US 7245299

Here's a concise summary of US Patent 7245299:

US Patent 7245299: Bicubic surface real-time tesselation unit

• Title: Bicubic surface real-time tesselation unit
• Assignee: ALLIACENSE LIMITED, LLC (as of August 29, 2022, based on assignment records within the patent document).
• Inventor: Adrian Sfarti
• Filing Date: December 9, 2003
• Issue Date: July 17, 2007
• Abstract: The patent describes a graphics processing unit (GPU) for rendering objects from a software application. The objects are sent to the GPU as control points of bicubic surfaces. The GPU includes a transform unit, a lighting unit, a renderer unit, and a tessellate unit positioned between the transform and lighting units. This tessellate unit is designed to tessellate both rational and non-rational object surfaces in real-time.

Plain-Language Overview of Independent Claims:

• Claim 1: This claim describes a Graphics Processing Unit (GPU) that can render objects. It works by receiving object data as "control points" for bicubic surfaces over a bus. The key components of this GPU are a transform unit, a lighting unit, a renderer unit, and a tessellate unit. The tessellate unit is specifically located between the transform unit and the lighting unit, and its function is to perform real-time tessellation (breaking down surfaces into smaller, simpler shapes like triangles) for both rational and non-rational object surfaces.
• Claim 11: This claim describes a computer system that includes a central processor and a GPU. The GPU has the same core units as in Claim 1 (transform, lighting, renderer, and a tessellate unit between transform and lighting). The processor sends object control points to the GPU. The transform unit processes these control points. The tessellate unit then executes instructions to perform real-time tessellation of surfaces into triangles. After tessellation, the lighting unit applies lighting to the vertices of these triangles, and finally, the renderer unit executes instructions to render and display the triangles.
• Claim 19: This claim outlines a real-time method for tessellating and rendering object surfaces on a computer. The method involves several steps:
  • Transformation and Tessellation: Instead of transforming every single point on a surface, only 16 control points are transformed for each surface. The complex 3D surface subdivision is simplified by only subdividing two specific cubic curves on the surface. This subdivision stops when the curves meet a "flatness threshold" measured in screen coordinates (pixels), which also allows for automatic level of detail adjustment based on the viewer's perspective. To prevent visual "cracks" between adjacent surfaces, a common subdivision is used for all surfaces sharing a boundary. For the resulting subdivision, the method generates vertices, their normal vectors, texture coordinates, and displacement values (for advanced visual effects like bump and displacement mapping). Triangles are then formed by connecting these neighboring vertices. For each vertex, its normal is calculated and adjusted for bump mapping, and the vertex itself is displaced for displacement mapping, with these mapping steps executed pixel by pixel during rendering. Finally, a normal for each triangle is calculated for culling purposes.
  • Rendering: Each triangle is clipped against the viewing area, lighting is calculated for any new vertices created by clipping, and triangles facing away from the viewer ("backfacing") are discarded. All vertices are then projected into screen coordinates, and the final triangles are rendered and displayed.
• Claim 20: This claim details a method for rendering object surfaces (which can be non-rational or rational, including NURBS) on a computer system to enable real-time tessellation. Each surface is defined by sixteen control points and four boundary curves. The method involves: selecting a pair of orthogonal (at right angles to each other) boundary curves; then, only these two selected curves are repeatedly subdivided. The subdivision stops when these curves meet a defined "flatness threshold" when measured in screen coordinates. This approach minimizes the total number of computations needed to render the object, allowing for real-time rendering and display.

USPTO and CAFC Docket Search:

The patent US7245299B2 is listed as "Expired - Lifetime" with an expiration date of March 19, 2024, in the provided patent information.

While the provided patent text mentions ongoing litigation, including a "US case filed in Court of Appeals for the Federal Circuit" with case number "24-1909," a direct search for "CAFC docket 24-1909 2026" did not yield specific updates or filings for this case within 2026 in the provided search results. Therefore, I cannot confirm any specific activity for case 24-1909 in the CAFC dockets for 2026 with high confidence. The CAFC website generally allows for searching case information. General notices and events for the Federal Circuit in 2026 were observed, such as "August 2026 Court Week".