[kami]

Grass seems to always grow perpendicular to its geometry.


This is not what I would expect in reality
What could I do if I want the grass to always grow vertically? (for example on slopes)

[polynurb]

What could I do if I want the grass to always grow vertically?

realize the painful truth of rgb colormapping the angle slot.

[polynurb]

it is quite well documented in the help, but pretty tough, since first, everything is strictly world, and secondly color shifts can be so subtle, it is impossible to see with the bare eye what will be the outcome.

it is math done wit color.

besides that one can do pretty cool things with angle maps.. hope this will bey a bit easier in v3. (local coordinate override/object)

[kami]

AAAAARGH, I was really hoping that wouldn't be the response
my problem is that I have a landscape design which contains a lot of rounded and polygonal shaped cussions


This would be a huuuge amount of work to get it right .... Or would it be possible to render out the normal map of the top view and modify it?

[Bubbaloo]

Kami, what main 3D software do you use?

[kami]

Rhino3D! I know the geometry is a bit sloppy, but I'll correct that in another step.

But to be honest, I think the whole solution is not that difficult in my case ... I tried playing around with the normal map. And since it is corresponding to the world coordinates, it is enough to use a texture with the solid color R=128, G=255, B=128 to get the grass always growing towards the sky Not sure if that is already the final solution, because I have to experiment with some color noise to get a slight variation back in, because the variation value seems to be ignored now.

[Bubbaloo]

I asked because I was going to recommend scattering grass blades as an alternative method, but I'm not sure if Rhino has the tool. In Max, it's possible to use a particle system to scatter instances on a surface with a multitude of orientation options.