I am writing a thesis on taking a photo, extracting a roughness map from the photo, and finally applying it to actual rendering.
What I need is to know how to find roughness in existing and previous papers(references). Then, I took only one image and used the Blinn-Phong model to calculate the surface roughness using the formula R = (1 – H . V)^2.
1. About the formula below, which is the roughness extraction method proposed in the paper:
R = (1 – H.V)^2
R = (1 – H.V)^2
Why this is the estimated roughness value is explained based on the Blinn-Phong model on light-reflection meodl, Write additional formulas and explanations to describe the process through which the described formula was derived.
(ex. Formulas such as were created to empirically estimate surface roughness based on the basic principles of the Blinn phog reflection model. This formula uses the dot product between the half vector and the view vector to estimate the roughness of the surface. This is based on the assumption that the roughness of a surface can be estimated based on how parallel the half vector and the view vector are (i.e., how large the dot product is).
Empirical equations based on the Blinn phong model can be proposed in various studies that analyze the reflection properties of surfaces and thereby estimate their physical properties. These equations are usually developed based on the basic principles of reflection models and physical intuition.
Blinn, J. F. (1977). Models of light reflection for computer synthesized pictures. ACM SIGGRAPH Computer Graphics, 11(2), 192-198.
Phong, B. T. (1975). Illumination for computer-generated pictures. Communications of the ACM, 18(6), 311-317.
Phong, B. T. (1975). Illumination for computer-generated pictures. Communications of the ACM, 18(6), 311-317.
2. Show images of related previous papers and results that calculate surface roughness, and describe the meaning of the research results of this paper.