proper height map in a shader

[anupamd]

I cant believe Im having issues with this simple shader:

Trying to get a height map (well its actually a z-depth map) that has a very narrow range.

For example my furthest point is -2 on z and the nearest point is +2 on z. I want to generate a greyscale map that has a value from 0 to 1.

The math Im using is just pz-farplane. in this example our values will range from 0 where z is the farthest point and 4 where the point is at the near plane.

if I use a fitrange and remap the values 0->4 to 0->1 i should get a nice smooth ramp. But that is not working.

Is there a better way to do this or a shader that already exists? Thanks,

[anupamd]

bump.. anyone? its just a simple heightmap for crying out loud. I tried some other things, nothing is working.. the only thing that does work is embedding height via bounding box ($BBZ) as point color. This .. is not satisfactory. I need it to work in a shader so I can bake depth from displacements..etc.

I cant believe Im having issues with this simple shader:

Trying to get a height map (well its actually a z-depth map) that has a very narrow range.

For example my furthest point is -2 on z and the nearest point is +2 on z. I want to generate a greyscale map that has a value from 0 to 1.

The math Im using is just pz-farplane. in this example our values will range from 0 where z is the farthest point and 4 where the point is at the near plane.

if I use a fitrange and remap the values 0->4 to 0->1 i should get a nice smooth ramp. But that is not working.

Is there a better way to do this or a shader that already exists? Thanks,

[sam.h]

Could you post a scene that works (the one with $BBZ). I having trouble understanding what you need ....

[nord3d]

I need it to work in a shader so I can bake depth from displacements..etc.

I think, I understand. Maybe something like this:

Edited December 16, 2011 by nord3d

[dynamoanders]

Hi guys.

I am struggling on how to get a height map (black and white texture) to work on a grid.

I add a vopsop, and in here I usually use a turbnoise and connect it to displacement.

Now I am trying to use a texturenode to displace the grid, but I can´t get it to work.

Here is a simple setup that I tried to do. Can´t find where I should look in the help neither...

Does anybody have some ideas?

Thanks,

Anders

texture_to_heightfield_on_grid.hipnc.hip

Edited November 14, 2012 by dynamoanders

[dynamoanders]

Here is an old solutions that worked for me.

http://www.sidefx.com/index.php?option=com_forum&Itemid=172&page=viewtopic&p=93656&sid=b4a5605ea1e90a11881359baffff8fe2

[sl0throp]

Could you not just render a ramp using the object bounds on whatever axis you wanted that way getting a full range from 0-1 without having to worry about remapping to an objects specific. You could do it in a vop or simply uv project and texture with a ramp. I have rendered a lot of height maps for both terrain and parallax mapping this way