68 results about "Bounding volume hierarchy" patented technology

A method performed by a graphics processor searches for a candidate reinsertion for each of a plurality of input nodes of a current bounding volume hierarchy (BVH) which would move the input node from an old parent to a new parent, and which would reduce an expected computational cost of searching the BVH for a ray intersection; and performs a first update to update the current BVH with one or more selected reinsertions from among the candidates. The selection comprises a conflict check to determine whether any group of the candidates would affect a same part of the current BVH, and if so selecting only one of the group to include in the first update. At least one of the iterations further comprises, after the first update, performing a second update within the same iteration to update the current BVH with another of said group.

Apparatus and method for using multiple bounds to bound BVH child nodes. For example, one embodiment of an apparatus comprises: traversal hardware logic to traverse rays through a bounding volume hierarchy (BVH); and BVH construction circuitry to evaluate nodes of an N-wide BVH, the BVH construction circuitry to generate a union of multiple bounding boxes for one or more child nodes of the BVH to produce one or more corresponding union-bounded child nodes, wherein a node of the BVH stores N bounding boxes and each corresponding child node of the BVH is bounded by 0 to N of the bounding boxes; the traversal hardware logic to traverse a ray through the N-wide BVH and to determine a hit with respect to each union-bounded child node if any of the bounding boxes associated with the union-bounded child node are hit by the ray.

A technique for performing ray tracing operations is provided. The technique includes identifying triangles to include in a compressed triangle block; storing data common to the identified triangles as common data of the compressed triangle block; and storing data unique to the identified triangles as unique data of the compressed triangle block.

Systems and methods for faster BVH building that requires repeated sorting and partitioning of are described. Specific hardware circuitries are programmed to sort partitioned data and make reductions for each partition. The hardware units perform the initial sorting along a split axis and calculation of bounding box extents. The solutions presented herein improve performance of BVH builds, especially for cases where the geometry is comprised of many small BVH treelets. The most expensive processing steps in BVH construction are delegated to hardware thereby minimizing memory access latencies and increasing overall system efficiencies.

Techniques for constructing a bounding volume hierarchy are disclosed that include refining a candidate box node based on a resolution to generate a plurality of cells for the candidate box node, identifying a plurality of nodes of a triangle set collection that fall within the cell, generating a plurality of candidate splits based on the plurality of nodes, selecting the candidate splits based on a selection criterion to obtain selected candidate splits, and generating child box nodes for the box node of the bounding volume hierarchy being constructed based on the selected candidate splits.

This disclosure provides systems, devices, apparatus, and methods, including computer programs encoded on storage media, for traversing a low-resolution BVH. A processor may obtain a first indication of a low-resolution BVH that includes a set of conservative candidate nodes that are associated with corresponding internal nodes of a full-resolution BVH. The processor may traverse the low-resolution BVH by (a) determining whether a ray intersects a primitive leaf of a conservative candidate node of the set of conservative candidate nodes in response to a first determination that the ray intersects the conservative candidate node and (b) traversing an internal node of the full-resolution BVH that corresponds with the conservative candidate node in response to a second determination that the ray does not intersect the primitive leaf. The processor may output a second indication of a ray trace hit or a ray trace miss based the traversal.

Techniques are disclosed relating to ray tracing, e.g., in graphics processors. Ray tracing embodiments may utilize a bounding volume hierarchy (BVH) acceleration data structure (ADS) that includes a hierarchy of bounding volumes. A graphics processor may traverse the ADS, testing for intersections with bounding volumes, to determine which primitives to test for a given ray. Some nodes may be transform nodes (e.g., instance nodes) that correspond to a ray transform before further traversal. In disclosed embodiment, one or more levels below the transform node may be reverse transformed and included above the transform node. This may advantageously avoid a ray transform operation for rays that would not have hit in the first one or more levels of the transform sub-tree.

Techniques herein involve building bounding volume hierarchies for ray tracing using neural networks. Bottom-up BVH building techniques include nearest neighbor search operations and tree construction operations. The nearest neighbor search operations evaluate a set of candidate nodes that do not have any parents to identify nearest neighbor pairs and the tree construction operations “combine” the nearest neighbor pairs by generating new nodes that are parents of the nodes of the pairs. The nearest neighbor search is an expensive operation as it generally considers all possible combinations of the set to select one considered “best.” A neural network model is thus proposed herein which can perform this nearest neighbor search in a more efficient manner. Specifically, the neural network model accepts, as input, information characterizing the nodes of a set for which a search is performed and provides, as output, information characterizing the nearest neighbor pairs found for the set.

