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View Full Version : FiberFX 11.6 vs 2015



Chris Jones
09-10-2015, 09:35 PM
The same scene rendered in 11.6.3, then 2015.3:

129684

I've already established that Fiber Width renders incorrectly in 2015 when using Volume > Stroke, so I made some small adjustments to try and compensate for that, but there's something else going on here. Something's changed with the luminance, but what's really bothering me is the grid-like interference pattern that dissolves patches of fibers. What might be causing this?

spherical
09-10-2015, 10:45 PM
Seems not so much dissolves but enhances. IOW, there are fibers floating next to the cheek. The bright section on the neck is offset (perhaps only looks that way in perspective) from the bright section on the cheek; although the floating one does appear to line up with the second bright section close to the ear. I presume that there is no correlation to geometry boundaries?

Chris Jones
09-11-2015, 12:17 AM
Seems not so much dissolves but enhances. IOW, there are fibers floating next to the cheek. The bright section on the neck is offset (perhaps only looks that way in perspective) from the bright section on the cheek; although the floating one does appear to line up with the second bright section close to the ear. I presume that there is no correlation to geometry boundaries?

It appears to be actually clipping it - there are no fibers to be seen at all if I zoom into a blank patch. The pattern doesn't quite correlate with the geo, and as you can see it moves around quite a bit:

http://forums.newtek.com/attachment.php?attachmentid=129686&d=1441951525

spherical
09-11-2015, 03:13 AM
Hmmmm. In this latest image there is a triangular pattern in the right foreground. First thing that jumped to mind was either non-planars or duplicate geo. I know you're far and above remedial stuff like that but might lead somewhere useful. Now that I re-look at the 2015 first example, the pattern is also evident in the cheek on the far edge there, too, but is slightly different from the new render. Missed it before, but seeing the recent render queued me to it. Is there an extra layer turned on that shouldn't be rendering?

Skywatcher_NT
09-11-2015, 03:25 AM
I have a similar problem. Tried to track it down and seems to be the Shadow Depth in the FFX panel that is involved, also maybe the Self shadow.
Try to set Shadow Depth to 17 vs 16. When I do this the problem is gone ( at least most of it ) but the fur gets much brighter so I compensate this
by increasing the self shadow. It's not ideal but works for now.
Strange thing is that it's not on all objects. I have another character where I don't get this problem.
Definitely a bug. And I was so happy that the Bias Vmap finally works...

Chris Jones
09-11-2015, 06:01 AM
I managed to reproduce it with a new scene:

129688

Shadow Depth does indeed appear to be inextricably linked to the problem. I had to dial it up to 18 to make it go away in this instance, and around 22 in my main scene. Lower settings make the pattern more apparent and at 0 hardly any fibers show up at all.

I don't actually even want the shadows, but setting Self Shadow and Cast Shadow to 0.0% doesn't do anything to fix it. Shadow Depth frequently reverts to 16 as well for some reason, along with some other settings (another bug I think). To combat the brightness issue I have to turn the Tip Transparency up to 3000 or so.

The render looks radically different in 11.6, and who knows what other side effects are being caused by juggling all these workarounds, so I'll send through a bug report.

Thanks for pointing me in the right direction!

(c:

spherical
09-11-2015, 09:59 AM
Thanks for posting a scene to test with. I'm just dipping my toe into FFX, so not of much help on esoteric stuff regarding it. Glad you got a direction to go in that surely will result in a fix.

Chris Jones
09-11-2015, 07:07 PM
I was close to having to revert to 11.6, but I've got it looking roughly the way it used to now, albeit with some very strange settings. Took a couple of weeks to get there though!

spherical
09-11-2015, 10:58 PM
Yikes! Only LW3DG knows, or perhaps not, what they changed to make that huge a difference.

Snosrap
09-12-2015, 10:09 PM
Please report this to NewTek Chris. Of all people I think you can get their attention. :)

Greenlaw
09-13-2015, 02:14 AM
That does look pretty weird.

Shadows are cast from voxels and if the resolution is not fine enough, it can cast blocky shadows. But this looks pretty extreme to me, especially if Shadow Density set at 16. IMO, there's something else going on here and you should submit it.

Just wondering but what kind of light are you using? I know changes were made in 2015 to make shadows more compatible with multi-sample lights--for example, in 11.6 and earlier, if you were using Dome or DP Infinite as your light source, the effect of Shadow Depth would top out at around 20 or so. (This is why the fur in the Brudders excerpt flickers slightly; these scenes were primarily lit by one or two Dome lights and rendered using 11.5.1. I wound up hammering the shadows using Re:Vision FX De:Noise, and calling whatever flickering remained our 'look' but obviously it's not a look you normally want.) Admittedly, I haven't fully tested lighting FiberFX in 2015 and maybe this feature is still not quite right under certain conditions?

FYI, I didn't use FiberFX in 11.6 because it didn't generate motion vectors properly like 11.5.1 did, but this was fixed for 2015. Definitely report stuff--the multi-sample lights limitation and the broken motion buffer issue were things I reported and LW3DG got on it right away.

G.

Chris Jones
09-13-2015, 06:36 AM
Already reported. I'm using area lights but the same thing happens with any light type.

Greenlaw
09-13-2015, 01:19 PM
Okay, thanks for the heads up and for reporting the issue. At the moment were busy upgrading our mocap system and I haven't focused much on FiberFX for 2015.3 as I'd like to. The FiberFX render tests I've done so far with 2015.3 have been fairly simple but I should push a fully lit production scene through the farm this weekend and see what happens. We're going to need this pretty soon after all and I have no intention of going back to 11.5.1.

G.