algorithmic modeling for Rhino
Tell me please at least where to start?
I would start with something like this;
Probably a good idea to create a sort of 'bump' map with grasshopper, some reading here:
See also this discussion:
This is hasty and I've never used 'Image Sampler' before... There must be more effective (efficient!) ways of doing this because this approach is a MAJOR RESOURCE HOG!!! Getting a great result requires more patience than I have right now. WARNING!! This is painful.
I created a grid and used the brightness filter of the image sampler to set the 'Z' value for all the grid points; then created lines from the points and lofted them. Not sure if nurbs curves ('Degree (D)' = 1?) or polylines work better for the lines. Might want to play with the loft options too.
The more grid points, the higher the resolution but the slower the results. Baking the surface at 178 by 178 (31K total points!) effectively froze my laptop for awhile. But for the stone pattern, the higher the resolution, the better. The 'Scale' and 'jDistance' sliders make a difference too.
You might want to consider sampling one or just a few bricks separately and then repeating the surface in the brick pattern. To keep from freezing up when you open the file, I dropped the 'iNumber' slider from 178 down to 100.
I would also recommend checking out CrazyBump or other similar program. It will do well to convert your the grayscale into a better height map for use in GH since using the image directly as a heightmap is a little funny.
You could also consider simply using a displacement map in rhino.
Still a novice with Image Sampler but learned in another thread about X and Y Domain 'Settings' matching the grid size. This GH uses actual image size (entered manually) for H/W ratio and basis for sample grid size, 'Scale (Sample)'. Set at 0.5, that's 845 X 612 or 517,140 points. Lofting 1-Degree nurbs curves took 17 minutes! Results look good to me. 2-Degree curves loft in 7 seconds, not as "high def" (sharp) as 1-Degree, which are close to polylines.
'Flip' gives curves and loft at 90 degrees.
Code won't load because with Photoshopped image (trimming 'Levels' ), it's 11 MBytes.