UT, VT and UV release different pairs of emitter position and travel distance. Rotate the camera query to expose a plane’s grazing direction, then combine their densities with MIS.
A larger emitter enlarges the UV sheet and changes the balance between UV, UT and VT. It does not remove the angle between a sheet and the camera ray: each individual orientation still has a grazing condition.
All three named plane members have simple linear crossing tests. MIS evaluates the three compatible densities. Its benefit is robustness across viewing directions; on some scenes the best single plane remains cheaper at equal error.
Aᵤᵥ = L² |n·d| qₜ; Aᵤₜ = |(eᵤ × ω)·d|; Aᵥₜ = |(eᵥ × ω)·d|
wᵢ = pᵢ / Σⱼ pⱼ
These are the native local density numerators after the shared qω / t² factor cancels, for a square emitter of edge L and the same supported event (x,y). Arbitrary orientation is shown independently; it is not silently added to the three-plane mixture.
Computed geometry and local density ratios, derived from RadianceLab’s transport implementation. Line density, tube shading and glow are diagram styling. No native film, convergence curve or frame-time benchmark runs here.