has anyone yet found a way of animating background shader to rotate or pan sideways via either animate: or a uniform: call to 'Tunnel A' in the SCN code ?
Rotation of the shader, It can only be done in the shader code.
The fragment is the shape.
So for instance whe use a Quad or a rectangle as the shape.
The shaded then Paints onto that Shape..
It doesnt Matter if the Shape is straight, or Rotated..
The Painting takes place exactly the Same all the time Based on the code in the shader..
It Starts at the top left of the screen
Paints from left to right, then advances down to the next line
and paints that line.
Where ever the frgament is, it recieves color from the shader.
So if the fragment is rotated on an Angle like in your Picture.
then only that part of the fragment gets color applied by the shader.
Think of it like an Injet Printer..
If you print an Image on a full sheet of paper you get the FUll Image.
If you cut the paper into a Diamond shape
then Only that Portion of the Paper gets Ink.
Doesn't matter how you rotate the blank paper, the Ink is still printed from left to right