How to transfer render data from one object to another.?

Question

The other day I was thinking about wormholes and thought if it is possible to transfer the render view data of an object with a glass BSDF to another object, so the environment that we can see through the glass BSDF should look like that of the original object. Remember the wormhole in Interstellar, where they were able to see the other end of the wormhole through that sphere floating around.

Answer 1

Unfortunately, real time "portal viewports" are not supported in blender. However, one way around it is to transfer pre-rendered data into a new scene. Here's an example - see if it works for you.

Make your initial scene and put your object (sphere?) in it. Select the sphere and press Shift + S and select "Cursor to selected" to put the 3D cursor directly in the center of the object.

Then select your camera, and press Shift + S again, this time select "Selection to cursor" to put the camera where the cursor is (in the center of your object).

Now, remove your object (sphere) from the scene, leaving the camera in place. Don't just hide the object - it will still appear in the render if you hide it. Either move it or delete it.

Make sure you are using Cycles engine (this particular camera perspective only works in cycles), and in your camera settings, pick Panoramic - Equirectangular.

Now render and save your image. It should look something like this (bent).

In your other scene (other side of the wormhole), add your object (sphere) and for it's material, assign an Environment Texture (not an Image Texture), and pick the saved image you rendered. Use Reflection Texture Coordinates so the "wormhole image" will change perspective as you rotate the camera. (If you lower the roughness, the sphere will even reflect the current world environment, while still showing the "wormhole" environment inside)