PDA

View Full Version : some rendering problems



kthegene
06-02-2003, 08:15 AM
i was watching the conversation onf the GI flickering. i don't now if this is the same problem

i'm using two lights a spot and an area light, although i have had this problem in other renders.

it seems as though there is a real hotspot on my ground objects from the lights. it is really pixelated and kinda flickers....

i tried just about everything that was suggested in the other thread about increasing the rays using dithered motion blur low anti alias...

after a weekend of rendering.......... the same problem. i thought that i might have the specularity up too high so i turned that down...same problems....

......any suggestions?

kthegene
06-02-2003, 08:40 AM
oh ya,

when i render just one frame, everything looks swell....

Josh655
06-04-2003, 12:48 AM
I'm having the same problem. My volumetric lighting renders pixelated and everything else in the scene is razor sharp. I've tried all codecs and setting and still no luck. And as you mentioned, if I render one frame it comes out great but never in animation.

kthegene
06-04-2003, 10:00 AM
have you come up with any solutions so far?

is there anyone out there that can help.

it is obvious that other people don't have the problem
perhaps we are overlooking something obvious???

rabidgoalie
06-25-2003, 07:13 PM
I don't know if this will be any help to you, but I rendered an animation where I had similar results (bad flickering in certain areas, while others looked great). I tried many codecs to render with no success. Then I tried Divx 5.0.3 (http://www.divx.com) . It looked very good compared to the rendering that I did with the Cinepak codec. Not to mention the fact that a 12.4MB AVI was only 568KB with this codec. I was doing a quick render to get an idea of the quality of the final one.
There was still a small amount of pixelization, but not nearly as bad as the original! The only rendering that I did that looked really good was uncompressed. That is how I figured out that it was the codec that was the culprit. You can use the Divx codec for free for non-commercial use, but you have to pay to use it otherwise.
Again, I don't know if this will help you out because I was not using volumetrics, or even an extensive lighting rig. I know that you said that you tried all of the codecs Josh655, but the 'one frame comes out great' sounded sooo familiar that I had to mention this. I hope this helps out some.:)

toby
06-26-2003, 02:27 PM
somebody post one of these scenes, it sounds interesting, I've never had this problem

06-27-2003, 11:39 AM
As mentioned in lots of threads various.

If you're having problems DONT waste your render time by rendering straight to movie file (avi or mpg or whatever).
Render image sequences. then you can look at individual frames and see what the problems are, and if you have a crash you havn't lost all your rendering.
Its really quick to load the rendered images as a sequence, set them to composite as background, and run an 'empty' sceen with no anti-aliasing or anything to turn them into a movie.

NB Newbies, do remember that you still have to do the anti-aliasing in the original render, and render to your final frame size.

In turning an image sequence into a movie you can downsize ( to a lower resolution) and you can use the controls in the image editor to boost brightness/contrast/colour to rescue something where you got the lighting wrong. But you cannot increase the aount of information in the image, or smooth out bad movement or antialiasing. (It can of course be usefull to take lower res. movie files out for your records, or emailing to people)

(I suspect most of us only ever render direct to movie fill to make quickie previews of movements.)

kthegene
07-01-2003, 07:17 AM
i was just talking to a friend of mine

he found that he was having the same problem using the codec that comes as a default. he tried without it and had better results.

i have yet to try it out, but it sounds promising.

rabidgoalie
07-07-2003, 07:51 PM
I ALWAYS render image sequences for a final render. I DO use "quick" renders to see where I am at in a scene (I use a render farm, so that is an option for me). When I do this, I do see some artifacts in the render though (flickering and pixelization of some of the objects). That is why I suggested using Divx as the Codec for rendering the scene that kthegene was posting about. But I agree, [email protected], image sequences are the way to go if you have a compositer or you want to use the method that you described (really ingenius actually...I never thought of that!). Anyway, I still think that Divx is a great Codec to use, but you will still get some artifacts with it. The only way that I know of to overcome this (with Lightwave, 3DS Max, Maya, or XSI images) is to render to image sequences and composite them into a movie file in a compositer/DV editor (I missed the offer for DFX+ :mad: :mad: :mad: ).

toby
07-07-2003, 09:07 PM
Quicktime Pro can import image sequences and export artifact-free animations - for $30 bucks - and playback is better too

07-08-2003, 04:07 AM
Can we get this straight, where any degree of compression is involved;
There is no such beast as an 'artifact free animation file'.
To pretend otherwise can lead only to perpetual dissapointment, and anyway it can be difficult to breath with your head in the sand.
There is an level of artifacting that is imperceptable under the relevant viewing , which is what we strive for.
There is usually a level of artifacting which we end up with and hence consider acceptable.
Different codecs and setting produce different results depending on the relationships between colour range, detail & movement.
The 'best codec' will vary from animation to animation.
I think the best one can hope for is to find one that A) gives you the ability to change settings & be reasonably sure of what your changing, and B) gives you results that are acceptable to you for your specific type(s) of animation.
Personaly I use DivX most of the time.
but TMPGEnc for DVD creation - which is another can of worms altogether.

toby
07-08-2003, 06:33 PM
Originally posted by [email protected]
Can we get this straight, where any degree of compression is involved;
There is no such beast as an 'artifact free animation file'.

Sorry if my statement was too general...

Anything 'lossless' is artifact free, like the Animation codec. But no, I wasn't suggesting that anyone use a lossless codec for a finished product, I was referring to an animation that looks like, and if it is the finished product, might as well be, artifact free

iandavis
07-20-2003, 07:22 PM
two things.

ONE: I SO, SO, strongly recommend that any and all LW artists render their animations to a series of images. I switched over a year ago, and man it has saved my hump more times then I can count.

TWO: With volumetric lights check if 'texture' is set for the volumetric noise.. I know there is a setting, just like shadow maps that allow a resolution of the cast shadow. If this is active and the setting is something like 512, you will see pixelation and other crap...

cheers.

07-21-2003, 04:17 AM
Not quite; the texture setting in volumetric lights lets you apply a 3D variation in the 'atmosphere' that the light is illuminating. The texture is whatever you set it to be from the usual range of procedurals.Light beams look very bland without it, and I think it's usual to set a slight upward velocity for animations, and to use 'world co-ordinates' for the texture - otherwise if you have several light beams the smoke goes every which way !
- but it would only appear pixelated if you set something very weird and high contrast.
I presume the '512' refers to shadow map size, and I dont think you get much pixelation from that - a low number for shadow map does 2 things, first it messes up the shadow detail (like all other 'images' LW interpolates between the pixels on use - so the shadows can become sort of blurry-lumpy) second it decreases the memory used during the render. The number does not seem affect the rendering time at all - shadow maps seem to be calculated in 'full' detail, then simplified down to the number entered for storage.

iandavis
07-21-2003, 12:46 PM
YEAH!

what adrian said!

:D