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
Microsoft DirectX 9 and HLSL were used to implement Interval
mapping on a GeForce 6800 AGP graphics card.
Image of Interval Mapped displacement after two iterations as
opposed to established method Relief Mapping after the same number
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
we show a close up of a single interval mapped polygon. The stones display a
three dimensional structure.
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.