Link Search Menu Expand Document

ossia

Extract Attribute

This example demonstrates the two main tools for GPU-side geometry processing: extracting individual attributes from a mesh and reconstructing geometry from raw buffers.

Overview

A OBJ model is loaded, and its geometry attributes (position, normals, UVs, etc.) are extracted into separate GPU buffers using the Extract Attribute process. These buffers are then reassembled into a new mesh with the Buffers to Geometry process. An LFO drives a rotation animation through a micro-mapping expression. All data stays on the GPU throughout the pipeline.

Key concepts

  • Extract Attribute: Takes a geometry and fetches a specific attribute by name (position, color, UV, normal, tangent…), by index (attribute 0 to 8), or as a raw buffer from the source geometry data.
  • Buffers to Geometry: Takes multiple GPU buffers as input and recreates a renderable mesh, with configurable attribute layout (buffer, offset, stride, format, location), topology, and culling.
  • Geometry Info: Reports vertex count, index count, instance count, and attribute count from a geometry.
  • GPU-side processing: As far as possible, everything stays in GPU memory: geometry is never transferred back to the CPU, for maximum performance.

Data flow

  1. Object loader loads the goblet mesh
  2. Extract Attribute pulls position data into a GPU buffer
  3. Geometry Info reads the vertex count
  4. Buffers to Geometry rebuilds a mesh from the extracted buffer
  5. A solid color texture is applied, and Model display renders the result

Try it

Open this example to see GPU-side geometry attribute extraction and mesh reconstruction.

Download this example

Learn more