Realistic Rendering of Plant Leaves


Description

Realistic rendering of leaves requires accurate light computations and sophisticated light models. Biological tissues like leaves and skin exhibit subsurface scattering within the tissues and rough surface scattering on the surfaces. The BRDFs and BTDFs are spatially variant over the surfaces of leaves. Typically leaves also exhibit translucency and color bleeding on neighboring surfaces. The aim of this project is to provide an appearance model for leaves, which would take into account all these properties and render plant leaves realistically.

There are several challenges we have to meet to come up with such a rendering model. First, the BRDFs and BTDFs are varying, and brute-force representation could consume a lot of memory. So there should be some way of parametrizing this over the surface of the leaves, such that the BRDFs could be computed on-the-fly for lighting. Secondly, we need a good scattering model for leaves. Also, we need to have some form of a global illumination model to have the leaves radiate colors on the surrounding walls (bleeding of colors).

Goals

We aim at demonstrating a dynamic scene with several leaves falling close to some surface (could be a light-colored wall or the ground) in the presence of various light sources. The appearance of the leaves should be realistic , that is, the visible effects like translucency, color bleeding, gloss etc. should be modeled appropriately.

Novelty:- There has been work on subsurface scattering modes for leaves, but we are trying to improve the appearance by incorporating certain elements of backward raytracing to demonstrate properties like color bleeding.

Final Report

Paper: leaf-render.pdf
Final presentation slides: Leaf-Render.ppt



References

  1. Lifeng Wang and Wenle Wang and Julie Dorsey and Xu Yang and Baining Guo and Heung-Yeung Shum, "Real-Time Rendering of Plant Leaves", ACM Trans. Graph '05.
  2. Baranoski, G. V. G., and Rokne, J. 2002. Light Interaction with Plants. SIGGRAPH '02 Course Notes.
  3. Pat Hanrahan , Wolfgang Krueger, Reflection from layered surfaces due to subsurface scattering, Proceedings of the 20th annual conference on Computer graphics and interactive techniques, p.165-174, September 1993
  4. Jacquemoud, S., and Ustin, S. 2001. Leaf optical properties: A state of the art. In Proc. 8th Int. Symp. Physical Measurements and Signatures in Remote Sensing, 223--232.

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