What is going on with tangents? On a ground plane unwrapped (Project from view, bounds), the resulting output is a solid red (1,0,0). That works great for controlling aniso rotation using a 0/0.25 checker pattern for a tiled floormat thingy.
However, if I simply assign the color red, I get weird blocks possibly indicating corrupted data or something. If I mix it with 0.00001 z radial tangent, it works again. Same if I go through a vector transform point/world/world which to me logically does absolutely nothing. So why do these work and a solid color fail?
What would be the proper, least computationally heavy way, of assigning a simple color to define tangent in order to override the default radial tangent without UV unwrapping?