Camera simulation system
First Claim
1. A computer implemented method for rendering a three dimensional scene to generate a two dimensional image, the method comprising the steps of:
- (a) computing an exit pupil of a lens system;
(b) selecting a ray that passes through the exit pupil to an image point on an image plane;
(c) tracing the ray from the three dimensional scene through the lens system to the image point;
(d) calculating a radiance value for the ray;
wherein the calculation of the radiance value for the ray in step (d) comprises setting the radiance value to zero if the ray is vignetted;
(e) repeating steps (b)-(d) to obtain a plurality of radiance values; and
(f) combining the plurality of radiance values to generate the two dimensional image on the image plane.
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Accused Products
Abstract
A physical camera is modeled to render an image in a computer graphics system. When given the manufacturer'"'"'s specifications of the physical camera'"'"'s lenses, including the dimensions and indices of refraction of its lenses, stops, and shutter characteristics, the location of the film surface relative to the lens system, and the orientation of the camera within the scene, the invention accurately and efficiently mimics the physical principles of image formation creating an image which approximates an image produced by the physical camera. The procedure comprises four main elements: (1) the geometric relationships between the lens system, object, and film plane are modeled by precise placement and movement of lens elements, (2) image geometry is computed by using principles of geometric optics, (3) an exit pupil is calculated in order to define a region for efficiently sampling rays, (4) the image irradiance, or exposure at a pixel, is computed according to radiometric principles.
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Citations
25 Claims
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1. A computer implemented method for rendering a three dimensional scene to generate a two dimensional image, the method comprising the steps of:
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(a) computing an exit pupil of a lens system; (b) selecting a ray that passes through the exit pupil to an image point on an image plane; (c) tracing the ray from the three dimensional scene through the lens system to the image point; (d) calculating a radiance value for the ray; wherein the calculation of the radiance value for the ray in step (d) comprises setting the radiance value to zero if the ray is vignetted; (e) repeating steps (b)-(d) to obtain a plurality of radiance values; and (f) combining the plurality of radiance values to generate the two dimensional image on the image plane. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A computer implemented method for rendering a synthetic two dimensional image of a three dimensional scene in a manner that accurately simulates a physical lens system, the method comprising the steps of:
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(a) computing an exit pupil of the lens system; (b) selecting a ray that passes through the exit pupil from a point on the image surface; (c) tracing the ray through the lens system to determine an ultimate direction of the ray in object space; (d) repeating steps (b)-(c) to obtain a first plurality of directions for a first plurality of rays; (e) computing from the first plurality of rays and the first plurality of directions a selected second plurality of rays and a second plurality of directions; wherein step (e) includes the use of a thick lens approximation; (f) calculating radiance values for the second plurality of rays; and (g) combining the plurality of radiance values to compute an image value at each pixel. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
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25. A computer implemented method for rendering a three dimensional scene to generate a two dimensional image, the method comprising the steps of:
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(a) computing an exit pupil of a lens system, wherein the exit pupil defines a boundary between rays blocked by the lens system and rays passing through the lens system; (b) selecting a ray that passes through the exit pupil to an image point on an image plane; (c) tracing the ray from the three dimensional scene through the lens system to the image point; (d) calculating a radiance value for the ray; (e) repeating steps (b)-(d) to obtain a plurality of radiance values; and (f) combining the plurality of radiance values to generate the two dimensional image on the image plane.
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Specification