves, I tried almost 10 times and in every scene I made this trick made those artifacts. I've try lowering min/max radius and push until 1024 rays but nothing change. I think is not a FG settings problem...I hope to be wrong, anyway, try a test!
Bye

gmask
04-23-2004, 06:18 PM
Originally posted by loden
Ok, after a full revision of my scene I undestood...believe it or not it was the camera!!!

OK my encounter with this problem is coming back to me.. I tried to scale a camera to flip the image.. a big nono MR does not like this one bit.

loden
04-23-2004, 06:54 PM
Hey Gmask, my poor english is not good enough:)
Do u mean that I have to flip my camera upside-down scaling it in the Y axis?
Thanks!

gmask
04-23-2004, 06:56 PM
Originally posted by loden
Hey Gmask, my poor english is not good enough:)
Do u mean that I have to flip my camera upside-down scaling it in the Y axis?
Thanks!

Don't do that .. I think I also had problems with MR when I tried to group the camera and then assign it to a motion path.

For your situation I guess what you'd have to do is to scale up the model so that the camera can be inside the wall.

loden
04-24-2004, 10:37 AM
Ah, ok ;)
In other words there is not a solution to this problem? But say I have a shot with my camera outside the wall and I want to use FG, the only thing I can do is uncheck primary visibility for the offending walls?Or I could push the faces of the walls back to the camera.....Ok, this could be a solution, but I think it is also a bit limiting....Right now I have something like 15 shot of that interior with a camera setup like that....

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