Drape Control Point Spacing



I’m having difficulties controlling the control point spacing when using the Drape command in Rhino. I’m using AutoSpacing=Yes, Spacing=15, AutoDetectMaxDepth=Yes. The control points of the resulting surface are not at the desired spacing of 15 and appear to vary depending on the positioning of the camera. It is important that I can control the location and spacing of the resulting control points in the XY plane so that I can repeat the same procedure on other meshes. I’ve also experimented with AutoSpacing=No but am experiencing similar problems.

Any help is appreciated.

(Pascal Golay) #2

Hi JBurd- how does that work if you set AutoSpacing=No?



Sorry for butting into this thread, but I think my questions may be inline with JBurd’s…

I find the options for this command unintuitive. Unfortunately the Help on this is a bit cryptic.
-Why is the spacing value the inverse of the surface density?
-What exactly does that number correspond to? I seem to remember that the command was based on the viewport resolution(?), then does the number correspond to pixels between surface points?
-If the Spacing-No option is selected, the “u” and “v” numbers are completely different than the “Spacing” numbers. To what do these numbers correspond?



I’m draping in the XY plane. If I set AutoSpacing=No, define a square drape region, and set equal number of control points in the u- and v- directions, I would expect the resulting drape surface to have control points with equal spacing in the x- and y- directions - correct? This is not the result that i’m getting.

(Pascal Golay) #5

Hi all- this thing is a view-based, pixel based thing so spacing density (auto spacing) is in pixels - i.e. smaller = denser., more distant view = looser. As far as I can see, setting the point count explicitly seems to be predictable so far- spacing is even except at the the edges- is that what you see?

(I don’t think this command has got any love in a loooong time, I agree it is not what it should be. I also find it odd that the output is degree 2- there may well be a good reason for this, but it seems odd to me…)



It would be great if it got some love. It gets used here for making site models. Not necessarily the best tool for the job, but sometimes useful for consolidating a lot of messy surfaces.

(Syburnmcdonald) #7

Is there another tool the recreates laying a table cloth or sheet over an object and falling naturally like cloth?