GroundPlane

The ground: the plane y = 0 with the normal (0, 1, 0), the world up of the construct camera.

Declared in src/libs/libconstruct/construct/layers/GroundPlane.hpp.

Detailed description

It is a translucent layer, so it draws after the opaque layers of the roster (SDF, mesh, proxy, tet volume) and tests the depth they publish: a part of a model below the plane is behind the ground, and a surface in front of the plane hides the ground (2026-10-16). The fragment shader intersects each pixel's ray with the plane and writes the window depth of the hit with the convention of the SDF geometry pass.

Each of those passes moves its depth toward the eye by the depth tiebreak of its item's key. The ground reads the G-buffer's raw id under each pixel and moves its depth by the key of that item, with its hovered and selected bits (groundTiebreakKey() in GroundPlane.glsl), so the ground and every item meet where they cross, from every camera angle (plan row 5.18).