Pith Number

pith:WHQVFGXV

pith:2026:WHQVFGXV4PHASWPAMJ6IKU45OI

not attested not anchored not stored refs pending

Rendering-Aware Sparse Sampling for BRDF Acquisition

D. J\"onsson, J. Unger, W. Cao, Z. Huang

A sampler optimized via gradients from a fixed hypernetwork reconstructor selects sparse BRDF directions that improve low-budget material reconstruction.

arxiv:2604.26740 v2 · 2026-04-29 · cs.CV · cs.GR

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\usepackage{pith}
\pithnumber{WHQVFGXV4PHASWPAMJ6IKU45OI}

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Record completeness

1 Bitcoin timestamp

2 Internet Archive

3 Author claim open · sign in to claim

4 Citations open

5 Replications open

✓ Portable graph bundle live · download bundle · merged state

The bundle contains the canonical record plus signed events. A mirror can host it anywhere and recompute the same current state with the deterministic merge algorithm.

Claims

C1strongest claim

Experiments on the MERL dataset show that the proposed sampler improves low-budget reconstruction quality at 8 and 16 measurements compared with neural reconstruction baselines, while PCA-based methods remain strong at larger budgets.

C2weakest assumption

That a pretrained hypernetwork reconstructor fixed during sampler training will produce gradients that reliably identify measurement directions informative for unseen materials outside the training distribution.

C3one line summary

A sampler network learns to select informative sparse BRDF measurement directions by optimizing against a fixed pretrained hypernetwork reconstructor and differentiable renderer, improving low-budget reconstruction on the MERL dataset.

Receipt and verification

First computed	2026-05-26T01:03:31.345502Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

b1e1529af5e3ce0959e0627c85539d722b9bffd6c678c9d9ac21d2ff65f95ec5

Aliases

arxiv: 2604.26740 · arxiv_version: 2604.26740v2 · doi: 10.48550/arxiv.2604.26740 · pith_short_12: WHQVFGXV4PHA · pith_short_16: WHQVFGXV4PHASWPA · pith_short_8: WHQVFGXV

Agent API

Resolver JSON Graph JSON Events JSON Schema Signing key

Verify this Pith Number yourself

curl -sH 'Accept: application/ld+json' https://pith.science/pith/WHQVFGXV4PHASWPAMJ6IKU45OI \
  | jq -c '.canonical_record' \
  | python3 -c "import sys,json,hashlib; b=json.dumps(json.loads(sys.stdin.read()), sort_keys=True, separators=(',',':'), ensure_ascii=False).encode(); print(hashlib.sha256(b).hexdigest())"
# expect: b1e1529af5e3ce0959e0627c85539d722b9bffd6c678c9d9ac21d2ff65f95ec5

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "27b10f189e8f74156eb4a574813bb14bf77426fb6e6b3f3ade87708b3dddff05",
    "cross_cats_sorted": [
      "cs.GR"
    ],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "cs.CV",
    "submitted_at": "2026-04-29T14:39:23Z",
    "title_canon_sha256": "d87c21fe2f48afa1297f2fcfe80b1222ffe1ed4ab7793ef6061800d02ac2298d"
  },
  "schema_version": "1.0",
  "source": {
    "id": "2604.26740",
    "kind": "arxiv",
    "version": 2
  }
}