| 1. |
- Akenine-Möller, Tomas, et al.
(författare)
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Efficient Depth of Field Rasterization Using a Tile Test Based on Half-Space Culling
- 2012
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Ingår i: Computer Graphics Forum. - : Wiley. - 1467-8659 .- 0167-7055. ; 31:1, s. 3-18
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Tidskriftsartikel (refereegranskat)abstract
- For depth of field (DOF) rasterization, it is often desired to have an efficient tile versus triangle test, which can conservatively compute which samples on the lens that need to execute the sample-in-triangle test. We present a novel test for this, which is optimal in the sense that the region on the lens cannot be further reduced. Our test is based on removing half-space regions of the (u, v) -space on the lens, from where the triangle definitely cannot be seen through a tile of pixels. We find the intersection of all such regions exactly, and the resulting region can be used to reduce the number of sample-in-triangle tests that need to be performed. Our main contribution is that the theory we develop provides a limit for how efficient a practical tile versus defocused triangle test ever can become. To verify our work, we also develop a conceptual implementation for DOF rasterization based on our new theory. We show that the number of arithmetic operations involved in the rasterization process can be reduced. More importantly, with a tile test, multi-sampling anti-aliasing can be used which may reduce shader executions and the related memory bandwidth usage substantially. In general, this can be translated to a performance increase and/or power savings.
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| 2. |
- Munkberg, Jacob, et al.
(författare)
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Backface culling for motion blur and depth of field
- 2011
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Ingår i: Journal of Graphics Tools. - 2151-237X. ; 15:2, s. 123-139
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Tidskriftsartikel (refereegranskat)abstract
- For triangles with linear vertex motion, common practice is to backface cull a triangle if it is backfacing at both the start and end of the motion. However, this is not conservative. We derive conservative tests that guarantee that a moving triangle is backfacing over an entire time interval and over the area of a lens. In addition, we present tests for the special cases of only motion blur and only depth of field. Our techniques apply to real-time and offline rendering, and to both stochastic point sampling and analytical visibility methods. The rendering errors introduced by the previous technique can easily be detected for large defocus blur, but in the majority of cases, the errors introduced are hard to detect. We conclude that our tests are needed if one needs guaranteed artifact-free images. Finally, as a side result, we derive time-continuous Bézier edge equations.
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| 3. |
- Gribel, Carl Johan, et al.
(författare)
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Theory and Analysis of Higher-Order Motion Blur Rasterization
- 2013
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Ingår i: HPG '13 Proceedings of the 5th High-Performance Graphics Conference. - New York, NY, USA : ACM. - 9781450321358 ; , s. 7-15
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Konferensbidrag (refereegranskat)abstract
- A common assumption in motion blur rendering is that the triangle vertices move in straight lines. In this paper, we focus on scenarios where this assumption is no longer valid, such as motion due to fast rotation and other non-linear characteristics. To that end, we present a higher-order representation of vertex motion based on Bézier curves, which allows for more complex motion paths, and we derive the necessary mathematics for these. In addition, we extend previous work to handle higher-order motion by developing a new tile vs. triangle overlap test. We find that our tile-based rasterizer outperforms all other methods in terms of sample test efficiency, and that our generalization of an interval-based rasterizer is often fastest in terms of wall clock rendering time. In addition, we use our tile test to improve rasterization performance by up to a factor 5x for semi-analytical motion blur rendering
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| 4. |
- Munkberg, Jacob, et al.
(författare)
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Per-Vertex Defocus Blur for Stochastic Rasterization
- 2012
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Ingår i: Computer Graphics Forum. - : Wiley. - 1467-8659 .- 0167-7055. ; 31:4, s. 1385-1389
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Tidskriftsartikel (refereegranskat)abstract
- We present user-controllable and plausible defocus blur for a stochastic rasterizer. We modify circle of confusion coefficients per vertex to express more general defocus blur, and show how the method can be applied to limit the foreground blur, extend the in-focus range, simulate tilt-shift photography, and specify per-object defocus blur. Furthermore, with two simplifying assumptions, we show that existing triangle coverage tests and tile culling tests can be used with very modest modifications. Our solution is temporally stable and handles simultaneous motion blur and depth of field.
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| 5. |
- Munkberg, Jacob, et al.
(författare)
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Hyperplane Culling for Stochastic Rasterization
- 2012
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Ingår i: Eurographics 2012: Cagliari, Italy - Short Papers. - 1017-4656. ; , s. 105-108
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Konferensbidrag (refereegranskat)abstract
- We present two novel culling tests for rasterization of simultaneous depth of field and motion blur. These tests efficiently reduce the set of xyuvt samples that need to be coverage tested within a screen space tile. The first test finds linear bounds in ut - and vt -space using a separating line algorithm. We also derive a hyperplane in xyuvt - space for each triangle edge, and all samples outside of these planes are culled in our second test. Based on these tests, we present an efficient stochastic rasterizer, which has substantially higher sample test efficiency and lower arithmetic cost than previous tile-based stochastic rasterizers.
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| 6. |
- Munkberg, Jacob, et al.
(författare)
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Hierarchical stochastic motion blur rasterization
- 2011
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Ingår i: HPG '11 Proceedings of the ACM SIGGRAPH Symposium on High Performance Graphics. - New York, NY, USA : ACM. - 9781450308960 ; , s. 107-118
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Konferensbidrag (refereegranskat)abstract
- We present a hierarchical traversal algorithm for stochastic rasterization of motion blur, which efficiently reduces the number of inside tests needed to resolve spatio-temporal visibility. Our method is based on novel tile against moving primitive tests that also provide temporal bounds for the overlap. The algorithm works entirely in homogeneous coordinates, supports MSAA, facilitates efficient hierarchical spatio-temporal occlusion culling, and handles typical game workloads with widely varying triangle sizes. Furthermore, we use high-quality sampling patterns based on digital nets, and present a novel reordering that allows efficient procedural generation with good anti-aliasing properties. Finally, we evaluate a set of hierarchical motion blur rasterization algorithms in terms of both depth buffer bandwidth, shading efficiency, and arithmetic complexity.
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