Creates a square block with the size defined by xsize, zsize and zsize. The surface is shaded with the algorithm and surface parameters specified by shaderhandle. The block is centered about the origin.
Texture is the texture mapping algorithm to use for the object. The NATURAL texture mapping is similar to CYLINDRICAL but the x coordinate is not taken from projection on a cylinder but is evenly distributed around the perimeter. An odd thing in all the 2D mappings (all except WORLD) for the block is that the top face will have texture coordinates (0.0, 1.0) while the bottom will get (0.0, 0.0). Optional, WORLD is the default.
An object handle that references the new object is returned.