I have an idea for a render i am standing on a riverbank between 2 canyon walls. as i look downstream i see a tall alpine snow topped mt. my question is how to create, should do the following
use a heightfield merge shader, one with a mt and the other one a canyon or
add a mt using frankb method to a heightfield with canyon walls ad if i use the merge shader idea is it best to sstack the fields or use the mergeshader itself, as i have used oe of these before ay advice etc would be appreciated
I'd use 2 or 3 heightfields:
1 + 2 = left/right canyon wall. Create two heightfield adjacent to each other by using the coordinate settings in the heightfield shader (red shader).
Add a heightfield-operator "adjust height" in between the heightfield generate (green) and heightfield shader (red), for both heightfields.
Increase the "add height" value to the height of your canyon wall.
You can use a 3rd heightfield for the mountain if you'd like and place that far away in the background.
You can also use a powerfractal based terrain and use a distance shader to blend the mountaineous terrain in over distance.
You will need a distance shader anyway because you likely want to exclude the surfacing/texturing for the canyon from the mountain.
It would be most logical to blend in a terrain over distance and use that same distance shader to blend in the surfacing/texturing for the mountain.
The best way to do that is to connect the compute terrain to 2 separate surface layers without colour and merge those.
Surface layer one = canyon surface
Surface layer two = mountain surface
Connect the distance shader to the blend inputs of the surface layer and set "inverse blendshader" for the canyon surface.
This approach would be the first thing I'd try.
Let us know how it goes.