By John A. Johnson (Johnny) (65.58.46.184) on Monday, January 20, 2003 - 07:37 pm:

I have been working on a scene to improve my lighting chops, and set up a 120-frame animation in which one of the objects (glass sphere) moves through the scene. there are two other glass objects in the scene, a 'floor' and 3 lights: key, fill, and rim. Only the key light affects caustics.

the caustics of the glass objects appear to be flickering as tho the light affecting them is vibrating, but there is no kind of animation on the light.

Does anyone know what the source of this unwanted flickering is?

Johnny

By Wizlon (Wizlon) (194.176.153.162) on Tuesday, January 21, 2003 - 02:50 am:

I had a similar problem with radiosity, the only solution i could come up with was to cache the radiosity solution - this is applicable to caustics also, but if your animating lights/objects this might not be possible.

By John A. Johnson (Johnny) (63.215.119.25) on Tuesday, January 21, 2003 - 07:27 am:

sigh...so, if we animate lights or objects which affect or receive caustics, we're stuck with this flickering?

hard to believe that people would do serious animation not involving caustics!

J

By Russ Tingley (Rtingley) (67.119.29.26) on Tuesday, January 21, 2003 - 02:52 pm:

post your work in the "gallery" forum or browse through it... you may get some insights about this specific issue... i seem to remember someone having a simmilar problem a few months back... though for the life of me I can't remember where.

By John A. Johnson (Johnny) (199.4.18.2) on Tuesday, January 21, 2003 - 03:10 pm:

good suggestion..I'd thought about doing that.
I'll post back here if I discover a fix or workaround!

J

By Russ Tingley (Rtingley) (67.119.29.26) on Tuesday, January 21, 2003 - 04:16 pm:

Ah, I finally found it... go to the post in this Mac forum and look for:

Hypervoxel flicker...maybe an explanation
12/20 05:09pm

hope it helps.

By John A. Johnson (Johnny) (166.90.69.145) on Saturday, January 25, 2003 - 03:38 pm:

OK...I did some extensive render tests involving caustics...I cranked the accuracy (to 10000) and the antialiasing to enhansed extreme, and, while the flickering was lessened a bit, it's still maddeningly there.

I can't imagine a) that a filmmaker would do without caustics in a scene that required them, and b) would put up with flickering!

Caustics that flicker are unacceptable...Newtek mentions the flickering in their manual, and I get the feeling that theirs may be a 'that's the way it is' position, but I'm sure they'd like to have flicker-free caustics (and radiosity and hypervoxels, etc.)

how would you categorize this? as a bug? a broken function? what's the approach here?

J

By John A. Johnson (Johnny) (166.90.69.145) on Saturday, January 25, 2003 - 03:41 pm:

By John A. Johnson (Johnny) (166.90.69.145) on Saturday, January 25, 2003 - 03:37 pm:

OK...I did some extensive render tests involving caustics...I cranked the accuracy (to 10000) and the antialiasing to enhansed extreme, and, while the flickering was lessened a bit, it's still maddeningly there.

I can't imagine a) that a filmmaker would do without caustics in a scene that required them, and b) would put up with flickering!

Caustics that flicker are unacceptable...Newtek mentions the flickering in their manual, and I get the feeling that theirs may be a 'that's the way it is' position, but I'm sure they'd like to have flicker-free caustics (and radiosity and hypervoxels, etc.)

how would you categorize this? as a bug? a broken function? what's the approach here?

J

By Christian Avalos (Cavalos) (64.213.56.192) on Saturday, January 25, 2003 - 04:33 pm:

I think we can understand this kind of things as a "rendering engine weaknesses". It happens all the time with radiosity, it happens with real lens effects and refraction, it happens with texture filtering and many more.
I really think this is a serious problem for LW and for me, I can live without multiple undos in layout, UV´s, non integrated Modeler/Layout, slow AA, etc. But this is too important.

Best
Christian