What was the last name of the person who painted an enormous panoramic painting?  Answer the above question based on the context below:  The visual arts during the Song dynasty were heightened by new developments such as advances in landscape and portrait painting. The gentry elite engaged in the arts as accepted pastimes of the cultured scholar-official, including painting, composing poetry, and writing calligraphy. The poet and statesman Su Shi and his associate Mi Fu (1051–1107) enjoyed antiquarian affairs, often borrowing or buying art pieces to study and copy. Poetry and literature profited from the rising popularity and development of the ci poetry form. Enormous encyclopedic volumes were compiled, such as works of historiography and dozens of treatises on technical subjects. This included the universal history text of the Zizhi Tongjian, compiled into 1000 volumes of 9.4 million written Chinese characters. The genre of Chinese travel literature also became popular with the writings of the geographer Fan Chengda (1126–1193) and Su Shi, the latter of whom wrote the 'daytrip essay' known as Record of Stone Bell Mountain that used persuasive writing to argue for a philosophical point. Although an early form of the local geographic gazetteer existed in China since the 1st century, the matured form known as "treatise on a place", or fangzhi, replaced the old "map guide", or tujing, during the Song dynasty.The imperial courts of the emperor's palace were filled with his entourage of court painters, calligraphers, poets, and storytellers. Emperor Huizong was a renowned artist as well as a patron of the arts. A prime example of a highly venerated court painter was Zhang Zeduan (1085–1145) who painted an enormous panoramic painting, Along the River During the Qingming Festival. Emperor Gaozong of Song initiated a massive art project during his reign, known as the Eighteen Songs of a Nomad Flute from the life story of Cai Wenji (b. 177). This art project was a diplomatic gesture to the Jin dynasty while he negotiated for the release of his mother from Jurchen captivity in the north.
Zeduan