Generation of glow effect

1. A method for generating a glow effect in an image, comprising:

selecting an area within a scene that is to glow to produce a two-dimensional selected area image;

generating glow by blurring the two-dimensional selected area image to produce a two-dimensional glowing area image; and

adding the two-dimensional glowing area image to the scene to provide the glow effect,

wherein the generating comprises:

generating multiple versions of the two-dimensional selected area image; and

forming a sum of the multiple versions to provide the two-dimensional glowing area image.

2. A method according to claim 1 , wherein the sum is a weighted sum.

3. A computer-readable medium having computer-executable instructions for performing the method recited in claim 1 .

4. An apparatus for generating a glow effect in an image, comprising:

area formation logic configured to select an area within a scene that is to glow to produce a two-dimensional selected area image;

glow generation logic configured to generate glow by blurring the two-dimensional selected area image to produce a two-dimensional glowing area image; and

glow application logic configured to add the two-dimensional glowing area image to the scene to provide the glow effect,

wherein the glow generation logic is configured to produce the glowing area image by:

generating multiple versions of the two-dimensional selected area image; and

forming a sum of the multiple versions to provide the two-dimensional glowing area image.

5. An apparatus for generating a glow effect in an image, comprising:

means for selecting an area within a scene that is to glow to produce a two-dimensional selected area image;

means for generating glow by blurring the two-dimensional selected area image to produce a two-dimensional glowing area image, and

means for adding the two-dimensional glowing area image to the scene to provide the glow effect,

wherein the means for generating comprises:

means for generating multiple versions of the two-dimensional selected area image; and

means for forming a sum of the multiple versions to provide the two-dimensional glowing area image.

6. A method for generating a glow effect in an image, comprising:

selecting an area within a scene that is to glow to produce a selected area image by:

rendering the scene to provide a rendered scene image;

creating a mask that defines the area which is to glow; and

applying the mask to the rendered scene image to produce the selected area image;

generating glow using the selected area image to produce a glowing area image by:

generating multiple versions of the selected area image; and

forming a sum of the multiple versions to provide the glowing area image; and

adding the glowing area image to the scene to provide the glow effect.

7. A method according to claim 6 , wherein the applying comprises:

providing luminance values respectively associated with the scene elements within the rendered scene image;

performing a masking test by comparing the stencil values in the stencil buffer with corresponding luminance values associated with respective scene elements in the rendered scene image;

outputting a masking color value for scene elements in the rendered scene image that fail the masking test; and

outputting a non-masking color value for scene elements in the rendered scene image that pass the masking test.

8. A method according to claim 7 , wherein the sum is a weighted sum.

9. A method of claim 7 , wherein the multiple versions comprise two-dimensional images that are displaced from a reference center point in different respective directions.

10. A computer-readable medium having computer-executable instructions for performing the method recited in claim 6 .

11. An apparatus for generating a glow effect in an image, comprising:

area formation logic configured to select an area within a scene that is to glow to produce a selected area image by:

rendering the scene to provide a rendered scene image;

creating a mask that defines the area which is to glow; and

applying the mask to the rendered scene image to produce the selected area image;

glow generation logic configured to generate glow using the selected area image to produce a glowing area image by:

generating multiple versions of the selected area image; and

forming a sum of the multiple versions to provide the glowing area image; and

low application logic configured to add the glowing area image to the scene to provide the glow effect.

12. An apparatus for generating a glow effect in an image, comprising:

means for selecting an area within a scene that is to glow to produce a selected area image, wherein the means for selecting comprises:

means for rendering the scene to provide a rendered scene image;

means for creating a mask that defines the area which is to glow; and

means for applying the mask to the rendered scene image to produce the selected area image;

means for generating glow using the selected area image to produce a glowing area image, wherein the means for generating glow comprises:

means for generating multiple versions of the selected area image; and

means for forming a sum of the multiple versions to provide the glowing area image; and

means for adding the glowing area image to the scene to provide the glow effect.