I don't know, but it could help you : http://laeti.perrierbrusle.free.fr/projections_ESRI.pdf http://www.madore.org/~david/math/carto.pdf It's in french and about world map.
Jack Le 17 oct. 07 à 23:08, Alex a écrit : > I started trying to draw a hemisphere with the appropriate texturing > coordinates using GEMgl commands, but that was getting too complicated > so I copied the sphere object source, made it draw a hemisphere, and > changed how it does texturing... I'll share it once I get all of the > kinks ironed out. > > -Alex > > On 10/17/07, marius schebella <[EMAIL PROTECTED]> wrote: >> hmm... no, I don't know how to do it. with gem you can only do >> rectangular projection/texturing. so you would have to find a way to >> distort the texture so that it will be displayed correctly on one >> half >> of the sphere. you probably need some vertex shader to do that... >> marius. >> >> >> Alex wrote: >>> so to make this easy think of a square texture that has a picture >>> the >>> globe centered inside it. >>> i want to take that picture and map the flat image of the globe >>> onto a >>> hemisphere so that you see [in this virtual world] 1/2 of a globe, >>> warped so that, in the virtual world, it looks correct. >>> >>> -Alex >>> >>> On 10/15/07, marius schebella <[EMAIL PROTECTED]> wrote: >>>> Hi alex, >>>> I am not sure what you're trying to do, but I am eager to help >>>> you... >>>> do you want to project the video onto a wall/ceiling hemisphere >>>> inside a >>>> real room? or are you talking about virtual projections? >>>> I guess what you have to do first is distort the circled video >>>> back into >>>> a square and then use that to texture the sphere. >>>> marius. >>>> >>>> >>>> sphere with a ? is it just the mapping on the spherefor any >>>> distortion you >>>> >>>> Alex wrote: >>>>> Maybe a different subject will inspire some help? >>>>> >>>>> basically, I have video that was shot on a mirrored spherical >>>>> ball.. >>>>> this gives a circular image inside a rectangular video, I've >>>>> figured >>>>> out how to crop it so that I just get the square that surrounds >>>>> the >>>>> circle, but I cannot figure out how to correctly map this >>>>> texture onto >>>>> a sphere so that it is only on one hemisphere and so that the >>>>> circle's >>>>> circumference is on a "great circle" of the sphere? [ie it the >>>>> circle >>>>> is warped out so that it becomes a hemisphere]. >>>>> >>>>> I figure maybe I have to do some GEMgl stuff for this? >>>>> >>>>> if anyone has done this, would you please share? >>>>> >>>>> If not, any advice? >>>>> >>>>> Thanks, >>>>> -Alex >>>>> >>>>> >>>>> On 10/10/07, Alex <[EMAIL PROTECTED]> wrote: >>>>>> I have some panoramic video that I want to use to texture a >>>>>> hemisphere >>>>>> [or rather, the bottom half of a sphere]. >>>>>> >>>>>> I cannot simply texture the sphere with the video because the >>>>>> warping >>>>>> is not correct.. it seems that I need some sort of non- >>>>>> rectangular >>>>>> warping of the image before I texture the object, or a non- >>>>>> rectangular >>>>>> mapping of the texture onto the sphere. >>>>>> >>>>>> Any ideas or advice? Does anyone else have experience working >>>>>> with >>>>>> panoramic video in Gem? >>>>>> >>>>>> -Alex >>>>>> >>>>> _______________________________________________ >>>>> [email protected] mailing list >>>>> UNSUBSCRIBE and account-management -> http:// >>>>> lists.puredata.info/listinfo/pd-list >>>>> >>>> >>> >> >> > > _______________________________________________ > [email protected] mailing list > UNSUBSCRIBE and account-management -> http://lists.puredata.info/ > listinfo/pd-list _______________________________________________ [email protected] mailing list UNSUBSCRIBE and account-management -> http://lists.puredata.info/listinfo/pd-list
