Blended texture illumination mapping

A method to render bumpy self-shadowed textured computer graphics, the method comprising the steps of:

• creating a plurality of N illuminated texture images of a bumpy surface, wherein the N illuminated texture images are created by positioning a light source at predetermined positions;
• mapping the N illuminated texture images to a selected surface of a geometric model of an object based on illumination contribution from a light source;
• superimposing the N illuminated texture images on top of each other;
• and
• blending the N illuminated texture images according to an illumination equation:
• ##EQU3## where intensity is a combined pixel intensity at (x,y) to be computed, image i is an illuminated texture image pixel normalized intensity, N is the number of illuminated texture images, Light is a normalized light vector from a center of an illuminated texture image to a light source, and DirVec.sub.i is a normalized direction vector paired with the illuminated texture image.sub.i ;
• wherein resulting values of (Light.multidot.DirecVec.sub.i) are clamped between 0-1.

A method to render bumpy self-shadowed textured computer graphics, the method comprising the steps of:

• a) creating a geometric model of an object;
• b) creating a plurality of N illuminated texture images of a bumpy surface having at least two illuminated texture images, wherein each of the N illuminated texture images is created by positioning a light source at a predetermined position;
• and
• c) mapping the N illuminated texture images to a selected surface of the geometric model of the object by performing the following steps:
• d) disabling blending function;
• e) setting depth function to allow coplanar rendering;
• f) enabling depth buffer;
• g) enabling shading function;
• h) disabling graphics substantive lighting function;
• i) drawing the object in ambient lighting;
• j) enabling blending function;
• k) selecting an illuminated texture image;
• l) selecting a vertex of the selected surface;
• m) computing red, green, blue (RGB) and transparency (Alpha) values based on illumination contribution from the light source;
• n) drawing the selected vertex of the selected surface using the RGB and Alpha values computed;
• o) repeating steps (l)-(n) for all vertices of the selected surface;
• and
• p) repeating steps (k)-(o) for all illuminated texture images.

A computer system adapted to render bumpy textured computer graphics, the computer system comprising:

• a processor coupled to the bus;
• memory coupled to the bus, the memory storing a geometric model of an object and a plurality of N illuminated texture images of a bumpy surface, the memory further storing instruction codes, the instruction codes, when executed by the processor, maps the N illuminated texture images to a selected surface of the geometric model of the object, the N illuminated texture images including at least two illuminated texture images, wherein illumination contribution from the light source is calculated according to:
• intensity (x,y)=clamp(Light.multidot.DirVec.sub.i)
• where intensity is a pixel intensity at (x,y) to be computed, Light is a normalized light vector from a center of an illuminated texture image to a light source, and DirVec.sub.i is a normalized direction vector paired with the illuminated texture image;
• wherein resulting values of (Light.multidot.DirecVec.sub.i) are clamped between 0-1.