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View Full Version : LW 10.1 Radiosity Errors Galore w/ Morph



Chrusion
01-21-2012, 10:48 AM
Can someone tell me what the heck is causing such massive and grotesque radiosity artifacts in the attached video clip?

Specs:
Object layer is a simple, single morph using morph mixer.
The object at 100% morph has all the panels arranged in an inverted V, morphing to all panels flat horizontally.
The object layer is also being translated downward on Y.

Animated Radiosity Cache baked at 5 frame step (every 5th frame renders artifact-free) and saved to the /radiosity folder in the content directory (all render nodes see/use the cache).

The rest of the 800-frame anim renders without these temporal GI sampling interpolation artifacts, although there are a couple of spots on other layers of the object that have some flickering shading that I attribute to the presence of this morph obj layer affecting the cache.

What option might be enabled or one not checked that's to blame?

GI settings:
Monte Carlo
Interpolated = on
Use Transparency = on
Use Gradients = on
Use Behind Test = on
Int. = 100%
IB = 2
RPE = 250
SBR = 10
AT = 40
MinPS = 1
MaxPS = 10
Multiplier = 50%

Camera = Persp.
AA = 1
AS = 0.03
PRMB = 1 pass 70%

Danner
01-21-2012, 11:55 AM
You might need to add all those missing inbetween frames to the cache on that part of the sequence.

Animated cache is really painful because testing can take so long. A cleaner sampling can be had with more RPEs (say 1000) and higher MinPS (15) and MaxPS (100). This will result in similar calculation times but the look is different (less noise but also loss of smaller details).
I also see you have your multiplier at 50% that is not a good idea for animated cache if the advice from Exept's radiosity guide for LW9.6 Still Holds true.

Chrusion
01-21-2012, 01:21 PM
Ah! Good work around (baking at 1 frame step for the 100 frame duration of this part of the anim). I'm also rebaking at the higher GI settings suggested.
Thanks.

Still, I wonder if this is a bug, "feature," or limitation of the GI inter-frame interpolation code to deal with morphing verts.

.

RebelHill
01-21-2012, 01:25 PM
interpolated GI doesnt support morfs, or any kind of deforming geometry. You will get errors.

Chrusion
01-21-2012, 01:27 PM
multiplier at 50% that is not a good idea for animated cache if the advice from Exept's radiosity guide for LW9.6 Still Holds true.
Yes, great guide, but he really needs to at least change the title to reflect the current version of LW so that it appears relevant and not out-dated. And while at it, update the change/addition/subtraction of option names/labels.

.

Chrusion
01-21-2012, 01:33 PM
interpolated GI doesnt support morfs, or any kind of deforming geometry. You will get errors.
Thanks for the confirmation. Now by "interpolated" you mean temporal, right. That is, it works when baked at 1 frame step, but not when temporal, inter-frame interpolation (frame step greater than 1) is used, yes? I say that because every 5th frame (the frame step) had no artifacting, so stands to reason that if set to 1 during this part of the anim that no interpolation for missing frames is done, so the GI is locked down on each frame, thus no rendering artifacts.
.

RebelHill
01-22-2012, 04:37 AM
No I mean if u have interpolated checked... frame step is irrelevant. Interpolated GI will only work properly with moving camera, or non deforming moving objects (objects being pretty tricky to get cached correctly). Deformations and moving lights are a no go.

Surrealist.
01-23-2012, 05:05 AM
Yep. No dice.

The only "solution" is to brute force it with no interp. Kinda slow in LW. But for deformations there is no other choice. In fact most programs struggle a bit with this. One thing you can do if you want is render out the background with interpolated cache and then render the deformed object with some other method and composite the deformed object/shadow.