DIRECT ENVIRONMENTAL MAPPING METHOD AND SYSTEM
There is provided a method for mapping a panoramic image to a 3-D virtual object of which a projection is made for display on a screen. The method includes: providing the panoramic image in a memory, the panoramic image being defined by a set of pixels in a 2-dimensional space; providing a model of the object, the model having a set of vertices in a 3-dimensional space; selecting a vertex on the model, the selected vertex being characterized by a set of angular coordinates; applying a transformation to the angular coordinates to obtain a set of polar coordinates; identifying a pixel whose position in the panoramic image is defined by the polar coordinates; and storing in memory an association between the selected vertex on the model and a value of the identified pixel.
1 . A method for mapping a panoramic image to a 3-D virtual object of which a projection is made for display on a screen, comprising:
providing the panoramic image in a memory, the panoramic image defined by a set of picture elements (pixels) in a 2-dimensional space;
providing a model of the object, the model comprising a set of vertices in a 3-dimensional space;
selecting a vertex on the model, the selected vertex characterized by a set of angular coordinates;
applying a transformation to the angular coordinates to obtain a set of polar coordinates;
identifying a pixel whose position in the panoramic image is defined by the polar coordinates;
storing in memory an association between the selected vertex on the model and a value of the identified pixel.
2 . The method defined in claim 1 , wherein the selected vertex on the model is further characterized by a radial component that is constant over a range of vertices on the model.
3 . The method defined in claim 1 , wherein the selected vertex on the model is further characterized by a radial component that is constant for all vertices on the model.
4 . The method defined in claim 1 , wherein the selected vertex on the model is further characterized by a radial component that is a function of at least one of the angular coordinates.
5 . The method defined in claim 1 , wherein the selected vertex on the model is further characterized by a radial component that is not independent of the angular coordinates.
6 . The method defined in claim 1 , further comprising repeating the selecting, identifying and storing for a plurality of vertices on the model.
7 . The method defined in claim 1 , wherein the transformation is a function of optical properties of an image acquisition device used to capture the panoramic image.
8 . The method defined in claim 1 , wherein said association defines a surface pixel for the 3-D object.
9 . The method defined in claim 1 , wherein the angular coordinates include an azimuth coordinate and a polar coordinate.
10 . The method defined in claim 1 , further comprising: determining a desired viewing orientation in 3-D space; identifying a viewing window corresponding to the desired viewing orientation, the viewing window occupying a plane in 3-dimensional space; projecting the model onto the viewing window in order to determine a set of surface pixel of the 3-D virtual object that are visible in the desired viewing orientation.
11 . The method defined in claim 1 , wherein the panoramic image is a 360-degree image and wherein the set of pixels of the panoramic images defines an ellipse.
12 . The method defined in claim 1 , wherein the 3-D model is a dome.
13 . The method defined in claim 1 , wherein the 3-D model is a box.
14 . A non-transitory computer-readable medium comprising instructions which, when executed by a computer, cause the computer to carry out a method for mapping a panoramic image to a 3-D virtual object of which a projection is made for display on a screen, the method comprising:
providing the panoramic image in a memory, the panoramic image defined by a set of picture elements (pixels) in a 2-dimensional space;
providing a model of the object, the model comprising a set of vertices in a 3-dimensional space;
selecting a vertex on the model, the selected vertex characterized by a set of angular coordinates;
applying a transformation to the angular coordinates to obtain a set of polar coordinates;
identifying a pixel whose position in the panoramic image is defined by the polar coordinates;
storing in memory an association between the selected vertex on the model and a value of the identified pixel.
15 . A method of assigning a value to a vertex of an object of interest, comprising:
obtaining 3-D coordinates of the vertex;
using a shader to derive 2-D coordinates based on the 3-D coordinates; and
consulting a panoramic image to obtain a value corresponding to the 2-D coordinates.
16 . The method defined in claim 15 , wherein the panoramic image is an elliptical image.
17 . The method defined in claim 15 , wherein the shader is a vertex shader.
18 . The method defined in claim 15 , wherein the shader utilizes the following geometry in deriving the 2-D coordinates based on the 3-D coordinates:
{
r
E
=
f
(
θ
)
θ
E
=
ϕ
.
(
2.1
)