Reverse Perspective in Blender

Click to download .blend file

A .blend file containing a reverse perspective camera.

See an explanation of reverse/inverse perspective at Wikipedia. In short, objects closer to the camera appear smaller and objects further away appear larger. As a consequence, parallel lines (such as the edges of the table in the example image) diverge towards infinity, rather than converging (perspective) or staying parallel (orthogonal). This sort of perspective was used in some Byzantine iconography.

Note that this will only work in Cycles, not in Eevee or the viewport, since it puts another lens in front of the camera. Specifically, there is a hypercentric lens in front of the camera, which must be much larger than the scene, which must lie between the lens and the focal point of point. This is possible in real life, but unfeasible for large objects.

Usage

Copy the camera, which has the lens as a child, into your seen. You may have to delete the old camera, or change the render settings to use the new camera. The easiest way to change the degree of the inverse perspective is to change the the IOR of the lens. Large values will make the lens have a larger effect. You can change the shape of the lens itself, since it was created with geometry nodes, but it takes a bit of fiddling. To zoom in or out, change the Orthographic Scale in the camera settings.

Note: you will need the scene to be sufficiently small in order to fit between the lens and its focal point, since behind the focal point, objects are flipped upside-down.

References

• https://www.coroflot.com/p/1280834 contains the original concept

• https://blenderartists.org/t/reverse-perspective-rendering/1213342 contains the model scene, and further discussion. In addition, if you want a more complete reverse perspective experience, there are builds of Blender which implement it much more fully than this, such as in the viewport - though, you may have to build it yourself.

2023-07-06