Imagine a house/building, seen from outside, at sunrise. As the the sun moves in the horizon, a) the shadow of the house is displaced/deformed, and b) some faces of the house have more/less sunlight in the afternoon than in the morning.
I need to predict those changes along the day and along the year. Besides the external 3D shape of the house, this only depends on space & time. Space: the latitude, longitude and orientation of the house/building. Time: the hour, day, month of interest.
I have the exterior measurements of the house. At this point I treat the house as a solid object (ie I don't care about the light inside the house; I also don't care about cases where light which passes thorough the building eg two opposite windows).
I only need to predict two interrelated things (along the day/year) for planning and visualization purposes:
1) the shadow of the house
2) the faces of the house which will be receiving light
With (1) I can predict how the adjacent buildings/parks/spaces would be affected by sunlight decrease and with (2) I can plan to put more/less and/or smaller/larger windows in different places of each wall of the house.
I know that many years ago this was possible with a plugin for Google Sketchup, but for different reasons I would like not to use this option but a free application (if FOSS, even better). Given the recent surge of 3D modeling/design programs I thought maybe there are other programs which are capable of doing this.