How did early renaissance artists learn to create more realistic art than their predecessors?

Early Renaissance artists learned to create more realistic art through a revival of classical techniques, the study of anatomy, and the use of perspective. They closely observed the human form and nature, often employing live models to enhance their understanding of proportions and movement. Additionally, advancements in perspective, notably linear perspective, allowed artists to create a sense of depth and space in their works. This combination of observation, technical skill, and classical knowledge resulted in a more lifelike representation of subjects compared to their predecessors.