Automated stereoscopic computer-animation techniques for determining scaled stereo parameters

1. A computer-implemented method for determining scaled-parallax constraints for placement of a pair of stereoscopic cameras within a computer-generated scene, the pair of stereoscopic cameras having a focal length, the method comprising:

obtaining the focal length of the pair of stereoscopic cameras;

obtaining a lower-bound value and upper-bound value for a range of focal lengths;

obtaining a set of bounded-parallax constraints including a near-parallax value and a far-parallax value;

if the focal length is less than the lower-bound value,

calculating a scaled near-parallax value based on the near-parallax value and a lower-scale factor that is based on the lower-bound value, and

calculating a scaled far-parallax value based on the far-parallax value and the lower-scale factor;

if the focal length is greater than the upper-bound value,

calculating the scaled near-parallax value based on the near-parallax value and an upper-scale factor that is based on the upper-bound value, and

calculating the scaled far-parallax value based on the far-parallax value and the upper-scale factor;

if the focal length is greater than or equal to the lower-bound value and less than or equal to the upper-bound value,

setting the scaled near-parallax value as the near-parallax value, and

setting the scaled far-parallax value as the far-parallax value; and

storing, in a computer memory, the scaled near-parallax value and scaled far-parallax value as the scaled-parallax constraints.

2. The computer-implemented method of claim 1 , wherein the lower-scale factor is computed as a ratio of the lower-bound value divided by the focal length.

3. The computer-implemented method of claim 1 , wherein the upper-scale factor is computed as a ratio of the upper-bound value divided by the focal length.

4. The computer-implemented method of claim 1 , further comprising:

positioning each camera of the pair of stereoscopic cameras relative to each other based on the scaled-parallax constraints;

creating a stereoscopic image of the computer-generated scene with the pair of stereoscopic cameras; and

storing, in the computer memory, the stereoscopic image.

5. The computer-implemented method of claim 1 , further comprising:

calculating a camera separation value and a convergence value for the pair of stereoscopic cameras based on the scaled near-parallax and scaled far-parallax values; and

storing, in the computer memory, the camera separation value and the convergence value.

6. The computer-implemented method of claim 5 , further comprising:

positioning each camera of the pair of stereoscopic cameras relative to each other within the computer-generated scene based on the camera separation value and the convergence value.

7. The computer-implemented method of claim 5 , further comprising:

positioning a camera sensor of the pair of stereoscopic cameras within the computer-generated scene based on the camera separation value and the convergence value.

8. The computer-implemented method of claim 1 , wherein:

if the focal length is less than the lower-bound value,

calculating the scaled near-parallax value as the near-parallax value times a ratio of the lower-bound value divided by the focal length, and

calculating the scaled far-parallax value as the far-parallax value times the ratio of the lower-bound value divided by the focal length; and

if the focal length is greater than the upper-bound value,

calculating the scaled near-parallax value as the near-parallax value times a ratio of the upper-bound value divided by the focal length, and

calculating the scaled far-parallax value as the far-parallax value times the ratio of the upper-bound value divided by the focal length.

9. The computer-implemented method of claim 1 , wherein the lower-bound value is 22 millimeters and the upper-bound value is 28 millimeters.

10. The computer implemented method of claim 1 , wherein obtaining the set of bounded-parallax constraints comprises:

calculating a minimum scene depth, wherein the minimum scene depth is the distance from the pair of stereoscopic cameras to a nearest point of interest in the computer-generated scene;

calculating a near-parallax value based on a focal length of the pair of stereoscopic cameras and the minimum scene depth,

wherein calculating the near-parallax value includes selecting a baseline stereo-setting entry from a set of stereo-setting entries,

wherein each stereo-setting entry of the set of baseline stereo-setting entries includes a recommended scene depth, a recommended focal length, and a recommended near-parallax value,

wherein for the selected baseline stereo-setting entry:

the recommended scene depth corresponds to the minimum scene depth, and

the recommended focal length corresponds to the focal length; and

calculating a far-parallax value based on the focal length.

