This study explores the emotions that pre-service teachers (PSTs) experience when they interact with geometric knowledge and 3D design in a project focused on the way of Saint James pilgrimage route. The sample was made up of 101 PSTs from the University of Santiago de Compostela, the final point of the pilgrimage path. An emotional questionnaire, together with a participant observation notebook and a rubric, served as data collection instruments. The analytical frameworks included the didactical suitability criteria for mediational and affective facets, and SAMR (substitution, augmentation, modification, and redefinition) model for the effective integration of technology in schools. The results show a greater presence of pleasant emotions, highlighting the emotions of curiosity and cheerfulness. Despite this, less pleasant emotions such as brain-taster or bewilderment were notable. Pleasant emotions shown, as well, higher correlation rates. In conclusion, 3D design seems to indicate great potential for working on emotions with this group of students.