Cinerender - another grass material problem

[Anonymous]

Hi all

i've been able to produce a correct grass material rendering for my office's past projects without any problem.
The 3D grass showed up just fine in each of the projects.

Somehow, on my current project, the 3D grass effect didn't show up

What i've done:
1. Turned on the 3D grass option in the surface material setting
2. Turned on the 3D grass option in the rendering setting
3. Not changing any preset whatsoever from the previous rendering

After a few attempts of trying to find out the source of the problem, i've found that:
1. if i set the 3D grass material on a single surface (top side) of a mesh object, the render output showed up just fine without any problem
2. but if i set the 3D grass material on a single surface (top side) of a slab object the 3D grass effect didn't show up in the render output

I don't know if this is a known issue, but does anybody here has had the same problem?
Any other solution other than the one i wrote?

Thanks in advance
Cheers
-JS

[David Maudlin]

John:

I am not getting this problem, 3D Grass on both Slab and Mesh. You could substitute a Mesh for the Slab in your problem project.

David

[Erwin Edel]

Does the slab have curved edges maybe? Or something else that a mesh won't be able to do that would result in weird behaviour?

[Erwin Edel]

BTW, I found that liberally applying the 3d grass to any and all grass surface increases rendering times dramatically, so I've gone for a method of having 2d grass as the default and applying a single morph surface with a 3d grass material to the areas close to camera where you would acutally see the 3d effect.

That said, the Netherlands is very flat, so I don't have to worry about changes in terrain height ussually.

[Anonymous]

Hi David, Erwin,

My slab is a composite slab with no custom edges whatsoever, and for the moment, my solution is exactly like Erwin said, i have to go with the morph surface with 3D grass mat. on top of the slab with a plain 2D grass mat.

Maybe my problem is a "project file" specific problem, i don't know yet, i'll try to do some of the following tomorrow and give you guys feedback as soon as i'm finished:

1. Using default AC18 template file and material on generic slab and hit render
2. Using default AC18 template file and material on Composite slab representing greenroof construction like the one on my project file
3. Using my project file, then delete everything else except the Composite slab and hit render

i'm just curious if it's a bug or something, because if it is, better if we detect it sooner than later 😉

Cheers!
-JS

[David Maudlin]

John:

No issue with using a Composite Slab here.

David

[Cosminn]

Hi everyone, I am on the same position like John.

John, any luck with your research?

Thank you

[Cosminn]

Same thing, a composite slab.

[Anonymous]

Hi Cosminn, it's been a long while since i was having that problem, can't remember exactly what the cause was, after starting all over from the default grass material on a default template, everything works fine, and it's not happening anymore, guess it's the miss-tweaking of surface settings or view map setting of my camera on my part

Maybe you should try that too, or try to import surface attribute of grass surface from another file (preferably fresh from default to exclude any unwanted variable).

Oh and try to render the objects side by side as previously been shown by David.

The only problem i came across with recently with grass material was on a morph surface resulted from a boolean operation, somehow the resulting morph outside face was considered inside face, so when i rendered my scene the grass wasn't there at all untill i noticed that it was there, only upside down :s

[Cosminn]

Thank you John.