Z Depth all white in final render

[GimbalLocked]

Hi,

When I try to do an infochannel Z Depth render it turns out all white, although in the IPR and the F9 preview window they look as intended. Only the final output pops up all white. It makes no difference how I set the depth limit.

[juanjgon]

Have you checked what's inside this pass? Be aware that it is a floating type AOV in real units, so anything farther than 1 unit (usually 1 meter) is going to be white without the proper tone mapping.

Thanks,
-Juanjo

[stef]

Hi !

Yess check Zdepht max, in meters,
A range for that, will be very useful !



But i don't think this is the problem,
Seem more exposure lighting problem,
Use png for export, with correct gamma ?

Can we switch black / white background ?
Should be very useful too !

Best regards.
_

[juanjgon]

Hmm, I don't think that exporting the zdepth pass as a png file could be useful. As I've said it is a floating AOV that should be not tonemapped at all for comp. Once clamped (and perhaps even tonemapped) to the png integer formal all the depth data makes no sense. You should work with floating exr files if you are planning to do any comp in your project.

Thanks,
-Juanjo

[GimbalLocked]

Hi,

Thank you for the replies. Unfortunately I still can't get it to work. I've created a simple scene that should demonstrate the problem, and I hope someone might have a minute to try and load it up.
If simply opening the scene and activating IPR, you'll get a proper z pass. Depth is set to 20 meters, which is just about the size of the object. In IPR it looks fine.
If you hit F9 and get a glimpse of the render preview window (it may render too fast) that will look correct as well. However, the final output will turn up all white.

Saving in linear or different formats doesn't seem to change anything, the output is perfect white.

I haven't had problems with any other render passes (that I've used). But I've had to save out gigantic IPR renders to work around this particular issue.

[Lewis]

Hmm, are you sure you uploaded proper scene ? your scene don't even have Passes/Z-depth ON ? There is only Beauty channel active and no passes node and you used infochannel kernel ? Why not using PT kernel and then passes node for Z-depth into EXR?

You should connect passes node and activate z-depth and then if you want to use it in Photoshop you'll have to normalize it, otherwise it'll be all white (PS sucks with 32bit files). Open image in PS and do HDR Toning in to tweak white/black levels, like this:
http://prntscr.com/pqv5l9

[juanjgon]

It is perfectly white because it stores floating distances far away 1 unit. You can check it yourself even in the LightWave image viewer picking over any pixel in the image to see that the values are usually greater than 1.0. Be aware that a z-depth image is not designed to see anything, it stores the distance from the camera to the objects in each pixel ... of course, you can always tone map the image, but then the distances are destroyed.

Thanks,
-Juanjo

[GimbalLocked]

Hmm, are you sure you uploaded proper scene ? your scene don't even have Passes/Z-depth ON ? There is only Beauty channel active and no passes node and you used infochannel kernel ? Why not using PT kernel and then passes node for Z-depth into EXR?

You should connect passes node and activate z-depth and then if you want to use it in Photoshop you'll have to normalize it, otherwise it'll be all white (PS sucks with 32bit files). Open image in PS and do HDR Toning in to tweak white/black levels, like this:
http://prntscr.com/pqv5l9

Thanks - I was trying to make it work with the infochannel kernel because I can crank out any pass I need for a project that way very easily, and they do work, except Z Depth. It seems like it should, since it looks like I want it to in the IPR and render progress window. If you try the IPR in my test scene, it looks correct.

[GimbalLocked]

It is perfectly white because it stores floating distances far away 1 unit. You can check it yourself even in the LightWave image viewer picking over any pixel in the image to see that the values are usually greater than 1.0. Be aware that a z-depth image is not designed to see anything, it stores the distance from the camera to the objects in each pixel ... of course, you can always tone map the image, but then the distances are destroyed.

Thanks,
-Juanjo

Thanks. I think this makes sense. I've been using Z Depth as an alpha mask for layers etc, ranging from 100%-0% black.
I'm confused by the IPR and render result not showing the same.

[Lewis]

Thanks - I was trying to make it work with the infochannel kernel because I can crank out any pass I need for a project that way very easily, and they do work, except Z Depth. It seems like it should, since it looks like I want it to in the IPR and render progress window. If you try the IPR in my test scene, it looks correct.

Sure but you are rendering scene twice that way - PT kernel and then infochannel kernel, while you can do all of those in one pass with multiEXR and render pass node .