Deformable Triangle Splatting: Flexible Primitives for Real-Time Radiance Field Rendering

Recent radiance field methods represent scenes with 2D prim-itives that offer surface alignment and efficient rasterization, from Gaus-sian disks to triangles, yet all rely on convex boundaries: curved and con-cave structures demand excessive primitives. We introduce DeformableTriangle Splatting, which augments each triangle with K control pointsper edge, each parameterized by a single learnable scalar displacementthat shifts the boundary inward or outward, enabling non-convex shaperepresentation while preserving the three base vertices that define the 3Dplane. To render these non-convex primitives differentiably, we designa rasterization pipeline in the triangle’s barycentric coordinate space,ensuring view-consistent rendering. A winding number test determineswhether each pixel lies inside the deformed primitive, and a windowfunction controlled by two learnable parameters, sharpness and cornersmoothness, together with a per-primitive scalar opacity, produces thesmooth opacity transition from interior to boundary. Validation is donein a variety of real-world scenes, outperforming recent works based onnon-volumetric primitives in terms of visual quality and versatility whilestill achieving competitive rendering efficiency.Project page: orioljim1.github.io/detris