11. A computer system for determining scaled-parallax constraints for placement of a pair of stereoscopic cameras within a computer-generated scene, the pair of stereoscopic cameras having a focal length, the system comprising:

a computer memory; and

a processor for executing computer-readable instructions, the instructions comprising:

obtaining the focal length of the pair of stereoscopic cameras;

obtaining a lower-bound value and upper-bound value for a range of focal lengths;

obtaining a set of bounded-parallax constraints including a near-parallax value and a far-parallax value;

if the focal length is less than the lower-bound value,

calculating a scaled near-parallax value based on the near-parallax value and a lower-scale factor that is based on the lower-bound value, and

calculating a scaled far-parallax value based on the far-parallax value and the lower-scale factor;

if the focal length is greater than the upper-bound value,

calculating the scaled near-parallax value based on the near-parallax value and an upper-scale factor that is based on the upper-bound value, and

calculating the scaled far-parallax value based on the far-parallax value and the upper-scale value;

if the focal length is greater than or equal to the lower-bound value and less than or equal to the upper-bound value,

setting the scaled near-parallax value as the near-parallax value, and

setting the scaled far-parallax value as the far-parallax value; and

storing, in the computer memory, the scaled near-parallax value and scaled far-parallax value as the scaled-parallax constraints.

12. The computer system of claim 11 , wherein the lower-scale factor is computed as a ratio of the lower-bound value divided by the focal length, and the upper-scale factor is computed as a ratio of the upper-bound value divided by the focal length.

13. The computer system of claim 11 , the instructions further comprising:

positioning each camera of the pair of stereoscopic cameras relative to each other based on the scaled-parallax constraints;

creating a stereoscopic image of the computer-generated scene with the pair of stereoscopic cameras; and

storing, in the computer memory, the stereoscopic image.

14. A non-transitory computer-readable storage medium including computer-readable instructions that when executed on a computer processor cause the computer processor to determine scaled-parallax constraints for placement of a pair of stereoscopic cameras within a computer-generated scene, the pair of stereoscopic cameras having a focal length, the instructions comprising:

obtaining the focal length of the pair of stereoscopic cameras;

obtaining a lower-bound value and upper-bound value for a range of focal lengths;

obtaining a set of bounded-parallax constraints including a near-parallax value and a far-parallax value;

if the focal length is less than the lower-bound value,

calculating a scaled near-parallax value based on the near-parallax value and a lower-scale factor that is based on the lower-bound value, and

calculating a scaled far-parallax value based on the far-parallax value and the lower-scale factor;

if the focal length is greater than the upper-bound value,

calculating the scaled near-parallax value based on the near-parallax value and an upper-scale factor that is based on the upper-bound value, and

calculating the scaled far-parallax value based on the far-parallax value and the upper-scale factor;

if the focal length is greater than or equal to the lower-bound value and less than or equal to the upper-bound value,

setting the scaled near-parallax value as the near-parallax value, and

setting the scaled far-parallax value as the far-parallax value; and

storing, in a computer memory, the scaled near-parallax value and scaled far-parallax value as the scaled-parallax constraints.

15. The non-transitory computer-readable storage medium of claim 14 , wherein the lower-scale factor is computed as a ratio of the lower-bound value divided by the focal length, and the upper-scale factor is computed as a ratio of the upper-bound value divided by the focal length.

16. The non-transitory computer-readable storage medium of claim 14 , the instructions further comprising:

positioning each camera of the pair of stereoscopic cameras relative to each other based on the scaled-parallax constraints;

creating a stereoscopic image of the computer-generated scene with the pair of stereoscopic cameras; and

storing, in the computer memory, the stereoscopic image.

17. The non-transitory computer-readable storage medium of claim 14 , the instructions further comprising:

calculating a camera separation value and a convergence value for the pair of stereoscopic cameras based on the scaled near-parallax and scaled far-parallax values; and

storing, in the computer memory, the camera separation value and the convergence value.

18. The non-transitory computer-readable storage medium of claim 17 , further comprising:

positioning each camera of the pair of stereoscopic cameras relative to each other within the computer-generated scene based on the camera separation value and the convergence value.

19. The non-transitory computer-readable storage medium of claim 17 , further comprising:

positioning a camera sensor of the pair of stereoscopic cameras within the computer-generated scene based on the camera separation value and the convergence value.

20. The non-transitory computer-readable storage medium of claim 14 , wherein:

if the focal length is less than the lower-bound value,

calculating the scaled near-parallax value as the near-parallax value times a ratio of the lower-bound value divided by the focal length, and

calculating the scaled far-parallax value as the far-parallax value times the ratio of the lower-bound value divided by the focal length; and

if the focal length is greater than the upper-bound value,

calculating the scaled near-parallax value as the near-parallax value times a ratio of the upper-bound value divided by the focal length, and

calculating the scaled far-parallax value as the far-parallax value times the ratio of the upper-bound value divided by the focal length.