SMART TRANSPARENCY FOR HOLOGRAPHIC OBJECTS

• US 20160025982A1
• Filed: 05/27/2015
• Published: 01/28/2016
• Est. Priority Date: 07/25/2014
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Inventors: Sutherland, Jeff, Sugden, Ben, Salter, Tom
• Granted Patent: US 10,451,875 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G02B 2027/0141 characterised by the informative content of the display
• CPC Class Codes: G02B 2027/0174 holographic
• CPC Class Codes: G02B 2027/0178 Eyeglass type eyeglass details G02C
• CPC Class Codes: G02B 27/0093 with means for monitoring data relating to the user, e.g. head-tracking, eye-tracking
• CPC Class Codes: G02B 27/017 Head mounted
• CPC Class Codes: G02B 27/0172 characterised by optical features
• CPC Class Codes: G06F 3/011 Arrangements for interaction with the human body, e.g. for user immersion in virtual reality blind teaching G09B21/00
• CPC Class Codes: G06F 3/04815 Interaction with a metaphor-based environment or interaction object displayed as three-dimensional, e.g. changing the user viewpoint with respect to the environment or object

Abstract

A head mounted display (HMD) device is configured with a sensor package that enables head tracking to determine the device user'"'"'s proximity to holographic objects in mixed reality or virtual reality environments. A fade volume including concentrically-arranged volumetric shells is placed around the user including a near shell that is closest to the user, and a far shell that is farthest from the user. When a holographic object is beyond the far shell, the HMD device renders the object with full opacity (i.e., with no transparency). As the user moves towards a holographic object and it intersects the far shell, its opacity begins to fade out with increasing transparency to reveal the background behind it. The transparency of the holographic object increases as the object gets closer to the near shell and the object becomes fully transparent when the near shell reaches it so that the background becomes fully visible.

Claims

1. A method performed by a head mounted display (HMD) device employed by a user occupying a physical environment, the HMD device supporting rendering of a mixed reality or virtual reality environment that includes holographic objects, comprising:

placing a fade volume around the user, the fade volume having a near shell that is proximate to the user and a far shell that is distal to the user;

determining a location of a holographic object with respect to the near and far shells by tracking the user'"'"'s location within the mixed reality or virtual reality environment; and

rendering the holographic object with transparency when it is located between the near and far shells, the transparency increasing as the object becomes closer to the near shell.

2. The method of claim 1 further including rendering the holographic object with full opacity when the holographic object is located beyond the far shell of the fade volume.

3. The method of claim 1 further including rendering the holographic object with full transparency when the holographic object intersects the near shell of the fade volume.

4. The method of claim 1 further including performing the rendering of the holographic object using alpha compositing and interpolating an alpha value based on a transparency curve that is established over a spatial distance between the near and far shells of the fade volume or performing the rendering of the holographic object using ordered dithering.

5. The method of claim 4 in which the transparency curve is a linear curve and the alpha value is interpolated on a linear basis.

6. The method of claim 4 further including performing the alpha compositing for the holographic object on a per-pixel basis.

7. The method of claim 1 further including performing head tracking to determine a proximity of the fade volume to the holographic object.

8. The method of claim 7 in which the head tracking utilizes a sensor package in the HMD device for generating depth data.

9. The method of claim 8 further including generating the depth data using one or more depth-from-stereo imaging analyses or using a depth sensor.

10. The method of claim 8 further including using the sensor package to determine a current height of the user'"'"'s head above the ground of the physical environment.

11. The method of claim 10 further including sizing the fade volume according to the height of the user'"'"'s head.

12. The method of claim 1 further including configuring a radius of the far shell to be between one and one-half and two and one-half times a radius of the near shell.

13. The method of claim 12 further including configuring the radius of the near shell to be approximately one-half meter and the radius of the far shell to be approximately one meter.

14. The method of claim 1 further including performing the transparent rendering of the holographic object to show a background of the mixed or virtual reality environment, the background including one or more of virtual ground, real ground, other holographic objects, or real objects.

15. The method of claim 1 further including configuring the near and far shells using one of cylinder, sphere, capsule, or non-radial volume.

16. The method of claim 1 further including configuring the near and far shells as concentrically aligned cylinders having different radii or as spheres having different radii that share a common center.

17. A head mounted display (HMD) device operable by a user in a physical environment, comprising:

one or more processors;

a display having areas onto which a mixed reality or virtual reality environment is rendered to the user;

a sensor package; and

one or more memory devices storing computer-readable instructions which, when executed by the one or more processors, perform a method comprising the steps of;

performing head tracking of the user within the physical environment using the sensor package,

maintaining a holographic geometry including one or more holographic objects having known locations within the mixed reality or virtual reality environment,

responsively to the head tracking, determining the user'"'"'s location with respect to the holographic geometry, and

rendering portions of the holographic geometry with transparency based on the user'"'"'s location so that the rendered portions increase in transparency as the distance between the user'"'"'s location and rendered portions decreases.

18. The HMD device of claim 17 further including determining a ratio of distances of the rendered portions with respective near and far shells of a fade volume that is placed around the user and controlling alpha blending depending on the ratio on a per-pixel basis.

19. One or more computer readable memories storing computer-executable instructions for rendering a mixed reality or virtual reality environment within a variable field of view of a head mounted display (HMD) device operating in a real world environment, the method comprising the steps of:

configuring display optics incorporated into the HMD device for selectively rendering a holographic object with varying degrees of opacity;

dynamically determining a location of a holographic object with respect to each of a near and a far threshold using sensors incorporated into the HMD device;

setting opacity for a rendered holographic object to a maximum value when the holographic object is located beyond the far threshold; and

when the holographic object is located between the near threshold and the far threshold, based on the location, setting opacity for a rendered holographic object from a range spanning a minimum value and the maximum value.

20. The one or more computer-readable memories of claim 19 in which the opacity is increased using one of alpha compositing or dithering as the distance between the holographic object and the near threshold increases and further including enclosing the user within a fade volume having a near shell that is located at the near threshold and a far shell that is located at the far threshold, the near and far shells being selected from one of cylinder, sphere, capsule, or non-radial volume.