Background. The most common method of generating realistic trees is by using a non-interactive and fully automatic algorithm, however, an interactive method can create realistic results as well. In an effort to show the potential of an interactive method, this thesis proposes a method of generating realistic-looking trees interactively and evaluating their level of perceived realism.

Objectives. To evaluate the realism, trees generated by an interactive script, rendered in equal conditions in a game engine, need to be evaluated through a user study.

Methods. A tool was implemented in Maya 2022 using PyMel, that can generate trees interactively, in different levels of geometric resolution. Through a user study with a single stimulus setup, the trees were evaluated by students at Blekinge Institute of Technology.

Results. The data extracted from the stimulus testing show that all categories of trees created for this study receive a passing grade of realism for video games. What is shown is also that trees categorized as Large have a higher level of perceived realism. A higher level of detail adds to the realism factor.

Conclusion. It has been demonstrated that an interactive method can create sufficiently realistic looking trees for a static video game setting. A higher level of detail is shown to increase the level of perceived realism. This thesis concludes by identifying future research and improvements to the methods used for this study.