motion blur and layer mask bug[NOT A BUG] Tweet

[Delphis]

Hello,
I rendered out some passes and noticed some bugs.
1. When Motion vector is activated motion blur still remains on layer masks. It should be turned off on all passes when you render motion vectors pass, right?

2. Tried to make substitute with ObjectID pass but in my scene in frame 38 all objcets change id colour.
Tracked source of problem, it is Displacement on material applied to boole object.
Boole is sphere without cylinder which "eats" sphere until it disappear and in that moment obj id changes color.
When I remove displacement problem is not present, but if I disable boole problem also disappears so its combination of those two.

Also noticed that objects are different size/position when disable/enable motion blur (case when motion vector pass is activated), not sure is this a bug or it just works that way.
Its the same if Shutter alignment is After, so I guess its solved.

Scene is included, just render those two frames and check Layer/single pass to see problems.

motionblur_and_objID_bug.rar

(72.29 KiB) Downloaded 174 times

Windows 10 Pro, 64-bit
GTX 1080Ti + 3x780Ti
RAM 32GB
Driver 385.41
C4D R18.057 and Octane 3.07.0 Test3a and 3.06.2 also

[aoktar]

Thanks for detailed report! But i cannot see any bug/unexpected results.
1-Disabling of motion blur in render with motion vector pass is normal behavior.
2-Having some displacement on motion blur effects is expected result.
3-I cannot see color changes on object layerId pass.

[Delphis]

Hello aoktar,

Did you render the attached scene and checked the images?

Thanks for detailed report! But i cannot see any bug/unexpected results.
1-Disabling of motion blur in render with motion vector pass is normal behavior.

It should be disabled on all renders/passes in that case but its not on layer masks, see pic:

2-Having some displacement on motion blur effects is expected result.
3-I cannot see color changes on object layerId pass.[/quote]

When provided scene is rendered here is change I get in frames 37 and 38:

So obj id changes colour from frame 38, and those colors should be consistent through whole sequence.
I just narrowed the reason, it happends when object is "eaten" completely by another object (Boole operation A without B)
Also noticed that if I remove displacement from material of that object problem disappears and colors on object ID are consistent.

[aoktar]

There's not any bugs, that's logic of how numbering works on ObjectID. They are produced by order of appearance to octane geometry structure. Here some objects are disappearing at frame 38/39 so automatised color assign is changing. You should use Render Layer ID pass from Info passes not objectID pass.
Other than this about mask + blur effect in "Render Layer Mask", you should do as in picture. I'll remove this topic from BUG section.

[Delphis]

Thank you.

[bleepurchin]

There's not any bugs, that's logic of how numbering works on ObjectID. They are produced by order of appearance to octane geometry structure. Here some objects are disappearing at frame 38/39 so automatised color assign is changing. You should use Render Layer ID pass from Info passes not objectID pass.
Other than this about mask + blur effect in "Render Layer Mask", you should do as in picture. I'll remove this topic from BUG section.

lol, THE most important part of this entire answer is in the image and the highlighted 'Non-distributed without pixel filtering which you don't even mention!

This option is the only way to have the layer masks rendered out free of motion blur. The amount of Octane jobs I've done where the compositor receives a beauty pass, free of camera rendered motion blur, a Motion Vector pass BUT along with this he receives all the IDs are with the blur rendered into the sequences all because the sampling mode was set to the default Distributed rays. HOW on earth is that ever going to be useful?? The sampling mode should be an automatic change and across all passes whenever motion vectors are rendered out. Pure and simple Octane!