{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2019:3CCGTFLGCPIL64HQRSJVN3WPQT","short_pith_number":"pith:3CCGTFLG","canonical_record":{"source":{"id":"1906.03027","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by-nc-sa/4.0/","primary_cat":"cs.CG","submitted_at":"2019-06-07T11:52:52Z","cross_cats_sorted":["cs.GR"],"title_canon_sha256":"b93ac390366d429c96c199368b7f0d6f3e6a4f04f1ef50f25bad9d0a0ffe4f73","abstract_canon_sha256":"d894f8003c7e80bb040ee32e91aa94ec0724a9e8d2fa54a582b9ddbf3bcaf7de"},"schema_version":"1.0"},"canonical_sha256":"d88469956613d0bf70f08c9356eecf84d0b06042bc0a29eaf25b482144912df0","source":{"kind":"arxiv","id":"1906.03027","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1906.03027","created_at":"2026-05-17T23:43:55Z"},{"alias_kind":"arxiv_version","alias_value":"1906.03027v1","created_at":"2026-05-17T23:43:55Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1906.03027","created_at":"2026-05-17T23:43:55Z"},{"alias_kind":"pith_short_12","alias_value":"3CCGTFLGCPIL","created_at":"2026-05-18T12:33:07Z"},{"alias_kind":"pith_short_16","alias_value":"3CCGTFLGCPIL64HQ","created_at":"2026-05-18T12:33:07Z"},{"alias_kind":"pith_short_8","alias_value":"3CCGTFLG","created_at":"2026-05-18T12:33:07Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2019:3CCGTFLGCPIL64HQRSJVN3WPQT","target":"record","payload":{"canonical_record":{"source":{"id":"1906.03027","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by-nc-sa/4.0/","primary_cat":"cs.CG","submitted_at":"2019-06-07T11:52:52Z","cross_cats_sorted":["cs.GR"],"title_canon_sha256":"b93ac390366d429c96c199368b7f0d6f3e6a4f04f1ef50f25bad9d0a0ffe4f73","abstract_canon_sha256":"d894f8003c7e80bb040ee32e91aa94ec0724a9e8d2fa54a582b9ddbf3bcaf7de"},"schema_version":"1.0"},"canonical_sha256":"d88469956613d0bf70f08c9356eecf84d0b06042bc0a29eaf25b482144912df0","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-17T23:43:55.305811Z","signature_b64":"AUBsTTbnWCY365q5HEB5azT7/Z0K+0yDbq/2CIqBMv0aGspR0AL586fM+vAv+KXJKruCeHuSNxpi1FWOVq7fCA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"d88469956613d0bf70f08c9356eecf84d0b06042bc0a29eaf25b482144912df0","last_reissued_at":"2026-05-17T23:43:55.305235Z","signature_status":"signed_v1","first_computed_at":"2026-05-17T23:43:55.305235Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1906.03027","source_version":1,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-17T23:43:55Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"me/Wui/2PHfxm6hCGbgKz1bMhKt6nA936fivK8yZjg0pyCv0rkmz7PEwvGEQZbsz9/Ri8wjcj5r3uQ2w5rtgAg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-30T12:35:49.834833Z"},"content_sha256":"0e7abf3090e49f9a0db433c32d6b21bc7ccf09f9a1ed6db2c5dde20bcd767085","schema_version":"1.0","event_id":"sha256:0e7abf3090e49f9a0db433c32d6b21bc7ccf09f9a1ed6db2c5dde20bcd767085"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2019:3CCGTFLGCPIL64HQRSJVN3WPQT","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"CrossFill: Foam Structures with Graded Density for Continuous Material Extrusion","license":"http://creativecommons.org/licenses/by-nc-sa/4.0/","headline":"","cross_cats":["cs.GR"],"primary_cat":"cs.CG","authors_text":"Charlie C. L. Wang, Jun Wu, Tim Kuipers","submitted_at":"2019-06-07T11:52:52Z","abstract_excerpt":"The fabrication flexibility of 3D printing has sparked a lot of interest in designing structures with spatially graded material properties. In this paper, we propose a new type of density graded structure that is particularly designed for 3D printing systems based on