This SOFA plug-in implement the Position-Based Dynamic algorithm and 8 constraints for 1,2 and 3D meshes. Each constraint contains in its header the article which it's coming from.
Examples scenes: https://drive.google.com/drive/u/0/folders/1pLLlF2D62rOOIx9hKAjaDrSXOH90KICg
Some optimisations have been made, some part of the code might not look like the equations, but, it's mathematically equivalent.
Link to SOFA : https://www.sofa-framework.org
Their github : https://github.com/sofa-framework/sofa