Overdraw analyzer
Returns overdraw statistics using a software rasterizer
Results may not match actual GPU performance
Vertex transform cache analyzer
Returns cache hit statistics using a simplified FIFO model
Results may not match actual GPU performance
Vertex fetch cache analyzer
Returns cache hit statistics using a simplified direct mapped model
Results may not match actual GPU performance
Meshlet builder
Splits the mesh into a set of meshlets where each meshlet has a micro index buffer indexing into meshlet vertices that refer to the original vertex buffer
The resulting data can be used to render meshes using NVidia programmable mesh shading pipeline, or in other cluster-based renderers.
When using buildMeshlets, vertex positions need to be provided to minimize the size of the resulting clusters.
When using buildMeshletsScan, for maximum efficiency the index buffer being converted has to be optimized for vertex cache first.
Cluster bounds generator
Creates bounding volumes that can be used for frustum, backface and occlusion culling.
Vertex buffer filters
These functions can be used to filter output of meshopt_decodeVertexBuffer in-place.
Index buffer decoder
Decodes index data from an array of bytes generated by meshopt_encodeIndexBuffer
Returns 0 if decoding was successful, and an error code otherwise
The decoder is safe to use for untrusted input, but it may produce garbage data (e.g. out of range indices).
Index sequence decoder
Decodes index data from an array of bytes generated by meshopt_encodeIndexSequence
Returns 0 if decoding was successful, and an error code otherwise
The decoder is safe to use for untrusted input, but it may produce garbage data (e.g. out of range indices).
Vertex buffer decoder
Decodes vertex data from an array of bytes generated by meshopt_encodeVertexBuffer
Returns 0 if decoding was successful, and an error code otherwise
The decoder is safe to use for untrusted input, but it may produce garbage data.
Index buffer encoder
Encodes index data into an array of bytes that is generally much smaller (<1.5 bytes/triangle) and compresses better (<1 bytes/triangle) compared to original.
Input index buffer must represent a triangle list.
Returns encoded data size on success, 0 on error; the only error condition is if buffer doesn’t have enough space
For maximum efficiency the index buffer being encoded has to be optimized for vertex cache and vertex fetch first.
Index sequence encoder
Encodes index sequence into an array of bytes that is generally smaller and compresses better compared to original.
Input index sequence can represent arbitrary topology; for triangle lists meshopt_encodeIndexBuffer is likely to be better.
Returns encoded data size on success, 0 on error; the only error condition is if buffer doesn’t have enough space
Set index encoder format version
version must specify the data format version to encode; valid values are 0 (decodable by all library versions) and 1 (decodable by 0.14+)
Vertex buffer encoder
Encodes vertex data into an array of bytes that is generally smaller and compresses better compared to original.
Returns encoded data size on success, 0 on error; the only error condition is if buffer doesn’t have enough space
This function works for a single vertex stream; for multiple vertex streams, call meshopt_encodeVertexBuffer for each stream.
Note that all vertex_size bytes of each vertex are encoded verbatim, including padding which should be zero-initialized.
Set vertex encoder format version
version must specify the data format version to encode; valid values are 0 (decodable by all library versions)
Generate index buffer that can be used as a geometry shader input with triangle adjacency topology
Each triangle is converted into a 6-vertex patch with the following layout:
Generate index buffer that can be used for more efficient rendering when only a subset of the vertex attributes is necessary
All vertices that are binary equivalent (wrt first vertex_size bytes) map to the first vertex in the original vertex buffer.
This makes it possible to use the index buffer for Z pre-pass or shadowmap rendering, while using the original index buffer for regular rendering.
Note that binary equivalence considers all vertex_size bytes, including padding which should be zero-initialized.
Generate index buffer that can be used for more efficient rendering when only a subset of the vertex attributes is necessary
All vertices that are binary equivalent (wrt specified streams) map to the first vertex in the original vertex buffer.
This makes it possible to use the index buffer for Z pre-pass or shadowmap rendering, while using the original index buffer for regular rendering.
Note that binary equivalence considers all size bytes in each stream, including padding which should be zero-initialized.
Generate index buffer that can be used for PN-AEN tessellation with crack-free displacement
Each triangle is converted into a 12-vertex patch with the following layout:
Generates a vertex remap table from the vertex buffer and an optional index buffer and returns number of unique vertices
As a result, all vertices that are binary equivalent map to the same (new) location, with no gaps in the resulting sequence.
Resulting remap table maps old vertices to new vertices and can be used in meshopt_remapVertexBuffer/meshopt_remapIndexBuffer.
Note that binary equivalence considers all vertex_size bytes, including padding which should be zero-initialized.
Generates a vertex remap table from multiple vertex streams and an optional index buffer and returns number of unique vertices
As a result, all vertices that are binary equivalent map to the same (new) location, with no gaps in the resulting sequence.
Resulting remap table maps old vertices to new vertices and can be used in meshopt_remapVertexBuffer/meshopt_remapIndexBuffer.
