Resynthesizer Plugin. Works like Photoshop content aware selector.
Pixabay royalty-free images.
Add background and image Make shadow of image insert
Save the image (.xfc) Save the image as "01.jpg"
3D Backgound Layer
Hide the main image and shadow New transparent layer (bg1)
Create Another transparent layer (bg2)
Drag-and-drop BOTH images to a Facebook post. Facebook will recognize the PAIR as a 3D image, and convert automatically!
If you have multiple layers, and you don't remember which layer a particular item in your image is on, click on the item using Alt+MMB and Gimp will select the layer AND show the layer name at the bottom!
The canvas rotation mode can be activated with any currently selected tool. Just press Shift and start dragging the middle mouse button up or down.
Use the additional Ctrl modifier to rotate with 15° step.
To reset the rotation: