decimate_qem — 3D `mesh_process` op

• 数据种类:mesh → mesh

• 调用: import fullseye as fs; fs.ledger.decimate_qem(V, F, target_faces, protect=None)(要直接调用实现,import meshrepair; meshrepair.decimate_qem(V, F, target_faces, protect=None);从台账取用则 ops3d.get("decimate_qem"))

用法

面向 *target_faces* 的二次误差度量(QEM)边坍缩简化。

> 以下的详细说明为原文 —— 摘要与标题已翻译。

*protect* (optional, (nv,) bool): vertices that must survive untouched —

no edge incident to a protected vertex is collapsed, so the faces around a

crater rim, a boulder or any region you flagged keep their exact geometry

(`meshres.mesh_decimate_preserving` derives the mask from the detail map

and reports what the rest of the reduction lost).

Garland & Heckbert 1997: each vertex carries the sum of the squared-distance

quadrics of its incident face planes; the cheapest edge is collapsed to the

position minimising that quadric (a midpoint/endpoint fallback when the 3x3

system is singular, e.g. on a flat face), quadrics are accumulated onto the

surviving vertex, and incident edge costs are re-queued. Collapses that would

flip a face normal or land on a non-manifold edge are skipped, so the result

stays a sane surface.

Honest scope: this is a practical QEM, not production-grade. It has no

boundary-preservation term, no attribute (colour/UV) quadrics and no

aggressive validity recovery, so on awkward meshes a few non-ideal collapses

can survive and the collapse may stop a little short of *target_faces* when

every remaining candidate is blocked by the flip/manifold guard. Good enough

for a cheap collision proxy; not a replacement for a dedicated remesher.

背景知识指南(该算子背后的物理与约定)

• blender_interop — Blender との併用 — 形を作って fullseye で測る(軸・単位・正解データの罠)

参考(示例数据・文献)

• 示例数据目录(下载 URL / 许可证) —— 2-D 用 skimage.data(BSD/公有领域)加合成图,3-D 给出真实数据源(Stanford/PDS 等)的下载 URL。

• 算子来历与参考文献 —— 该算子族所依据的研究/方法出处。

可运行的示例(实际调用该算子并已验证的样例)

• mesh_decimate — py -3.11 examples_3d/mesh_decimate.py

• mesh_lod_download — py -3.11 examples_3d/mesh_lod_download.py

• mesh_resolution_demo — py -3.11 examples_3d/mesh_resolution_demo.py

类型可衔接的下一个算子(可接受 `mesh` 作为输入)

mesh_to_voxel · mesh_to_points · to_points · fuse_to_voxel · ambient_occlusion · cast_shadow · supersample_mesh · render_beauty

同类别(`mesh_process`)

laplacian_smooth · taubin_smooth · face_normals · vertex_normals · mesh_area · vertex_curvature · face_areas · mesh_volume

*Provenance: meshrepair.py — 3D 算子登记表。本条目由 tools/opdocs.py md 自动生成(请勿手工编辑)。*

decimate_qem — 3D mesh_process op

用法