Illumination brush: interactive design of image-based lighting

ABSTRACT

To help artists design customized lighting environments, we present a simple user interface for designing image-based lighting. Our system allows the artist to directly and interactively specify the appearance of the resulting image by painting and dragging operations. Our system constructs an image-based lighting model that produces the desired (and painted) appearance by solving the inverse shading problem [Ramamoorthi and Hanrahan 2001]. To obtain realistic lighting effects, we design diffuse and specular lighting effects separately. We represent diffuse lighting using low frequency spherical harmonics and pre-computed radiance transfer[Sloan et al. 2002]. For specular lighting, we simply project the painted highlights onto a cube map texture. We also provide an interface with which the artist can drag highlights and shadows on the surface to control the orientation of the entire lighting environment. We demonstrate that our technique is useful and practical for adding lighting effects to synthetic objects. We also show an application of seamlessly merging synthetic objects into photographs.

References

1. Ramamoorthi, R., and Hanrahan, P. 2001. A signal-processing framework for inverse rendering. In SIGGRAPH 2001, 117--128.
2. Sloan, P.-P., Kautz, J., and Snyder, J. 2002. Precomputed radiance transfer for real-time rendering in dynamic, low-frequency lighting environments. In SIGGRAPH 2002, 527--536.

Index Terms

• Computing methodologies

  • Artificial intelligence

    • Computer vision

      • Computer vision tasks

  • Computer graphics

    • Image manipulation

    • Shape modeling

      • Parametric curve and surface models

      • Volumetric models

  • Machine learning

    • Machine learning algorithms

      • Feature selection