# OpenCAD Studio User Manual This manual describes the user-facing workflows of OpenCAD Studio. The initial version establishes the help structure and high-level guidance; individual commands should be expanded and verified against released behavior before the manual is published as complete. ## Getting Started ### What OpenCAD Studio does OpenCAD Studio is a desktop and web CAD application for opening, creating, editing, visualizing, and saving two- and three-dimensional drawings. It works with DWG and DXF drawings and provides command-line, ribbon, automation, and plugin-oriented workflows. ### A first drawing 1. Create a new drawing or open an existing DWG or DXF file. 2. Confirm the active workspace, units, layer, and object-snap settings. 3. Create geometry with a drawing command such as **Line**, **Circle**, or **Polyline**. 4. Edit the result with grips or a modification command. 5. Save the drawing under a new name until its compatibility has been verified. > **Data safety:** Keep an untouched copy of important third-party drawings. > Confirm geometry, layouts, external references, and plotted output before > replacing the original file. ### How to use this manual Use the chapter navigation for broad workflows, the search box for a command or concept, and the previous/next links for sequential reading. Command names, system variables, keys, and file extensions appear in `monospaced text`. ## Files and Drawings ### Create and open drawings Use **New** for a blank document and **Open** for an existing DWG, DXF, backup, or autosave drawing. After opening a file from another CAD system, inspect its units, layers, blocks, fonts, raster references, layouts, and model extents. ### Save and Save As **Save** updates the current drawing. **Save As** changes its path, format, or version. Prefer Save As when validating interoperability or recovering an older drawing. A successful write does not replace visual inspection of a reopened copy. ### Recovery and backups OpenCAD Studio recognizes drawing backups and autosave-style files where the underlying data is DWG or DXF. If strict loading rejects malformed entities, use the recovery workflow and review what was discarded before continuing work. ### External resources Raster images, underlays, fonts, materials, and external references may depend on paths outside the drawing. Keep referenced files together when moving a project and verify that relative paths still resolve. ## Workspace and Navigation ### Model space and paper space Model space is the primary drawing environment. Paper-space layouts arrange views for plotting through layout viewports. Always confirm the active space before drawing or editing. ### Pan, zoom, and orbit Use pan and zoom to navigate without changing drawing geometry. Use orbit and view controls for three-dimensional inspection. **Zoom Extents** is useful when the drawing appears empty or geometry is far from the expected location. ### Multiple model viewports Model viewports can show different views of the same document. Grid, snap, camera, and render mode may vary by viewport; confirm which viewport is active before entering coordinates. ### Selection and object snaps Selection identifies the objects a command will modify. Object snaps target precise geometric locations such as endpoints, midpoints, centers, and intersections. Zoom in and verify the snap marker when precision matters. ## Create and Edit Geometry ### Basic drawing commands Create lines, arcs, circles, ellipses, polylines, splines, points, text, hatches, and other supported entities from the ribbon or command line. Follow the active prompt: multi-step commands remain active until they complete or are cancelled. ### Modify geometry Common modification workflows include move, copy, rotate, scale, mirror, offset, trim, extend, fillet, chamfer, stretch, join, explode, and erase. Locked layers can prevent modification. ### Grips and direct manipulation Select an entity to expose its grips. Dragging a grip previews and then commits a geometric change. Constrained neighboring geometry may update with it. ### Undo, redo, and OOPS **Undo** reverses recorded document operations and **Redo** reapplies them. **OOPS** restores the most recently erased entities without reversing later commands. Save before a risky sequence and verify that associated dimensions, hatches, groups, and constraints were restored with their geometry. ## Layers and Properties ### Layers Layers organize geometry and control visibility, locking, color, line type, line weight, and plot behavior. Set the intended active layer before creating objects. Avoid editing objects on locked layers. ### Object properties Properties can be assigned explicitly or inherited **ByLayer** or **ByBlock**. Use the Properties surface or commands such as `CHPROP` to inspect and change selected objects. ### Styles Text, dimension, multiline, table, and visual styles centralize presentation. Changing a shared style can update many objects, so inspect affected layouts before saving. ## Blocks and References ### Create and insert blocks A block definition groups reusable drawing content; an INSERT places an instance with its own position, rotation, scale, attributes, and optional array settings. Editing a definition affects every reference to it. ### Array inserts Array inserts place multiple block instances with row and column counts and spacing. Large counts can generate substantial geometry. Validate scaled and rotated arrays when exchanging drawings with another CAD system. ### Attributes and external references Attributes attach editable values