3D point classification

3d point classification covers both semantic and instance segmentation each class is configured as either semantic (all points of that class share a single label) or instance (each painted region becomes its own object) when you annotate a 3d point classification task, there are 5 steps you need to master understand what is moving and what is stationary annotate moving classes frame by frame, with aggregation off lock the finished moving classes before continuing turn aggregation on; annotate stationary instance classes, then semantic classes last one class at a time, locking each class as you finish understand the sequence first scrub through the sequence before you start painting note which classes have moving objects (vehicles, pedestrians) and which are stationary (road, buildings, vegetation) this decides the order you work in and whether you use aggregation use prelabel boxes to start each class if the task includes 3d prelabel boxes, use them as the opener for any class whose objects are mostly captured by a box hover over an object, then press r (or shift+click ) to classify all points inside the box in one action this works for both semantic and instance classes move to the next frame and repeat the previous steps until you have annotated the moving object with prelabels throughout the sequence read more about how to classify points from 3d prelabel boxes in box classification tool docid\ m8j33puzyfef6gzpz7iuk annotate moving objects first, aggregation off aggregation smears moving objects across frames keep aggregation off ( alt+a toggles it) and annotate moving instance classes frame by frame work one class at a time — for instance, finish all cars before starting pedestrians when you finish a class, lock it at the class level ( alt+l ) so the next class you paint cannot overwrite it switch to aggregation for stationary work once the moving classes are locked, turn aggregation on ( alt+a ) the stationary parts of the scene now appear as a single, complete cloud, making it faster and more accurate to paint large surfaces (roads, buildings, vegetation) annotate the stationary instance classes first, then the semantic classes drawing tools pick the tool that fits the shape of what you are painting use shift+b to cycle between the cylinder brush, sphere brush, box classification tool, and polygon classification tool the cylinder brush — for classifying large areas with broad strokes the sphere brush — for details and tight spaces works specifically well for annotating poles and other similar infrastructure box classification tool docid\ m8j33puzyfef6gzpz7iuk — for vehicles and other objects that fit cleanly inside a box polygon classification tool docid\ jhivsyhtgqy8oz6d9k5ms — for large irregular regions; every point inside the polygon, visible from the current camera view, gets classified when you press enter projection classification tool docid\ qbm9vpk9ynwmymqspuzjo — for classifying from a camera image; place \<font color="#22c55e">green\</font> points on the object, alt+click \<font color="#ef4444">red\</font> points on occlusions, then press enter other tools that help at each stage quick erase press alt while a drawing tool is active this will temporarily activate the eraser in other words, once you let go of the shortcut, you will return to drawing mode for the box and polygon classifications tools, press alt+enter to erase for the cylinder and sphere brush, press alt while drawing to erase eraser ( n ) erases whatever is under the brush, regardless of class — locking the classes you have finished prevents accidents point cloud slicing docid\ gtv4dz53czr jkxl1l1ly ( ctrl+scroll to set the upper bound, ctrl+shift+scroll for the lower, alt+scroll for fine adjustments, or select window → point cloud slicing to open the dialog) use it to isolate a height range, especially for road surfaces and small free standing objects temporary region of interest docid\ m33dlujifgb1umfhyppbh draw a polygon to hide everything outside it useful when two objects sit close together and are hard to separate by eye it is a focusing aid, not a primary tool — keep using the standard drawing tools to do the actual painting show/ hide selected ( shift+h ) and show/ hide selected object ( alt+y ) use these to declutter the view while you work on a specific class or instance locate unlabelled areas docid\ pjhfysmx9pnqw12xynior at the end of the task, hide the labeled points to reveal anything you missed common mistakes painting stationary classes with aggregation off — you are only painting one frame's slice of the object; turn aggregation on ( alt+a ) and paint the whole shape at once painting moving objects with aggregation on — aggregation smears moving objects; turn aggregation off and work frame by frame skipping the class level lock between classes — without alt+l , an erase or stray brush stroke can wipe points you already painted using temporary region of interest as the main tool — it scopes the view; the standard drawing tools should still do the painting related resources 3d point classification docid\ pjhfysmx9pnqw12xynior point slicing docid\ gtv4dz53czr jkxl1l1ly temporary region of interest docid\ m33dlujifgb1umfhyppbh