Published · 2026-10-03
What AUTOLAYER is, in short
AUTOLAYER is the CVCAD feature that, after converting a raster image into a vector drawing, assigns every polyline to a thematic CAD layer (for example walls, openings, cornices, joints) instead of leaving them all on Layer 0. You choose 2 to 8 layers, name each one and optionally describe what it contains; the result is a DXF with a populated layer table, readable in AutoCAD, BricsCAD, DraftSight, Rhino and QGIS.
It costs 1 credit, which also unlocks the regular downloads of the same conversion (SVG, DXF, PDF). Later manual corrections are free.
The Layer 0 problem in vectorization
Any vectorizer, from Image Trace to raster-to-vector converters, returns a single set of lines. On a historic elevation that means thousands of entities on the same layer: to isolate openings, hide joints or colour cornices you must select them one by one in CAD. It is the slowest part of the job, often slower than the drawing itself.
A layered drawing is usable right away: you toggle categories, assign plot weights and colours, and reuse the base for thematic sheets such as UNI 11182 degradation mapping.
Three ways to get an organized DXF from an image| Method | DXF organization | Manual work required | Main limit |
|---|
| Generic vectorization | Everything on Layer 0 | Full selection in CAD | No distinction between elements |
| Manual tracing in CAD | Layers chosen by the drafter | Drawing and organizing from scratch | Time: hours to days |
| CVCAD + AUTOLAYER | 2–8 layers named by you | Only review and fix doubtful cases | Ambiguity on shared edges |
How the processing works
AUTOLAYER works on the vector drawing already generated, not on the photo: lines are neither redrawn nor moved, only their layer changes. That is why the millimetre scale set during calibration stays identical.
What the professional decides
- Number of layers. From 2 to 8.
- Name of each layer. Up to 40 characters; it is the name you will find in the DXF (for example WALL, OPENINGS, CORNICES).
- Optional instructions. Up to 300 characters describing the subject or criteria (for example "separate mortar joints from stones").
What the algorithm does
Each polyline is classified by its geometry and context: length and continuity, closed outline, position relative to neighbouring elements, repetition (masonry joints, for instance, are numerous and similar). Lines with uncertain classification are listed in the "To review" box.
What you get
A DXF where every LWPOLYLINE entity carries its own layer (group code 8) and each layer has a distinct ACI colour, plus a browser preview with legend, line count per layer and a toggle to show or hide each layer.
Manual correction in the browser
No automatic classification is 100% correct on a real survey. That is why the result can be corrected without leaving CVCAD and without opening CAD software.
- Open the editor
Below the layer legend, press "Fix layers manually".
- Select wrong lines
Click a line, or drag a box to pick many at once; hold Shift to add more. Selected lines turn orange.
- Move to the right layer
Press the target layer button: lines change colour and the per-layer count updates.
- Navigate the drawing
Use "Pan" and the mouse wheel to zoom into details; "Undo" reverts the last step.
- Save
"Save corrections" updates both the preview and the layered DXF. Saving is free and repeatable.
Strengths
- Layers with your names. The scheme follows your specification or office standard, not a fixed classification.
- Geometry untouched. Lines and scale remain those of the conversion; only organization changes.
- Instant check. Toggling layers in the preview shows right away what went where.
- Correction without CAD. Doubtful cases are fixed in the browser, even thousands of lines with one selection box.
- Standard DXF. Native layer table and ACI colours: opens in any CAD software without plugins.
Suggested layer schemes as a starting point| Field | Suggested layers |
|---|
| Architectural elevation | WALL · OPENINGS · CORNICES AND MOULDINGS · ROOF |
| Stone masonry / restoration | STONES · JOINTS · LOSSES · DECORATIVE ELEMENTS |
| Floors and decorated surfaces | OUTLINES · PATTERN · GROUT |
Technical limits and when to be careful
- Shared edges. A line separating two adjacent elements (a cornice edge against the wall) can belong to only one layer: choose it manually or split it in CAD.
- Image quality. Weak contrast, hard shadows, dirty surfaces or blurry photos produce noisier vectors and therefore less reliable classification. See how to photograph an elevation.
- Overly fine categories. Eight very similar layers overlap and increase errors; fewer, well-separated categories work better.
- Rescaling. If you recalculate the scale of the conversion, the AUTOLAYER result is reset and must be generated again.
- Not an expert assessment. AUTOLAYER organizes the drawing; diagnostic interpretation and responsibility for the survey remain with the professional.
Best practices
Start with 3–4 clear macro-categories, check the "To review" box, fix doubtful cases in the editor and only then download the DXF. If your source is an orthophoto, first follow the guide how to convert an orthophoto to CAD to get a correctly scaled base. You can try the feature on your own image in the CVCAD app.