Sync Loop Selection Overview and User Guide

Sync Loop Selection 功能简介与使用说明

1. Overview

1. 功能简介

Sync Loop Selection is an interactive loop selection tool built with the Cinema 4D C++ SDK, designed to preview and apply continuous face, edge, or point loop selections directly in the viewport.

Sync Loop Selection 是一个基于 Cinema 4D C++ SDK 实现的交互式环选择工具，用于直接在视口中预览并应用连续的面环、边环或点环选择。

Its core features are:

它的核心特点是：

  • Supports three selection modes: Face Loop, Edge Loop, and Point Loop

  • 支持三种选择模式：Face Loop、Edge Loop、Point Loop

  • Generates a live preview while the mouse hovers over the model

  • 鼠标悬停在模型上时可即时生成预览

  • Applies the preview result to the current selection with a left click

  • 左键单击即可将预览结果写入当前选择集

  • Recalculates the result from the most recent valid hover position after parameter changes in the Attribute Manager

  • 修改属性管理器中的参数后，会基于最近一次有效悬停位置重新计算结果

  • Provides control over loop gap, selection interval inside a loop, loop count, and loop length

  • 可控制跨环间隔、单环内部间隔、环数量以及环长度

This tool is intended for modeling workflows that require fast loop expansion on regular quad topology.

这个工具适合需要在规则四边面拓扑上快速扩展选择范围的建模流程。

2. Scope and Limitations

2. 适用范围与限制

The current implementation is primarily designed for PolygonObject and depends on relatively stable quad topology.

当前实现主要面向 PolygonObject，并且依赖较稳定的四边面拓扑。

Known limitations:

已知限制如下：

  • Only polygon objects are supported

  • 仅支持多边形对象

  • Preview and propagation depend on quad polygons and usually stop at triangles

  • 预览与传播依赖四边面，遇到三角面时通常会停止

  • Loop propagation may end early at topology boundaries, breaks, or discontinuities

  • 遇到拓扑边界、断开位置或不连续结构时，环选择可能提前结束

  • All modes use the currently hovered topology element as the seed

  • 三种模式都会以当前鼠标悬停命中的拓扑元素作为种子

3. Mode Descriptions

3. 三种模式说明

3.1 Face Loop

  • Starts from the hovered quad polygon

  • 以鼠标悬停到的四边面为起点

  • Uses the hovered edge direction to infer the face loop direction

  • 结合当前命中的边方向推导面环方向

  • Displays the preview as translucent polygon highlighting

  • 预览结果以半透明面高亮显示

  • Writes the result to the polygon selection after clicking

  • 单击后写入多边形选择集

3.2 Edge Loop

  • Starts from the hovered edge

  • 以鼠标悬停到的边作为起点

  • Displays the preview as highlighted line segments

  • 预览结果以高亮线段显示

  • Writes the result to the edge selection after clicking

  • 单击后写入边选择集

3.3 Point Loop

  • Starts from the hovered point

  • 以鼠标悬停到的点作为起点

  • Automatically resolves a neighboring direction and builds a point loop

  • 工具会自动推导相邻方向并构造点环

  • Displays the preview using highlighted point handles

  • 预览结果以点句柄高亮显示

  • Writes the result to the point selection after clicking

  • 单击后写入点选择集

4. Parameter Reference

4. 参数说明

Selection Type

Switches the selection mode:

用于切换选择类型：

  • Face Loop: face loop selection

  • Face Loop：面环选择

  • Edge Loop: edge loop selection

  • Edge Loop：边环选择

  • Point Loop: point loop selection

  • Point Loop：点环选择

When the mode changes, the tool attempts to resolve a new seed from the most recent hover position.

切换模式时，工具会尽量基于最近一次悬停位置重新解析新的种子。

Loop Gap

Controls how many parallel loops are skipped between selected loops.

控制相邻被选中环之间要跳过多少条平行环。

  • 0: select adjacent loops continuously

  • 0：连续选择相邻环

  • 1: select every other loop

  • 1：每隔一条环选择一次

  • Higher values: skip more parallel loops

  • 更大值：跳过更多平行环

Loop Count

Controls how many loop bands are selected in total. The minimum value is 1.

控制总共选择多少条环带，最小值为 1。

Step Along Loop

Controls the selection interval inside a single loop.

控制在单条环内部按什么间隔跳选元素。

  • 0: select elements continuously along the loop

  • 0：环上的元素连续选中

  • 1: select every other element

  • 1：隔一个选一个

  • Higher values: create a sparser pattern

  • 更大值：按更稀疏的节奏选取

Length Mode

Defines how the selection pattern is distributed around the seed.