To remap vertex buffers, you will need to call meshopt_remapVertexBuffer for each vertex stream.
Note that binary equivalence considers all size bytes in each stream, including padding which should be zero-initialized.
Experimental: Meshlet optimizer
Reorders meshlet vertices and triangles to maximize locality to improve rasterizer throughput
Overdraw optimizer
Reorders indices to reduce the number of GPU vertex shader invocations and the pixel overdraw
If index buffer contains multiple ranges for multiple draw calls, this functions needs to be called on each range individually.
Vertex transform cache optimizer
Reorders indices to reduce the number of GPU vertex shader invocations
If index buffer contains multiple ranges for multiple draw calls, this functions needs to be called on each range individually.
Vertex transform cache optimizer for FIFO caches
Reorders indices to reduce the number of GPU vertex shader invocations
Generally takes ~3x less time to optimize meshes but produces inferior results compared to meshopt_optimizeVertexCache
If index buffer contains multiple ranges for multiple draw calls, this functions needs to be called on each range individually.
Vertex transform cache optimizer for strip-like caches
Produces inferior results to meshopt_optimizeVertexCache from the GPU vertex cache perspective
However, the resulting index order is more optimal if the goal is to reduce the triangle strip length or improve compression efficiency
Vertex fetch cache optimizer
Reorders vertices and changes indices to reduce the amount of GPU memory fetches during vertex processing
Returns the number of unique vertices, which is the same as input vertex count unless some vertices are unused
This functions works for a single vertex stream; for multiple vertex streams, use meshopt_optimizeVertexFetchRemap + meshopt_remapVertexBuffer for each stream.
Vertex fetch cache optimizer
Generates vertex remap to reduce the amount of GPU memory fetches during vertex processing
Returns the number of unique vertices, which is the same as input vertex count unless some vertices are unused
The resulting remap table should be used to reorder vertex/index buffers using meshopt_remapVertexBuffer/meshopt_remapIndexBuffer
Generate index buffer from the source index buffer and remap table generated by meshopt_generateVertexRemap
Generates vertex buffer from the source vertex buffer and remap table generated by meshopt_generateVertexRemap
Set allocation callbacks
These callbacks will be used instead of the default operator new/operator delete for all temporary allocations in the library.
Note that all algorithms only allocate memory for temporary use.
allocate/deallocate are always called in a stack-like order - last pointer to be allocated is deallocated first.
Mesh simplifier
Reduces the number of triangles in the mesh, attempting to preserve mesh appearance as much as possible
The algorithm tries to preserve mesh topology and can stop short of the target goal based on topology constraints or target error.
If not all attributes from the input mesh are required, it’s recommended to reindex the mesh using meshopt_generateShadowIndexBuffer prior to simplification.
Returns the number of indices after simplification, with destination containing new index data
The resulting index buffer references vertices from the original vertex buffer.
If the original vertex data isn’t required, creating a compact vertex buffer using meshopt_optimizeVertexFetch is recommended.
Experimental: Point cloud simplifier
Reduces the number of points in the cloud to reach the given target
Returns the number of points after simplification, with destination containing new index data
The resulting index buffer references vertices from the original vertex buffer.
If the original vertex data isn’t required, creating a compact vertex buffer using meshopt_optimizeVertexFetch is recommended.
Returns the error scaling factor used by the simplifier to convert between absolute and relative extents
Experimental: Mesh simplifier (sloppy)
Reduces the number of triangles in the mesh, sacrificing mesh appearance for simplification performance
The algorithm doesn’t preserve mesh topology but can stop short of the target goal based on target error.
Returns the number of indices after simplification, with destination containing new index data
The resulting index buffer references vertices from the original vertex buffer.
If the original vertex data isn’t required, creating a compact vertex buffer using meshopt_optimizeVertexFetch is recommended.
Experimental: Mesh simplifier with attribute metric
The algorithm ehnahces meshopt_simplify by incorporating attribute values into the error metric used to prioritize simplification order; see meshopt_simplify documentation for details.
Note that the number of attributes affects memory requirements and running time; this algorithm requires ~1.5x more memory and time compared to meshopt_simplify when using 4 scalar attributes.
Spatial sorter
Generates a remap table that can be used to reorder points for spatial locality.
Resulting remap table maps old vertices to new vertices and can be used in meshopt_remapVertexBuffer.
Experimental: Spatial sorter
Reorders triangles for spatial locality, and generates a new index buffer. The resulting index buffer can be used with other functions like optimizeVertexCache.
Mesh stripifier
Converts a previously vertex cache optimized triangle list to triangle strip, stitching strips using restart index or degenerate triangles
Returns the number of indices in the resulting strip, with destination containing new index data
For maximum efficiency the index buffer being converted has to be optimized for vertex cache first.
Using restart indices can result in ~10% smaller index buffers, but on some GPUs restart indices may result in decreased performance.
Mesh unstripifier
Converts a triangle strip to a triangle list
Returns the number of indices in the resulting list, with destination containing new index data