Method for processing image data to provide for soft shadow effects using shadow depth information

A computer-implemented method for processing image data that includes depth information and shadow effects, the method comprising:

• under the control of one or more computer systems configured with executable instructions:
• obtaining a scene description describing elements of a scene to be rendered into a computer-generated image, the elements comprising at least a point light source and a plurality of objects, the plurality of objects including obscuring objects, wherein the point light source has a light source position in the scene and an obscuring object of the plurality of obscuring objects has an obscuring object position in the scene whereby the obscuring object at the obscuring object position obscures, partially or entirely, light from the point light source;
• determining, from the scene description, a shadow map of the point light source, wherein the shadow map encodes for shadows cast by the obscuring objects;
• determining area light parameters for an area light, wherein the area light is represented by a geometry positioned in the scene, the geometry having an area greater than zero;
• determining, for a given point, P, in the scene, whether obscuring objects of the plurality of obscuring objects would obscure light from the area light to the given point P;
• determining, for the given point P, an occlusion point, B, on an occluding object;
• determining, for the given point P and the occlusion point B, a projection of the area light though occlusion point B to a first region representing an area light fall of the area light;
• determining, for the first region, a corresponding region of the shadow map;
• determining, for the corresponding region, a ratio of occluded rays of the corresponding region to rays of the corresponding region;
• and
• computing a shadow effect of the area light and the obscuring objects on points of the scene.