Multi-level stroke textures for sketch based non-photorealistic rendering

This paper presents a novel method for sketch based rendering of three-dimensional models using a single texture containing multiple levels of stroke distributions. The proposed method eliminates the need for loading several mipmapped sequences of images in a tonal art map. Instead, stroke textures are embedded into different levels of the intensity range to create a single texture. Appropriate values of the intensity threshold and texture scale parameter are then computed to map stroke lines with the required density and resolution to polygonal elements. Most computations are performed inside the geometry shader of the OpenGL-4 pipeline. Various aspects of non-photorealistic rendering including edge rendering, curvature alignment, procedural stroke generation and texture computations are discussed. The paper also details the complete implementation aspects of the proposed method, and provides some experimental results.