Zdepth Fake, Simple And Fast

[michael-paixao]

ok, so ive seen alot of people making alot of suggestions on how to approach fake Zdepth, and of all the solution, i didnt find a similar answer, or a simple one, so here i am to offer one now

quick edit: just so you guys know, this IS NOT A FAKE, its what Zdepth normally renders, the only difference is that it removes the distance calculation maya does, and gives you that manual control. (also notice that regardless of having lights in the scene or not, it ignores them )

1: create a surface shader (name it something obvious zDepthShader, so the TD can stay happy with you )

2: in the color channel your going to create (as projection) a ramp.. black to white as you need

3: in your hypershade now, choose the surface shader, hit the map input connections button ( looks like a square with an arrow on the left side of it)

4: your work area should now have the surface shader and 4 other nodes, select the projection node and go into attribute editor (projection type should be planar by default, else choose it )

5: now choose the "placed3dTexture$ node" notice to grab the 3D texture node, and not the 2D one ($ is whatever number maya assigns it) from here you PARENT this node to your render cam.

6: zero out the translation and rotations, then choose rotateX , rotate 90 degrees ( has to be X, because Y may look similar, but the direction of the Z will be off )

7: with the 3D texture node still highlighted, take the move tool, make sure you have it set to local or object type movement, from here you scale it bigger, and move it around so that it can covers your entire scene

8: now render and enjoy your Zdepth, same as the regular maya render, easy to control, and renders in all renderers ( unless you video card is not able to support it... at wich time you choose any other option to render )

pictures to be added soon on what it looks like to setup each step

[joojaa]

ok sorry about this. i cant help myself.*

QUOTE(MikePaixao @ 10/09/08, 09:47 PM) [snapback]293125[/snapback]
quick edit: just so you guys know, this IS NOT A FAKE, its what Zdepth normally renders, the only difference is that it removes the distance calculation maya does, and gives you that manual control.

Huh? You do understand that non-fake Z is the raw zbuffer. that has no maximum or range whatsoever, its range is floating point. So yes this makes the same kind of fake z what we normally call fake z buffer. (maya does not put in range the comp software does that to illuminate that to you) The second reason its fake is that it anti aliases since the real z does not do that. (tough you could certainly do 2 other z buffers taht work with aa but unbounded range or without aa bounded)

So its called fake because you set a maximum controlled range in render wich causes clip. The real z does contain values that are unbounded:

so the values ken be 1 unit 0.0001 unit or 3000 units or even 3000000000000 units. If you encounter a zwhere this fluctuates its because you do not set the rangeslize you need. Yes real z can measure ANY distace on the plate.

Now a misunderstanding happens to people on this fact because when you initially shown it it normalizes max range to really use z you should tell how to bound it in your comp app. If it hapens to be AE then i understand the problem.

So yes this is definitely what ones call fake zepth. Sicne you loose the ability to accurately measure actual scene unit distances in your image.

Please note just because we call it fake z does not make it bad alternative. Its just called something else to signify your not using the raw data. In way its a bit biassed name. And yes many people get this wrong. Me personally i get a bad taste in mouth whenever i see fake z depth in use because it represents a 2 times over step to do something you got for free anyway. Its a bit liek insisting on paying for something thats free of charge.

yours is what we called normalized fake Z

QUOTE
8: now render and enjoy your Zdepth, same as the regular maya render, easy to control, and renders in all renderers ( unless you video card is not able to support it... at wich time you choose any other option to render )

this is a good merit. other then that its better to use the sampler info node instead its faster.

*The reason im telling this is that its not a very good world where we allow false positives to go around all day. And it a bit bothers me how taking the easy way out continuously perverts the work flows day by day. I feel it curious that in general peopel did pull better off in the 90's than in 2008? Tough many studies show thats normal progression. I just dont like the regression phase. And i feel its good to let peopel know what is the idea.

Nothing wrong in good misunderstanding.

I cant to this day understand how itis possible that 30% of the entire carbon dioxide problem was sloved by a person form the 1700's and ist still not in wide use.

[joojaa]

oops my original post had a MAJOR thinking typo corrected now.