View Full Version : depth maps from fprime????

10-29-2004, 03:45 PM
title really says it all - is tehre anyway to get a depth map from fprime? want to get some sasquatch grass into a fprime render and well jsut dumping it in with photoshop well it works but its not a very elegant solution is it

10-29-2004, 04:35 PM
If you have DF or DFX+, you can do it in post.

Do a normal LW with an RLA export (quickshade mode is fine), and then use Channel Booleans in DF.

10-29-2004, 05:13 PM
i do indeed have dfx+ but to be honest all i know how to do with it is turn image sequences into movie files

i found depth merge easily enough but that requires both files to have depth info in them =/

10-29-2004, 05:25 PM
edit: nevermind it seems to ahve done it all by itself

though the depth info on the grass from sasquach doesn't seem very accurate =/

10-29-2004, 05:33 PM
ok anyone know how to fix this?

i'm assuming its a problem with depth buffer outputted from sasquatch if i'm jstu doing something simple wrong please let me know

10-29-2004, 05:36 PM
I've found that I've had to multiply the depth value LW writes by a factor of 100.

It seems LW determines the depth value by meters. So, if one object is 1 meter from the camera and another 1.5, it will write out "1" and "1.5." But DF doesn't seem to like such small values; it would prefer "100" and "150."

10-29-2004, 05:42 PM
ok showing my severe lack of knowledge about such things but how would i go about doing that?

10-29-2004, 06:06 PM
Tools>Miscellaneous>Custom Tool>Channels>Z Expression = "z1*100" :)

10-29-2004, 07:01 PM
hmmmm ok tried that but still no good =/

is there any secret to getting a nicer z buffer out of sasquatch?

Robert Zeltsch
10-30-2004, 02:06 AM

With "Render Buffer Export" (Image Filter) you can save the depth information of the scene. The depth output of sasquatch is OK. It works well with LW`s depth information. Be sure to check if "LW & Sasquatch" is enabled in the sasquatch pixel filter. ;)

Do you have an alpha channel in your "sasquatch layer"? If no, try to re-render your sasquatch-scene with an alpha channel (check "LW & Sasquatch"). If yes try to multiply the sas-layer with the alpha channel.

If nothing works, try the following:
1. Create a scene where all your objects are set to "matte objects" with black color. The alpha channels are set to constant black. When you render this scene, only the grass should be rendered. (You can use Ray Trace Options to get shadows on the grass). The alpha channel shows only the sasquatch output. (Use the options described above in the pixel filter)
2. Now you have the following images:
a) The full RGB color render made by fprime
b) The grass layer rendered by Sasquatch/LW (with alpha channel)
3. Compose it in an painting/compositing application

I have a test scene prepared for you. Test Scene (3 KB) (http://www.flow-m-ocean.de/forum/alpha_depth_test.zip)

EDIT: Here is a flow for DFX+ and some images from the scene above.
Test Flow (250 KB) (http://www.flow-m-ocean.de/forum/flow_test.zip)

I hope you can use it. ;)

10-30-2004, 05:55 AM
Tools>Miscellaneous>Custom Tool>Channels>Z Expression = "z1*100" :)

..good grief Kvaalen I have been mucking about with this for weeks.. you have solved the depth scale problem in an instant - cheers! ( I find z1 *10 works best)


10-30-2004, 07:39 AM
thanks guys

i think i'll have to do it with your alpha channel method Robert - i cant work out the other method you suggested =/ though i think i understand what you are trying to get at

would be nice if worley supprised us all and released a update for fprime where it would link with sasquatch - preferably within the next week :D

anyway thanks again to everyone for your help

Triple G
11-01-2004, 11:46 PM
Why not just cheat it and do a fog pass to use as your depth? I haven't used Sasquatch in a while, but I'm reasonably sure it works with LW fog...