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Posted: Fri May 30, 2008 10:44 pm
by BbB
Hi Dr. Why did you use a carpet map for displacement and not a greyscaled version of the grass texture?

Posted: Fri May 30, 2008 11:38 pm
by drBouvierLeduc
@BbB : I don't know why, but with carpet map it looks much better.

Posted: Fri May 30, 2008 11:50 pm
by pxl666
did u guys see www.crazybump.com ? this piece of software will drop ur jaws down heheh

Posted: Sat May 31, 2008 12:01 am
by suvakas
I made one grass test too. It needs at least one more sub-div level, but I'm on a very old machine at the moment.

Posted: Sat May 31, 2008 12:20 am
by pixie
@suvakas:
It looks at the same time fluffy and poinky. I don't know weather I would lay down or stay well clear of it!

Posted: Sat May 31, 2008 12:23 am
by suvakas
Yeah, the strands in the foreground are quite sharp. I think the higher subdiv would make it look a bit better.

Posted: Sat May 31, 2008 12:28 am
by BbB
Perhaps try with less displacement. And also adding darker and lighter spots on your displacement maps to vary the length of the grass. I don't think it necessarily needs more subdivision.

Posted: Sat May 31, 2008 12:56 am
by suvakas
I'm still towards more subdivs.
More tris = thinner strands = softer look...I think.

Posted: Sat May 31, 2008 1:41 am
by BbB
Dunno. What about slightly less displacement.
The Doc's grass looks like it was freshly mown...

Posted: Sat May 31, 2008 3:50 am
by suvakas
BbB wrote:Dunno. What about slightly less displacement.
The Doc's grass looks like it was freshly mown...
Yes, shorter would be nicer, but I wanted to test more weed type of look - longer grass.

Posted: Sat May 31, 2008 3:58 am
by BbB
In that case you might really be better off with instanced meshes. Especially if you're going to cover such a large terrain. Then again, it's hard to bend meshes to a terrain like this one.

But as a displacement test, of course, I find it really interesting. Maybe it's just the case that realism really depends on the map you're using...

Posted: Sat May 31, 2008 6:50 pm
by pxl666
maybe we should announce "perfect grass field competition"? such threads are so productive and often result as great tutorials for newbies.
personally i would go for many instanced and different alpha mapped planes as much more memorywise and more "photo-like"

Posted: Sun Jun 01, 2008 3:57 am
by drBouvierLeduc
Wanted to see if displacement worked with blended material. It does !
The current preview scene is not really appropriate with that kind of material, so I replaced the sphere with a simple curved plane (the circle around the logo is where the plane intersects with the sphere).

To create the displacement map, I followed that tutorial : it's a height map based on real geometry, made in blender. It takes slightly more time than creating a map from a photography, but it's much more accurate. Though in that case, a 16bit images wouldn't hurt.

Regarding the grass, I second BbB, I don't think you can create nice-looking long grass with displacement, the leaves are too "straight". It's ok for a short grass, you know, where you play golf.

Posted: Sun Jun 01, 2008 4:59 am
by zsouthboy
Fence looks great - you modeled the fence section and then rendered a heightmap? That's something i hadn't thought of before..

Posted: Sun Jun 01, 2008 5:26 am
by drBouvierLeduc
I'm posting that one to show an issue encountered with 8-bit image.
Here I think a 16-bit image would solve the problem.