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I've rendered a character in Blender and created a multi-layer EXR, which I want to edit and color in Photoshop. I separately rendered different body parts like arms, shoulder armor, the head etc.

Sadly, Blender rendered all of these things COMPLETELY, so now the whole thing is jumbled in Photoshop since they're just 2D images now.

Question:

Is it possible to tell Blender to ONLY render the part of the objects that are visible from the camera's point of view and leave out the ones that are hidden behind other objects?

This would be a great help. :) Someone got an idea? As of now, it looks like this. Pretty messy since nothing fits together anymore.

example image

Doomed to Consume
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1 Answers1

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Separate the object you want to render by layer.

  1. Place the render object on layer 2. (e.g. Torus)
  2. Place the masking objects (all other objects) on layer 1. (e.g. Cube)
  3. Make both layers visible in the Scene's layers.
  4. Set the Layer to layer 2 in the render layers tab.
  5. Set the Mask Layer to layer 1 (or more) in the render layers tab.

The objects on layer 1 will now act as a mask.

enter image description here

Compositing in Photoshop

Sadly, stacking these image on top of each other messes up the premultiplication / alpha / hard to explain.

Here's how to composite these two layers in Photoshop.

Basically, we add all akphas together, add all colors together, then use the alphas as a mask.

  1. Create layers containing only the alphas.
  2. Set the lowest alpha layer to Normal blending mode, the others to Add.
  3. Merge the alpha layers creating an alpha for all layers together (you could also render this from Blender).

enter image description here

  1. Create a group (folder) for each layer. In each group add a black solid layer below the imported image.
  2. Set the lowest group's blending mode to Normal and all other group's blending modes to Add.

You should have the original image infront of black now.

  1. Group all existing groups into a new folder. Set the alpha mask for this folder.

enter image description here

Although this setup is tedious, you can now edit the individual parts, while previewing the final result.

Leander
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  • It worked, thank you so much! Sadly there are veeery small seams of empty space between each layer, but I guess that's just how it is. Again, thank you. – Doomed to Consume Feb 02 '17 at 19:51
  • I know what you mean, but the "seam" isn't exactly a random gap between objects. The objects can be composited together exactly as if they were rendered combined. Where are you combining the objects? Blender or Photoshop? – Leander Feb 02 '17 at 20:25
  • Mh, the scene consists of 6 layers. One has the head, one the arms, one the legs and so on. I link those scene layers to the render layers and use the masks as you told me.

    I then render it, open the EXR in PS and then these very small gaps between the layers are visibible, they are like 1pixel but they are visible with a white background. I'm not sure if that is what you asked. :-\

     – Doomed to Consume Feb 02 '17 at 20:29
  • @DoomedtoConsume I have updated the answer with an explanation of compositing the layers in photoshop. Does this help? – Leander Feb 02 '17 at 21:39
  • Okay this kinda broke my brain, I will have to fiddle around a bit till I get what you mean. :D But I really appreciate your effort to help me, thanks! – Doomed to Consume Feb 03 '17 at 10:08
  • I guess you'll get there, if you upload the exr layers I could configure them for you and upload the photoshop file. Then you can analyze it yourself. – Leander Feb 03 '17 at 10:38
  • Well another problem is, in my EXR file, after I've opened it in PS, there are only regular layers with transparency as the "background" and no alpha layers like in your example. Guess that got something to do with my rendering properties.

    But I will post a new question regarding my problem, maybe someone knows a better way. :)

     – Doomed to Consume Feb 03 '17 at 10:49
  • You get an alpha mask by simply ctrl clicking on a layer, then filling that selection. Maybe you should go to the graphics forum, since this seems more of a photoshop topic. – Leander Feb 03 '17 at 10:54
  • I've got it now, it works! It makes the PS document really clustered and harder to work with, but it seems like this is the only good way. Thanks alot. – Doomed to Consume Feb 03 '17 at 15:30
  • @DoomedtoConsume Yes, it is far from a good workflow. Don't stop experimenting, maybe you can find a better way. If you do it would be great if you posted an answer. Good luck! – Leander Feb 03 '17 at 16:38