{'fraction_non_alphanumeric': 0.014857142857142857, 'fraction_numerical': 0.0, 'mean_word_length': 5.079861111111111, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Project Assignment Relief Texture Mapping using Hardware Shaders

This report presents an approach for generating and displaying relief textures using hardware shading capabilities found in the latest generation of consumer graphics boards. A relief texture is a texture that has an orthogonal depth value per pixel. This can be used to generate new textures that are able to simulate parallax movement and the illusion of three-dimensional information on a flat surface. The relief texture representing the new view is generated mainly using fragment shading, where a small program is run for each textured pixel of the output image. Since the original relief texture mapping algorithm calculates new positions and colors given a certain input texel, we had to find a way to " invert " this and find the place to sample correctly given a certain output texel position. This inversion is non-trivial since the problem is not one-to-one. Our approach to solving this problem uses a technique resembling the Occlusion-Compatible Ordering presented by Oliveira. Using fragment shaders the warping is performed at a per-pixel basis instead of on the entire texture at once. To speed up the per-pixel algorithm, the amount of texels to scan is reduced by introducing restrictions based on information from the epipolar line and using negative displacement values. A shader-based implementation of relief texture mapping has the potential to increase the frame rate and visual appearance of relief textures many times, compared to software-based implementations. Pixel shaders also form a suitable framework to further improve relief texture mapping with sophisticated lighting techniques such as environment mapping and realistic lighting with HDR images.