Orientation Fields of a Rotating “Blobby” Object

In research I will be presenting in a few days at VSS (the Vision Sciences Society annual meeting), I will be demonstrating how we may use orientation flow fields of texture and shading when making perceptual judgments of 3D shape structure (see Fleming, Holtmann-Rice, & Bülthoff, 2011 for additional information). Since I find visualizations fun, I decided to use some spare CPU cycles overnight to visualize the orientation fields of a rotating blobby object.



The object on the left in the above video is a textured and shaded object with a small amount of specular reflection (lit using the Debvec Funston Beach at Sunset light probe). On the right, I’m illustrating the dominant orientations in the image, across the surface of the object.

Click through for some more visualizations.



The above video illustrates the vector field’s dominant orientations as well as the kurtosis/”peakedness” of the orientated filter response distributions (reflected in the size of the vectors).



Using line integral convolution, we get a better visualization of the global structure of the orientation field. Note that the above LIC images were computed in MATLAB using the Matlab Vector Field Visualization toolkit.



The LIC images in the video above were computed in Mathematica and colored as a function of the orientation field’s dominant orientation.



Finally, a video illustrating all the aforementioned visualization techniques simultaneously.

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