With Cycles, Freestyle lines render one frame ahead for object with driver #50066

New Issue

Michael Malahe · 2016-11-17T21:30:17+01:00

Michael Malahe commented

2016-11-17 21:30:17 +01:00

With Cycles, if an animated object has a property that is driven, Freestyle lines are drawn based on the value of that property at the next frame.

In the attached example, the z rotation of the cube is driven by its x location. At each frame, Freestyle renders the lines based on the correct location for the cube, but based on the rotation at the next frame.

Example .blend: example.blend
Output from example .blend: example.avi

Generic reproducibility steps:

Switch to Cycles Render.
Enable Freestyle.
Add driver to object that modifies its location or rotation in time.
Render Animation.

This does not happen:

When rendering stills.
When Blender Render is used.
For properties that are not driven.

System:

Blender: 2.78a
OS: Ubuntu 16.04
CPU: Intel Core i7-2630QM
RAM: 12GB
GFX: NVIDIA GeForce GTX 560M, 1.5GB
Graphics driver version: 367.57
System info file: system-info.txt

With Cycles, if an animated object has a property that is driven, Freestyle lines are drawn based on the value of that property at the next frame. In the attached example, the z rotation of the cube is driven by its x location. At each frame, Freestyle renders the lines based on the correct location for the cube, but based on the rotation at the next frame. Example .blend: [example.blend](https://archive.blender.org/developer/F402791/example.blend) Output from example .blend: [example.avi](https://archive.blender.org/developer/F402793/example.avi) Generic reproducibility steps: 1. Switch to Cycles Render. 2. Enable Freestyle. 3. Add driver to object that modifies its location or rotation in time. 4. Render Animation. This does not happen: - When rendering stills. - When Blender Render is used. - For properties that are not driven. System: - Blender: 2.78a - OS: Ubuntu 16.04 - CPU: Intel Core i7-2630QM - RAM: 12GB - GFX: NVIDIA GeForce GTX 560M, 1.5GB - Graphics driver version: 367.57 - System info file: [system-info.txt](https://archive.blender.org/developer/F402794/system-info.txt)

Michael Malahe commented

2016-11-17 21:30:17 +01:00

Changed status to: 'Open'

Michael Malahe commented

2016-11-17 21:30:17 +01:00

Added subscriber: @MichaelMalahe

Bastien Montagne commented

2016-11-18 12:32:43 +01:00

Added subscribers: @kjym3, @mont29

Bastien Montagne commented

2016-11-18 12:32:43 +01:00

@kjym3 Care to check this one? thanks :)

Tamito Kajiyama commented

2016-11-18 20:05:28 +01:00

Thanks Bastien for the triage, and I confirmed the issue on my side. I will look into it as soon as time permits.

Sergey Sharybin commented

2017-08-23 15:47:14 +02:00

Added subscriber: @Sergey

Sergey Sharybin commented

2017-08-23 15:47:14 +02:00

Changed status from 'Open' to: 'Archived'

Sergey Sharybin closed this issue

2017-08-23 15:47:14 +02:00

Sergey Sharybin self-assigned this 2017-08-23 15:47:14 +02:00

Sergey Sharybin commented

2017-08-23 15:47:14 +02:00

This is a dependency graph issue.

What happens here is you're using own location in the driver source, but the way you're using it assume you're trying to access final object transform (after all animation, parenting and constraints applied). This will work fine to driver some, say, modifier property but using that source for rotation component causes chicken-and-egg situation: rotation driver wants final object transform to be already evaluated, but rotation is required to calculate that transformation. You can see that if you hit shift-right arrow twice.

What you can do for now is to change your x variable to use "Single Property", and use location- [x] as the path. here's a file: example_workaround.blend

Surely would be nice if such situation was handled correctly, but this is not currently considered a bug. However, noted this issue here https://wiki.blender.org/index.php/Dev:Source/Development/Todo/Animation#Dependency_Graph

So thanks for the report, but archiving it for now.

This is a dependency graph issue. What happens here is you're using own location in the driver source, but the way you're using it assume you're trying to access final object transform (after all animation, parenting and constraints applied). This will work fine to driver some, say, modifier property but using that source for rotation component causes chicken-and-egg situation: rotation driver wants final object transform to be already evaluated, but rotation is required to calculate that transformation. You can see that if you hit shift-right arrow twice. What you can do for now is to change your `x` variable to use "Single Property", and use `location- [x]` as the path. here's a file: [example_workaround.blend](https://archive.blender.org/developer/F722504/example_workaround.blend) Surely would be nice if such situation was handled correctly, but this is not currently considered a bug. However, noted this issue here https://wiki.blender.org/index.php/Dev:Source/Development/Todo/Animation#Dependency_Graph So thanks for the report, but archiving it for now.

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With Cycles, Freestyle lines render one frame ahead for object with driver #50066