A method and system for traversing a bounding volume hierarchy (BVH) structure associated with a given 3D scene using a ray tracing algorithm are provided. The method comprises: determining an escape probability value for a given node of the BVH structure of a given ray traversing the given node without reflecting off any mesh element contained therein; propagating a ray in the given 3D scene that intersects the respective bounding volume of the given node; in response to determining that the ray is to traverse the respective bounding volume, determining whether the ray is to traverse or to reflect off an other respective bounding volume; and in response to determining that the ray is to reflect off the respective bounding volume: rendering a mesh element contained in the respective bounding volume of the given BVH node.

Apparatus and method for a BVH with oriented boundaries using quantized shared orientations. For example, one embodiment of an apparatus comprises: traversal hardware logic for traversing rays through a bounding volume hierarchy (BVH); and BVH construction circuitry for generating a BVH with one or more oriented bounding boxes (OBBs), wherein the BVH construction circuitry projects a geometry of one or more child nodes along one or more orientation directions to determine corresponding upper and lower bounds; wherein the traversal hardware logic comprises OBB processing logic for: projecting a ray along the one or more orientation directions;in response, determining beam-plane intersection distances to one or more near and far boundary planes corresponding to the orientation directions; and determining a hit or miss based on the beam-plane intersection distances to the near and far boundary planes.

A graphics processor includes circuitry configured to generate a bounding volume hierarchy (BVH) data structure for a graphics scene to be rendered. The BVH includes a leaf node that includes: node data that specifies quantization frame data for quantized primitive children of the leaf node, a quantized primitive block that includes quantized vertex components of the primitive children, and a vertex residual block that includes additional vertex data for the primitive children. The vertex residual block may not include redundant data with the quantized primitive block and the quantized primitive block and vertex residual block may include, for the primitive children, sufficient data to reconstruct an original-precision representation of their vertices. The circuitry may traverse the BVH to perform ray tracing operations during render of the graphics scene, including to perform one or more ray primitive intersect tests based on the quantized primitive block and the vertex residual block.

Embodiments of the present disclosure relate to a method, an electronic device and a computer storage medium for compressing a bounding volume hierarchy, and relate to the field of information processing. According to the method, a node in a bounding volume hierarchy and a plurality of child nodes of the node are acquired; a maximum number difference between a plurality of primitives included in the plurality of child nodes is determined; if it is determined that the maximum number difference is less than or equal to a representation range of a primitive number difference field in a first compressed node format, the node and the plurality of child nodes are compressed based on the first compressed node format; and if it is determined that the maximum number difference is greater than the representation range of the primitive number difference field in the first compressed node format, the node and the plurality of child nodes are compressed based on a second compressed node format, the second compressed node format having a length greater than a length of the first compressed node format. Thus, the bounding volume hierarchy can be efficiently compressed.

Apparatus and method for box-box testing. For example, one embodiment of a processor comprises: a bounding volume hierarchy (BVH) generator to construct a BVH comprising a plurality of hierarchically arranged BVH nodes; traversal circuitry to traverse query boxes through the BVH, the traversal circuitry to read a BVH node from a top of a BVH node stack and to read a query box from a local storage or memory, the traversal circuitry further comprising: box-box testing circuitry and / or logic to compare maximum and minimum X, Y, and Z coordinates of the BVH node and the query box and to generate an overlap indication if overlap is detected for each of the X, Y, and Z dimensions; distance determination circuitry and / or logic to generate a distance value representing an extent of overlap between the BVH node and the query box; and sorting circuitry and / or logic to sort the BVH node within a set of one or more additional BVH nodes based on the distance value.

Techniques herein involve generating a bounding volume hierarchy in a fast and accurate manner. The techniques begin with a quickly built initial BVH and traverse that initial BVH in a bottom-up manner to generate a new BVH. The algorithm begins at the bottom level, setting the bottom-most primitive nodes as nodes in the new BVH and follows the initial BVH up, collecting uncombined nodes from lower levels to higher nodes. When the algorithm has collected a threshold number of such nodes at a node of the initial BVH, the algorithm builds a new subtree for that node by combining the threshold number of such nodes, and adds that new subtree to the new BVH. This algorithm is efficiently parallelizable by immediately switching from the traversal phase to the combining phase and using all work-items of a wavefront for such combining.

The invention relates to a method and system for constructing a ray tracing acceleration structure. A computer-implemented method of creating a bounding volume hierarchy, BVH, for a model is disclosed. The model is defined with respect to a local coordinate system of the model. The method comprises defining a BVH branch node within the model, establishing a plurality of local transformation matrices for the BVH, and for each BVH branch node, determining a first bounding volume and associating the branch node with one of the plurality of local transformation matrices that maps between the first bounding volume and a second bounding volume in the local coordinate system.

