tracing ray differentials homan igehy speaker: haoji

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Tracing Ray Differentials Homan Igehy Speaker: Haoji

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Page 1: Tracing Ray Differentials Homan Igehy Speaker: Haoji

Tracing Ray Differentials

Homan Igehy

Speaker: Haoji

Page 2: Tracing Ray Differentials Homan Igehy Speaker: Haoji

• Ray tracing

• ray differentials– derivatives of the ray with respect to image

space coordinates, by applying the derivatives of the functions.

Page 3: Tracing Ray Differentials Homan Igehy Speaker: Haoji
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Initial value

Page 5: Tracing Ray Differentials Homan Igehy Speaker: Haoji

Transfer

Page 6: Tracing Ray Differentials Homan Igehy Speaker: Haoji

Reflection

Page 7: Tracing Ray Differentials Homan Igehy Speaker: Haoji

• If we know the formula for how a ray is affected by a phenomenon, then we can differentiate it to get a formula for how a ray differential is affected without any understanding of the phenomenon

Page 8: Tracing Ray Differentials Homan Igehy Speaker: Haoji

Texture Filtering

• If we can approximate the difference between the texture coordinates corresponding to a ray and its neighboring rays, then we can find the size and shape of a filtering kernel in texture space.

pixel’s footprint in texture spacebased on the pixel-to-pixel spacing:

Page 9: Tracing Ray Differentials Homan Igehy Speaker: Haoji

• Given this parallelogram, one of several texture filtering methods can be used – mip mapping

• level-of-dital =>

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