Display priority for 2D CAD documents

1. A method, comprising:

determining an element priority, a level priority, and a model reference priority for at least two elements in a two-dimensional (2D) CAD image, wherein the elements are 2D;

determining a display priority for the elements as a function of the element priority, the level priority, and the model reference priority for respective elements;

determining an order of precedence of the elements based on their display priority; and

displaying the elements in the CAD image based in part on the order of precedence.

2. The method of claim 1 , wherein determining the display priority further comprises:

determining an element priority multiplier, a level priority multiplier, and a model reference priority multiplier; and

combining the element priority, the level priority, and the model reference priority with the element priority multiplier, the level priority multiplier, and the model reference priority multiplier.

3. The method of claim 1 , further comprising:

determining a level attribute for the element; and

obtaining the level priority based on the level attribute.

4. The method of claim 1 , further comprising displaying elements with higher display priorities on top of elements with lower display priorities.

5. The method of claim 1 , wherein determining the display priority is based on a mathematical function.

6. The method of claim 1 , further comprising receiving user input defining the element priority, level priority, and model reference priority.

7. The method of claim 1 , further comprising receiving user input defining the element priority multiplier, level priority multiplier, and model reference priority multiplier.

8. A method of setting an image depth in a two-dimensional computer assisted design (CAD) image, comprising the steps of:

determining each of an element priority multiplier value, a level priority multiplier value, and a model reference priority multiplier value for a CAD project containing at least one two-dimensional CAD image, wherein the CAD image includes a plurality of 2D CAD image elements;

determining each of an element priority value, a level priority value, and a model reference priority value for a CAD image element;

determining an image depth for the CAD image element based on a combination of the element priority value, level priority value, model reference priority value, element priority multiplier value, level priority multiplier value, and model reference priority multiplier value; and

using the image depth to position the CAD image element relative to other CAD image elements in the CAD image.

9. The method of claim 8 , further comprising storing the image depth for the CAD image element in a z-buffer for the CAD image.

10. The method of claim 8 , further comprising:

receiving user input on at least one of the element priority value, level priority value, model reference priority value, element priority multiplier value, level priority multiplier value, and model reference priority multiplier value.

11. The method of claim 8 , further comprising: setting a default element priority multiplier value of 1, a default level priority multiplier value of 2 8 , and a default model reference priority multiplier value of 2 16 , wherein the z-buffer has a size of 2 24 bits.

12. The method of claim 8 , wherein the step of determining an image depth comprises calculating the sum of the product of the element priority value with the element priority multiplier, the product of the level priority value with the level priority multiplier, and the product of the model reference priority value with the model reference priority multiplier.

13. A system for setting an image depth in a two-dimensional computer assisted design (CAD) image, comprising:

means for setting each of an element priority multiplier value, a level priority multiplier value, and a model reference priority multiplier value for a CAD project containing at least one two dimensional CAD image, wherein the CAD image includes a plurality of 2D CAD image elements;

means for setting each of an element priority value, a level priority value, and a model reference priority value for the CAD image element;

means for determining an image depth for the CAD image element based on a combination of the element priority value, level priority value, model reference priority value, element priority multiplier value, level priority multiplier value, and model reference priority multiplier value; and

means for using the image depth to position the CAD image element relative to other CAD image elements in the CAD image.

14. The system of claim 13 , further comprising means for storing the image depth for the CAD image element in a z-buffer for the CAD image.

15. The system of claim 13 , further comprising:

means for receiving user input on at least one of the element priority value, level priority value, model reference priority value, element priority multiplier value, level priority multiplier value, and model reference priority multiplier value.

16. The system of claim 13 , further comprising: means for setting a default element priority multiplier value of 1, a default level priority multiplier value of 2 8 , and a default model reference priority multiplier value of 2 16 , wherein the z-buffer has a size of 2 24 bits.

17. A computer useable information storage medium storing computer readable program code for causing a computer to perform:

determining an element priority, a level priority, and a model reference priority for at least two elements in a 2D CAD image, wherein the elements are 2D;

determining a display priority for the elements as a function of the element priority, the level priority, and the model reference priority for respective elements;

determining an order of precedence of the elements based on their display priority; and

displaying the elements in the CAD image based in part on the order of precedence.

18. A computer useable information storage medium of claim 17 , further comprising computer readable program code for causing a computer to perform:

determining an element priority multiplier, a level priority multiplier, and a model reference priority multiplier; and

combining the element priority, the level priority, and the model reference priority with the element priority multiplier, the level priority multiplier, and the model reference priority multiplier.

19. A computer useable information storage medium of claim 17 , further comprising computer readable program code for causing a computer to perform:

determining a level attribute for the element; and

obtaining the level priority based on the level attribute.

20. A computer useable information storage medium of claim 17 , further comprising computer readable program code for causing a computer to perform:

defining an element priority that is assigned to each element; and

storing the element priority as an attribute of the element.

21. A computer useable information storage medium of claim 17 , further comprising computer readable program code for causing a computer to perform:

receiving user input defining at least one of the element priority, the level priority, and the model reference priority.

22. A computer useable information storage medium of claim 17 , further comprising computer readable program code for causing a computer to perform:

displaying elements with higher display priorities on top of elements with lower display priorities.

23. A computer useable information storage medium of claim 17 , further comprising computer readable program code for causing a computer to perform:

storing the display priority value in a z-buffer.