Question about Camera Motion Blur / unexpected behaviour

[ROUBAL]

Hi, as currently we have only camera motion blur, I am a bit surprised by what I see on my current animation.

The camera copies the location of a vertex of an object parented to the armature of the car. The object has a Shrinkwrap modifier allowing to follow an invisible wall along the road.

The goal of this rig is to allow distance variations between the camera and the car, while avoiding the camera passing behind poles set on the side of the road.

The camera has a damped traking constraint on the Helmet of the pilot. So there is few movement between the car and the camera, but the camera moves very fast related to the road (90Km/h)... and yet the road is almost not blurred while the car is very blurred.

The result is the opposite of the expected result...

Any explanation ?

[grimm]

I think it's relative distance, you can see that the back of the car is less blurred than the front. Things that are farther away from the camera move slower and so are blurred less.

[ROUBAL]

It was also my first thought. The linear speed of the car and the camera are almost equal as the camera is parented to the armature of the car. So the car souldn' be blured due to the linear speed. Added to that, with my camera rig/tracking constraint the camera rotates when the car goes closer to the camera. So the angular speed should have an equal effect on the car and the background imho...

[grimm]

I see, very strange, I don't know then. Sorry.

[ROUBAL]

I will experiment with a different camera rig when I will have time...

Maybe Octane 2.0 will solve the problem in a close future.