🤖 AI Summary
This study addresses the challenges of low accuracy, high computational cost, and the difficulty of unifying real-time rendering with differentiable optimization in vector graphics rasterization. To this end, this work proposes Windfoil, an algorithm that for the first time treats both tasks as a unified problem. By deriving a closed-form analytical solution for the box-filtered winding number of quadratic Bézier contours, it eliminates the need for approximate sampling and enables efficient, GPU-friendly computation. Experimental results demonstrate that Windfoil surpasses Skia and Slug in rendering fidelity while maintaining comparable performance. Furthermore, in differentiable optimization tasks, it achieves equivalent or superior reconstruction quality with substantially reduced per-step computational costs, thereby supporting interactive rendering of scenes comprising tens of thousands of shapes.
📝 Abstract
We present Windfoil, a GPU-friendly algorithm that treats rasterisation and differentiable vector graphics as two sides of the same problem by evaluating the box-filtered winding number of quadratic Bézier contours in closed form. We implement this in WebGPU, allowing it to run across a range of environments, including a web browser on a consumer laptop, and apply the system to real-time 2D rendering, high-resolution rasterisation for print media, and a differentiable renderer. We compare our renderer against Skia, a production-grade engine, and Slug, a popular GPU rasterisation algorithm for games and real-time applications, measuring fidelity to a reference box-filtered coverage. Our renderer matches the reference more closely than either, at performance comparable to Slug. We also compare our optimiser against DiffVG and Bézier Splatting, where it reaches equivalent or better reconstruction quality at a fraction of the per-step cost, scaling to tens of thousands of shapes at interactive rates.