filament extrusion. In order to ensure high-quality fabrication results, extrusion-based 3D printing requires not only that the structures are self-supporting, but also that extrusion toolpaths are continuous and free of self-overlap. The structure proposed in this paper, called CrossFill, complies with these requirements. In part"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1906.03027","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"},"verdict_id":null},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-17T23:43:55Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"U3G0QSo5KEWhdCThuBOez0GJZ4jvuAG5+Ol112ssXhk5KRY4GxExcdkbw99orxyFXVwMs9EpoamZ+x2vmODdDw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-30T12:35:49.835448Z"},"content_sha256":"240215a075057786d23d1a87b5fce7dc1c0f0adda862225fadccf4a94be0965a","schema_version":"1.0","event_id":"sha256:240215a075057786d23d1a87b5fce7dc1c0f0adda862225fadccf4a94be0965a"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/3CCGTFLGCPIL64HQRSJVN3WPQT/bundle.json","state_url":"https://pith.science/pith/3CCGTFLGCPIL64HQRSJVN3WPQT/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/3CCGTFLGCPIL64HQRSJVN3WPQT/bundle.json","status":"primary"}],"public_keys":[{"key_id":"pith-v1-2026-05","algorithm":"ed25519","format":"raw","public_key_b64":"stVStoiQhXFxp4s2pdzPNoqVNBMojDU/fJ2db5S3CbM=","public_key_hex":"b2d552b68890857171a78b36a5dccf368a953413288c353f7c9d9d6f94b709b3","fingerprint_sha256_b32_first128bits":"RVFV5Z2OI2J3ZUO7ERDEBCYNKS","fingerprint_sha256_hex":"8d4b5ee74e4693bcd1df2446408b0d54","rotates_at":null,"url":"https://pith.science/pith-signing-key.json","notes":"Pith uses this Ed25519 key to sign canonical record SHA-256 digests. Verify with: ed25519_verify(public_key, message=canonical_sha256_bytes, signature=base64decode(signature_b64))."}],"merge_version":"pith-open-graph-merge-v1","built_at":"2026-05-30T12:35:49Z","links":{"resolver":"https://pith.science/pith/3CCGTFLGCPIL64HQRSJVN3WPQT","bundle":"https://pith.science/pith/3CCGTFLGCPIL64HQRSJVN3WPQT/bundle.json","state":"https://pith.science/pith/3CCGTFLGCPIL64HQRSJVN3WPQT/state.json","well_known_bundle":"https://pith.science/.well-known/pith/3CCGTFLGCPIL64HQRSJVN3WPQT/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2019:3CCGTFLGCPIL64HQRSJVN3WPQT","merge_version":"pith-open-graph-merge-v1","event_count":2,"valid_event_count":2,"invalid_event_count":0,"equivocation_count":0,"current":{"canonical_record":{"metadata":{"abstract_canon_sha256":"d894f8003c7e80bb040ee32e91aa94ec0724a9e8d2fa54a582b9ddbf3bcaf7de","cross_cats_sorted":["cs.GR"],"license":"http://creativecommons.org/licenses/by-nc-sa/4.0/","primary_cat":"cs.CG","submitted_at":"2019-06-07T11:52:52Z","title_canon_sha256":"b93ac390366d429c96c199368b7f0d6f3e6a4f04f1ef50f25bad9d0a0ffe4f73"},"schema_version":"1.0","source":{"id":"1906.03027","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1906.03027","created_at":"2026-05-17T23:43:55Z"},{"alias_kind":"arxiv_version","alias_value":"1906.03027v1","created_at":"2026-05-17T23:43:55Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1906.03027","created_at":"2026-05-17T23:43:55Z"},{"alias_kind":"pith_short_12","alias_value":"3CCGTFLGCPIL","created_at":"2026-05-18T12:33:07Z"},{"alias_kind":"pith_short_16","alias_value":"3CCGTFLGCPIL64HQ","created_at":"2026-05-18T12:33:07Z"},{"alias_kind":"pith_short_8","alias_value":"3CCGTFLG","created_at":"2026-05-18T12:33:07Z"}],"graph_snapshots":[{"event_id":"sha256:240215a075057786d23d1a87b5fce7dc1c0f0adda862225fadccf4a94be0965a","target":"graph","created_at":"2026-05-17T23:43:55Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"graph_snapshot":{"author_claims":{"count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","strong_count":0},"builder_version":"pith-number-builder-2026-05-17-v1","claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"paper":{"abstract_excerpt":"The