What kind of photo
A normal phone photo from the street or the driveway. Daylight, the whole roof in the frame, the sun behind you rather than behind the house. Portrait or landscape both work. Drone photos work and are good for big roofs. Screenshots from a listing or from street view also work, though the quality of the render follows the quality of the photo.
Which houses it handles
Gables, hips, dormers, valleys, multiple roof sections, flat roofs, attached garages and porches. Two-storey houses, ranches, cabins, townhouses and commercial buildings. The render finds every roof surface in the photo and changes them all to the new material.
Trees, cars and things in the way
A tree in front of part of the roof is fine. The render changes the roof it can see and leaves the tree. The same goes for power lines, cars and the neighbour's fence. If more than half the roof is hidden, take a photo from a different spot.
One photo, many roofs
The photo is uploaded once. Every render after that uses it, so trying a second colour or a different material is one tap. Most people try three or four before they settle.
What happens to the photo
It is stored privately in your account so you can come back to your renders. It is not public and it is not used for anything else. You can delete any render, and the photo with it, from your history.
