How to model these sand shapes


Can you advice me on how I would be able to model these shapes in the best way?

Dear Diana, what purpose to you need the Data for ? just some visualisation or a big scale weather simulation or local Turbulences …
will mesh / polygon Data do the job ?
Do you really need nurbs-Surfaces ?
What experience do you have with rhino ?
this will help to answer the question.


I would import this picture into Rhino and trace over the obvious contours already drawn in the illustration. From there you can convert the curves into surfaces. and add in elevation contouring by using the points on command so that the surface points can be selected and moved upwards on the z-axis.

each example is a little different… so specifics will vary but the general principles of tracing, creating surfaces, and then re-contouring the surface (altering z-axis elevations) will be similar for all of them.

Command summary for Example B in this illustration would be:

  1. PictureFrame (to import the image).
  2. Curves (for tracing over the image).
  3. Sweep2

with the surface selected from the Sweep2 command.

  1. turn PointsOn
  2. and start selecting some points, and Move them upwards on the z axis.

the surface contours will follow accordingly and you turn off the point with the PointsOff command.

for selecting an entire row or column of points (with one point already selected) use SelU and/or SelV to get all of the others added to the active selection… Then go in and move the gizmo tools z-axis to move the entire row upwards.

BUT, you probably don’t want to have all of the points in the same row at the same height, so at point individual control points can be moved as you see fit, once the basic form start shaping up.

Better still:

You can abandon the illustration and model a little larger example of it… and probably get better results.

For example… You can use the points command directly on the original contour curves that you draw… so that they already have elevations build into them prior to using the Sweep2 command. Doing this will save you from having to rework so much of the vertical contour… and Rhino will have few problems drawing a surface that follows along with the changes in elevation that you add into the paths.

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Thank you so much for your elaborate explanation! :pray: