Two-dimensional drawing environment utilizing perspective grids

• US 6,771,276 B1
• Filed: 10/27/2000
• Issued: 08/03/2004
• Est. Priority Date: 10/27/2000
• Status: Active Grant

• Current Assignee: Adobe Inc.
• Original Assignee: Macromedia, Inc. (Adobe Inc.)
• Inventors: Yu, Fan, Halpin, David, Highsmith, Delores
• Primary Examiner(s): Kincaid, Kristine
• Assistant Examiner(s): NGUYEN, LE V
• Application Number:
  US09/697,856
• Time in Patent Office: 1,376 Days
• Field of Search: 345/419-619
• US Class Current: 345/619
• CPC Class Codes: G06T 15/20 Perspective computation

Abstract

A two dimensional drawing environment which includes one or more perspective grids is disclosed. The preferred embodiment method for providing a perspective view of an object in the two dimensional drawing environment, comprises the steps of creating a two dimensional perspective grid drawing environment; drawing an object in the two dimensional drawing environment; selecting a grid in the two dimensional drawing environment; and applying the drawn object to the selected grid thereby automatically providing a perspective view of the object.

Claims

1. A method for providing a perspective view of an object in a two dimensional drawing environment, comprising the steps of:

creating a two dimensional perspective grid drawing environment;

drawing an object in said two dimensional drawing environment;

selecting a grid in said two dimensional drawing environment; and

applying said drawn object to said selected grid thereby automatically providing a perspective view of said object, wherein said applying includes;

mapping points from said drawn object to said selected grid utilizing the formula [X*,Y*]=[X/(pX+qY),Y/(pX+qY)], wherein [X,Y] is a location of a respective point in said drawn object, [X*,Y*] is a location of a point on said grid, and p and q are variable parameters.

2. The method of claim 1, wherein said creating step comprises the step of:

selecting one or more parameters for creating said two dimensional perspective grid drawing environment.

3. The method of claim 2, wherein said two dimensional drawing environment in addition to said grid comprises:

a horizon line; and

at least one vanishing point on said horizon line which acts as a vanishing point for said grid.

4. The method of claim 3, wherein said two dimensional drawing environment further comprises:

a floor line, wherein said floor line is substantially parallel to said horizon line.

5. The method of claim 3, wherein said one or more parameters is selected from a group consisting of number of vanishing points, grid cell size, a location of said horizon line, a location of said grid, and a location of said vanishing point.

6. The method of claim 5, wherein said selecting one or more parameters step is performed by selecting from a graphical user interface.

7. The method of claim 1, wherein said selecting step comprises the step of:

selecting a predefined grid from said two dimensional drawing environment, wherein said predefined grid has been previously stored on a memory of a computer system.

8. The method of claim 1, wherein said grid is selected from a plurality of predefined grids.

9. The method of claim 1, wherein said applying step comprises the step of:

dragging said object onto said grid in said two dimensional drawing environment.

10. The method of claim 1, wherein said two dimensional drawing environment is a 1-point perspective drawing environment further comprising a second grid, a floor line, a horizon line, and a vanishing point, wherein said selected grid is a horizontal grid and said second grid is a vertical grid.

11. The method of claim 1, wherein said two dimensional drawing environment is a 1-point perspective drawing environment further comprising a second grid, a floor line, a horizon line, and a vanishing point, wherein said selected grid is a vertical grid and said second grid is a horizontal grid.

12. The method of claim 1, wherein said two dimensional drawing environment is a 2-point perspective drawing environment further comprising a second grid, a third grid, a floor line, a horizon line, a first vanishing point and a second vanishing point, wherein said selected grid is a horizontal grid and said second grid is a vertical grid associated with said first vanishing point, and wherein said third grid is a vertical grid associated with said second vanishing point.

13. The method of claim 12, wherein said second grid and said third grid meet at a third vanishing point.

14. The method of claim 1, wherein said two dimensional drawing environment is a 2-point perspective drawing environment further comprising a second grid, a third grid, a floor line, a horizon line, a first vanishing point and a second vanishing point, wherein said selected grid is a vertical grid associated with said first vanishing point, said second grid is a horizontal grid and wherein said third grid is a vertical grid associated with said second vanishing point.

15. The method of claim 14, wherein said selected grid and said third grid meet at a third vanishing point.

16. The method of claim 9, wherein said object is dragged onto said grid while pressing an arrow key to place said selected object onto said grid.

