Topography Mapping onto a Sphere from Topology Maps (planets)

Hi all,

I have recently been commissioned to create some 3d printable models of some of our solar systems planets for full color sandstone printing on shapeways. At first, I was working with other peoples models, like the ones on THIS website and trying to hollow them out to reduce the volume, leaving thin walls, while also adding a clean out hole. The hole was meant to be at the "south pole" of the planet, but every time I tried to Boolean out the insides and add a clean out hole in that location, the boolean failed. However, when I moved the clean out hole to other locations, the boolean difference worked fine.

From doing the meshrepair command, I found that the mesh had a seam that ran from the south to the north pole as shown in this image. I have found that if the clean out hole intersects this seam, the boolean won't work.

I set about to develop a way of making the planets myself, with the ability to control the prominence of features, and hoped to be able to create a closed mesh that could be cleanly booleaned from.

My basic technique was to sample a topology image at the uv coordinates of a flat plane, and then move the vertices of a spherical mesh outwards along their normal vectors based on those values, and then rebuild the mesh. I think the attached definition will make it clearer.

The issue that I'm having is that my new mesh still has the same seam, and there are noticeable gaps along the seam. Does anyone have a better way to do this/ a way to ensure that a closed mesh is made during this process?

Again, I have had success in making 3d printable parts from this method as shown in the screenshots, but I really want to know how to make a clean spherical mesh.

Thanks for the help,

Ben

Attachments:

Surface MAPPING NEW.gh, 356 KB
mars_1k_topo.jpg, 91 KB

Replies to This Discussion

Permalink Reply by Deer on September 14, 2016 at 3:13am

I am not quite sure what you want. Since I never use any plugin in GH since 2009. I don't have human installed.

Here is an example below. Does it solve your problem?

Permalink Reply by BEN WILDE on September 14, 2016 at 6:21pm

Not really. The only thing added in your definition is a vertex color image sampler. The final mesh from this definition is still not closed and able to be booleaned at the south and north poles.

Permalink Reply by Hyungsoo Kim on September 14, 2016 at 10:58pm