Open-source alternatives to Mitsuba3

Mitsuba is a physically based rendering engine that calculates realistic light interactions to produce accurate synthetic images using both biased and unbiased numerical integration techniques. It is designed for computer graphics research and supports interactive three-dimensional scene inspection through a graphical interface that provides progressive real-time previewing, refining images iteratively when movement stops. The system features a plugin-based architecture that dynamically loads modular components at runtime to incorporate custom materials, light sources, and complete rendering

Autograd is an automatic differentiation library and numerical gradient engine for Python. Its primary purpose is to compute the gradients of mathematical functions to enable numerical optimization and the training of mathematical models. The library automates the calculation of derivatives to simplify the implementation of optimization algorithms. This supports activities such as machine learning research, gradient-based learning, and the optimization of numerical models.

This repository is a comprehensive collection of functional 2D and 3D demo projects and implementation samples for the Godot Game Engine. It serves as an interactive tutorial and reference library, providing a working codebase to demonstrate how to apply engine features in real-world scenarios. The collection focuses on practical implementation guides, covering a wide array of technical capabilities from basic engine fundamentals to advanced rendering and scripting techniques. It allows users to study the application of node-based composition, asset pipelines, and game logic through direct ex

GPUImage2 is a Swift framework for applying real-time filters and effects to images and video using the GPU. It provides a real-time video filter library, an image geometry manipulation engine, and an OpenGL shading pipeline for processing visual data on graphics hardware. The framework enables the construction of visual effect pipelines by chaining image sources to consumers in sequential flows. It supports the development of custom fragment and vertex shaders for bespoke image processing and offers the ability to bundle these operations into reusable units via graph-based grouping. Capabil

This project is an open-source 3D game engine designed for building high-fidelity games, simulations, and cinematic environments. It functions as a robotics simulation platform with native integration for ROS 2 to model robot controllers and sensors. The engine features a multi-threaded Forward+ physically based renderer that supports hardware-accelerated ray tracing and global illumination. The system is built on a modular extension architecture using Gems to add or replace features without modifying core binaries. It includes a native SDK for AWS cloud integration, enabling IAM authenticati

Orillusion is a WebGPU 3D rendering engine designed for high-fidelity scenes and visual effects in the browser. It functions as a GPU compute framework for parallel mathematical operations and a physically-based rendering graphics pipeline for realistic materials and surfaces. The system also includes a web-based 3D animation toolkit for driving skeletal animations and interpolating vertex positions. The engine is distinguished by its use of an entity component system for scene logic and a macro-based shader generation system that creates multiple shader variants. It optimizes performance thr

WebGLStudio.js is a browser-based IDE and graphics editor for creating 3D scenes, textures, and animations using WebGL. It functions as a spatial design environment where users can arrange 3D meshes and assets directly within the browser to build interactive visual experiences. The project features a visual shader graph editor that allows for the development of custom rendering effects and post-processing shaders through a node-based interface. It also includes a virtual file system for organizing 3D models, audio, and textures, and uses URL-state serialization to share entire project configu

This project is an educational platform and research toolkit designed to teach deep learning through a combination of mathematical theory, visual diagrams, and executable code. It provides a comprehensive environment for building, training, and evaluating neural networks, grounding complex concepts in interactive computational notebooks that allow for hands-on experimentation. The framework distinguishes itself by interleaving theoretical foundations—including linear algebra, calculus, and probability—with practical implementations across multiple industry-standard libraries. It supports flex

Kajiya is a physically based rendering engine and real-time global illumination renderer. It utilizes a GPU-accelerated path tracer to simulate real-world material properties, such as roughness and metalness, to achieve photorealistic visual results. The engine incorporates a temporal super-resolution upscaler to increase final render resolution by reconstructing images from lower-resolution internal frames. It also generates high-fidelity reference images through path-tracing to verify the visual accuracy of real-time lighting outputs. The system covers 3D scene visualization and asset mana

This project is a browser-based, physically based path-tracing renderer built on WebGL and integrated with Three.js. It functions as a real-time global illumination engine, calculating light bouncing, soft shadows, reflections, refractions, and color bleeding interactively within web environments. The rendering system incorporates progressive multi-pass accumulation to refine noisy images iteratively over multiple frames, alongside GPU-accelerated spatial acceleration structures and bounding volume hierarchies to handle complex geometry. It supports diverse material types such as refractive

Habitat-sim is a high-performance 3D simulation platform designed for training and benchmarking embodied AI agents within photorealistic indoor and outdoor environments. It serves as a simulator for AI and robotics, providing a system for generating synthetic data and simulating physical interactions. The project is distinguished by a native C++ core that enables high-throughput simulation and a rendering pipeline using physically based rendering and baked global illumination. It features a navigation system based on pre-computed navigation meshes to ensure collision-free traversal and a rigi

PyTorch3D is a 3D geometric deep learning library and mesh processing toolkit designed for learning from point clouds and complex 3D surface geometries. It provides a collection of reusable components and data structures for deep learning with 3D data, including a framework for training and evaluating neural radiance fields to enable photorealistic view synthesis. The project features a differentiable 3D renderer that converts meshes and point clouds into 2D images while allowing gradients to flow back into the geometry and textures. This enables 3D shape optimization, where mesh geometry, te

This project is a cross-platform game engine and development toolkit designed for creating high-performance 2D and 3D games. It serves as a 3D graphics rendering engine and a web-based game framework that allows applications to be deployed across mobile, desktop, and web environments from a single codebase. The engine features a configurable render pipeline that supports both forward and deferred rendering paths. It utilizes a cross-platform graphics abstraction layer and universal shader translation to ensure consistent visual output across different hardware and platforms. The toolkit incl

