Method and system for antialiased procedural solid texturing

• US 6,788,304 B1
• Filed: 12/05/2000
• Issued: 09/07/2004
• Est. Priority Date: 06/11/1998
• Status: Expired due to Term

• Current Assignee: Rockwell Collins Simulation and Training Solutions, LLC
• Original Assignee: Evans & Sutherland Computer Corp. (Elevate Entertainment, Inc.)
• Inventors: Tibbitts, Stephen A., Hart, John C., Coleman, Terrence J.
• Primary Examiner(s): Zimmerman, Mark
• Assistant Examiner(s): MCCARTNEY, LINZY T
• Application Number:
  US09/719,079
• Time in Patent Office: 1,372 Days
• Field of Search: 345/582-588, 345/430
• US Class Current: 345/586
• CPC Class Codes: G06T 11/001 Texturing; Colouring; Generation of texture or colour inpainting G06T5/77
• CPC Class Codes: G06T 15/04 Texture mapping

Abstract

A procedural solid texturing system which uses a parameterized function capable of reproducing the most common procedural solid textures, specifically wood, marble, clouds and fire (32). This model is simple enough to be implemented in hardware, and can be realized in VLSI with as little as 100,000 gates. The invention also includes a method for antialiasing the parameterized procedural textures (34, 36). The antialiasing includes an expression for the necessary box filter width, a technique for efficiently box filtering the procedural texture by either MIP mapping the color table or using a summed area color table (38).

Claims

1. A method for generating procedural texture for use in a computer generated image by mapping geometric coordinates into a color space, comprising the steps of:

(a) creating a quadric function generator to provide a quadric mapping function in three dimensional space;

(b) creating at least one noise function generator to modulate the output of the quadric function with stochastic values based on geometric coordinates;

(c) passing parameters to the quadric function generator and at least one noise function generator to determine a type of texturing that will be applied to the computer generated image;

(d) using a single procedure which can generate a plurality of procedural textures which are represented by the following equation;

$p<br><br>\left(s\right)=c<br><br>\left(q<br><br>\left(s\right)+\underset{i}{\sum <br><br>}<br><br>a_i<br><br>n<br><br>\left(T_i<br><br>\left(s\right)\right)\right)$

 

wherein

q(s) represents a quadric function generator,

n is a noise function generator,

a_i is the amplitude of the noise function,

T_i is the frequency and phase of each noise function, and

c represents the color map which associates a red, blue, green, alpha (RGBα

) color with each index produced by the quadric function generator and the noise function generator; and

(e) determining color lookup table indexes to provide colors for the procedural texture wherein indexes are generated by the quadric function generator combined with the noise function generator.

2. The method as in claim 1 wherein the step of creating at least one noise function generator further comprises the step of using a noise function generator that uses the Perlin noise function.

4. The method of claim 1 wherein the step of passing parameters to the quadric function generator and the noise function generator to determine a type of texturing that will be applied to a computer generated image further comprises the step of determining the type of texturing that will be applied based on the parameters passed to the quadric function generator and noise function generator wherein the type of texturing is selected from the group consisting of wood, clouds, water, marble, fire, and terrain.

5. The method as in claim 1 wherein the step of passing parameters to the noise function generator further comprises the step of using a fractal sum of noise to produce cloud texture when selected parameters are received.

6. The method as in claim 1 wherein the step of passing parameters to the quadric function generator further comprises the step of using a collection of concentric cylinders and a modulation of a noise function generator to produce a wood texture when selected parameters are received.

7. The method as in claim 1 wherein the step of passing parameters to the quadric function further generator comprises the step of using a texture coordinate offset with fractal noise to produce marble and fire when selected parameters are received.

8. The method as in claim 1 wherein the step of creating a quadric function generator further comprises the step of creating a quadric function generator which uses a quadric function of the form, q(s,t,r)=As²+2Bst+2Csr+2Ds+Et²+2Ftr+2Gt+Hr²+2Ir+J.

9. The method as in claim 1 wherein the step of creating a quadric function generator further comprises the step of creating a quadric function generator which uses a quadric function of the form, q′

(s,t,r)=As²+Et²+Ir+J wherein the quadric function generator can be implemented in fewer hardware gates than a function using more than four terms.

10. The method as in claim 1 wherein the step of using a noise function generator further comprises the step of using a noise function generator which linearly interpolates the noise produced.

11. The method as in claim 1 wherein the step of using a noise function generator further comprises the step of using a noise function generator which uses cubic interpolated noise.

12. The method as in claim 1 further comprising the step of differentiating the procedural texture by differentiating a quadric function and noise functions with respect to screen coordinates for computing an appropriate filter width for antialiasing the texture generated.

3. A method for generating procedural texture for use in a computer generated image by mapping geometric coordinates into a color space, comprising the steps of:

(a) creating a quadric function generator to provide a quadric mapping function in three dimensional space;

(b) creating at least one noise function generator to modulate the output of the quadric function with stochastic values based on geometric coordinates;

(c) passing parameters to the quadric function generator and at least one noise function generator to determine a type of texturing that will be applied to the computer generated image;

(d) differentiating the procedural texture by differentiating the quadric function and noise functions with respect to screen coordinates for computing an appropriate filter width for the texture generated; and

(e) determining color lookup table indexes to provide colors for the procedural texture wherein indexes are generated by the quadric function generator combined with the noise function generator.