checker board grass problem

[PixelJockey]

My grass displacement is turning into a checker board. Can't figure out whats wrong with my settings here. I've used the same map and settings before without a problem, but I must be missing something here. No textures have been applied at the material level just 2D displacement. If I enable "filter texmap" the checker pattern is less noticeable but I still get noticeable banding. Any help here would be greatly appreciated. Thanks.

Unfiltered map:


Filtered map: Note: I also chaned AA to Catmull-Rom on this one.

Setting:


Displacement map:

[J_Bug]

If you take your map into PS and perform an extreme Gaussian blur on it you can see why it's doing this (there is an obvious light corner). Not sure how to make a properly random map but maybe use one of the many floating around here on the forum that have worked for others.

--Jon

[Dynedain]

if you use a max noise map instead, it will be procedural and have no repeating bands....thats what i had to do

[PixelJockey]

J_BUG,

I thought that might be the case too. I rotated the map, did a little cloning in Pshop but the pattern came out the same.

Dynedian,

I've tried using procedural but It seems to take much longer because I have to increase the subdivisions to something like 256 to get a nice "spikey" look.

[kippu]

i just noticed...... and just curious .....but there are 2 uvw map modifiers .....why??

[Dynedain]

i just noticed...... and just curious .....but there are 2 uvw map modifiers .....why??

In my case, I had 2 UVW maps, one to control the size of the map used for displacement, and one to control the texturemap

[PixelJockey]

Yep. I had one map for the displacement and another for textures.

After smacking around that bloody noise map for a few hours I finally grabbed the maps Goncalo posted:
http://www.gprospero.com/vray/grassmaps.zip

Worked like a charm. Now why did I try to reinvent the wheel? Oh well, it was a learning exercise.

Here is a current WIP. Still working on lighting and materials.