Extracting thumbnails

thumbnail() extracts a preview already embedded in a DWG. It does not render the drawing.

Required command: LibreDWG dwgbmp. See External tools.

Extract an embedded preview

use Mattmy\DwgConverter\Facades\Dwg;

$thumbnail = Dwg::thumbnail($request->file('drawing'))->extract();

$extension = $thumbnail->extension(); // bmp, png, or wmf
$mimeType = $thumbnail->mimeType();

The extension and MIME type come from the output bytes, not the filename supplied by LibreDWG.

Validation boundary

The package checks the basic structure of BMP, PNG, and WMF previews. A preview that fails these checks throws DwgOperationFailed with reason thumbnail_invalid.

The preview is returned unchanged, without repairs or re-encoding. These are basic format checks, not a full image decode, so a successful result is not a guarantee that every image viewer can open it. No additional image decoder is needed.

Store the thumbnail

The name is optional. The trusted detected extension is applied automatically:

$path = $thumbnail->storeAs(
    path: 'drawing-thumbnails',
    disk: 's3',
);

storeAs() consumes the result. Calling output() or storeAs() again on the same object throws LogicException.

No thumbnail

A valid DWG may not contain a preview. In that case the operation throws DwgOperationFailed with reason thumbnail_not_found. It does not return null and does not fall back to toImage().

Use image previews when you need a rendered whole-model-space image.