A fused bounding volume hierarchy, which is a combination of a base bounding volume hierarchy and one or more non-base bounding volume hierarchies, is generated. For each non-base bounding volume hierarchy, multiple subtrees in the non-base bounding volume hierarchy that include less than a threshold number of child nodes are identified. Each of these subtrees is then fused with the base bounding volume hierarchy at one of the nodes of the base bounding volume hierarchy, and an identifier of the level of detail for the non-base bounding volume hierarchy is included in the node. When displaying a scene or image, for a particular portion of the scene or image the level of detail to use is identified. The fused bounding volume hierarchy is traversed and the geometric objects in the nodes of the fused bounding volume hierarchy corresponding to the identified level of detail are displayed.

Aspects of the disclosure are directed to ray tracing. In accordance with one aspect, the disclosure includes determining if a node state is a leaf node, wherein the node state is at a current node of a bounding volume hierarchy (BVH); determining a ray intersection of a first child node In one example, from the current node using the ray hit information and a traversal stack. In one example, the method further includes updating a state information about a second child node and subsequent child nodes using the traversal stack.

A technique for performing a ray tracing operation is provided. The technique includes traversing to a pre-filtering node for a tested ray intersecting a geometry associated with the bounding volume hierarchy, the pre-filtering node including information of triangles for filtering out leaf nodes of the bounding volume hierarchy; evaluating quantized rays corresponding to the rays for the quantized triangles of the pre-filtered nodes to filter out one or more triangles of the leaf nodes without consideration; and testing unfiltered triangles of the leaf nodes and not testing filtered triangles of the leaf nodes.

A technique for building a bounding volume hierarchy is disclosed. The technique includes for a subject node, selecting a dimension along which to perform a split to form child nodes of the subject node; assigning primitives of the subject node to the child nodes; and updating bounds for the child nodes in a next split dimension and not in the other dimensions.

In various examples, a supported pattern of triangles may be associated with multiple cluster templates that represent optimized triblock layouts with different levels of compression. In some embodiments, an application running on a host (e.g., a CPU) may specify an applicable compression level for a cluster of triangles or a device (e.g., a GPU) may identify one (e.g., by inspecting the vertex positions on the fly). As such, the device may look up a set of cluster templates associated with a specified pattern of triangles, identify the cluster template associated with the applicable compression level, copy that cluster template into allocated memory for the cluster, copy or transcode the vertex positions in the cluster into a precomputed triblock layout represented by the cluster template, and build a bounding volume hierarchy subtree over the cluster of triangles using a precomputed range assignment represented by the cluster template.

Techniques are disclosed relating to ray intersection tests for ray tracing in graphics processors. In some embodiments, a ray cache stores, transformed ray direction corresponding to a transform of a ray based on its dominant direction axis. Ray intersect acceleration circuitry may determine whether a ray intersects a bounding volume of a bounding volume hierarchy (BVH) data structure. Ray-plane test circuitry may perform a set of six ray-plane tests for the bounding volume using at most four floating-point multiplication operations by four multiplier circuits. The floating-point operations may operate on the transformed ray direction components from the ray cache circuitry and coordinate information for the bounding volume. Disclosed techniques may reduce area and power consumption by avoiding multiplier circuitry for some ray-plane tests.

A graphics processing apparatus comprising bounding volume hierarchy (BVH) construction circuitry to perform a spatial analysis and temporal analysis related to a plurality of input primitives and responsively generate a BVH comprising spatial, temporal, and spatial-temporal components that are hierarchically arranged, wherein the spatial components include a plurality of spatial nodes with children, the spatial nodes bounding the children using spatial bounds, and the temporal components comprise temporal nodes with children, the temporal nodes bounding their children using temporal bounds and the spatial-temporal components comprise spatial-temporal nodes with children, the spatial-temporal nodes bounding their children using spatial and temporal bounds; and ray traversal / intersection circuitry to traverse a ray or a set of rays through the BVH in accordance with the spatial and temporal components.

This invention discloses a spatiotemporal data indexing query method, system, medium, and device based on GPU ray tracing, belonging to the field of spatial data indexing technology. The method includes responding to a point query request, obtaining the query coordinates, query time, and target object identifier from the point query request, emitting a vertical ray along a preset direction starting from the query coordinates and starting height, performing GPU ray traversal of the nearest intersection point on the vertical ray using a pre-established spatiotemporal index structure, and returning the intersecting geometric primitive with the smallest ray parameter, whose object identifier matches the target object identifier, and is a valid data record, as the query result of the point query request. This invention achieves hardware acceleration of spatiotemporal indexing query by uniformly mapping two-dimensional spatial coordinates and time dimension to a three-dimensional coordinate system and utilizing a bounding volume hierarchy and its corresponding geometric acceleration structure.

