The use of three-dimensional visual resources in higher education contributes to the development of spatial skills, thereby enhancing students’ mental geometric representation of the object under study, deepening their understanding, and improving their problem-solving abilities—particularly in disciplines such as engineering.

In this context, the present work presents the results of the project “3D-PDF as an Educational Technological Resource in Geological Civil Engineering Training,” funded by the Teaching Support Fund of the UCSC (Universidad Católica de la Santísima Concepción). The project aimed to design, develop, and implement interactive educational material in 3D-PDF (three-dimensional Portable Document Format) to enhance 3D visualization and problem-solving skills among students enrolled in the course Fundamentals of Mineralogy, during the early phase of the Geological Civil Engineering program. The technology enabled the teaching of crystal systems, where students study symmetry elements associated with unit cells or networks. These topics have historically generated many difficulties for students, resulting in low model comprehension, insecurity, and frustration when attempting to solve problems.

The project was developed in three phases. In the first, critical course content was selected and 3D models were designed in PDF-3D format. In the second phase, these models were integrated into student-centered activities, including application exercises and assessments mediated by ICT. From 2021 to 2025, the course was implemented with an impact on 70 students. Finally, a perception survey was administered to gather student feedback regarding the tool’s usefulness. This survey was anonymous and voluntary, with an average response rate of 55%.

The results show a positive impact on academic performance: on average, 60% of students achieved a grade above 4.0 (on a 1-to-7 Chilean scale). Compared to previous evaluations without the use of 3D-PDF, there was a substantial improvement in concept comprehension and in the ability to solve complex structural problems. The perception survey, with a 55% response rate, showed very positive evaluations of the tool. While 82% of students were previously unfamiliar with it, they highlighted its usefulness in visualizing structures, improving understanding, and increasing motivation. Moreover, 99% expressed a desire for the tool to be applied in other courses.

The use of 3D-PDF as an educational resource proved to be an effective, accessible, and well-received innovation among students. Beyond improving academic performance, it supported a more visual, interactive, and inclusive learning experience. The continued use of this resource is planned for the mentioned course in the coming years, as well as its adaptation to other contexts and disciplines with high spatial visualization demands.

Keywords: Three-dimensional visualization, spatial skills, geological engineering, educational innovation.