The frescoes by Giotto on the Life of St Francis are presently in good shape for being nearly 800 years old.
At present there is an Exhibition with a virtual presentation showing how the frescoes would have been seen as if newly painted all those years ago. It is in Assisi.
The exhibition is entitled I Colori di Giotto (The Colours of Giotto)
It coincides with the 800th Anniversary of the Confirmation of the Rule of St Francis by Pope Innocent III and is part of the celebration proceedings.
Here is The Confirmation of the Rule as it is and how it would have been about 800 years ago
Giotto di Bondone 1267 -1337
Legend of St Francis: 7. Confirmation of the Rule
Fresco, 270 x 230 cm
Upper Church, San Francesco, Assisi
(Upper: As it is at present; Two Lower: as they would have been when new)
At the exhibition there is also a 3D virtual presentation on the frescoes of which the following are frames which amongst other things demonstrate the perspective employed in the composition.
More about the 3D Grapics and animation can be seen in the following Youtube video link~