This shader assumes the entire scene is enclosed in a mapped sphere.
TAG   is the tag for the Texture Shader.
ROT   is the rotation about the world Y axis.
MASK  controls the blending method.
BLEND controls the amount of blending.

This must be connected to a soft_color_2D Texture Shader box;
which contains the miTag and mapping features for a texture file.

This must be a scalar.  The default is 0.0, no rotation.
This is used to control the animation of the reflection.
The rotation is about the world Y axis.

This must be an interger.  The default is 0, always opaque.
This controls the blending method, the alpha of the texture.
0 = always opaque 1 = use texture alpha 2 = use texture intensity
The result of the MASK calculation is multiplied by the BLEND factor.

This must be a scalar.  The default is 1.0, opaque.
This controls the amount of blending, 0 ignores the texture.
The BLEND factor is multiplied by the result of the MASK calculation.

This returns a EnvTex pointer to the Texture Shader for soft_env_sphere.