motion blur on propeller problem in houdini

[nezgro79]

Hi !

I have this scène when i try to appli some motion blur on my propeller i cant have a round propeller whit blur.

On my propeller in my geo node

a transform node whit this expression on x axes ($F-$FSTART)*45

a trail node on compute velocity and compute acceleration cheked whit accel attribute

on my geo node

deform keys on 2 ( nothing affect the render )

velocity checked on v

acceleration blur on accel

on my render node

transform key on 8 ( nothing affect the render )

deform keys on 2 ( nothing affect the render )

shuter lentgh on 1

[nezgro79]

Hello!
I can get a round blur motion effect on a two-pointed propeller, but I can't do it on three.

Why ?

Can you help me please ?

[lee_griggs]

Increasing transform_keys should fix this. Deform keys/velocity blur should not be necessary for a non-deforming object such as this. Do you have a simplified scene that you can upload somewhere?

[nezgro79]

I'm gonna do one.

[nezgro79]

i have found for a propeller whit 4 axes its ok , but not for 3

[lee_griggs]

Are the pivots of the blades on the center of the axis of rotation?

[julian.hodgson]

Try using only transform motion blur, and using say 4 keys.

Here's an example scene:

propellor_xform.hip.zip

Let me know if that's working for you.

Cheers

Julian