决定选择图案围绕种子的位置分布方式。

  • Center on Click: expands as symmetrically as possible around the clicked position

  • Center on Click：以点击位置为中心，向两侧尽量对称展开

  • From Click: grows from the clicked position in one direction

  • From Click：从点击位置开始，沿一个方向延伸

Loop Length

Limits how far the selection can propagate along the loop.

限制单次选择沿环传播的长度。

  • 0: no extra limit, use the reachable range from topology

  • 0：不额外限制，按当前拓扑可达范围计算

  • Greater than 0: limit the propagation length from the seed

  • 大于 0：限制从种子出发可扩展的长度

5. How to Use

5. 使用方法

Basic Workflow

基本流程

  1. Activate a PolygonObject in Cinema 4D.

  2. 在 Cinema 4D 中激活一个 PolygonObject。

  3. Switch to the Sync Loop Selection tool.

  4. 切换到 Sync Loop Selection 工具。

  5. Choose Face Loop, Edge Loop, or Point Loop as needed.

  6. 根据需要选择 Face Loop、Edge Loop 或 Point Loop。

  7. Move the mouse over the model to inspect the live preview in the viewport.

  8. 将鼠标移动到模型表面，在视口中查看实时预览。

  9. Adjust Loop Gap, Loop Count, Step Along Loop, Length Mode, and Loop Length.

  10. 调整 Loop Gap、Loop Count、Step Along Loop、Length Mode、Loop Length。

  11. Left click when the preview matches the expected result.

  12. 预览符合预期后，左键单击应用选择结果。

Selection Write Modes

选择集写入方式

Clicking supports three common behaviors:

单击应用时支持三种常见行为：

  • Left click: replace the current selection of the same type

  • 直接左键：替换当前同类型选择集

  • Shift + Left Click: add the preview result to the current selection

  • Shift + 左键：把预览结果追加到当前选择集

  • Ctrl + Left Click: subtract the preview result from the current selection

  • Ctrl + 左键：从当前选择集中减去预览结果

6. Interaction Behavior

6. 交互行为说明

  • The tool caches the most recent valid hover position in the viewport

  • 工具会缓存最近一次有效命中的视口位置

  • While the tool stays active, parameter changes usually refresh the preview without requiring the mouse to move back over the model

  • 在工具保持激活状态时，修改参数通常不需要重新把鼠标移回模型上，也能刷新预览

  • If the active object changes, the cached hover context is cleared and the tool waits for a new valid hit

  • 如果切换了活动对象，工具会清空之前缓存的悬停上下文，等待新的命中结果

  • When the mode changes, the document selection mode is synchronized to point, edge, or polygon mode

  • 模式切换后，文档选择模式会同步切换到对应的点、边或面模式

7. Recommended Use Cases

7. 推荐使用场景

  • Quickly selecting continuous edge loops for beveling, extruding, or deleting

  • 需要快速选择连续边环进行倒角、挤压或删除时

  • Selecting multiple parallel loops with a fixed rhythm

  • 需要按固定节奏选择多条平行环时

  • Batch-selecting points, edges, or polygons on regular quad meshes

  • 需要在规则四边面网格上做点、边、面的批量选择时

  • Precision workflows where previewing before committing is important

  • 需要先预览再确认应用结果的精细建模流程中

8. Notes

8. 注意事项

  • This tool works best on regular quad meshes and is not intended for messy topology or heavy triangle usage

  • 该工具更适合规则的四边面网格，不适合大量三角面或杂乱拓扑

  • If no preview appears while hovering, first verify that the active object is an editable polygon object

  • 如果悬停时没有出现预览，优先检查当前对象是否为可编辑多边形对象

  • If the hovered location cannot form a valid loop, the topology at that position does not satisfy the propagation requirements

  • 若命中位置无法形成有效环，说明当前拓扑不满足传播条件

  • The current kPluginId in the plugin source is still a temporary local ID and should be replaced with a registered Maxon Plugin ID before release

  • 当前插件中的 kPluginId 仍是本地临时 ID，正式发布前应替换为已注册的 Maxon Plugin ID

9. One-Sentence Summary

9. 一句话总结

This is an interactive loop selection tool for quad-based modeling workflows, centered on hover preview, parameter-driven updates, and one-click application.

这是一个面向四边面建模工作流的交互式环选择工具，重点在于悬停预览、参数联动和单击应用。

Changelog
GitHub Bilibili