publications

2022

1. ACM

   Rho-NLR: A Neural Lumigraph Renderer with Controllable Illumination

   Perkins, Laura

   In Proceedings of the 53rd ACM Technical Symposium on Computer Science Education V. 2 2022

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   The field of computer graphics has seen the rapid development of a class of solutions to difficult inverse problems such as determining 3D structure and view-dependent properties of an object from a sparse set of images. The Neural Lumigraph Rendering (NLR) approach disentangles geometry and appearance into two separate implicit neural representations, leveraging the unique fitting capabilities of sinusoidal representation networks (SIRENs), and then exports the result into a mesh with the unstructured lumigraph rendering technique for real-time rendering. While this technique presents robust reconstruction and synthesis quality, the problem of modelling illumination and reflectance properties in Neural Lumigraph Renderers has not yet been treated. We propose a straightforward modification of the NLR neural pipeline, dubbed rho-NLR, which demonstrates the robust capabilities of the NLR structure for high-fidelity view synthesis while allowing controllable illumination. By altering the appearance model to output the coefficients of a reflectance distribution function in a finite spherical harmonic basis, we obtain a lightweight representation which requires one small matrix multiplication per pixel to evaluate, allowing for dynamic scene relighting which is real-time within a given viewpoint. Finally, we publish an open-source implementation of Neural Lumigraph Rendering in TensorFlow 2.5.0, as well as our own rho-NLR.

2. Conceptual Metaphor Games: An Embodied Approach to Mathematics Pedagogy

   Perkins, Laura

   2022

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   In the theory of embodied cognition, mathematical activity is thought to be facilitated in large part by epistemic “mappings” that translate bodily intuitions about the world into abstract conceptual domains. Since their popularization, these ideas have influenced discourse in mathematics education. Another currently popular topic in mathematics education is the growing evidence that learning games can enhance learning outcomes. Combining these facts, this work proposes to construct real-world or virtual games which directly map onto mathematical concepts via conceptual metaphors. Games of this kind, which I dub conceptual metaphor games, intend to encourage learning as exploration, making for an approach to inclusive pedagogy which is both person-centric and theoretically sound such that it can be accessibly presented as separate from the underlying theory. I argue that play and discussion of these games can serve as “grounding” experiences with mathematics that confer understanding through a lighthearted medium. An example is given involving the embodied source domain of frogs hopping on lily pads, demonstrating an implementation of such a conceptual metaphor game in a pedagogical context. Additionally, I implement a demo level of a virtual browser-based game which can extend to a larger project for empirical evaluation.