Apparatus and method for high quality ray-traced level of detail transitions

A graphics processor comprising:

• ray traversal hardware logic to traverse a ray through an acceleration structure to determine intersections between the ray and one or more object instances;
• and
• a level of detail selector to:
• set an instance comparison mask associated with an object instance to a first level of detail (LOD), the instance comparison mask comprising an N-bit value and one or more bits to indicate a type of comparison operation,
• compare a value from a ray mask with the N-bit value in accordance with the type of comparison operation to generate a comparison result, and
• determine whether to use the first LOD or a second LOD to render one or more pixels in accordance with the comparison result.

A machine-readable medium having program code stored thereon which, when executed by a machine, causes the machine to perform the operations of:

• setting an instance comparison mask associated with an instance to a first level of detail (LOD), the instance comparison mask comprising an N-bit value and one or more bits to indicate a type of comparison operation;
• comparing a value from a ray mask with the N-bit value in accordance with the type of comparison operation to generate a comparison result;
• and
• determining whether to use the first LOD or a second LOD to render one or more pixels in accordance with the comparison result.