Is this Boolean difference?


Does anyone know how I go on about to model something similar to this (see img) but with my own design and spatial organization?


Sure, You can use Boolean Difference here (for all of the cut out areas)… and also Boolean Union (for all of the raised areas).

But you’ll need to start off with a Ground Plane to establish where the middle (common) ground is, so that all of the cut outs or raised areas will be relative to that surface.

You can also decide if you want the ground plane should be flat, or have some contour to it (…as most terrain usually will).

For a flat ground plane you can just use the Plane command, and draw in a wide rectangle.

To add some contouring to the ground plane… use the Rebuild commands and increase the Point Count. Activate the PointOn command to select some, and move them around on the z-axis.

Once you have you’re ground surface sorted out… you can use any number of shapes to add or subtract additional contours. I usually like to draw out my curves and profile shapes… and then extrude them, or run the Loft command between them to generate surfaces.

In your photo you would be able to get a lot of use just by using Rhino’s Sphere tool.

The animation below is showing a rectangular curve being converted into a surface which will originally only have control point around it’s perimeter.

The Rebuild command it then used to add in extra control points… and with the PointOn command all of those control points are visible, and you select them to change the surface contour by moving them along the z-axis.

To add extra thickness to the surface OffsetSrf was used… followed by the Split command in order to create a flat bottom for the results of the OffsetSrf command.

The Rest is just a Sphere being added in,… flattened out a little bit,… and positioned to set up for the Boolean Difference, and Boolean Union Commands.

You obviously don’t need to do all of these things. the surface doesn’t have to be contoured, or have extra thickness added to it, only to turn around and cut some of it off so it can have a flat bottom. I added some this stuff in because of your other topics which you posted up recently… and in some way’s this reminded me of those… mainly the tidal (/wind) effects on sandy beaches.

In any event, another command that is useful when trying to superimpose a design onto any surface is the Project command. That would be worth taking a look at to see you find it useful for getting you designs transferred onto other objects in Rhino.

Take Care and good luck,

Jim D


you may want to give that heightfield another thought i have seen it was discussed in one of your former topics but dont give up on it that fast. paint your landscape in any photoeditor photoshop like, elevate surfaces make whiter, impressed parts make darker, and load it in as a heightfield. use the command rebuild to get it down to a decent still representative surface and experiment with the command smooth.

depending on your needs that may fulfill it already.

another quick and probably more precise method is to take a surface, draw your elevations as closed curves or at least touching the boundary of the surface, split the face with those curves then subselect the split edges (ctrl shift) and elevate them carefully. it will rebuild the deformed surfaces as patches with the advantage that the boarders will already fit. at least something to experiment with.