Creating mountains from topo data for 3D printing (noob)

Hi All,

I’m a total Blender (and 3D modeling) noob.

What I’d like to do is export an stl file of a mountain range that I can 3D print.

I have a greyscale png file (that represents elevation levels) I extracted from some USGS data and imported into Blender using Import > “Images as planes.”

I switched to edit mode and subdivided into 500 cuts.

Back in object mode, I applied a displacement modifier of the texture I imported, setting UV coordinates and the strength to 0.25.

I have a few questions:
Say my png image is 2500x2200 pixels, is the plane that is created the same proportions?

Most important: How do I get rid of the edges that are created (see image)?

How should I subdivide a plane to maximize resolution based on the resolution of the image I start with?

Is there a better way to do this than how I am doing it?

Any other advice you’d like to offer?

Thanks,
Scott


I switched to edit mode and subdivided into 500 cuts.
Use a subdivision surface modifier above the displacement modifier. You can then add additional subdivisions non destructively and have different levels for the viewport and at render/export time.

Say my png image is 2500x2200 pixels, is the plane that is created the same proportions?
The plane has the resolution of the subdivision you’ve given it. If the plane is made of 100 faces, even if you applied a texture that is 10000x10000 pixels, it will still only consist of 100 faces.

Most important: How do I get rid of the edges that are created (see image)?
edit your source texture or apply the modifier and delete the vertices

How should I subdivide a plane to maximize resolution based on the resolution of the image I start with?
That’s up to you. The more subdivisions the larger the stl file will be and the more taxing it will be on your computer to export it. Why not just try it yourself and see if you get any benefit with higher subdivisions.

Thanks for the quick reply, Richard.

In regards to the edges: the source texture doesn’t have those edge artifacts - it looks like they are created because Blender is tiling the image. I found in the image mapping properties that I should choose the “extend” extension - this does exactly what I want.

Next question: how can I “extrude” this surface to make it a 3D ‘cube’ with the texture only on the top (i.e. something I can 3D print)?

I’ve been doing a lot of google searching, but not finding the information that I need. I realize this is pretty elementary stuff for you folks, but it’s a whole new world for me.

Thanks,
Scott

Several ways:

  • Edit mode: select all and from Menu - Select Select Boundary Loop. Extrude down, scale z zero, F or try Space bar - Grid Fill and it’s options on T panel.

  • Solidify modifier. Apply and scale selected bottom vertices z 0.

  • Could start out of flattened cube and assign top faces minus border row of faces to a new Vertex group having Weight=1 which you then use in Displacement modifier. The rest of the faces (Ctrl-I) should have Weight=0; weights are assigned right below Vertex Groups on Object Data tab.