how do I get a z depth pass?

[cloudfx]

Hi all,

I am using pop and sop to make snow.

Top view.

I need to make a Zdepth pass for the particle..

Is there any Vex Shader so

just color the snow as black to white based on certain distance??

Thanks,

J

[old school]

Easiest way is to use a Mantra ROP Output driver and generate an extra image plane. In the VEX Variable parameter choose Pz. That way you don't need to render an extra pass. You generate this for free (well the time it takes to write the extra image information to disk).

When you render to ip (Mplay) you will see an extra image plane that is your Pz render under the C-A... chooser at the top left.

Only .rat, .pic (sesi format) and openEXR (.exr) support extra image planes rendered to a single image format.

To generate a separate image you first have to render the primary image to disk. Doing that enables the checkbox to generate each extra image plane to disk as a discrete file. You can use whatever image format is supported by Houdini.

Settings for the Extra Image Plane to generate a good Pz channel as a separate image sequence to disk:

- set to render to disk in the Output Picture parameter

- Add an Extra Image Plane

- VEX Variable: Pz

- VEX Type: Float Type (Pz is a single float)

- Channel Name 1: Zdepth (whatever you want here to identify the image)

- Toggle on Different File and type in name of image sequence: Zdepth.$F4.tif

- Pixel Filter: minmax min (choose Closest Sample Filtering. This will ensure that the image does not have any antialiasing which will screw up your depth comp)

-jeff

[cloudfx]

Easiest way is to use a Mantra ROP Output driver and generate an extra image plane. In the VEX Variable parameter choose Pz. That way you don't need to render an extra pass. You generate this for free (well the time it takes to write the extra image information to disk).

When you render to ip (Mplay) you will see an extra image plane that is your Pz render under the C-A... chooser at the top left.

Only .rat, .pic (sesi format) and openEXR (.exr) support extra image planes rendered to a single image format.

To generate a separate image you first have to render the primary image to disk. Doing that enables the checkbox to generate each extra image plane to disk as a discrete file. You can use whatever image format is supported by Houdini.

Settings for the Extra Image Plane to generate a good Pz channel as a separate image sequence to disk:

- set to render to disk in the Output Picture parameter

- Add an Extra Image Plane

- VEX Variable: Pz

- VEX Type: Float Type (Pz is a single float)

- Channel Name 1: Zdepth (whatever you want here to identify the image)

- Toggle on Different File and type in name of image sequence: Zdepth.$F4.tif

- Pixel Filter: minmax min (choose Closest Sample Filtering. This will ensure that the image does not have any antialiasing which will screw up your depth comp)

-jeff

How do I control the depth??

and I am using this as Top View. which is Y-Axis.. , right?

So, I cant use Pz, right? should I use Py or P??

or is there any camera option that I have to change?

or in renderer???

perhaps, is there any example scene??

Thanks a lot!!!!!

-J

Edited July 19, 2008 by Jae Yoo