Projecting surface points?


(Marc Gibeault) #1

I’m trying to have a surface’s control points lying on a polysurface (to ultimately have this surface act as a custom mapping object).
There must be a better way than what I’m doing;
-Create a simple surface with enough control points (48 x 36 in this case) over the polysurface
-Create a CPlane for the projection direction
-Extract the surface control points
-Project the extracted control points onto the target polysurface
-Lock the projected points
-In a slightly angled view, move every surface control point to the corresponding projected point. That part is time consuming!
I tried Drape but I don’t get the control I want, such as projecting from two different CPlanes.
Thanks


(Brian James) #2

Hi Marc,

PanelingTools ( http://wiki.mcneel.com/labs/panelingtools ) may help a lot here… The two commands that come to mind are ptSurfaceFromGridOfControlPoints and ptSurfaceFromGridOfEditPoints

Here’s a file showing a paneling grid and the projected pts on a polysrf before making the new reference surface.
SrfThroughPts.3dm (202.8 KB)


(Pascal Golay) #3

Hi Marc- see if this script helps- an old one I dug up but it seems to work ok in most cases - not so well if the surface has more than one possible target- like if the surface can be hit twice in the projection direction.

To use the script, extract and save the .rvb file from the attached zip archive, then drag and drop the saved rvb over an open Rhino V4 or v5 window. This will load the script, set it up to load on startup in the future and register the alias

ProjectGrips
PullGrips

that will run the script much like a regular command. An alias can be typed or added to a toolbar button or keyboard shortcut (F-key).

ProjectGrips (2).zip (909 Bytes)
-Pascal


(Marc Gibeault) #4

Thanks Brian and Pascal,
I tried both and the results are pretty close one to another. Pascal’s script is simpler to use in this case.
I found that once I have a surface with an even grid with its control points projected onto my object, if I mesh it with settings to get again an even grid (with an aspect ratio of 1 for example) I have an object that’s pretty good for a custom mapping.
Some work could be done to automate/facilitate this process and get better results (minimal deformation of the grid). This custom mapping option is very powerful but it seems something is missing to use it fully.

Thanks!