Medieval artists in Europe, like those in the Islamic world and China, were aware of the general principle of varying the relative size of elements according to distance, but even more than classical art was perfectly ready to override it for other reasons. Buildings were often shown obliquely according to a particular convention. The use and sophistication of attempts to convey distance increased steadily during the period, but without a basis in a systematic theory. Byzantine art was also aware of these principles, but also used the reverse perspective convention for the setting of principal figures. Ambrogio Lorenzetti painted a floor with convergent lines in his "Presentation at the Temple" (1342), though the rest of the painting lacks perspective elements. Other artists of the greater proto-Renaissance, such as Melchior Broederlam, strongly anticipated modern perspective in their works but lacked the constraint of a vanishing point.