VO1D 0 Report post Posted July 31, 2018 In the source code of RTI viewer, I found the following formula to calculate the normal of each pixel from the 6 coefficients: Where does it derive from? Does any paper or book mention this topic? Quote Share this post Link to post Share on other sites

gianpaolo 2 Report post Posted July 31, 2018 It is simply the stationary point of the paraboloid described by the 6 coefficients. The formula is described in the original PTM paper: http://www.hpl.hp.com/research/ptm/papers/ptm.pdf 1 Quote Share this post Link to post Share on other sites

VO1D 0 Report post Posted July 31, 2018 39 minutes ago, gianpaolo said: It is simply the stationary point of the paraboloid described by the 6 coefficients. The formula is described in the original PTM paper: http://www.hpl.hp.com/research/ptm/papers/ptm.pdf Thanks a lot, it solves my problem. Quote Share this post Link to post Share on other sites