# How to create an infinite plane in cycles?

I have already found one similar question, however it doesn't correctly address what I am talking about.
I have only found this, and this, but both use a curved plane to do the trick, which would work unless the object is to be rotated(in animation) to view from every angle.

Yes, again we could rotate the object instead of the camera but, what about a large array of object, that would really distort the scene and setting the camera accordingly would be very difficult.

Setting the camera at this angle would be good even for a large array of objects:
, but what if we need a more acute view like this:
, (even if we set the world background color to white this would be impossible to actually blend if taking the lighting into account, as it would emit light and the edges of planes would be visible.)

I don't know if there is a workaround with the lightpath node with this to only make the area where the shadow falls visible.
And I don't know how to take only the shadow information into the compositor to make this?

Primarily focusing two problems:
1) how to make such a world in cycles, infinite, only the shadow information and the object?
2) How to make such a world in cycles, infinite, only the shadow information and the object and a slight gradient in the infinite world?

Therefore, I resolved here.

• Imagine real world sitaution where you make photoshots for advertisment. Let say it's beer can. Do you rotate whole photo studio with it or just the can? If you don't care about light changing around object (when using HDRI) you can always rotate back plane with camera. Sep 15, 2016 at 9:52
• For that case you don't really create infinite ground plane, rather than setup adjacent world background and composite object with its shadows and the rest with nodes. See blender.stackexchange.com/questions/17877/… and blender.stackexchange.com/questions/518/… Sep 15, 2016 at 19:47
• Mr Zak, that would give me a gray background and objects on top of the shadow would be masked Sep 16, 2016 at 1:50

It's not really possible to create a truly infinite plane in blender, but such a plane wouldn't help you isolate an object on a uniform background. Even an infinite plane still has a horizon.

To isolate an object (with its shadow) against an arbitrary background, what you really want is a shadow catcher. This is an object which renders as alpha transparency except where shadows fall on it. With a large plane acting as a shadow catcher, we can easily render transparent images with shadows. Using an alpha-over node in the compositor, any background can then be inserted with ease:

Cycles doesn't quite have this feature yet, but development on it is well underway and a working version (used to produce the above image) should be in development builds soon.

Unless you care to compile blender yourself (it's not as hard as it sounds!), you'll have to wait for a little while yet to use this.

## Bent backdrop

If you just want to mitigate the distracting contrast of a hard horizon, perhaps a backdrop with a bent bottom section such those used in studio photography will do:

See What is the fastest way to create a curved plane? for a wealth of techniques to create such a shape.

For your case of a turn-table animation, you could rotate the model itself, or, if you wish to keep the lighting constant relative to the model, you could orbit the camera around in a bowl-like shape:

## Perfectly reflective plane

If you create a diffuse ground plane with a color (albedo) of 1, it will reflect all light that hits it. Provided the only source of light near the horizon is the sky, then it will reflect exactly the same amount of light as the sky emits, resulting in a seamless transition:

## Compositing tricks

Using a combination of renderlayers, the shadow pass, and general node trickery, you can probably come up with something which works pretty well in your case. See the following questions for some examples:

• I wish I could give more than just one upvote. Sep 16, 2016 at 12:44
• @BumbleBee I just upvoted, and I'll let you take credit for it. ;)
– user27640
Sep 17, 2016 at 21:18
• The shadow catcher is a part of blender now, see this tutorial youtube.com/watch?v=lXJca9D_TRM
– Oli
Mar 31, 2022 at 12:59