helidon

This document provides an overview of Helidon and Mitsuba 3, two distinct projects with different focuses. Helidon is a set of Java libraries for building microservices, leveraging Java 21's virtual threads for improved performance and simplified development. Mitsuba 3, on the other hand, is a research-oriented rendering system offering high-performance, cross-platform capabilities and Python integration. Both projects offer extensive documentation and are available for use under permissive open-source licenses.

Helidon: Java Libraries for Microservices

Project Helidon is a set of Java Libraries for writing microservices.

Helidon supports two programming models:

In either case your application is a Java SE program running on the

new Helidon Níma WebServer that has been written from the ground up to

use Java 21 Virtual Threads. With Helidon 4 you get the high throughput of a reactive server with the simplicity of thread-per-request style programming.

The Helidon SE API in Helidon 4 has changed significantly from Helidon 3. The use of virtual threads has enabled these APIs to change from asynchronous to blocking. This results in much simpler code that is easier to write, maintain, debug and understand. Earlier Helidon SE code will require modification to run on these new APIs. For more information see the Helidon SE Upgrade Guide.

Helidon 4 supports MicroProfile 6. This means your existing Helidon MP 3.x applications will run on Helidon 4 with only minor modifications. And since Helidon’s MicroProfile server is based on the new Níma WebServer you get all the benefits of running on virtual threads. For more information see the Helidon MP Upgrade Guide.

New to Helidon? Then jump in and get started.

Java 21 is required to use Helidon 4.

License

Helidon is available under Apache License 2.0.

Documentation

Latest documentation and javadocs are available at https://helidon.io/docs/latest.

Helidon White Paper is available here.

Get Started

See Getting Started at https://helidon.io.

Downloads / Accessing Binaries

There are no Helidon downloads. Just use our Maven releases (GroupID io.helidon).

See Getting Started at https://helidon.io.

Helidon CLI

macOS:

Linux:

Windows:

See this document for more info.

Build

You need JDK 21 to build Helidon 4.

You also need Maven. We recommend 3.8.0 or newer.

Full build

Checkstyle

Copyright

Spotbugs

Documentation

Build Scripts

Build scripts are located in etc/scripts. These are primarily used by our pipeline,

but a couple are handy to use on your desktop to verify your changes.

Get Help

Contributing

Stay Informed

example:

Mitsuba Renderer 3

Documentation	Tutorial videos	Linux	MacOS	Windows	PyPI

️

Warning

️

There currently is a large amount of undocumented and unstable work going on in

the master branch. We'd highly recommend you use our

latest release

until further notice.

If you already want to try out the upcoming changes, please have a look at

this porting guide.

It should cover most of the new features and breaking changes that are coming.

Introduction

Mitsuba 3 is a research-oriented rendering system for forward and inverse light

transport simulation developed at EPFL in Switzerland.

It consists of a core library and a set of plugins that implement functionality

ranging from materials and light sources to complete rendering algorithms.

Mitsuba 3 is retargetable: this means that the underlying implementations and

data structures can transform to accomplish various different tasks. For

example, the same code can simulate both scalar (classic one-ray-at-a-time) RGB transport

or differential spectral transport on the GPU. This all builds on

Dr.Jit, a specialized just-in-time(JIT) compiler developed specifically for this project.

Main Features

• Cross-platform: Mitsuba 3 has been tested on Linux (x86_64), macOS

  (aarch64, x8664), and Windows (x8664).

• High performance: The underlying Dr.Jit compiler fuses rendering code

  into kernels that achieve state-of-the-art performance using

  an LLVM backend targeting the CPU and a CUDA/OptiX backend

  targeting NVIDIA GPUs with ray tracing hardware acceleration.

• Python first: Mitsuba 3 is deeply integrated with Python. Materials,

  textures, and even full rendering algorithms can be developed in Python,

  which the system JIT-compiles (and optionally differentiates) on the fly.

  This enables the experimentation needed for research in computer graphics and

  other disciplines.

• Differentiation: Mitsuba 3 is a differentiable renderer, meaning that it

  can compute derivatives of the entire simulation with respect to input

  parameters such as camera pose, geometry, BSDFs, textures, and volumes. It

  implements recent differentiable rendering algorithms developed at EPFL.

• Spectral & Polarization: Mitsuba 3 can be used as a monochromatic

  renderer, RGB-based renderer, or spectral renderer. Each variant can

  optionally account for the effects of polarization if desired.

Tutorial videos, documentation

We've recorded several YouTube videos that provide a gentle introduction

Mitsuba 3 and Dr.Jit. Beyond this you can find complete Juypter notebooks

covering a variety of applications, how-to guides, and reference documentation

on readthedocs.

Installation

We provide pre-compiled binary wheels via PyPI. Installing Mitsuba this way is as simple as running

pip install mitsuba

on the command line. The Python package includes thirteen variants by default:

• scalar_rgb

• scalar_spectral

• scalarspectralpolarized

• llvmadrgb

• llvmadmono

• llvmadmono_polarized

• llvmadspectral

• llvmadspectral_polarized

• cudaadrgb

• cudaadmono

• cudaadmono_polarized

• cudaadspectral

• cudaadspectral_polarized

The first two perform classic one-ray-at-a-time simulation using either a RGB

or spectral color representation, while the latter two can be used for inverse

rendering on the CPU or GPU. To access additional variants, you will need to

compile a custom version of Dr.Jit using CMake. Please see the

documentation

for details on this.

Requirements

• Python >= 3.8

• (optional) For computation on the GPU: Nvidia driver >= 495.89

• (optional) For vectorized / parallel computation on the CPU: LLVM >= 11.1

Usage

Here is a simple "Hello World" example that shows how simple it is to render a

scene using Mitsuba 3 from Python:

# Import the library using the alias "mi"import mitsuba as mi# Set the variant of the renderermi.setvariant('scalarrgb')# Load a scenescene = mi.loaddict(mi.cornellbox())# Render the sceneimg = mi.render(scene)# Write the rendered image to an EXR filemi.Bitmap(img).write('cbox.exr')

Tutorials and example notebooks covering a variety of applications can be found

in the documentation.

About

This project was created by Wenzel Jakob.

Significant features and/or improvements to the code were contributed by

Sébastien Speierer,

Nicolas Roussel,

Merlin Nimier-David,

Delio Vicini,

Tizian Zeltner,

Baptiste Nicolet,

Miguel Crespo,

Vincent Leroy, and

Ziyi Zhang.

When using Mitsuba 3 in academic projects, please cite:

@software{Mitsuba3,title = {Mitsuba 3 renderer},author = {Wenzel Jakob and Sébastien Speierer and Nicolas Roussel and Merlin Nimier-David and Delio Vicini and Tizian Zeltner and Baptiste Nicolet and Miguel Crespo and Vincent Leroy and Ziyi Zhang},note = {https://mitsuba-renderer.org},version = {3.1.1},year = 2022}