Houdini Expressions

Rotate camera 360 degress in 100 frames

Frame 1101 will match 1001 so 1001-1100 is the loop

fit(@Frame, 1001, 1101, 0, 360)

Link Camera DOF to Null

Make a null object as a sibling to the camera, name it ‘focus’ and use this expression in the camera’s focal distance parm to get the distance between the two objects

vlength(vtorigin(".","../focus"))

Frame Sequence offset

We always start frameranges from 1001 instead of 1 to make it a little easier when dealine with preroll - so often one needs to offset an image sequence from 1 to 1001 For example in the background of a camera:

Subtract 1000 frames but importantly add the frame padding again!

$JOB/MySequence.`padzero(4, $F4-1000)`.jpg