PM4Flower: A Scriptable Parametric Modeling Interface for Procedural Flower Generation Using PM4VR

Flowers possess intricate structures, including petals, stamens, pistils, anthers, stems, and other components that exhibit biological accuracy and aesthetic variation [19, 20]. Traditionally, artists have manually modeled these components, but this method is time-consuming and rigid, making it difficult to generate a variety of flowers or adjust designs rapidly. With the rapid development of computer graphics technologies, procedural modeling offers scalable and efficient methods to generate complex structures with minimal manual input [3, 18, 21]. Procedural modeling has transformed the landscape of digital content creation, proposing algorithms to generate complex geometries of virtual worlds that will otherwise require intensive manual labor [1, 23, 25]. One of the demanding areas of procedural content generation [22, 24] is the creation of natural elements, such as terrain [6, 7], landscape [5, 6], plants [2], trees [17], and flowers [26], which exhibit complexity.

In this paper, we introduce PM4Flower, a scriptable parametric modeling interface designed to streamline the procedural generation of flowers. Built on the foundation of PM4VR, PM4Flower enhances procedural modeling by offering a programming interface that allows users to create highly customizable flower models in virtual reality using simple scripting commands. PM4VR, which stands for Parametric Modeling for Virtual Reality, was initially developed for conceptual architectural design in VR environments [4] and has since been adapted for various industrial and artistic applications [8, 9, 10, 11, 12, 13, 14, 15, 16]. The primary objective of PM4Flower is to provide a VR-driven solution for procedural flower modeling by offering a scriptable interface that enables fast and customizable parametric flower creation. By dynamically modifying parameters, users can iteratively refine flower models in VR, fostering a deeper understanding of floral anatomy, making PM4Flower a practical tool for applications in digital content creation, video game authoring, scientific visualization, and even STEM education on VR platforms.

As shown in Fig. 1, PM4Flower enables designers to write Java^♭ script as input for defining the parameters of flower models, as depicted in Fig. 1(a). Through this scripting interface, users can control various aspects of flower design, such as petal shape, color, and overall structure. By inputting these specifications in Java^♭ script, designers have the flexibility to create complex flower models with ease. Once the script is executed within the PM4Flower interface and enter a VR setting, as illustrated in Fig. 1(b), user can further interact with and refine their designs. This VR-based interface allows for real-time adjustments of the parametric values, offering an intuitive, hands-on approach to fine-tuning the flower's geometry and aesthetics. Users can directly manipulate attributes like the shape and color of petals and the arrangement of floral elements, gaining immediate visual feedback as they adjust these parameters. Finally, as shown in Fig. 1(c), the detailed and finalized 3D parametric flower model is generated, providing a representation of the flower based on the initial Java^♭ script and VR-based modifications.

To demonstrate the effectiveness of the PM4Flower interface in generating a wide range of realistic flower models, we conducted several numerical experiments that showcase its creativity, flexibility, and adaptability in procedural flower generation. These experiments highlight the ability of PM4Flower to produce diverse and intricate floral structures through the use of Java^♭ scripts. As shown in Fig. 2, various Java^♭ scripts, such as stamen.javab, pistil.javab, and anther.javab, were employed to generate the corresponding components of a flower, illustrating the granular control PM4Flower provides over the individual parts of the flower model. Fig. 4 showcases different Java^♭ scripts alongside their outputs, which include a variety of flower shapes generated using PM4Flower. For instance, the system successfully generates diverse floral forms: shape 1 represents a lily, shape 2 represents a peony, shape 3 corresponds to a leaf, shape 4 represents a vase, and shape 5 represents a stem. Similarly, Fig. 5 highlights additional Java^♭ scripts and their outputs, including shape 6, a rose, and shape 7, which represents the disk flower of a sunflower. These examples illustrate the system's versatility in modeling different species of flowers, along with related structures such as vases and leaves. Finally, Fig.  7 demonstrates how users can further manipulate flower models in real-time using VR controllers. In this case, a user adjusts the parameters of a procedurally generated sunflower whose Jave^♭ script is shown in Fig. 1, fine-tuning its appearance and structure interactively. This hands-on adjustment using VR controls emphasizes the creative and dynamic nature of the PM4Flower interface, allowing for highly customized and realistic flower generation. For a detailed demonstration, please refer to the user study video available via the following link: https://youtu.be/dPGkxOz2Avg

This paper introduces PM4Flower, a groundbreaking scriptable parametric modeling interface designed for procedural flower generation within the VR environment. The results from various experiments and user studies demonstrate that PM4Flower offers a robust and flexible solution for creating flowers procedurally. PM4Flower strikes a balance between user-friendliness and extensive customization options. The numerical experiments conducted reveal that PM4Flower not only reduces the manual effort required for modeling but also enhances design flexibility and creativity, positioning it as a valuable tool across various applications in VR/AR, gaming, STEM education, and visualization in virtual classrooms.

Future work will focus on expanding PM4Flower's capabilities to incorporate more complex plant structures, thereby broadening the scope of procedural generation beyond flowers. Additionally, efforts will be made to enhance its real-time performance in VR environments, ensuring that users can interact with and manipulate their designs in a fluid and responsive manner. This ongoing development aims to elevate PM4Flower's functionality and usability, making it an essential tool for users seeking to create realistic and dynamic plant models in virtual spaces.