Why DWG is invisible without CAD
A DWG file describes geometry and can also contain a preview image written when the file was saved. Windows does not read that embedded image itself, so an icon is often all you get.
What the preloader does differently
JB Thumbnail Preloader reads a PNG or BMP preview already embedded in the DWG file and makes it available to Explorer. The app does not render drawing geometry.
Not only DWG
DXF, IFC, RVT and further engineering and building formats run through the same process. Anyone moving between CAD, BIM and 3D gets one consistent view instead of a collection of special cases.
What the DWG file must contain
The DWG file must already contain an embedded PNG or BMP preview. If no such preview is present, JB Thumbnail Preloader does not generate an image from the geometry and Explorer shows the file type icon instead. AutoCAD does not need to be installed on this computer, but a CAD application must previously have stored the preview in the file.
Frequently asked questions
Do I need AutoCAD installed?
No. JB Thumbnail Preloader reads the preview already stored in the DWG file without AutoCAD installed. The app does not render the drawing geometry itself.
Are IFC and RVT supported too?
Yes, both are included, as are DXF, SKP and further engineering and building formats.