Data for nodes of a bounding volume hierarchy can be represented in fixed-point format for compression. For good precision, fixed-point bounds are stored along with each node, where these bounds represent the minimum and maximum representable numbers in the format. While this provides good compression, there are ways in which this technique can produce undesirable results. For example, if the size of many or most of the bounding volumes in the fixed-point number space is significantly smaller than the bounds, then the representation of such bounding volume in the fixed-point space may be unnecessarily large, resulting in a large number of false positive intersections during BVH traversal. Thus, techniques are provided herein for setting certain bounding volumes as “always hit” in order to eliminate the bounding volumes from inclusion in the fixed-point bounds. This shrinks the fixed-point bounds, giving better precision for smaller bounding volumes.

It is often desirable to perform a search for objects in a scene. Specifically, it is useful to determine whether objects are located within a search area and / or to identify the nearest objects to a search point. Ray tracing systems have capabilities that are nearly sufficient to perform such a search. For instance, ray tracing systems build acceleration structures such as bounding volume hierarchies (“BVHs”) that help to accelerate the evaluation of a ray. These BVHs are also useful for performing object searches. Ray tracing hardware includes functionality related to performing a ray-box test, which can be adapted for searching whether an object is within a search area. Ray tracing hardware also includes functionality related to instances. In ray tracing, instances are copies of geometry, with an instance transform (e.g., scale, shear, rotation) applied. As objects being searched for may be instances, the instance-related functionality is useful for object searching.

A method and apparatus for efficiently constructing a bounding volume hierarchy (BVH). For example, one embodiment of an apparatus comprises: a primitive sampler to identify a representative subset of input primitives of a graphics scene; bounding volume hierarchy (BVH) builder hardware logic to construct an approximate BVH based on the representative subset of input primitives; hardware logic to insert input primitives not in the representative subset into leaves of the approximate BVH; and the BVH builder or a different BVH builder to construct a final BVH based on the primitives inserted into the leaves of the approximate BVH.

A graphics processor includes circuitry configured to generate a bounding volume hierarchy (BVH) data structure for a graphics scene to be rendered. The BVH includes a leaf node that includes: node data that specifies quantization frame data for quantized primitive children of the leaf node, a quantized primitive block that includes quantized vertex components of the primitive children, and a vertex residual block that includes additional vertex data for the primitive children. The vertex residual block may not include redundant data with the quantized primitive block and the quantized primitive block and vertex residual block may include, for the primitive children, sufficient data to reconstruct an original-precision representation of their vertices. The circuitry may traverse the BVH to perform ray tracing operations during render of the graphics scene, including to perform one or more ray primitive intersect tests based on the quantized primitive block and the vertex residual block.

A graphics processor includes circuitry configured to generate a bounding volume hierarchy (BVH) data structure for a graphics scene to be rendered. The BVH includes a leaf node that includes: node data that specifies quantization frame data for quantized primitive children of the leaf node, a quantized primitive block that includes quantized vertex components of the primitive children, and a vertex residual block that includes additional vertex data for the primitive children. The vertex residual block may not include redundant data with the quantized primitive block and the quantized primitive block and vertex residual block may include, for the primitive children, sufficient data to reconstruct an original-precision representation of their vertices. The circuitry may traverse the BVH to perform ray tracing operations during render of the graphics scene, including to perform one or more ray primitive intersect tests based on the quantized primitive block and the vertex residual block.

A method performed by a graphics processor obtains a starting bounding volume hierarchy (BVH), being a data structure comprising nodes representing different 3D regions of space in a modelled environment, the data structure comprising a tree in which the nodes are arranged hierarchically from a root node down to a plurality of leaf nodes, wherein the region modelled by each leaf node encompasses at least one primitive or part of a primitive. The method further comprises performing one or more iterations, starting with a first iteration which starts with the starting BVH as a current BVH, which search for candidate reinsertions to move input nodes to new parents in the tree to reduce expected computational cost.

A processor is provided to perform a raytracing process, wherein the raytracing process includes: determining a bounding volume hierarchy (BVH) structure with leaf nodes; storing a plurality of triangles as meshlets in leaf nodes; obtaining a ray tracing acceleration data structure (RTAS) comprising BVH leaf nodes and triangles; transforming vertices of the triangles into a unit ray coordinate space; perform a culling procedure on the transformed triangles; and intersect remaining triangles with a ray in the unit ray space.