source:https://www.etsy.com/uk/listing/96811589/chapel-windows-print
source: http://www.pinterest.com/pin/431571576763218482/
The architect use traditional roundness in the wall (the fist picture). It presents a soft and gentle feeling. However, compare with the fist, in the next picture, the shape of rectangle makes the space more hard.
source: http://www.dreamtheend.com/#/?cat=596
Transparent wall always make people a mysterious sense.And it can connect with tow full space.( I don't know how to explain in English, Like a hollow-out wall can can connect withe tow full wall.) it play a role in transitive space. Because when the transparency of material is more less, the space will turn more big. So this technique is widely use in the wall of passage, balcony or small space. If some big space use a little hollow-out wall, some sunshine come inside, it also make this space soft and silent.