Volume VOP inline code

[hellomrjack]

Hi, Im currently trying to make a Volume VOP node that will be able to strip out all densities except in a narrow range. I was thinking of using an inline code node containing something like this:

$outDensity=0.0;
if ($density>1.1)
{
   if ($density<1.2)
   {
      $outDensity=$density;
   }
}

The name for my output is outDensity.

Am I going about this the write way? Even when I just use:

$outDensity=1.0;

It wont just set everything to 1.0.

Thanks

Jack

[symek]

I can't help you with your code at the moment (no Houdini around), but I would suggest to take a look on VolumeRampSOP or using clamp() function or recreating volumeramp with vex's ramp parameter. Conditional statements (if/then) misbehave, since they output unfiltered data.

[hellomrjack]

Ah I've just worked out the problem, I was in render view and it wouldn't properly update until i was in the scene view. Ive managed to implement that code now. Im using it to analyse MRI scans.

[Macha]

Here is something silly I played with.

I like the ramp but the problem I often have with it is it's range 0..1 and the lack of control you have over the curves.

So here is a version of the ramp that uses bezier curves. Woohoo!

Just for fun, don't expect wonders.

Edit: The volumevop in that network serves no purpose. I forgot to delete it.

sillyvol.hipnc

Edited April 27, 2011 by Macha