Rock Tutorial

Credit: https://www.youtube.com/watch?v=4EqLyGsu3AA, https://www.youtube.com/watch?v=nJ0PM7m9TJc

Blender Steps:

-Highpoly Stage

Subdivide the cube, displacement it using voronoi texture with global texture coordinate.

Find a PBR rock texture online, import it using Node Wrangler Addon.

Create Brighten edges: HueSaturationValue, Geometry/pointiness, ColorRamp, Multiply, Mix Color

Create Randomness: Object Info/Random, Custom ColorRamp, Overlay

-Lowpoly Stage

Duplicate the Highpoly, Decimate (by angle method is not friendly to physics engines), Apply Modifier, Vertex/AutoSmoothing, Smart UV Projection.

Create a new material for the lowpoly. Create Image Texture. Render/Bake tab, increase ray distance, selected to active.

For lighting, can consider darken the ground side

Select highpoly then lowpoly then texture node. Bake Combined. Bake Normal. Save Normal map to the disc and select Non-Color color space.

Export FBX. only selected obj, only mesh