A Practical Real-Time Model for Diffraction on Rough Surfaces

Olaf Clausen, Martin Mišiak, Arnulph Fuhrmann, Ricardo Marroquim and Marc Erich Latoschik
In: Journal of Computer Graphics Techniques

Upper row: The macro photo on the left shows a rough aluminum sample under a forward- (upper half) and backscattering (lower half) case. On the right, renderings with our new RGB model, including speckle patterns, the original spectral approach by Clausen et al. [2023] and the Cook-Torrance GGX model are depicted. Lower row: The teapot renderings demonstrate the visual impact of diffraction-induced color shifts and speckle patterns.










Wave optics phenomena have a significant impact on the visual appearance of rough conductive surfaces even when illuminated with partially coherent light. Recent models address these phenomena, but none is real-time capable due to the complexity of the underlying physics equations. We provide a practical real-time model, building on the measurements and model by Clausen et al. [2023], that approximates diffraction-induced wavelength shifts and speckle patterns with only a small computational overhead compared to the popular Cook-Torrance GGX model. Our model is suitable for Virtual Reality applications, as it contains domain-specific improvements to address the issues of aliasing and highlight disparity.


Paper Preprint

Link to preprint version (high resolution)
 Link to preprint version (low resolution)

Unity VR-Demo


Unity Source Code




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