I'm rendering an i3d file with 3d Texture Cloud .
when using adaptive step I get these square artefacts on the edges of the cloud
(see attached pics)
I tried to change resolution,compression,variance when generating the texture but no luck ..
searching in old posts it seems to be a known problem , but didn't find any solutions.
I'm using 8.1.666 on gentoo.

Hmm, I wonder if this post is related? They seem to exhibit similar artefacts…
http://www.sidefx.com/index.php?option=com_forum&Itemid=172&page=viewtopic&t=6043 [sidefx.com]

No solution yet

I always get weirdness from Adaptive these days, I believe it's a bug…

Cheers,

peter B

well thanks . too bad.
my density is very sharp (ie binary 0/1 values)
if I blur the density a little bit it's better but still not satisfying.

Ahhh well binary density will likely always have problems with a ray marcher, though the Adaptive Step is still a separate problem.

Cheers,

Peter B

jason , I tried to render without mycropolygon (mantra -r) but it's even worse.
thanks for your answers.
luc

Here's a couple of things to try:

In the 3D Texture Generator ROP:

• Reduce the Oversampling parameter to 1
  Change the Variance parameter to 0 When the i3d file is too small (in resolution) you tend to see blockyness all over, so I don't think that's what is happening in your image. I'm guessing that Oversampling to “1” will fix it. It removed the black tiles I was seeing in my alpha's. (ahem: Thanks goes to MarkE & Andrew!!)
  
  cheers,
  ben.

oversampling is already at 1
I will try the variance thing asap.

thanks
luc

ben simons
It removed the black tiles I was seeing in my alpha's. (ahem: Thanks goes to MarkE & Andrew!!)

I thought they'd fixed those peskies. Oh bugga!