I am fairly new to houdini and am wanting to move some points based on an image look up. I have thought of a expression to do it but need to get at the parameters of the pixel or another COP, e.g. image size and pixel channel values.

For example, I what to be able to say in the expression: Move the point up the Y based on the red channel value at this x,y coord. Is there a COP that i can reference these values from?

Thanks

basically exactly how u said it, it will be done

create a File COP - grab a file (any picture)

then create a grid SOP, give a decent resolution, like 30, 30, orient XZ

then connect it to a Point SOP

and then in the TY channel of ur point SOP (transformation along the Y)

type in the following expression

$TY+pic(“/img/img1/file”, $BBX, $BBZ,D_CR)

the $BBX and $BBZ is dependent on how ur orientate ur Grid
D_CR is ur red channel

let me know if there are any problems

aracid

the ‘pic’ function was what i was looking for.

Thanks