Was the era of European discovery an outgrowth of the Renaissance?
No, it was more of a reaction to the fall of the Byzantine empire. For centuries, the trade with Asia to Europe had been mostly from Asia, to the Byzantines, to western Europeans. But with the fall of the Byzantine empire in 1453, the Ottoman Turks replaced the Byzantines as middlemen in this chain. The Muslim Turks decided they should charge Christians a high premium on trade goods. To avoid this premium, Columbus sought a route to India. When it seemed that sailing south was not effective, Europeans sought a more northerly route; seeking out the Northwest Passage. Spanish exploration was also an outgrowth of the Reconquista; the drive for Spanish Christians to take back Spain from the Muslims. After the Spanish peninsula was reconquered, the Spanish and Portugese turned thier energies towards the Americas.