Forest Pack scatters grass in a drastically different way with compared to CPU

[Alex_M]

Hi. I've got grass surface scattered with Forest Pack. It renders fine with CPU, but with GPU the scattering pattern changes drastically. See screenshot below. Why does this happen? By the way, I've got a texture that drives the scattered objects' scale. Maybe this is not fully supported with GPU?

[fixeighted]

If the map you're using is procedural then that would cause this, as GPU does procedurals differently.
If that's the case then this solution may fix it https://forums.chaos.com/forum/v-ray...p-inconsistent

[Alex_M]

The map is a texture in JPG format loaded through VrayBitmap. Sorry, I forgot to mention this.

[fixeighted]

That's odd then. I've used images for scale recently and had no issues, plus I just tried this with a random map and it's fine also, so maybe
something else is conflicting.
Can you post the map you used maybe?

[dlparisi]

OT-that grass looks really great...is it a standard FP preset or something you worked up. Even the patchy one looks pretty nice (at least for patchy grass). I've always been a little disappointed with the standard preset "lawns" looking too regular and unrealistic - wondering if I should revisit them.

[Alex_M]

Hi, dlparisi . The grass is an asset I bought from 3dsky and modified the diffuse textures a bit. The unevenness comes from the stripes texture used in the scale slot of the 2 Forest Pack objects.

[dlparisi]

Hi, dlparisi . The grass is an asset I bought from 3dsky and modified the diffuse textures a bit. The unevenness comes from the stripes texture used in the scale slot of the 2 Forest Pack objects.

As I suspected. Thanks for the explanation.