Three-dimensional displays using electromagnetic field computations

Patent metadata

Field	Value
Publication number	US-11410384-B2
Application number	US-202117209998-A
Country	US
Kind code	B2
Filing date	Mar 23, 2021
Priority date	Jan 16, 2018
Publication date	Aug 9, 2022
Grant date	Aug 9, 2022

Abstract

Methods, apparatus, devices, and systems for three-dimensional (3D) displaying objects are provided. In one aspect, a method includes obtaining data including respective primitive data for primitives corresponding to an object, determining an electromagnetic (EM) field contribution to each element of a display for each of the primitives by calculating an EM field propagation from the primitive to the element, generating a sum of the EM field contributions from the primitives for each of the elements, transmitting to each of the elements a respective control signal for modulating at least one property of the element based on the sum of the EM field contributions, and transmitting a timing control signal to an illuminator to activate the illuminator to illuminate light on the display, such that the light is caused by the modulated elements of the display to form a volumetric light field corresponding to the object.

First claim

What is claimed is:

1. A method comprising:
for each primitive of a plurality of primitives corresponding to an object, determining an electromagnetic (EM) field contribution to each display element of a plurality of display elements of a display by computing, in a three-dimensional (3D) coordinate system, EM field propagation from the primitive to the display element; and
for each display element of the plurality of display elements,
generating a sum of the EM field contributions from the plurality of primitives to the display element,
multiplying a scale factor to the sum of the EM field contributions for the display element to obtain a scaled sum of the EM field contributions, and
generating a respective control signal based on the scaled sum of the EM field contributions of the plurality of primitives to the display element,
wherein the respective control signal is configured to modulate at least one property of the display element based on the scaled sum of the EM field contributions from the plurality of primitives to the display element.

2. The method of claim 1 , wherein the plurality of primitives comprise at least one member selected from the group consisting of a point primitive, a line primitive, and a polygon primitive.

3. The method of claim 1 , further comprising obtaining respective primitive data for each primitive of the plurality of primitives,
wherein the respective primitive data for the primitive comprises at least one member selected from the group consisting of:
texture information of the primitive;
shading information on one or more surfaces of the primitive;
color information of the primitive; and
coordinate information of the primitive in the 3D coordinate system.

4. The method of claim 1 , wherein determining the EM field contribution of the primitive to each display element of the plurality of display elements of the display comprises:
determining, in the 3D coordinate system, at least one distance between the display element and the primitive based on corresponding coordinate information of the display element and corresponding coordinate information of the primitive, and
determining the EM field contribution of the primitive to the display element based on a predetermined expression for the primitive and the at least one distance.

5. The method of claim 4 , wherein the predetermined expression is determined by analytically calculating the EM field propagation from the primitive to the display element.

6. The method of claim 4 , wherein the predetermined expression corresponds to a solution of Maxwell's equations with a boundary condition defined by the display.

7. The method of claim 4 , wherein the predetermined expression comprises at least one member selected from the group consisting of functions comprising a sine function, a cosine function, and an exponential function, and
wherein determining the EM field contribution comprises identifying a value of the at least one of the functions in a table stored in a memory.

8. The method of claim 1 , comprising:
determining first respective EM field contributions of the plurality of primitives to a first display element of the plurality of display elements and summing the first respective EM field contributions for the first display element; and
determining second respective EM field contributions of the plurality of primitives to a second display element of the plurality of display elements and summing the second respective EM field contributions for the second display element.

9. The method of claim 1 , comprising:
determining first respective EM field contributions from a first primitive of the plurality of primitives to each display element of the plurality of display elements;
determining second respective EM field contributions from a second primitive of the plurality of primitives to each display element of the plurality of display elements; and
accumulating the EM field contributions for each display element of the plurality of display elements by adding the first and second respective EM field contributions corresponding to the display element.

10. The method of claim 1 , further comprising:
transmitting a timing control signal to an illuminating device to emit light on the display; and
transmitting the respective control signals to the plurality of display elements to modulate the plurality of display elements so as to cause the light to form a volumetric light field corresponding to the object in an 3D space.

11. The method of claim 1 , comprising performing a mathematical function using fixed point number representations by at least one member selected from the group consisting of:
receiving an expression in a first fixed point format and outputting a value at a second fixed point format that has a level of accuracy different from that of the first fixed point format;
looking up a table for calculation of the mathematical function, wherein the table comprises at least one member selected from the group consisting of a fully enumerated look-up table, an interpolated table, a semi-table based polynomial functions, and a semi-table based on full minimax polynomials;
applying a specialized range reduction for an input; and
transforming a trigonometric calculation from a range [−π, π] into a signed 2's compliment representation in a range [−1,1].

12. The method of claim 1 , comprising calculating respective EM field contributions of each primitive of the plurality of primitives to each display element of the plurality of display elements,
wherein the calculation of the respective EM field contributions is without at least one member selected from the group consisting of: expanding a geometry of the object into the plurality of display elements; applying visibility tests before packing wavefronts; and decision making or communication between parallel calculations for different primitives of the plurality of primitives; and
wherein the calculation of the respective EM field contributions is configured to cause at least one member selected from the group consisting of: tuning parallel calculations for multiple primitives to speed, cost, size or energy optimization; reducing latency between initiating a draw and a result being ready for display; increasing an accuracy using fixed point number representations; and optimizing computation speed by optimizing mathematical functions.

13. The method of claim 1 , further comprising representing values using fixed point number representations during calculation,
wherein representing the values using the fixed point number representations is without at least one member selected from the group consisting of: denormal floats for gradual underflow; handling NaN results from operations including division by zero; altering floating point rounding modes; and raising floating point exceptions to an operating system.

14. The method of claim 1 , further comprising:
obtaining respective primitive data of the plurality of primitives corresponding to the object;
scaling a first primitive adjacent to a second primitive by a predetermined factor using the respective primitive data for the first primitive and the second primitive; and
updating the respective primitive data for the first primitive based on a result of the scaling.

15. The method of claim 14 , wherein the scaling is performed such that a gap between a reconstruction of the first and second primitives in an 3D space is big enough to separate the first and second primitives to minimize an overlapping effect and small enough to make the reconstruction appear seamless.

16. The method of

Assignees

• Pacific Light & Hologram Inc

Inventors

• Blackley Jonathan Seamus
• Qin Tina
• Sefami Asher Zelig
• Qaderi Kamran
• Sararu Mark Anthony
• Wiensch Joshua D
• Kumar Rajay
• Colin Sylvain Marcel

Classifications

• H04N13/275

  from three-dimensional [3D] object models, e.g. computer-generated stereoscopic image signals · CPC title

• G03H1/04 Primary

  Processes or apparatus for producing holograms (G03H1/26 takes precedence) · CPC title

• G06T15/205

  Image-based rendering · CPC title

• G02B30/56

  by projecting aerial or floating images · CPC title

• G03H2210/45

  Representation of the decomposed object · CPC title