motion blur breaks depending on null arrangement and object Tweet

[boxfx]

open the attached project
Note that the "blade instance" object has a scale of -1 in the X axis to flip the model
render to picture viewer
The spinning blade will blur correctly

Set the "blade instance" scale from -1 to 1 to reset the model back to its real shape
render to picture viewer
bug: there is no motion blur

There is a second odd / related behaviour. If you drag the "blades" object from being a child of "group 1" and move it to "group 2", then the motion blur will work again.

My guess is that octane is looking at the "group 2 object" being instanced, sees the only thing inside is a null, and doesnt then check the children to see if there is any moving geometry it should consider. The fact that a -1 scale on the model fixes it though I cannot explain.

octane 2023.1.2 r5
c4d 2024.2.0
win 11
gf 3090

[aoktar]

Try this. Octane tag should be on the animated geometry. Post looks like done with wrong impression.

[boxfx]

Your screenshot shows the geometry is still inverted with a -1 scale. Change the scale of "blade instance" from -1, 1, 1. to 1, 1, 1 and you will see the motion blur breaks. The -1 scale is magically fixing the motion blur... somehow.

File attached with the octane tag on the instance as you suggest, but still broken.