39 results about "Shadow volume" patented technology

The present invention is directed to systems and methods for all-frequency relighting by representing low frequencies of lighting with spherical harmonics and approximate the residual high-frequency energy with point lights. One such embodiment renders low-frequencies with a precomputed radiance transfer (PRT) technique (which requires only a moderate amount of precomputation and storage), while the higher-frequencies are rendered with on-the-fly techniques such as shadow maps and shadow volumes. In addition, various embodiments are directed to a systems and methods for decomposing the lighting into harmonics and sets of point lights. Various alternative embodiments are directed to systems and methods for characterizing the types of environments for which the described decomposition is a viable technique in terms of speed (efficiency) versus quality (realism).

A processor for image processing in accordance with shadow polygons defining together a current shadow volume is configured to determine a set of tiles, each tile being formed of a set of pixels and having a respective tile volume defined by the set of pixels and depth values relating to the set of pixels. The processor is further configured to determine whether a tile is a potential boundary tile or a non-boundary tile, a potential boundary tile having a tile volume intersected by at least one of the shadow polygons. A method and device for image processing are also discussed.

A method for real-time shadow rendering in a 3-D graphics scene uses an inverted z-test to mark a shadow area in a stencil buffer. Front and back facing shadow volume polygons are rendered subsequent to rendering the scene and corresponding stencil buffer entries are incremented for pixels viewing the back facing polygon when the new z-test is passed and decremented for pixels viewing the front facing polygons when the new z-test is passed. The new z-test is passed for pixels having depth (z) values greater than the corresponding depth value stored z-buffer.

The present invention provides for accelerating the generation of graphical images that include shadow effects by, for example, reducing the amount of data transmitted and/or stored necessary to render graphics based on stencil shadow volumes. In one embodiment, an exemplary apparatus is configured to render shadows using stencil shadow volumes. The apparatus includes a memory to store a degree of shadowing for each sample. A co-processor, which is coupled to the memory, is configured to generate an indicator that represents a common degree of shadowing associated with the subset of samples. In some cases, the apparatus includes a graphics processing unit (“GPU”), which is coupled to the co-processor, that is configured to render one or more shadows for a computer-generated image based on the indicator.

Systems and methods are provided for controlling texture sampling in connection with computer graphics in a computer system. In various embodiments, improved mechanisms for controlling texture sampling are provided that enable 3-D accelerator hardware to greatly increase the level of realism in rendering, including improved mechanisms for (1) motion blur; (2) generating anisotropic surface reflections (3) generating surface self-shadowing (4) ray-cast volumetric sampling (4) self-shadowed volumetric rendering and (5) self-shadowed volumetric ray-casting. In supplementing existing texture sampling techniques, parameters for texture sampling may be replaced and/or modified.

Data partitioned onto two or more storage devices is presented to a user as if the data resided on a single storage area. Data is divided between the storage areas based on policies. Data on the primary storage can utilize frequent back up or other storage management to ensure the accuracy of the data. The data on the secondary storage can employ other data management than the data management for the primary storage. The subdirectory structure is replicated in each area so a data file can be located in either physical area. This allows data files to migrate between the storage areas based on policy.

The computer graphics system is configured to generate a shadow effect with a stencil shadow volume method using a combination of compressed and uncompressed stencil buffers in coordination with compressed and uncompressed depth data buffers. An uncompressed stencil buffer is capable of storing stencil shadow volume data for each pixel and a compressed stencil buffer is capable of storing stencil shadow volume data for a group of pixels.

The invention relates to a real-time illumination plotting method under virtual stage environment, mainly comprising: combining Deferred shading technique and clustering method to do optimization; using 3D texture to organize medium attribute information; clustering a plurality of light sources into a virtual light source; real-timely plotting the participating media under the illumination of a plurality of stage light sources. The invention combines shadow map, shadow volume and ray marching techniques and the like, to provide a method for real-time plotting indoor scene object shadows. Tests prove that the real-time illumination plotting method can actually simulate complex illumination under virtual stage environment, and has the advantages of high real-time property.