Ogre is a high-level 3D rendering engine designed for creating games, simulations, and visualizations without requiring low-level graphics API code. It functions as a framework for real-time 3D graphics processing, providing a physically based renderer to simulate lifelike surfaces and lighting. The engine includes specialized systems for skeletal animation to control character movement and a terrain generation system for producing large textured landscapes. These features are supported by automatic levels of detail and distance-based mesh management to maintain performance. The project cove

TRELLIS.2 is a generative image-to-3D system that creates high-resolution 3D assets with physically based rendering materials from 2D images. It utilizes a sparse voxel representation to handle complex topologies and internal structures without relying on iso-surface fields. The project features a structured latent space representation that maps geometry and texture attributes to maintain visual fidelity. It employs an optimization-free geometry reconstruction process to decode latent representations directly into voxel grids and includes a PBR texture generator for synthesizing base color, r

Tixl is a node-based motion graphics engine and procedural generation tool used to create 3D geometry and shaders. It utilizes a directed acyclic graph of operators and GPU-accelerated compute kernels to generate complex 3D shapes, particularly through the use of signed distance functions and particle simulations. The engine is highly extensible via a C# development framework that supports hot code reloading, allowing custom operator logic to be injected into the active runtime without restarting. It further distinguishes itself as a lighting controller, capable of translating 3D spatial attr

LumixEngine is a high-performance C++ 3D game engine designed for building interactive 3D applications. It is built on a data-oriented component system that organizes objects in contiguous memory blocks to maximize CPU cache performance. The engine features a dynamic binary plugin architecture for loading external modules at runtime and an embedded scripting virtual machine that exposes internal logic for external control without recompilation. Computational workloads are managed via a task-based parallel execution model that distributes jobs across multiple processor cores. The framework in

EveryRay Rendering Engine is a high-performance graphics framework designed for real-time three-dimensional rendering. It utilizes a physically based deferred rendering pipeline to simulate realistic light behavior, incorporating global illumination, cascaded shadow mapping, and advanced volumetric effects to produce high-fidelity visual output. The engine distinguishes itself through a unified graphics abstraction layer that enables consistent performance across diverse hardware backends by translating high-level commands into specific instructions. It further optimizes complex environments

Renderer is a low-level software graphics engine implemented in standard C for educational and experimental real-time computer graphics. It functions as a CPU rasterizer that computes vertex transformations, clipping, texturing, and lighting entirely through software computation without requiring hardware acceleration. The software includes a geometry pipeline supporting depth and alpha testing, geometry clipping and culling, and perspective-correct attribute interpolation. Its lighting and shading subsystem provides advanced physical simulation including metallic-roughness and specular-gloss

Genesis is an embodied AI simulation platform and parallelized robotics simulator designed for training general-purpose robotic agents. It integrates a physics engine for robotics that calculates collisions and movements for rigid bodies, soft tissues, and fluids, alongside a photorealistic 3D rendering engine. The platform features a domain randomization framework to vary environment parameters across parallel simulations, aiding in sim-to-real transfer. It supports the integration of real-world captured light fields and Gaussian splatting to provide photorealistic backgrounds within simulat

This project is a ray tracing reference implementation and educational resource for building a Monte Carlo path tracer from scratch. It serves as a guide for physically based rendering, demonstrating how to simulate the behavior of light and materials to create realistic images. The implementation includes a spatial hierarchy accelerator to optimize intersection tests and a system for generating images in the portable pixmap format. It provides a community reference library of implementations across various programming languages and distributes complete source code archives for study. The pr

This project is a high-performance numerical computing library designed for large-scale scientific and machine learning workloads. It functions as an automatic differentiation framework and a just-in-time compilation engine, transforming high-level Python code into optimized machine instructions. By enforcing pure functional programming patterns and immutable array semantics, the library ensures that mathematical functions remain compatible with automated graph transformations and symbolic differentiation. The platform distinguishes itself through its distributed array computing capabilities,

Math.js is a comprehensive JavaScript library for scientific, complex, and arbitrary precision calculations. It functions as a symbolic computation engine, a linear algebra toolkit, a statistical analysis library, and a unit conversion system. The project distinguishes itself by providing a symbolic engine capable of parsing, simplifying, and manipulating mathematical expressions algebraically without requiring immediate numerical evaluation. It includes a framework for defining and converting physical quantities with units of measure and automatic prefix support. The library covers a broad

Pyro is a deep probabilistic programming library and differentiable probabilistic modeler designed for Bayesian inference. It functions as a probabilistic programming language that allows for the construction of complex graphical models using PyTorch tensors and automatic differentiation. The framework enables the definition of universal probabilistic models as standard Python functions. It integrates deep learning with probabilistic modeling to compute posterior distributions and estimate latent variables through gradient-based optimization and algorithmic solvers. The system provides a pro

DeepXDE is a scientific machine learning library and deep learning PDE solver used to compute solutions for forward and inverse ordinary, partial, and integro-differential equations. It functions as a physics-informed neural network library that embeds physical laws and boundary conditions directly into the neural network loss function. The project provides a deep operator network framework for learning operator mappings that approximate relationships between functions in multiphysics problems. It is implemented as a multi-backend tensor library, allowing the system to switch between differen

JAX is a hardware-accelerated array library and automatic differentiation system for numerical computing. It provides a framework compatible with NumPy that extends array operations with a just-in-time compiler to transform Python functions into optimized kernels for execution on GPU and TPU accelerators. The system differentiates itself through the use of an XLA-based compiler and a single program multiple data sharding model. These capabilities allow the library to distribute large-scale computations across multiple hardware accelerators using both automatic parallelization and manual shard