Population placement issues

[Balletdude]

I seem to be having nothing but issues lately, could be I'm trying new techniques that I haven't tried before to this degree. But it's always a learning experience

I've created a riverbed and added water, using the technique in the slit canyon tutorial by terra tuts on here.

I've now tried to add a population of grass to the image but when I try to plug anything into the density shader to mask out the river area, it takes the simple shape shader into account for some reason ie just a straight rectangle through the image, instead of using the shape of the river. This also happens if I use a distribution node and set the altitude settings.

I've even placed the grass way above there terrain and still have the same issue. any ideas?

[KlausK]

hi, something like that, I guess.

[Balletdude]

Yeah like that, but I can't get it to follow the near bank like you have

[KlausK]

The experts will surely find a less cumbersome solution to this, but this works.

First, set the node on the "Anchor" / "Sit on terrain" tab of the "Pop Grass01_2.tgo" to "Redirect Shader".
Not the "Compute Terrain".
That feeds the shape of the river into the population.
If you use the same node in the "Use density shader" it already populates the plants to the edge of the riverbed.
But somehow one has to raise the "Object spacing in a,b" quite high to fill the space.

Because of that I tried to get a mask out of the "Redirect shader".
I won`t describe how, take a look at the project.
Btw, I changed a lot of settings in your file to get faster response and renders, so be sure to use your own tgd again and rebuild what you need.

Hope that helps.

CHeers, Klaus

[Balletdude]

Thanks. Yeah I tried to get a mask out of the redirect shader as well

[Dune]

It's usually better to use a warped simple shape for a river, and use that (warped) mask also for pops. Your setup is a bit unorthodox, with the redirect at the end.
There are several setups to be found on this forum.