A shadow body generation unit 1711 generates a shadow model defined by a limited numbers of lines extending from a position of a light source to an outline of a hand. If the virtual object is partially or fully included in the shadow model and a position of the virtual object is further away from the position of the light source, the shadow body generation unit 1711 generates a shadow for partially obscured area included in the shadow model.

A method and apparatus for generating shadow by using an adaptive shadow volume algorithm are disclosed. By accumulating the number of Z pass and Z fail during shadow volume rendering, the performance can be improved by adaptively selecting the z pass algorithm or the z fail algorithm. Accordingly, one of the algorithms (z-pass or z-fail) with better performance is used as the shadow volume algorithm for next frame.

The invention discloses a real-time rendering method and device based on dynamic illumination change. The method comprises the steps that a 3D model and an HDRI environment map of a scene are acquired; performing illumination estimation on the scene based on the 3D model of the scene and an HDRI environment map; performing basic rendering on the virtual object by adopting a shadow volume algorithmbased on the illumination estimation; performing HDRI mapping on the virtual object environment after basic rendering to obtain a current environment diagram, and performing enhanced rendering on thevirtual object based on the current environment diagram to obtain a real shadow of the virtual object; and when the illumination in the scene changes, updating the current environment map to match the current illumination based on the latest illumination estimation of the scene, and performing real-time rendering on the virtual object by using the updated current environment map. The rendering method and device solve the problem that in the prior art, a rendering method and device cannot create realistic illumination of the virtual object in the outdoor environment with dynamic illumination changes.

The invention relates to an illumination probe generation method, an illumination probe generation device, a storage medium and computer equipment. The method comprises the following steps of: selecting the shadow points of a target object in a virtual scene; converting the selected shadow points into a voxelized shadow voxel object; reducing the number of vertexes in the shadow voxel object to obtain a reduced shadow voxel object; and generating illumination probes at the vertex positions of the vertex-reduced shadow voxel object. With the method provided by the technical schemes of the invention adopted, when the illumination probes are distributed, the occupation of a large amount of memory and the consumption of a large amount of distribution time can be effectively avoided.

Various methods and systems are provided for generating a volume-rendered image with shading from a three-dimensional ultrasound dataset. As one example, a method for ultrasound imaging includes generating a volume-rendered image with shading and shadowing from a three-dimensional ultrasound dataset, the shading and shadowing based on an angle between a probe axis of a transducer probe used to acquire the three-dimensional ultrasound dataset and a viewing direction of the volume-rendered image.

The invention provides a backup virtualization-based method. The method provides a unique backup solution, and real-time backup of a virtual image can be realized without pausing system IO reading-writing; a Windows virtual machine image does not depend on a shadow volume, Linux image backup does not depend on a VM snapshot, a backup format is compatible with a VMDK of a virtual machine, is immediately recovered after backup and is completely consistent with a format of the VM snapshot, and multi-version automatic management of the virtual machine image is realized. The recovery of a single data file in an image volume can be realized. A new method is provided for secure and quick recovery of information.

The embodiment of the invention provides a shadow volume optimization method based on a KD tree; the method comprises the following steps: extracting sharing edges, located on two sides of a light source, of adjacent surfaces as shared contour edges of the shadow volume; segmenting scene data according to the KD tree, extracting the edge with only one adjacent surface to make shading calculation, and extracting boundaries with no shading as the shadow volume boundary contour edges; building the shadow volume according to the shared contour edges and boundary contour edges; segmenting the shadow volume data according to the KD tree, using the shadow volume to remove a bounding volume, removing shadows, and improving the shadow volume peak processing rate. The shadow volume optimization method can solve the problems that a conventional shadow volume algorithm cannot process a non-closed geometry scene, and uses the CPU end shadow volume cutting works to greatly save data bulk inputted into a GPU, thus reducing the GPU burdens.

This invention discloses one shade generation method and device by adapting shade space, wherein, when rendering one frame shadow volume, the statistics deep deduces the number of z fail through z pass to compute the graph effect. So it can make the next frame shallow space formula according to the next best.