Shadows and Tonal Values

This is a study of shadows and tonal values in architecture using graphite, the drawing took approximately 1 hour due to all the shading and feedback. Using graphite to show the different tonal values to create the sense of a 3D drawing. Shading that darkest areas of the drawing to give the rest of the drawing a greater tonal range. The light source is coming from the bottom floor and bouncing off the wooden floor but there is also light coming from the top floor window on the right. Both light sources add to the tonal values on the floor and objects around, those are the light values, the dark values are the objects in shadow such as the object on the right where the pillars are, the light cannot reach most of it, and the cast shadows showing where the light is coming from casting shadows, such as the display cases down on the bottom floor. The focal point of the drawing would be the lightest area as it so big, the composition of the drawing shows the rule of thirds has been applied, with the pillars on the right and the big cylindrical thing on the left.
This is a successful finished drawing, with shadows and tonal values shown well, with methods of drawing architecture applied, it is also successful as the drawing looks 3 dimensional.