Grassy area - scatter test

[simmsimaging]

Well, that could be a problem for your man Simon, but not for me

We only do stills so I have no idea how you would go about animating something like that regardless of how you do the grass.

b

[PIXELBOX_SRO]

mayas paint effect could probably do that, since they can eb animated, however, i dont see the point for raising that up.....

[Da_elf]

more or less all im saying is sure... animating grass and plants interacting with characters is cool. but its not really needed is it. It was only after the 2nd time of watching Bolt that i noticed that there was no plant interaction with characters. was more focused on the story.

[duke2]

That is correct. We remade the grass as separate blades so we could create better variation when needed, and follow contoured terrain better. I still have some clump proxies made though, and for some projects I can see mixing those in too.

We made 3 different basic blades (long/thinner through shorter/thicker). For each one we made 5 basic variations (minor length/width changes and major bend changes). I also made a duplicate set of two of these and nipped off the top poly's to make a set for fresh-cut grass.

Each one is assigned to a different VRS object and each one is given a different seed number.

There are also 3 weed objects that are assigned to 3 more VRS objects. In this test I think there about 150K proxies per VRS object, except for the weeds which were more like 300-500 each.

Render times have ranged a bit between 30 minutes and 3 hours depending on various settings like with or without DOF etc. That was using a variation of the universal method (BF/LC) and rendering with DR across 4 i7 920s, a Q6600, and an Xeon 5355. That was running between 3K and 4.5K wide.

I think the render time could be reduced a lot. I didn't even really try to optimize these tests - my goal was quality and I was not worried about times yet. I think there are quite probably 2X the proxies I actually needed for the scene, and I did not use the camera clipping function so many are not even in frame. I also used quite hi-poly blades, which are not really needed at this scale. We may make a lo-poly set for this sort of distance, but for my work 2-3 hour renders are acceptable (we only do stills )

Hope that helps.
b

Rendertime might not be an issue, but memory is. I mean, there's an upper limit to how many proxies you can scatter (I think the developer said it was like 20 million), so you may run into problems on larger sites.

[simmsimaging]

Maybe, but I think most areas that are large enough to need more proxies will also probably not need this much detail, so you can fade the proxies into a 2d map or something like that pretty easily. Maybe not, dunno

[voltron7]

the new version has a camera clipping feature

[PIXELBOX_SRO]

would it be possible to create a vector displacement map from these proxied grass blades???

[simmsimaging]

would it be possible to create a vector displacement map from these proxied grass blades???

Good question. I have no idea but it might be really handy if it could be done.

b

[skogskalle]

Even if you could, getting the same detail using vector displacement would probably use more memory than the scatter-version. Ive never been able to get really crisp and nice displacement with vector disp without having the ram-usage go through the roof. (but that could ofcourse be a user error (most likely) and not a limitation of the vector disp.)
k

[ShaunDon]

Hey guys!

I've really enjoyed lurking on this thread and wanted to join in but didn't have an excuse until now. I've got a project that we need to scatter a large amount of field grass over -- the last time we had to do that we used VRayFur, but the posts here convinced me to try VRayScatter and it's been a lot more effective once you get the hang of it.

Now I've run into a problem that I think may be a limitation of Scatter and I can't come up with an elegant solution. I want to be able to blend in a controlled fashion between grass that's greener and grass that's dry and sun baked. The issue is that I can't seem to find a way for the grass to take on UVW mapping coordinates from the scatter surface (similar to the way VRayFur works), so the only way I've been able to blend between two diffuse color maps is to use procedural maps mapped by world coordinates, but then I don't have any control.

Ideally I'd like to paint a vertex map channel on scatter surface that I can use as a mix map mask. I've been using vertex painting to define the VRayScatter distribution area, scale, and rotation to great effect, but from what I can tell the material can't use the scatter surface to map materials in the same way. Has anyone tried to do something similar and found a workaround?

Here's my render, with a split between the two different grass colors I'm working with.

Cheers!
Shaun

[jacksc02]

Shaun,
Did you check the UVW mapping on the grass before you proxied it?

[ShaunDon]

I do have mapping on the proxied grass for the vertical value of the blades, but once it's burned into the proxy it's going to reproduce the same UVW coordinates for every instance of the scattered object. Actually now that you put it that way, it makes sense that this is a limitation of VRayScatter since you can't affect the UVW of a proxy, at least not through modifiers. The UV for the area blending needs to be applied over all the scattered proxies, but it's probably not possible the way I'm doing it -- but I'm thinking there's a way to do it with VRayScatter that I'm not understanding.

[Karba]

Hey guys!
but from what I can tell the material can't use the scatter surface to map materials in the same way. Has anyone tried to do something similar and found a workaround?

Here's my render, with a split between the two different grass colors I'm working with.

Cheers!
Shaun

Use VRayScatterTexture in diffuse slot of grass material with option useObjectColor on.
In this way VRayScatterTexture will use Color from VRayScatter setting.

[duke2]

Use VRayScatterTexture in diffuse slot of grass material with option useObjectColor on.
In this way VRayScatterTexture will use Color from VRayScatter setting.

A very minor thing, but "useGizmoColor" would make more sense.

[Karba]

A very minor thing, but "useGizmoColor" would make more sense.

That is interesting idea. I will think about it.
Thank you.