Comments for CS 15-458/858: Discrete Differential Geometry
http://brickisland.net/DDGSpring2019
CARNEGIE MELLON UNIVERSITY | SPRING 2019 | TUE/THU 12:00-1:20 | GHC 4303Tue, 26 Mar 2019 18:18:50 +0000hourly1https://wordpress.org/?v=5.0.4Comment on Assignment 3 [Coding]: The Laplacian (Due 4/2) by karen
http://brickisland.net/DDGSpring2019/2019/03/19/assignment-3-coding-the-laplacian-due-4-2/#comment-141
Tue, 26 Mar 2019 18:18:50 +0000http://brickisland.net/DDGSpring2019/?p=1841#comment-141Can we post the slides for Laplacian on the website? Thanks!
]]>Comment on Assignment 2 (Written): Investigating Curvature (Due 3/19) by Mark
http://brickisland.net/DDGSpring2019/2019/02/27/assignment-2-written-investigating-curvature-due-3-19/#comment-140
Tue, 19 Mar 2019 17:47:37 +0000http://brickisland.net/DDGSpring2019/?p=1752#comment-140Yes, that’s exactly right. Sorry for the typo
]]>Comment on Assignment 2 (Written): Investigating Curvature (Due 3/19) by t-nice
http://brickisland.net/DDGSpring2019/2019/02/27/assignment-2-written-investigating-curvature-due-3-19/#comment-139
Tue, 19 Mar 2019 16:29:09 +0000http://brickisland.net/DDGSpring2019/?p=1752#comment-139When deriving the gradient of the total surface area and the gradient of the total discrete scalar mean curvature, wouldn’t moving vertex $$f_i$$ in the direction of $$-e_{ij}=f_i-f_j$$ provide the fastest increase for those quantities, rather than the $$f_j-f_i$$ stated?
]]>Comment on Assignment 2 (Coding): Investigating Curvature (Due 3/19) by Mark
http://brickisland.net/DDGSpring2019/2019/02/27/assignment-2-coding-investigating-curvature-due-3-19/#comment-138
Mon, 18 Mar 2019 19:25:57 +0000http://brickisland.net/DDGSpring2019/?p=1759#comment-138Please iterator over all of the vertices.
]]>Comment on Assignment 2 (Coding): Investigating Curvature (Due 3/19) by Adilet Segizekov
http://brickisland.net/DDGSpring2019/2019/02/27/assignment-2-coding-investigating-curvature-due-3-19/#comment-137
Mon, 18 Mar 2019 01:40:07 +0000http://brickisland.net/DDGSpring2019/?p=1759#comment-137For totalAngleDefect() are we supposed to iterate over all of the vertices or just simply use the euler characteristic.
]]>Comment on Assignment 2 (Coding): Investigating Curvature (Due 3/19) by Mark
http://brickisland.net/DDGSpring2019/2019/02/27/assignment-2-coding-investigating-curvature-due-3-19/#comment-136
Wed, 13 Mar 2019 18:56:34 +0000http://brickisland.net/DDGSpring2019/?p=1759#comment-136Yes, $\theta_{ij}$ is the dihedral angle.
]]>Comment on Lecture 15â€”Discrete Curvature I (Integral Viewpoint) by Keenan
http://brickisland.net/DDGSpring2019/2019/03/07/lecture-15-discrete-curvature-i-integral_viewpoint/#comment-135
Wed, 13 Mar 2019 11:01:03 +0000http://brickisland.net/DDGSpring2019/?p=1792#comment-135Thanks Josh. I fixed this issue and a couple others in the slides above. I also added a slide at the very end that gives the Steiner formula for smooth rather than polyhedral surfaces, using the expressions we derive in the earlier slides.
]]>Comment on Assignment 2 (Coding): Investigating Curvature (Due 3/19) by jzhanson
http://brickisland.net/DDGSpring2019/2019/02/27/assignment-2-coding-investigating-curvature-due-3-19/#comment-134
Wed, 13 Mar 2019 01:57:15 +0000http://brickisland.net/DDGSpring2019/?p=1759#comment-134Just to confirm, in Notes #2 in the formula for discrete Gauss curvature, $\theta_{ij}$ is the $\textit{dihedral}$ angle between $N_{ijk}$ and $N_{ijl}$, not just the angle between $N_{ijk}$ and $N_{ijl}$?
]]>Comment on Lecture 15â€”Discrete Curvature I (Integral Viewpoint) by jzhanson
http://brickisland.net/DDGSpring2019/2019/03/07/lecture-15-discrete-curvature-i-integral_viewpoint/#comment-133
Wed, 13 Mar 2019 01:49:22 +0000http://brickisland.net/DDGSpring2019/?p=1792#comment-133We probably said this in class (can’t remember) but on slide 20, discrete mean curvature and discrete Gauss curvature are swapped (discrete mean curvature is denoted by a $K$, and discrete Gauss curvature is denoted by a $H$).
]]>Comment on Assignment 2 (Written): Investigating Curvature (Due 3/19) by Mark
http://brickisland.net/DDGSpring2019/2019/02/27/assignment-2-written-investigating-curvature-due-3-19/#comment-132
Tue, 12 Mar 2019 15:30:09 +0000http://brickisland.net/DDGSpring2019/?p=1752#comment-132No, it looks like the slides just have a sign error. Thanks for catching it! We’ll try to update the slides with a fixed version soon.
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