Used by the [page:CubeCamera] as its [page:WebGLRenderTarget].
See [page:CubeCamera] for examples.
[page:Float size] - the size, in pixels. Default is `1`.
options - (optional) object that holds texture parameters for an auto-generated target
texture and depthBuffer/stencilBuffer booleans.
For an explanation of the texture parameters see [page:Texture Texture]. The following are
valid options:
[page:Constant wrapS] - default is [page:Textures ClampToEdgeWrapping].
[page:Constant wrapT] - default is [page:Textures ClampToEdgeWrapping].
[page:Constant magFilter] - default is [page:Textures .LinearFilter].
[page:Constant minFilter] - default is [page:Textures LinearFilter].
[page:Boolean generateMipmaps] - default is `false`.
[page:Constant format] - default is [page:Textures RGBAFormat].
[page:Constant type] - default is [page:Textures UnsignedByteType].
[page:Number anisotropy] - default is `1`. See [page:Texture.anisotropy]
[page:Constant encoding] - default is [page:Textures LinearEncoding].
[page:Boolean depthBuffer] - default is `true`.
[page:Boolean stencilBuffer] - default is `false`.
Creates a new [name]
[page:WebGLRenderer renderer] — the renderer.
[page:Texture texture] — the equirectangular texture.
Use this method if you want to convert an equirectangular panorama to the cubemap format.
Call this to clear the renderTarget's color, depth, and/or stencil buffers. The color buffer is set to the renderer's current clear color. Arguments default to `true`.
[link:https://github.com/mrdoob/three.js/blob/master/src/[path].js src/[path].js]