Motion blur

Photivra models subject motion by projecting a representative 3D point at the beginning and end of an exposure and measuring the sensor-plane displacement.

For constant world-space velocity, the position change over shutter-open time is:

The start and end positions are then projected through the selected camera geometry. When pixel pitch is known, sensor displacement can also be expressed in pixels.

Camera shake

Photivra separately models controlled yaw/pitch angular motion and can apply an explicitly labeled stabilization-equivalent attenuation. Subject motion and camera shake remain separate physical quantities.

Model limits

The current subject-motion model follows a representative point under constant linear velocity. It does not yet model extended-object scale blur, deformation, acceleration, occlusion change, or arbitrary rotation.