to block references. External references and underlays retain links to other files; preserve their paths when sharing or archiving a project. ## Annotation and Dimensions ### Text and annotation Single-line text, multiline text, leaders, multileaders, tables, tolerances, center marks, and centerlines communicate design intent. Missing fonts can change layout or substitute glyphs, especially in the web build. ### Dimensions Dimensions combine measured geometry with a dimension style. Associative dimensions update when their source geometry changes; non-associative or partially associated dimensions require manual verification. ### Annotation scale Annotative objects can display differently at different viewport scales. Confirm the active annotation scale before creating annotations and inspect all paper-space viewports before plotting. ## Layouts and Plotting ### Layouts and viewports Layouts represent sheets. Paper-space viewports expose model-space views at controlled scales. Lock finished viewports to avoid accidental view changes. ### Page setup and plot preview Choose the target device or file format, paper size, orientation, plot area, scale, style behavior, and output quality. Use preview to catch clipping, incorrect line weights, hidden layers, or an unintended plot area. ### Export checks Before distributing a PDF or plotted file, compare it with the drawing at the intended sheet size and verify text, dimensions, raster content, transparency, line types, and viewport scales. ## 3D Modeling and Visualization ### Solids and surfaces OpenCAD Studio can create and display solid primitives and modeled features such as extrusions and revolutions. Imported ACIS-backed bodies are tessellated for display while exact body data is retained where supported. ### Visual styles and lighting Wireframe, shaded, hidden-line, materials, lights, and shadows affect display, not the underlying object geometry. Switch to wireframe when diagnosing missing faces or material problems. ### Tessellation quality Curves and analytic surfaces are converted into display geometry according to view and tolerance settings. A coarse display does not necessarily mean the stored curve or solid is coarse. ## Parametric Constraints ### Geometric constraints Constraints capture relationships such as coincident, horizontal, vertical, parallel, perpendicular, equal, tangent, distance, angle, and radius. Use the degree-of-freedom and conflict indicators to understand the sketch state. ### Editing constrained geometry Moving or grip-editing constrained geometry can move neighboring objects. If a solve fails or becomes redundant, inspect the constraint glyphs and conflict status before deleting geometry. ### Persistence and history limitations Constraint data is stored as OpenCAD Studio extension data inside DWG and DXF. Other applications may preserve it without interpreting it. Constraint edits and geometry changes may currently occupy adjacent history entries; verify the result after undo, redo, erase, copy, and reopen operations. ## Commands and Shortcuts ### Command line Enter a command name or alias, then respond to its prompts. Press `Escape` to cancel the active command and `Return` to accept an available default. Exact prompt options vary by command and current selection. ### Discover commands Use command autocomplete and the ribbon to discover available operations. Some commands are one-shot actions; others maintain state across several point, number, keyword, or object-selection inputs. ### Shortcut conventions Application and operating-system shortcuts can differ between native and web builds. Avoid assigning browser-reserved shortcuts to web-only workflows. ## Automation and Plugins ### Automation interface The automation interface can inspect documents, run commands, query geometry, capture the viewport, and perform batches. Callers should use request IDs and document revisions to avoid repeating or applying work to stale state. ### Plugins Native plugins can contribute commands and ribbon surfaces through the plugin host. Install only trusted packages that match the host API, compiler, and CAD model compatibility requirements. ### Native and web differences The browser build uses in-memory file workflows and cannot load native plugin libraries. Some rendering, font, windowing, and parallel-processing behavior also differs from the desktop build. ## Troubleshooting and Recovery ### A drawing opens incorrectly Check units, extents, layers, layouts, block placement, missing references, and fonts. Reopen a copy after saving to detect serialization problems early. Keep the original file available for comparison. ### Geometry is missing or distorted Try Zoom Extents, enable relevant layers, switch to wireframe, and inspect block scale, array settings, clipping boundaries, object normals, and coordinates far from the origin. ### Rendering is incomplete Reduce unusually large images or material textures, simplify extreme hatch or array inputs, and compare another visual style. Record the graphics backend and the smallest drawing that reproduces the issue. ### Undo did not restore the expected state Stop editing and save a diagnostic copy. Try the next adjacent undo entry only when you understand what it represents. Compare the result with autosave or backup data before overwriting the original drawing. ### Report a reproducible problem Include the OpenCAD Studio version, platform, native or web build, exact steps, expected and observed results, and a minimal sanitized drawing when possible. Do not publish confidential drawings or external-reference paths.