perspective property

Perspective of the cylindrical projection.

A number between 0 and 0.01 where 0 means looking at the cylinder from infinitely far with an infinitely small field of view and 1 means looking at the cylinder from infinitely close with an infinitely large field of view (which cannot be rendered).

Defaults to an arbitrary but aesthetically reasonable number of 0.003. A larger number brings the vanishing point closer and a smaller number pushes the vanishing point further.

Must not be null and must be positive.