Missing preview image in compositing file output node #84815

New Issue

Reiner Prokein · 2021-01-18T10:31:31+01:00

Reiner Prokein commented

2021-01-18 10:31:31 +01:00

System Information
Operating system: Windows-10-10.0.19041-SP0 64 Bits
Graphics card: GeForce GTX 1060 6GB/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 460.89

Blender Version
Broken: version: 2.93.0 Alpha, branch: master, commit date: 2021-01-17 07:30, hash: 14bb9f09ab

Short description of error
The compositing file output node does not show a preview image when expanded.

Exact steps for others to reproduce the error

Open Blender.
Switch to Compositing Layout.
Render image.
Activate use Nodes.
Add a File Output node.
Expand it.
The place where the preview image should be shows empty.

**System Information** Operating system: Windows-10-10.0.19041-SP0 64 Bits Graphics card: GeForce GTX 1060 6GB/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 460.89 **Blender Version** Broken: version: 2.93.0 Alpha, branch: master, commit date: 2021-01-17 07:30, hash: `14bb9f09ab` **Short description of error** The compositing file output node does not show a preview image when expanded. **Exact steps for others to reproduce the error** Open Blender. Switch to Compositing Layout. Render image. Activate use Nodes. Add a File Output node. Expand it. The place where the preview image should be shows empty. ![preview.jpg](https://archive.blender.org/developer/F9585063/preview.jpg)

Reiner Prokein commented

2021-01-18 10:31:31 +01:00

Added subscriber: @tiles

Falk David commented

2021-01-18 10:50:19 +01:00

Added subscriber: @filedescriptor

Falk David commented

2021-01-18 10:50:19 +01:00

Changed status from 'Needs Triage' to: 'Confirmed'

Falk David commented

2021-01-18 10:50:19 +01:00

I can reproduce the issue, but it seems that even in 2.79 the output node did not have an image preview. I think this is a limitation for now.

Habib Gahbiche commented

2021-01-21 09:13:58 +01:00

Added subscriber: @zazizizou

Swayamjeet Swain commented

2021-04-04 09:28:08 +02:00

Added subscriber: @swain

Swayamjeet Swain commented

2021-04-04 11:16:51 +02:00

Hi, I am starting my journey to contribute to Blender and got curious about this issue as it would help me understand the inner working of nodes. I have recreated this issue and have been going through the code.
From my understanding the File Output node's preview should behave in the same way as Viewer node does. In COM_OutputFileNode.cc, I see converter.addNodeInputPreview being used the same way as in the COM_ViewerNode.cc but it doesn't seem to work in the former. In the Viewer node we are passing just the image socket to it, while in File Output node we are looping through and passing the inputs. Is this what should be done if we have just Png format instead of OpenEXR and there is only one input image socket?
I need to go a bit deeper into NodeConverter class and NodeOperation. The code comments do help but where can I find more about them.

Hi, I am starting my journey to contribute to Blender and got curious about this issue as it would help me understand the inner working of nodes. I have recreated this issue and have been going through the code. From my understanding the File Output node's preview should behave in the same way as Viewer node does. In COM_OutputFileNode.cc, I see converter.addNodeInputPreview being used the same way as in the COM_ViewerNode.cc but it doesn't seem to work in the former. In the Viewer node we are passing just the image socket to it, while in File Output node we are looping through and passing the inputs. Is this what should be done if we have just Png format instead of OpenEXR and there is only one input image socket? I need to go a bit deeper into NodeConverter class and NodeOperation. The code comments do help but where can I find more about them.

Jeroen Bakker commented

2021-04-12 13:21:22 +02:00

Added subscriber: @Jeroen-Bakker

Jeroen Bakker commented

2021-04-12 13:21:22 +02:00

Hmm a bit of a one off issue.

File output node is only executed when doing final composite.
Previews are only updated when editing.

This could be changed by changing the OutputFileNode::convertToOperations

  if (!context.isRendering()) {

Hmm a bit of a one off issue. File output node is only executed when doing final composite. Previews are only updated when editing. This could be changed by changing the `OutputFileNode::convertToOperations` ``` if (!context.isRendering()) { ```

Dean Jones commented

2021-04-16 16:58:44 +02:00

Added subscriber: @DeanKJones

Dean Jones commented

2021-04-16 16:58:46 +02:00

Removed subscriber: @DeanKJones

Dean Jones self-assigned this 2021-04-16 17:04:11 +02:00

Dean Jones commented

2021-04-16 17:04:11 +02:00

Hi, just submitted a possible fix #84815 : Missing preview image . I would be interested to know if I could have submitted the diff in a better way.

Hi, just submitted a possible fix [#84815 : Missing preview image ](https://developer.blender.org/D10995). I would be interested to know if I could have submitted the diff in a better way.

Alex commented

2021-04-26 12:26:39 +02:00

Added subscriber: @kotelifelif

Alex commented

2021-04-26 12:26:39 +02:00

In file node_edit.c in method compo_startjob() we set value of rendering, and use it in OutputFileNode::convertToOperations, that is why

if (!context.isRendering()) {
}

is false in all cases.

In file node_edit.c in method compo_startjob() we set value of rendering, and use it in OutputFileNode::convertToOperations, that is why ``` if (!context.isRendering()) { } ``` is false in all cases.

Hemang Pant commented

2022-01-06 05:52:36 +01:00

Added subscriber: @niyanx