Artist builds tileable forest floor in Substance 3D Designer using splines

Environment artist Zeqi Mu has explained how he built a forest ground material in Substance 3D Designer using only procedural nodes. The interview was published by 80 Level on 19 October 2026. His stated goal was to see whether he could reach scan-level quality without scanned data.

The roots were the main problem. He first used the Cells 2 node to generate root shapes, but found it could not reproduce the natural hierarchy of real root systems. He switched to spline generators that "grow" the roots, and used Scatter Splines on Splines to control density and thickness. He kept the density of main roots low on purpose, because fewer dominant shapes reduce visible repetition in a tileable material. He also multiplied several Gaussian noise patterns into the height map to vary elevation and surface shape.

For stones and moss he used the new Shape splatter v2 node. Small stones came from its SDF rock feature, with random values for roundness and facet count set in the function graph so each stone differs. He also placed moss in damp areas with the same node, and says generating moss normals directly from Shape splatter v2 gave better results than deriving them from the combined height map.

The material has many layers. From bottom to top they run: tree roots, large stones, small stones, tiny stones, moss, dead leaves, old twigs, micro-stones, clover, lichen, broken branches, grass, fallen leaves, fallen twigs, more clover and ferns.

For presentation, he used a studio HDRI in Marmoset Toolbag, plus a simple forest-style scene with one directional light and a high-quality HDRI. In Unreal Engine 5 he adjusted the default procedural sky to a sunset look, enabled Nanite displacement on the material and added a subsurface scattering mask to the clover leaves.

Mu says the material took about a week, with the first three days spent on the root spline system. His advice is to study real references first, and to look at how shapes grow and overlap, not only at individual forms. The interview is a first-person account, so the results are his own description.