Twist and Shear with the Stones Shader

Started by baizewizard, April 10, 2010, 03:33:22 PM

Previous topic - Next topic

baizewizard

Hi Guys

Having a little trouble when experimenting with the stones shader.
I would like stones in the foreground with a heightfield behind.
I have a nice heightfield that I have created using the Twist and Shear shader.
Trouble is I can't seem to restrict it's effect to the heightfield only.
It also affects the stones in my foreground.
I have tried setting the Base Altitude in the T&S shader but that doesn't seem to help me.

Any tips?

Cheers

TheBlackHole

Put up a few pics. A render and some screenshots. Maybe one or two of the node network.
They just issued a tornado warning and said to stay away from windows. Does that mean I can't use my computer?

Oshyan

"Fake Stones" is simply a displacement effect, so it will be affected by "twist and shear" unless you specifically mask them out. The altitude selection isn't going to work unless A: your fake stones are only at a particular altitude (note: this is not altitude above terrain surface, it is absolute altitude) and B: you use a Compute Normal to make sure the terrain normal is correct after your Twist and Sheer displacement.

A render of your scene as it is now might help illustrate your problem.

- Oshyan

baizewizard

Thanks Guys

I have attached a jpeg of the current scene and my tgd.
I am experimenting with DandelO's wonderful stones shader and I wanted to simply litter the foreground with stones.

Any help greatly appreciated.

Tim

Oshyan

In this case your stones are at a different altitude than your primary terrain form, so you should be able to use a Distribution Shader and control by altitude. But what you have to do is limit the Twist and Shear, not the Fake Stones, because by the time Fake Stones is applied, the Twist and Sheer is already in effect.

- Oshyan

neuspadrin

I did a bunch of playing around with fake stones and made a pdf from what I noticed the various values do:
http://www.mediafire.com/?1mmmjg54mzn

Feel free to dig through to get an idea what the various values do.