fabrication flexibility of 3D printing has sparked a lot of interest in designing structures with spatially graded material properties. In this paper, we propose a new type of density graded structure that is particularly designed for 3D printing systems based on filament extrusion. In order to ensure high-quality fabrication results, extrusion-based 3D printing requires not only that the structures are self-supporting, but also that extrusion toolpaths are continuous and free of self-overlap. The structure proposed in this paper, called CrossFill, complies with these requirements. In part","authors_text":"Charlie C. L. Wang, Jun Wu, Tim Kuipers","cross_cats":["cs.GR"],"headline":"","license":"http://creativecommons.org/licenses/by-nc-sa/4.0/","primary_cat":"cs.CG","submitted_at":"2019-06-07T11:52:52Z","title":"CrossFill: Foam Structures with Graded Density for Continuous Material Extrusion"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1906.03027","kind":"arxiv","version":1},"verdict":{"created_at":null,"id":null,"model_set":{},"one_line_summary":"","pipeline_version":null,"pith_extraction_headline":"","strongest_claim":"","weakest_assumption":""}},"verdict_id":null}}],"author_attestations":[],"timestamp_anchors":[],"storage_attestations":[],"citation_signatures":[],"replication_records":[],"corrections":[],"mirror_hints":[],"record_created":{"event_id":"sha256:0e7abf3090e49f9a0db433c32d6b21bc7ccf09f9a1ed6db2c5dde20bcd767085","target":"record","created_at":"2026-05-17T23:43:55Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"attestation_state":"computed","canonical_record":{"metadata":{"abstract_canon_sha256":"d894f8003c7e80bb040ee32e91aa94ec0724a9e8d2fa54a582b9ddbf3bcaf7de","cross_cats_sorted":["cs.GR"],"license":"http://creativecommons.org/licenses/by-nc-sa/4.0/","primary_cat":"cs.CG","submitted_at":"2019-06-07T11:52:52Z","title_canon_sha256":"b93ac390366d429c96c199368b7f0d6f3e6a4f04f1ef50f25bad9d0a0ffe4f73"},"schema_version":"1.0","source":{"id":"1906.03027","kind":"arxiv","version":1}},"canonical_sha256":"d88469956613d0bf70f08c9356eecf84d0b06042bc0a29eaf25b482144912df0","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"d88469956613d0bf70f08c9356eecf84d0b06042bc0a29eaf25b482144912df0","first_computed_at":"2026-05-17T23:43:55.305235Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-17T23:43:55.305235Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"AUBsTTbnWCY365q5HEB5azT7/Z0K+0yDbq/2CIqBMv0aGspR0AL586fM+vAv+KXJKruCeHuSNxpi1FWOVq7fCA==","signature_status":"signed_v1","signed_at":"2026-05-17T23:43:55.305811Z","signed_message":"canonical_sha256_bytes"},"source_id":"1906.03027","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:0e7abf3090e49f9a0db433c32d6b21bc7ccf09f9a1ed6db2c5dde20bcd767085","sha256:240215a075057786d23d1a87b5fce7dc1c0f0adda862225fadccf4a94be0965a"],"state_sha256":"f498d759973e5bc809285864325be626905d830c3ec823fc001085cbc71f5177"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"D8zLxaFClRYmSa1gr71BxURYxhUFLhI2Vy0K/+THN5dZA6Q2PTLcK6ymH4gLo4rOjB6HqRH3w9IqfEA017i1CA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-30T12:35:49.838606Z","bundle_sha256":"aa526c8f0139be30ad23233e102a4bdd4e0f92c40077b78cfa55fe565efa6284"}}