17. The method of claim 16, wherein said object is placed onto a left vertical grid when a left arrow key is pressed, said object is placed onto a right vertical grid when a right arrow key is pressed, said object is placed onto a floor plane associated with a left vanishing point when a down arrow key is pressed and said object is placed onto a floor plane associated with a right vanishing point when an up arrow key is pressed.

18. The method of claim 1, wherein said object is a vector object.

19. The method of claim 1, wherein said object is a non-vector object.

20. The method of claim 1, wherein said applying step comprises the steps of:

selecting said object;

determining a bounding box of said selected object;

creating a perspective envelope box in part from said determined bounding box; and

obtaining said perspective view of said selected object in part from said perspective envelope box.

21. The method of claim 14, wherein said determining step comprises the steps of:

determining a plurality of critical points on at least a first curve of said selected object; and

determining a set of control points from said plurality of critical points.

22. The method of claim 21, wherein a point on said at least first curve is a critical point if a first derivative at said point is zero.

23. The method of claim 21, wherein said step of determining said set of control points comprises the step of:

determining a topmost point (x1, y1), a leftmost point (x2, y2), a bottommost point (x3, y3), and a rightmost point (x4, y4) from said plurality of critical points.

24. The method of claim 23, further comprising the step of:

determining a set of reference points utilizing in part said set of control points to provide the corners of said bounding box.

25. The method of claim 24, wherein said set of reference points is given by (x2, y1), (x2, y3), (x4, y3) and (x4, y1).

26. The method of claim 25, wherein said creating step comprises the steps of:

mapping each of said set of reference points of said bounding box onto said selected grid to provide a set of mapped reference points; and

joining points within said set of mapped reference points to create said perspective envelope box.

27. The method of claim 26, wherein said step of obtaining said perspective view comprises the steps of:

a. dividing said bounding box into a plurality of segments;

b. dividing said perspective envelope box into an equal number of plurality of segments;

c. mapping a point on said object from said bounding box onto a corresponding segment of said perspective envelope box;

d. repeating step (c) until substantially all points on said object have been mapped onto a corresponding segment of said perspective envelope box thereby providing said perspective view of said object.

28. The method of claim 27, wherein the number of segments into which said bounding box is divided depends in part on a desired quality of mapping.

29. The method of claim 27, wherein said step of dividing said perspective envelope box comprises the steps of:

a. determining an intersection point of the diagonals of said perspective envelope box;

b. drawing a first line through said intersection point and a first vanishing point such that said first line intersects opposing sides of said perspective envelope box thereby dividing said perspective envelope box into two components; and

c. drawing a second line through said intersection point and a second vanishing point such that said second line intersects a different set of opposing sides of said perspective envelope box, wherein said first line and said second line divide said perspective envelope box into four components.

d. repeating steps (a), (b) and (c) with regard to each component of said perspective envelope box until said perspective envelope box is divided into said plurality of components equal in number to said plurality of components into which said bounding box is divided.

30. The method of claim 27, wherein said step of dividing said perspective envelope box comprises the steps of:

a. determining an intersection point of the diagonals of said perspective envelope box;

b. drawing a first line through said intersection point and a first vanishing point such that said first line intersects opposing sides of said perspective envelope box thereby dividing said perspective envelope box into two components; and

c. drawing a second line through said intersection point wherein said second line is parallel to a different set of opposing sides of said perspective envelope box, wherein said first line and said second line divide said perspective envelope box into four components.

d. repeating steps (a), (b) and (c) with regard to each component of said perspective envelope box until said perspective envelope box is divided into said plurality of components equal in number to said plurality of components into which said bounding box is divided.

32. The system of claim 30 wherein p is calculated utilizing a location and a distance of the location from a vanishing point associated with said grid.

33. The system of claim 30 wherein said first data structure defines a floor line.

34. The system of claim 30, wherein said first data structure defines a wall line.

31. A system, comprising:

a first data structure defining a grid in a two-dimensional drawing environment that defines a simulated perspective view of a plane in relation to three dimensions, wherein said data structure identifies at least one vanishing point;

a second data structure defining a graphical object in a plane defined by only two dimensions;

a mapping algorithm for displaying said graphical object, at a location on said grid determined in response to input from a user using said two-dimensional drawing environment, according to said simulated perspective view of said plane in relation to three dimensions by mapping elements of said second data structure according to said first data structure, wherein said mapping algorithm applies a mapping relationship defined by [X*,Y*]=[X/(pX+qY), Y/(pX+qY)], wherein [X,Y] is a location of a point in said graphical object, [X*,Y*] is location of a point on said grid, and p and q are parameters.