How do I export a ZDepth Image to Photoshop?

[Dpower357]

Hey Everyone.

Maya 2018.

I set up a Zdepth Render with Arnold.  So maybe this is an Arnold question.

Basically, added the AOV "Z" to my render.  I also selected driver and Merge AOVs in the attribute window.

When I view the image in render view it's all white.  If I adjust the exposure I can see the Depth.  I just want to export that to Photoshop and extract the Z Depth.  When I click save multi layer EXR and open in photoshop... I cannot see any Z Depth information.  I figure I'm missing a step somewhere.  Anyone have any ideas?

Thanks!!

[mspeer · Accepted solution]

Hi!

Please check this:

https://forums.autodesk.com/t5/maya-shading-lighting-and/arnold-depth-pass-help/td-p/6723256

[Dpower357]

Great.  Thanks!  I will check it out and report back.

[Dpower357]

Ok. I have read the linked article.  I'm still having issues.

I'm going in deep here.  Bare with me.

Current Set Up:

Maya 2019, Mac Catalina 10.14.6

Working Method:

• Just a test scene, default settings,  1 simple sphere in my scene. No lights. Sphere = 44 units from camera

• Activated "Z" AOV in Render Settings.  See Figure 1

• Clicked little down arrow triangle by Z AOV>select Drivers> Merge AOVs.

• Important Render Settings: Image Format = EXR, Frame/Animation Ext: name.3.ext, Have set up a 1 frame only frame range.  This is so I can also render using Render Sequence.

Render Using: 2 Methods. Described below.

Method 1:

• Render using Arnold> Render. Initiates the "Arnold RenderView", Drop down menu of window= pick the "Z" AOV to view. I get a pure white image. Adjusted Exposure in Arnold RenderView, (make sure to type in numbers not use the slider, the slider doesn't move far enough, also make sure to hit return and not tab after entering the numbers as TAB doesn't actually enter the number) I can see my sphere.  See figure 2.  However, If there is any Z Depth information there... I cannot see it.  I just see a flat grey sphere. 

Issue: 

Saving this image out is an issue: I cannot select any of the recommended settings of the solutions from the link above.  My options are different.   IF HOWEVER, if I use the method below- Calling it "Method 2", the settings are available.  BUT,  Currently, with Method 1, my options are Save>Save Image Options = "Apply Color Managment"  which I've Disabled, "View Transforms" which I've left at Use Display Settings and "Apply Gamma/Exposure". Which I've checked on.  After these adjustments are made-

I CAN, save out a file from the "Arnold RenderView" File>Save

Issues:

This ONLY saves out an 8 bit .jpg image which I don't want. I want to stay 32bit  Open it in Photoshop CC 20.0.6. Adjust exposure or levels, It looks terrible, severe banding. See Banding Image.

I can Save>Multi Layer EXR.

Issues:

There is no information in my saved EXR file.  Just an alpha channel.  No Image.  No Z Depth. 

Method 2:

• Render Using, Render>Render Sequence.  Just 1 frame. This does 2 things.  Maya saves out an EXR file automatically and brings up the "Render View" which is different than the "Arnold RenderView".  I can however, set the recommending settings/options from the linked solution listed above.

Issues:

I cannot choose to view the "Z" AOV and "RenderView" renders a black image.  So I have no idea if it's rendering properly.

The Rendered Image is saved to my "Images" project folder.  It is an EXR. The image has no information in it.  Again just an alpha channel.  If I open it in photoshop there is nothing there.  I can adjust exposure, level.  There is nothing and No information in the histogram.

If I save out an EXR image from within "Render View", again no information in that saved image just an alpha channel.

Regardless of Method 1 or 2. I'm getting no usable ZDepth Information.

I am missing an important step.  I would love to know what it is. Any help is appreciated.  

Thanks.

[mspeer]

Hi!

1. Photoshop does not support multi-layer EXR by default.

I recommend to use a "better" compositing application.

2. You can save the Z-Depth from Arnold Render View as EXR,

just add .exr as extension when entering the filename for Save Image.

This 32-bit image file can then be edited in Photoshop without any banding.

[Christoph_Schaedl]

I would use this plugin.

https://www.exr-io.com/

[Dpower357]

Unfortunately that didn't work for me. It's an .exe download file and I'm Mac. 

[Dpower357]

Hey mspeer, thanks for the help. You've answered many of my questions before.

1. I'd love to stick with photoshop.  This is less about compositing/post blur/fog and more about creating an image map.  Long story short. I'm using many Z Depth maps to create 1 big image map in Photoshop and then round trip it back into Maya as a displacement map as a BasRelief.   See BasRelief. 

2. This does not work very well for me.  Or at least I can't figure it out.  I can save out the image as EXR but if I open it in photoshop... There just isn't enough information to work with.  And I still get banding.  See RoughZDepth.  I don't know if it shows but If you can see the photoshop histogram there is only a really small section with information  and if I crush the levels to use it/see it/manipulate it... I get banding.

I did finally work out a solution. Using a method I found here.

https://www.youtube.com/watch?v=k2o9N10nxns

Note:

• There is a bit of a different work around from what he describes as the render layer tab from Maya 2016 is now (I'm Maya 2019) in a different location and works a bit differently.
•  I'm able to see the Z Depth in the Maya software render window without having to adjust any exposure. Not using Arnold for this.  And it's straight forward to save out a variety of formats.  Worked well, and the image is full of data when opened in Photoshop.

[mspeer]

Hi!

Please upload one of your EXR files (ZIP it first)

and also provide a Maya example scene where you created this from.

[Dpower357]

Sure thing.  Here is my Test

Included in the Zip:

• A 3D File.  It's set up to render an AOE with Arnold. And as a Maya Software Luminance Pass in Render Sequence

• A ZDepthTest_Method1 - Rendered in Arnold RenderView- I get a white image. I typed .exr as the extension and saved it.  (it's only 823kb).  There is an image in the file but not much information.

• A ZDepthTest_Method2 - using Maya Render Sequence, This File was saved from Maya RenderView as a .exr. (It's 8.3MB) Image looks great and loads of data. 

Thanks in advance.

[mspeer]

Hi!

Here is your Arnold EXR after editing in Photoshop.

I can't see any problems.

However as absolute values are used for min and max there is a fixed step size that can become visible, even for 32-bit EXR files.

If you really need more detail just increase object size, but please keep in mind that for Z-Depth information you may not need this amount of detail