Asteroids and rocks in Blender

Pieced together from various tutorials around the net, which tend to be focused on rendering an asteroid. We don't want to render an asteroid, we want an asteroid mesh.

Basic shape

• Start with an icosphere. I've given mine 4 subdivisions, and made it 500m radius.
• Add a lattice. Scale it appropriately to the icosphere - mine has 1000m edges.
• Add a 'Lattice deform' modifier to the icosphere, and link it to the lattice. Don't hit apply yet.
• Select the lattice, tab to edit mode, then give your asteroid its overall shape. You might want to increase the number of control points on the lattice.

Surface

Now were going to add 'noise' to the surface, using textures to generate it.

• Switch to Textures panel, and create two textures, one for the fine detail, one for larger perturbations.
• Set one to 'Clouds', and increase its size. 5 seems to work.
• Set one to 'Distorted noise', and increase its size to something bigger, say 100.
• Select the asteroid, and add 'Displace' modifiers, attaching them to the textures you've just created. Adjust 'Strength' appropriately. Numbers in the 10 - 200 range seem sane for an asteroid of this size.

Adding lumps

Before this stage, you'll need to apply the modifiers you've created to update the mesh.

• Tab to edit mode, ctrl-tab to vertex mode.
• Turn on 'Proportional editing mode' with the 'o' key. Choose an appropriate 'Proportional editing falloff' on the menu at the bottom.
• Hold the 'g' key and scroll the mousewheel to set 'Proportional size' to 100 or so. You can now manually add some natural looking lumps by grabbing several vertices at a time.

Textures and properties

Switch shading mode to 'Smooth'.

Craters and pockmarks

Haven't got that far yet, run out of polygons again... :-)

Tutorials and links

Lattice: http://www.youtube.com/watch?v=dfz0dTl7aeM Asteroid: http://www.youtube.com/watch?v=o7SdmYKirLI Rock generator script: http://wiki.blender.org/index.php/Extensions:2.6/Py/Scripts/Add_Mesh/Rock_Generator