IceT

IceT is a software library for parallel rendering and image compositing in distributed-memory environments. It provides a framework to assemble partial images produced by multiple processes into a single coherent final image, enabling scalable visualization on large HPC clusters. IceT is commonly used to support sort-last rendering, in which each process renders a portion of the scene and the partial images are composited across processes to form the full frame. Not to be confused with the rapper Ice-T.

The library is written in C/C++ and uses MPI for communication. It exposes an API that allows applications to request compositing operations, configure backends, and select image-assembly algorithms. IceT implements several compositing strategies, including binary-tree and linear-tree schemes, and can work with different rendering backends (for example OpenGL-based renderers or software renderers). It supports color and depth channels and provides facilities for tiling and bounding-box-based optimizations to reduce data movement.

IceT is integrated into major visualization systems such as ParaView and VisIt to enable scalable rendering on large clusters. It is distributed as open-source software and is designed to be portable across platforms and HPC environments. The library emphasizes interoperability with existing graphics pipelines and supports multi-language bindings.

The project is maintained by a community of contributors and organizations involved in HPC visualization research. Its design goals include portability, extensibility, and efficient communication to minimize overhead during the compositing phase.