Kaplanyan, Anton S.Hill, StephenPatney, AnjulLefohn, AaronUlf Assarsson and Warren Hunt2016-06-172016-06-172016978-3-03868-008-62079-8679https://doi.org/10.2312/hpg.20161201High-frequency illumination effects, such as highly glossy highlights on curved surfaces, are challenging to render in a stable manner. Such features can be much smaller than the area of a pixel and carry a high amount of energy due to high reflectance. These highlights are challenging to render in both offline rendering, where they require many samples and an outliers filter, and in real-time graphics, where they cause a significant amount of aliasing given the small budget of shading samples per pixel. In this paper, we propose a method for filtering the main source of highly glossy highlights in microfacet materials: the Normal Distribution Function (NDF). We provide a practical solution applicable for real-time rendering by employing recent advances in light transport for estimating the filtering region from various effects (such as pixel footprint) directly in the parallel-plane half-vector domain (also known as the slope domain), followed by filtering the NDF over this region. Our real-time method is GPU-friendly, temporally stable, and compatible with deferred shading, normal maps, as well as with filtering methods for normal maps.I.3.7 [Computer Graphics]Three Dimensional Graphics and RealismColorshadingshadowingand textureI.3.3 [Computer Graphics]Antialiasing10.2312/hpg.20161201151-162