I suppose that the column/row defining perspective/frustum is the one not used by translation... matrices have simply an overhelming amount of properties, that's totally flipping. Dark magic I'm outgalinette wrote:Homogeneous coordinates. An application of a math object known as "projective spaces". Hyper-useful for rasterized 3D.CTZn wrote:Seriously what are the fourth line and column for ?
For making it short, it generalizes the transformation matrix to translations, frustum projections, etc... using a 4x4 matrix. You can combine all the transformations (rotaton, scaling, skew, translation, perspective, etc...) just by multiplying 4x4 matrices, and with the resulting 4x4 matrix you have a transformation that will change object-local vertex coordinates into screen space coordinates in one matrix-vector multiplication. Isn't that magic?

Whatever the word play is about Headroom I abide by. I'm just getting a better notion of the properties of multiplications...
You should know that it took me about one week to get this guy right:
Code: Select all
periodX = fract(
paramTilesX() * texi() + paramMortarWidth() / 2.0
) / paramMortarWidth() * 3.14159265


What it does is to insert half a sin wave between two tiles whatever their spacing is. I should have asked for help much earlier, every day I was certain it would be the day I'd crack it... madness.