Need Help With A Gradient Controlled By The Z Value

[anokiernan]

I'm working with a 3d model of a landscape and I would like to be able to apply a ramp type gradient that would change color according to the z value of the model. As an example, at the bottom of the model i would like it to be a dark brown, towards the middle i would like it to fade to a beige, and from there fade to a dark green at the top of the model. I'm much more familiar with modeling rather then shading so I have limited shading experience. Any help would be greatly appreciated, thanks!

[gwelch]

1. Select the "projection" radio button (it will make a 3D world space projection node) when adding a 2d ramp texture to your color channel. turn on hardware textures in your view port to see the ramp, rotate the 3d placement node as needed.
2. Same Idea, if polys, planer map your UVs, then assign a 2D ramp texture, no projection need.

[joojaa]

or yuse a sampler info node which is much saner.

[anokiernan]

Could you further explain the sampler node method? I've tried for about 2 hours to figure it out with no avail. It seems like the only controlling factors of the ramps are UV's, camera position, and lighting, none of which will control the shading the way i'm intending.

[joojaa]

QUOTE(anokiernan @ 06/26/07, 06:38 PM) [snapback]268696[/snapback]
Could you further explain the sampler node method?

connect position z to your ramp v cord input slot?

Stop thinking white wire goes into white box just connect anything to anything and see what happens.

[anokiernan]

I tried that and realized one of my initial mistakes, I wanted to be using the Y axis not the Z axis, entirely different ballgame, as it appears that the UV's run in the XZ plane and not the XY plane. I'm used to Solidworks cad software where the xy plane is the base plane, I childishly assumed it was the same in Maya. Given this new info, would the process change? I spent 3 hours today playing around in the connection editor between the sample info node and ramp node to get the result I'm looking for, still no success.

[joojaa]

Exactly same process.

heres a example:

ramp.mov (~1.8 M h264 QT MOV)

You may need to scale/offset the ramps area tough so you may want to put a multiply divide/plus minus average node in between. you may also want to use point object or point camera instead of point wolrd. up to you really.

QUOTE
I'm used to Solidworks cad software where the xy plane is the base plane,

yes thats called a architectural order, its used in autocad for example. However many engineers who do dynamics calculation denote Y up because when they do calculations they planarize their problem but most stuff is seen from the side thus y being up. Solid works tries to capitalize on the knowledge of old time 2d cad users so they chose the architectural coordinate system. many apps choose the engineering system. You can change the cordinate space tough if you want in the prefs, i dont suggest you do that tough. (its in Window->Settings/Preferences->Preferences|Settings|world cordinate system)

PS: they are not cad programs i dont seem to remember anybody truly actually usng a 3d cad for a long (rhino would be the closest to that) time. They are CAE programs theres a wast difference. and also the entire mental paradigm behind them and mayas a a million years a apart so anything you learn in solidowrks is totally useless in maya, and by the way the gap keeps growing.

PP

[anokiernan]

Thanks that worked, when I tried it before the 2dplacement node was connected to the ramp by default, I didn't know any better to get rid of it. I just need to figure out how to find the max and min heights of the object in order to set the scale correctly. Thanks again.