Mesh with non-uniform grid looking down onto x-y plane
in [Matlab]
|
From: D on 8 Jun 2010 04:33 Hi everyone, I am trying to create a mesh of a surface using equally sized squares, instead of stretching the squares as is done by using mesh or surf functions. Therefore, looking down onto the x-y plane, the surface will be able to be 'visualized' by the size of each of the squares (The squares on flat surfaces will appear full size, while those that are on sloped surfaces will appear distorted and smaller). Any ideas on how to do this? Thank you
From: John D'Errico on 8 Jun 2010 06:47 "D " <dave.springer(a)gmail.com> wrote in message <hukv83$smh$1(a)fred.mathworks.com>... > Hi everyone, > > I am trying to create a mesh of a surface using equally sized squares, instead of stretching the squares as is done by using mesh or surf functions. > > Therefore, looking down onto the x-y plane, the surface will be able to be 'visualized' by the size of each of the squares (The squares on flat surfaces will appear full size, while those that are on sloped surfaces will appear distorted and smaller). > > Any ideas on how to do this? > > Thank you Just view the surface directly from above. help view help pcolor John
From: John D'Errico on 8 Jun 2010 06:56 "John D'Errico" <woodchips(a)rochester.rr.com> wrote in message <hul738$b2i$1(a)fred.mathworks.com>... > "D " <dave.springer(a)gmail.com> wrote in message <hukv83$smh$1(a)fred.mathworks.com>... > > Hi everyone, > > > > I am trying to create a mesh of a surface using equally sized squares, instead of stretching the squares as is done by using mesh or surf functions. > > > > Therefore, looking down onto the x-y plane, the surface will be able to be 'visualized' by the size of each of the squares (The squares on flat surfaces will appear full size, while those that are on sloped surfaces will appear distorted and smaller). > > > > Any ideas on how to do this? > > > > Thank you > > Just view the surface directly from above. > > help view > help pcolor Sorry. I was asleep when I made that response. View won't do it of course. I don't think you can do exactly what you are asking to do, at least not easily. Use pcolor perhaps. John
From: John D'Errico on 8 Jun 2010 08:13 "John D'Errico" <woodchips(a)rochester.rr.com> wrote in message <hul7k4$g17$1(a)fred.mathworks.com>... > "John D'Errico" <woodchips(a)rochester.rr.com> wrote in message <hul738$b2i$1(a)fred.mathworks.com>... > > "D " <dave.springer(a)gmail.com> wrote in message <hukv83$smh$1(a)fred.mathworks.com>... > > > Hi everyone, > > > > > > I am trying to create a mesh of a surface using equally sized squares, instead of stretching the squares as is done by using mesh or surf functions. > > > > > > Therefore, looking down onto the x-y plane, the surface will be able to be 'visualized' by the size of each of the squares (The squares on flat surfaces will appear full size, while those that are on sloped surfaces will appear distorted and smaller). > > > > > > Any ideas on how to do this? > > > > > > Thank you > > > > Just view the surface directly from above. > > > > help view > > help pcolor > > Sorry. I was asleep when I made that response. View won't > do it of course. I don't think you can do exactly what you > are asking to do, at least not easily. > > Use pcolor perhaps. And let me clarify this even more. Use pcolor on the norm of the local gradient. John
From: Tim on 9 Jun 2010 16:33 "John D'Errico" <woodchips(a)rochester.rr.com> wrote in message <hulc4g$87h$1(a)fred.mathworks.com>... > "John D'Errico" <woodchips(a)rochester.rr.com> wrote in message <hul7k4$g17$1(a)fred.mathworks.com>... > > "John D'Errico" <woodchips(a)rochester.rr.com> wrote in message <hul738$b2i$1(a)fred.mathworks.com>... > > > "D " <dave.springer(a)gmail.com> wrote in message <hukv83$smh$1(a)fred.mathworks.com>... > > > > Hi everyone, > > > > > > > > I am trying to create a mesh of a surface using equally sized squares, instead of stretching the squares as is done by using mesh or surf functions. > > > > > > > > Therefore, looking down onto the x-y plane, the surface will be able to be 'visualized' by the size of each of the squares (The squares on flat surfaces will appear full size, while those that are on sloped surfaces will appear distorted and smaller). > > > > > > > > Any ideas on how to do this? > > > > > > > > Thank you > > > > > > Just view the surface directly from above. > > > > > > help view > > > help pcolor > > > > Sorry. I was asleep when I made that response. View won't > > do it of course. I don't think you can do exactly what you > > are asking to do, at least not easily. > > > > Use pcolor perhaps. > > And let me clarify this even more. Use pcolor on the norm > of the local gradient. > > John I think I see what you are asking for. Let me make an analogy so others might see it as well. Let’s say I have a big hill and I want to cover this hill with 100s of 4x4 foot sheets of plywood. If I did this a bird flying overhead would see the flat areas as having bigger sheets than the steep areas. The extreme example would be a sheet on a cliff would not be visible from above. In this sense you could see the steep areas by looking for areas that contain a lot of sheets. You could see flat areas by looking for areas that contain few sheets. There is a problem with this though. Hills can not be covered with square sheets a plywood. The edges won't line up; you will either have gaps or overlaps. In computer graphics they use triangles, but these triangles aren't the same size. They use many small triangles for detailed areas, and few large triangles for less detailed areas. But in this case the number of triangles is proportional to the amount of detail, not the steepness. Geometrically speaking, I don't think this is possible.
|
Pages: 1 Prev: an older version MATLAB function Next: How to Store Pixel Intensity Values in Image Sequence |