3D object rendering using detected features

1. An augmented reality display system configured to align 3D content with a real object, the system comprising:

a frame configured to mount on the wearer;

an augmented reality display attached to the frame and configured to direct images to an eye of the wearer;

an eyepiece disposed on the frame, at least a portion of said eyepiece being transparent and disposed at a location in front of the wearer's eye when the wearer wears said display system such that said transparent portion transmits light from the environment in front of the wearer to the wearer's eye to provide a view of the environment in front of the wearer;

a light source configured to illuminate at least a portion of the skin of the wearer or of a person other than the wearer by emitting invisible light;

a light sensor configured to form an image of said at least a portion of the skin illuminated by said light source using said invisible light;

a depth sensor configured to detect a location of the skin; and

processing circuitry configured to:

detect a feature in the image formed using a reflected portion of the invisible light, the feature corresponding to a preexisting feature of said skin;

select and store said feature to be used as a marker for rendering augmented reality content onto a view of the skin through the eyepiece while the eyepiece is disposed between the wearer's eye and the skin; and

determine information regarding the location of said at least a portion of the skin, the orientation of said at least a portion of the skin, or both based on one or more characteristics of the feature in the image formed using a reflected portion of the invisible light;

wherein the processing circuitry is configured to monitor the location or the orientation of the skin using the depth sensor periodically at a first frequency, and to monitor the location of the feature using the light sensor at a second frequency less frequent than the first frequency.

2. The augmented reality display system of claim 1 , wherein the feature in the image formed using a reflected portion of the invisible light is invisible to the eye.

3. The augmented reality display system of claim 1 , wherein the invisible light comprises infrared light.

4. The augmented reality display system of claim 1 , wherein the invisible light emitted by the light source comprises a beam that forms a spot on said at least a portion of the skin.

5. The augmented reality display system of claim 1 , wherein the invisible light emitted by the light source comprises a light pattern.

6. The augmented reality display system of claim 1 , wherein said characteristic comprises the location of said feature.

7. The augmented reality display system of claim 1 , wherein said characteristic comprises the shape of said feature.

8. The augmented reality display system of claim 1 , wherein said characteristic comprises the orientation of said feature.

9. The augmented reality display system of claim 1 , wherein said processing circuitry is configured to determine a difference between a distribution of the emitted invisible light and a distribution of the reflected portion of the invisible light.

10. The augmented reality display system of claim 9 , wherein said processing circuitry is configured to identify a difference signature based on the determined difference.

11. The augmented reality display system of claim 10 , wherein said processing circuitry is configured to determine an orientation of the skin based on the location of the skin and a location of the difference signature.

12. The augmented reality display system of claim 10 , wherein said processing circuitry is configured to determine a location of the skin based at least in part on a location of the difference signature.

13. The augmented reality display system of claim 1 , wherein the preexisting skin feature comprises at least one of a birthmark, a mole, or scar tissue.

14. An augmented reality display system comprising:

a frame configured to mount on the wearer;

an augmented reality display attached to the frame and configured to direct images to an eye of the wearer;

an eyepiece disposed on the frame, at least a portion of said eyepiece being transparent and disposed at a location in front of the wearer's eye when the wearer wears said display system such that said transparent portion transmits light from the environment in front of the wearer to the wearer's eye to provide a view of the environment in front of the wearer;

a depth sensor configured to map a surface of a real object within a field of view of the wearer;

a light source configured to project light in at least a first wavelength and a second wavelength incident upon the surface of the real object;

a light detector configured to form an image using a portion of the light of the first wavelength and the second wavelength reflected by the surface of the real object; and

processing circuitry configured to determine a light difference marker based at least in part on the reflected portion of the light of at least the first wavelength or the second wavelength and render augmented reality content comprising a virtual object at a fixed displacement relative to the light difference marker, the light difference marker comprising a preexisting feature of the real object selected by the processing circuitry to be used as the light difference marker for rendering the augmented reality content onto a view of the real object through the eyepiece while the eyepiece is disposed between the real object and the wearer's eye;

wherein the processing circuitry is configured to monitor the location or the orientation of the real object using the depth sensor periodically at a first frequency, and to monitor the location of the light difference marker using the light detector at a second frequency less frequent than the first frequency.

15. The augmented reality display system of claim 14 , wherein rendering the virtual object at a fixed displacement relative to the light difference marker comprises:

receiving an initial location for rendering the virtual object relative to the real object at an initial time;

determining the fixed displacement based on a distance between the initial location and the light difference marker;

detecting a subsequent location of the light difference marker at a time subsequent to the initial time; and

rendering the virtual object at the fixed displacement relative to the detected subsequent location of the light difference marker.

16. The augmented reality display system of claim 14 , wherein the first wavelength and the second wavelengths are infrared wavelengths.

17. An augmented reality display system configured to align 3D content with a real object, the system comprising:

a frame configured to mount on the wearer;

an augmented reality display attached to the frame and configured to direct images to an eye of the wearer;

an eyepiece disposed on the frame, at least a portion of said eyepiece being transparent and disposed at a location in front of the wearer's eye when the wearer wears said display system such that said transparent portion transmits light from the environment in front of the wearer to the wearer's eye to provide a view of the environment in front of the wearer;

a depth sensor configured to map a surface of a real object within a field of view of the wearer;

a light source configured to illuminate at least a portion of the real object by emitting light;

a light sensor configured to image said at least a portion of said real object illuminated by said light source using said emitted light; and

processing circuitry configured to:

detect a feature in said image of said real object, the feature corresponding to a preexisting feature of said real object;

select and store said feature in said image of said real object to be used as a marker for rendering augmented reality content onto a view of the real object through the eyepiece;

determine information regarding the location of the real object, the orientation of the real object, or both based on one or more characteristics of the feature in said image of said real object; and

render augmented reality content onto a view of the real object through the eyepiece based on detecting the real object using the depth sensor and detecting the feature using the light sensor;

wherein the processing circuitry is configured to monitor the location or the orientation of the real object using the depth sensor periodically at a first frequency, and to monitor the location of the feature using the light sensor at a second frequency less frequent than the first frequency.

18. The augmented reality display system of claim 17 , wherein the light emitted by the light source comprises a beam that forms a spot on said portion of the object.

19. The augmented reality display system of claim 17 , wherein the light emitted by the light source comprises a light pattern.