A many-core capable flyweight in situ visualization and analysis infrastructure for multi-physics HPC simulations.



Ascent is an easy-to-use flyweight in situ visualization and analysis library for HPC simulations:

  • Supports: Making Pictures, Transforming Data, and Capturing Data for use outside of Ascent
  • Young effort, yet already includes most common visualization operations
  • Provides a simple infrastructure to integrate custom analysis
  • Provides C++, C, Python, and Fortran APIs

Ascent’s flyweight design targets next-generation HPC platforms:

  • Provides efficient distributed-memory (MPI) and many-core (CUDA or OpenMP) execution
  • Demonstrated scaling: In situ filtering and ray tracing across 16,384 GPUs on LLNL’s Sierra Cluster
  • Has lower memory requirements than current tools
  • Requires less dependencies than current tools (ex: no OpenGL)

Ascent focuses on ease of use and reducing integration burden for simulation code teams:

  • Actions are passed to Ascent via YAML files
  • Replay capability helps prototype and test actions
  • It does not require GUI or system-graphics libraries
  • It includes integration examples that demonstrate how to use Ascent inside existing HPC-simulation proxy applications

Getting Started

To get started building and using Ascent, see the Quick Start Guide and the Ascent Tutorial. For more details about building Ascent see the Building documentation.

Ascent Project Resources

Website and Online Documentation

Github Source Repo

Issue Tracker

Help Email


  • Cyrus Harrison (LLNL)
  • Matt Larsen (LLNL)
  • Eric Brugger (LLNL)
  • Jim Eliot (AWE)
  • Kevin Griffin (LLNL)
  • Hank Childs (LBL and UO)
  • Utkarsh Ayachit (Kitware, Inc)
  • Sudhanshu Sane (UO)
  • Seif Ibrahim (LLNL, UCSB)

Ascent Documentation

Indices and tables