jdtcc/femfx

AMD FEMFX v0.1.0

FEMFX is a multithreaded CPU library for deformable material physics, using the Finite Element Method (FEM). Solid objects are represented as a mesh of tetrahedral elements, and each element has material parameters that control stiffness, how volume changes with deformation, and stress limits where fracture or plastic (permanent) deformation occur. The model supports a wide range of materials and interactions between materials. We intend for these features to complement rather than replace traditional rigid body physics. The system is designed with the following considerations:

• Fidelity: realistic-looking wood, metal, plastic, even glass, because they bend and break according to stress as real materials do.
• Deformation effects: non-rigid use cases such as soft-body objects, bending or warping objects. It is not just a visual effect, but materials will resist or push back on other objects.
• Changing material on the fly: you can change the settings to make the same object behave very differently, e.g., turn gelatinous or melt
• Interesting physics interactions for gameplay or puzzles

The library uses extensive multithreading to utilize multicore CPUs and benefit from the trend of increasing CPU core counts.

Included in this release

• Source code for FEMFX library
• Houdini plugin for content creation
• Sample code for loading and preprocessing content for rendering
• Sample threading utilities
• A basic graphical sample

In a separate release, we provide a plugin for Unreal Engine that demonstrates more advanced rendering of FEM objects. Instructions for access are here: https://github.com/GPUOpen-LibrariesAndSDKs/GameEngineIntegrations

• Plugin: https://github.com/GPUOpenSoftware/UnrealEngine/tree/FEMFX-4.18
• Demo: https://github.com/GPUOpenSoftware/UnrealEngine/tree/FEMFX-AlienPods

Dependencies The sample code has some dependencies on external frameworks which must be downloaded separately:

• JSON for Modern C++: https://github.com/nlohmann/json
• GLFW: https://www.glfw.org/download.html

System requirements

• AMD Ryzen™ 7 2700X Processor or equivalent
• Windows® 10
• Visual Studio 2017 or Visual Studio 2019

Files:

1. Documentation
   • amd_femfx\docs\
2. Library
   • amd_femfx\inc\ : Public API (Look first at AMD_FEMFX.h)
   • amd_femfx\src\ : Implementation files
3. Sample code
   • samples\FEMFXViewer\ : Basic sample; displays tetrahedral meshes and debug information
   • samples\common\TestScenes.*: Setup for tech demo scenes used by FEMFXViewer
   • samples\common\FemResource.* : Container for the data loaded from a .FEM file
   • samples\common\LoadFem.*: Code for parsing a .FEM and loading into an FEMResource
   • samples\common\RenderTetAssignment.* : Assigns rendering mesh vertices to tetrahedra for skinning
   • samples\ExampleRigidBodies\ : Basic demonstration of interfacing an external rigid body system with FEMFX library
   • samples\sample_task_system\ : Sample task system library interfaced with FEMFX
4. Houdini plugin for content creation
   • houdini16.5\AMD_FEM_Assets.otl
5. External dependencies
   • external\glfw\ : Path to install GLFW for viewer; can download Windows pre-compiled binaries from https://www.glfw.org/download.html
   • external\json-develop\ : Path to install json parser used in LoadFemFile.*; can download from https://github.com/nlohmann/json
6. Some individual components
   • amd_femfx\inc\Vectormath\ : 3D vector/matrix math
   • amd_femfx\src\PrimitiveCollision\ : Triangle and box collision operations, intersection and CCD
   • amd_femfx\src\Common\FEMFXSvd3x3.* : 3x3 SVD
   • amd_femfx\src\Threading\ : Async parallel-for and task graph support
   • samples\sample_task_system\TL* : Async task system implementation