[Sidefx-houdini-list] transformation follow rgb of image

[herman]

hi all,

this one is done by grasshopper, http://madeincalifornia.blogspot.com/2008/11/circlepattern05.html , i think houdini can also do the task by expression specifying the width and height of cylinder to follow the grey tone of the image.

i remember in "procedural city"dvd, there was an expression- pic("/img/img1/blur2",$CEX,$CEY,D_CR)*0.6 to specify the transforming according to image created in img... i tried to apply the same principle but fail...

wonder if any master here can give enlightment! or any previous example! thanks!

cheers
herman