Interval Mapping: Quick Per-pixel Displacement Mapping

Eric Risser, Musawir A. Shah, Sumanta Pattanaik

Interval Mapping Interval Mapping offers an efficient method for adding per pixel height field based displacement to an arbitrary polygonal mesh in real time. The technique utilizes an interval based method in which bounds of the interval are computed in the beginning and are refined at every iteration until the intersection point is reached. The search space defined by the interval reduces and converges to the intersection point rapidly and outperforms currently popular binary search based method (relief mapping) used for performing this task. We compute the bounds using simple ray segment intersection method. We demonstrate the algorithm and show empirical and explicit evidence of the speedup.

Images

Microsoft DirectX 9 and HLSL were used to implement Interval mapping on a GeForce 6800 AGP graphics card.

A screenshot taken from our nature demo, we demonstrate how Interval Mapping can add an extra level of detail and realism to a scene, while still running in real-time.

Here we show a close up of a single interval mapped polygon. The stones display a three dimensional structure.

Here we show empirical performance results. Images in the first column are rendered normally using interval mapping. Images in the second and third columns show the number of per-pixel iterations required for convergence. The grey levels in these two columns are coded black for 1 iteration, up to white for a maximum of 10 iterations. The second column shows the results from interval mapping while the third column represents relief mapping.

Demo Executables

To be added.

Publications:

Eric A. Risser, Musawir A. Shah and Sumanta Pattanaik.

Paper:

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