I wounder whats the difference between xfade, alphablend, jit.op @*

Illustrated in the patch below. (save and reopen it to get all the loadbangs and loadmess)

difference-between-xfade-alphablend-jit-op

jit.alphablend is only for ARGB matrices, not vertex data. it blends two ARGB matrices together based on the alpha plane of the first matrix input.

jit.xfade is simply two jit.op @op * and one jit.op @op +

but why does the area move towards upper right when you increase xfade $1?

and how can I keep the area at the same spot if im using the matrixoutput turn off and matrix output turned on. I dont want the noise to move it towards the upper right. I want to keep it centrated

but why does the area move towards upper right when you increase xfade $1? 

and how can I keep the area at the same spot if im using the matrixoutput turn off and matrix output turned on. I dont want the noise to move it towards the upper right. I want to keep it centrated


Because jit.noise outputs normalized values in the range of 0 - 1. In OpenGL, 0. is the center coordinate of the GL world. To center your noise values in GL space, you can remap the output of jit.noise using jit.op or jit.map to a range where 0. is the center, for example jit.map @map 0 1 -1 1 or jit.op @op - @val 0.5.

Because jit.noise outputs normalized values in the range of 0 - 1. In OpenGL, 0. is the center coordinate of the GL world.  To center your noise values in GL space, you can remap the output of jit.noise using jit.op or jit.map to a range where 0. is the center, for example jit.map @map 0 1 -1 1 or jit.op @op - @val 0.5.


difference between xfade, alphablend, jit.op @* ...