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Nangleator
10-08-2008, 12:45 PM
I've been trying to do a field of grass/wheat, and I've made lots of progress. The low res renders look good. When I like what I see and start bumping up the resolution, a few bad things start happening.

My fiber density goes way down as I increase resolution.

My fibers become hair thin, when I'm aiming for coarse fibers.

At a certain point, I get a CTD.

Are the settings in FiberFX supposed to be resolution-dependent?

Nangleator
10-08-2008, 02:32 PM
My hair is thinning! These 3 images had the same settings, except the resolution was doubled each time. (The larger files were then downsampled so they all match in size.)

Note the thinning effect. I'd be fine with that, except upping the fiber thickness doesn't fix it!

http://home.comcast.net/~david.nangle/pic/a.jpg
http://home.comcast.net/~david.nangle/pic/b.jpg
http://home.comcast.net/~david.nangle/pic/c.jpg

spiroz
10-08-2008, 04:25 PM
This is due to the technique FF is using. My impression is that one fiber is one pixel (although antialiased) - no more, no less.
Instead it weights between thickness/density/transparency.
Using voxels might behave quite different (especially in render times).

evenflcw
10-17-2008, 02:26 PM
Interesting and unfortunate discovery. It seems the FiberFX implementation is dependent on alot of stuff which it should really be independent of - such as mesh density and now also apparently pixel size or resolution. Hopefully NT can, for starters atleast, figure out an ad hoc method to correct for these inconveniences (and no doubt sometimes dealbreakers).

*Rendering as volumetric didn't seem to help. (using LW9.5 demo though)