Viewport rendering isn't updating with changing of values of a material node group. but working if you change inside node group! #47870

New Issue

Souvik Karmakar · 2016-03-21T06:00:06+01:00

Souvik Karmakar commented

2016-03-21 06:00:06 +01:00

System Information
Windows 10 , Intel HD graphics (i3 1st gen)

Blender Version
Broken: 2.77 cc12fc1
Worked: 2.77 22a2853

Short description of error
It's not updating in the viewport when I change a value of the node! but when I go to object mode and then again to render mode it's working or if I change it inside the group it's also working..

see the image you will get it:
Thanks!

**System Information** Windows 10 , Intel HD graphics (i3 1st gen) **Blender Version** Broken: 2.77 cc12fc1 Worked: 2.77 22a2853 **Short description of error** It's not updating in the viewport when I change a value of the node! but when I go to object mode and then again to render mode it's working or if I change it inside the group it's also working.. see the image you will get it: Thanks! ![blender_group_issue.jpg](https://archive.blender.org/developer/F297508/blender_group_issue.jpg)

Souvik Karmakar commented

2016-03-21 06:00:06 +01:00

Changed status to: 'Open'

Campbell Barton was assigned by Souvik Karmakar

2016-03-21 06:00:06 +01:00

Souvik Karmakar commented

2016-03-21 06:00:06 +01:00

Added subscriber: @SouvikKarmakar

Lukas Tönne commented

2016-03-21 09:05:27 +01:00

Added subscriber: @LukasTonne

Lukas Tönne commented

2016-03-21 09:05:27 +01:00

The reason this doesn't work is that the output node is included in the group. Since 83824947ba nodes don't trigger a reset of the viewport render if they are "not connected to the output node", but the test for this condition only works on the top node level (so the group instance is not considered a used node).

IMO testing dependencies between nodes shouldn't really happen on the UI node level because of the complexity and potential non-standard behavior of connections (when is a socket connection actually "used"?). However, current Blender nodes lack an intermediate level between the UI nodes (bNodes in DNA) and the "machine code" of the renderer. Until this can be improved, the best solution would be just handling node groups as a special case i suppose.

@SouvikKarmakar: Please leave it to devs to assign a bug report to somebody. This is not really @ideasman42's area anyway.

The reason this doesn't work is that the output node is included in the group. Since 83824947ba nodes don't trigger a reset of the viewport render if they are "not connected to the output node", but the test for this condition only works on the top node level (so the group instance is not considered a used node). IMO testing dependencies between nodes shouldn't really happen on the UI node level because of the complexity and potential non-standard behavior of connections (when is a socket connection actually "used"?). However, current Blender nodes lack an intermediate level between the UI nodes (bNodes in DNA) and the "machine code" of the renderer. Until this can be improved, the best solution would be just handling node groups as a special case i suppose. @SouvikKarmakar: Please leave it to devs to assign a bug report to somebody. This is not really @ideasman42's area anyway.

Campbell Barton was unassigned by Lukas Tönne

2016-03-21 09:08:00 +01:00

Lukas Tönne self-assigned this 2016-03-21 09:08:00 +01:00

Lukas Tönne commented

2016-03-21 09:08:00 +01:00

Added subscriber: @ideasman42

Lukas Tönne commented

2016-03-21 09:17:10 +01:00

Added subscriber: @Sergey

Lukas Tönne commented

2016-03-21 09:32:58 +01:00

@Sergey I don't see an easy way to support node groups with this. The definition of "active output node" is shaky even in normal cases, but when you include it in a node group it becomes quite unpredictable which instance would be considered "active". I guess output nodes inside groups are just unsupported?

In future nodes i could imagine output nodes working more like node group outputs: The sockets on "global" output nodes for a graph would depend on the ntree context. In the top-level nodes you get the formal output parameters ("Material/Volume/Displacement" for cycles nodes). Inside node groups it would just should the respective group outputs, thus forcing you to always connect to the final output on the top level.

@Sergey I don't see an easy way to support node groups with this. The definition of "active output node" is shaky even in normal cases, but when you include it in a node group it becomes quite unpredictable which instance would be considered "active". I guess output nodes inside groups are just unsupported? In future nodes i could imagine output nodes working more like node group outputs: The sockets on "global" output nodes for a graph would depend on the ntree context. In the top-level nodes you get the formal output parameters ("Material/Volume/Displacement" for cycles nodes). Inside node groups it would just should the respective group outputs, thus forcing you to always connect to the final output on the top level.

Souvik Karmakar commented

2016-03-21 18:40:04 +01:00

In #47870#365103, @LukasTonne wrote:
The reason this doesn't work is that the output node is included in the group. Since 83824947ba nodes don't trigger a reset of the viewport render if they are "not connected to the output node", but the test for this condition only works on the top node level (so the group instance is not considered a used node).

IMO testing dependencies between nodes shouldn't really happen on the UI node level because of the complexity and potential non-standard behavior of connections (when is a socket connection actually "used"?). However, current Blender nodes lack an intermediate level between the UI nodes (bNodes in DNA) and the "machine code" of the renderer. Until this can be improved, the best solution would be just handling node groups as a special case i suppose.

@SouvikKarmakar: Please leave it to devs to assign a bug report to somebody. This is not really @ideasman42's area anyway.

ah I didn't get what you said .. and for the last statement .. I don't really that much here so I don't know about which campbell's area..
is campbell only handle new addons? thanks :P

> In #47870#365103, @LukasTonne wrote: > The reason this doesn't work is that the output node is included in the group. Since 83824947ba nodes don't trigger a reset of the viewport render if they are "not connected to the output node", but the test for this condition only works on the top node level (so the group instance is not considered a used node). > > IMO testing dependencies between nodes shouldn't really happen on the UI node level because of the complexity and potential non-standard behavior of connections (when is a socket connection actually "used"?). However, current Blender nodes lack an intermediate level between the UI nodes (bNodes in DNA) and the "machine code" of the renderer. Until this can be improved, the best solution would be just handling node groups as a special case i suppose. > > @SouvikKarmakar: Please leave it to devs to assign a bug report to somebody. This is not really @ideasman42's area anyway. ah I didn't get what you said .. and for the last statement .. I don't really that much here so I don't know about which campbell's area.. is campbell only handle new addons? thanks :P

Souvik Karmakar commented

2016-03-21 18:46:27 +01:00

and btw .. it's working on the stable version... but not the latest build .. hope you already know it :p .. so it's not that problem.. but it should be fixed in next build .. thanks :3

Lukas Tönne removed their assignment 2016-03-22 14:48:16 +01:00

Sergey Sharybin was assigned by Lukas Tönne

2016-03-22 14:48:16 +01:00

Sergey Sharybin commented

2016-03-23 15:42:37 +01:00

Changed status from 'Open' to: 'Resolved'

Sergey Sharybin closed this issue

2016-03-23 15:42:37 +01:00

blender-admin commented

2016-03-23 15:42:38 +01:00

This issue was referenced by 2103e2112c

This issue was referenced by 2103e2112cca3e3385ac057bbe8976925eadd6d4

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Viewport rendering isn't updating with changing of values of a material node group. but working if you change inside node group! #47870