---
title: "Differentiable Material Point Method"
type: "entity"
entity_kind: "concept"
status: "hub"
canonical_name: "Differentiable Material Point Method"
aliases: ["differentiable MPM","ChainQueen"]
first_seen: "2026-09-27T00:00:00.000Z"
writer_model: "claude-sonnet-5"
audit_status: "prose-repair 2026-10-09 (warden/claude-opus-4.8): opening sentence's reverse-mode-'first described in 1976' framing corrected to the vault's standing priority finding — Linnainmaa's earliest general formal statement is the 1970 Helsinki master's thesis (Fortran listing), published in BIT in 1976. Per [[claim-linnainmaa-reverse-mode-single-pass]] (Griewank 2014, Tier 1) and [[entity-seppo-linnainmaa]]'s own hub ('1970 Helsinki master's thesis ... the earliest general, formal statement'). Flagged by seek-flags 2026-10-09 [entity] and Cali's 2026-10-05 review. Only the dated clause on that one sentence was changed; no other prose or claim touched."
connects_to: ["Material Point Method","reverse-mode automatic differentiation","backpropagation","Seppo Linnainmaa","robotics / differentiable physics"]
seek_code_commit: "f8a723c"
---


A line of robotics and graphics research, beginning with Hu, Liu, Spielberg,
Tenenbaum, Freeman, Wu, Rus & Matusik's ChainQueen (ICRA 2019) and continued
independently by Bolliger, Fadini, Bambach & Rupenyan (2025), that applies
automatic differentiation — reverse-mode AD, whose earliest general, formal statement is
[[entity-seppo-linnainmaa|Seppo Linnainmaa]]'s 1970 Helsinki master's thesis (published in BIT in 1976) — to the [[entity-deborah-sulsky|Material Point Method]], the numerical
scheme [[entity-deborah-sulsky|Sulsky]], Chen/Zhou & [[entity-howard-schreyer|Schreyer]] developed
for penetration mechanics starting with SAND-91-7095 (1992). Matters to this vault
as the first confirmed genuine mechanism-level bridge between its automatic-differentiation
cluster and its Material Point Method cluster — two literatures that originated
independently, decades apart, and never cited each other directly; the technique arrived
through modern autodiff frameworks (TensorFlow, JAX) rather than through attribution to
either founding lineage.

## References
- [[claim-chainqueen-differentiates-mpm-via-linnainmaas-reverse-mode-technique]]
- [[claim-chainqueen-reference-list-directly-cites-sulsky-zhou-schreyer-1995-mpm-origin]]
- [[claim-bolliger-2025-second-independent-paper-confirms-standing-differentiable-mpm-technique]]
- [[claim-chainqueen-2019-full-reference-list-omits-ad-discovery-citations]] · [[claim-bolliger-2025-reference-list-omits-ad-discovery-names-names-jax-and-chainqueen]] · [[claim-difftaichi-2020-names-griewank-and-wengert-but-not-linnainmaa-or-speelpenning]] · [[claim-griewanks-name-reaches-differentiable-physics-literature-further-than-linnainmaas-or-speelpennings]] — added 2026-10-09
- [[observation-ansari-griewank-contamination-inheritance-cosine-086-pairing-is-embedding-false-friend]] · [[claim-difftaichi-griewank-citation-predates-chatgpt-launch-forecloses-contamination-explanation]] — added 2026-10-16: the DiffTaichi/Griewank citation dated and bridge-checked against Ansari's unrelated contamination-inheritance finding; resolves as a clean false friend, and DiffTaichi's citation is dated before ChatGPT existed
- [[entity-taichi-programming-language]] — the technical bridge connecting ChainQueen to DiffTaichi
- Captures: 10-inbox/raw/2026-09-27-recovered-capture-does-a-genuine-mechanism-connect-linnainmaas-fb616a.md, 10-inbox/raw/2026-10-05-does-chainqueen-2019-or-bolliger-et-al-2025.md