tag:blogger.com,1999:blog-1048411582271228135.post638160204377843770..comments2023-05-24T01:44:18.871-07:00Comments on journl do |post|: OpenGL ES Picking using Ray-BoundingBox Intersectioneigenclasshttp://www.blogger.com/profile/09562427129541978876noreply@blogger.comBlogger16125tag:blogger.com,1999:blog-1048411582271228135.post-57653121425136478792012-07-31T06:12:14.752-07:002012-07-31T06:12:14.752-07:00Please show me the source about inverting the matr...Please show me the source about inverting the matrix and the specifically last part.adminhttps://www.blogger.com/profile/10827265227385462347noreply@blogger.comtag:blogger.com,1999:blog-1048411582271228135.post-5094050379384558372011-09-21T03:21:11.455-07:002011-09-21T03:21:11.455-07:00Hi, I am not sure if the calculation of near_heigh...Hi, I am not sure if the calculation of near_height is correct using the field of view. I may be mistaken, but I think the conversion to radions isnt correct?<br /><br />I figured that out because I wrote a post on this topic too: http://schabby.de/picking-opengl-ray-tracing/<br /><br />Regards,<br /><br />JohannesJohannes Schabackhttps://www.blogger.com/profile/11382926542864921637noreply@blogger.comtag:blogger.com,1999:blog-1048411582271228135.post-18175794594311007982011-03-21T10:01:49.398-07:002011-03-21T10:01:49.398-07:00Hi,
I try to implement your tutorial in my openGL ...Hi,<br />I try to implement your tutorial in my openGL View but without success.<br />I have load an obj file from 3DS and i want to "touch" on part of my object drawing a circle for instance. What can I do ?<br />I have the x,y (2D) coordinate but how to convert them to my 3D object.<br /><br />ThanksToToHHhttps://www.blogger.com/profile/06147716804079448602noreply@blogger.comtag:blogger.com,1999:blog-1048411582271228135.post-69516888956487859782010-05-24T10:11:34.020-07:002010-05-24T10:11:34.020-07:00Here is a working sample for iPhone implementing g...Here is a working sample for iPhone implementing gluUnproject :<br /><br />http://blog.nova-box.com/2010/05/iphone-ray-picking-glunproject-sample.html#comment-formOphir Pazhttps://www.blogger.com/profile/16798717204116364890noreply@blogger.comtag:blogger.com,1999:blog-1048411582271228135.post-1329625604442717252010-03-02T20:34:41.562-08:002010-03-02T20:34:41.562-08:00Here is the code I used to get it working. NOTE: ...Here is the code I used to get it working. NOTE: This assumes the translation values are stored in the far right column instead of the bottom most row.<br /><br />typedef GLfloat Matrix3D[16];<br /><br />static inline void Matrix3DInvert(Matrix3D matrix, Matrix3D result)<br />{<br /> //Compute transpose of the rotation matrix<br /> result[0] = matrix[0]; result[4] = matrix[1]; result[8] = matrix[2];<br /> result[1] = matrix[4]; result[5] = matrix[5]; result[9] = matrix[6];<br /> result[2] = matrix[8]; result[6] = matrix[9]; result[10] = matrix[10];<br /> //Compute the inverse translate<br /> result[12] = (result[0]*matrix[12] + result[4]*matrix[13] + result[8]*matrix[14]) * -1.0f;<br /> result[13] = (result[1]*matrix[12] + result[5]*matrix[13] + result[9]*matrix[14]) * -1.0f;;<br /> result[14] = (result[2]*matrix[12] + result[6]*matrix[13] + result[10]*matrix[14]) * -1.0f;;<br /> //Fill in the bottom<br /> result[3] = result[7] = result[11] = 0;<br /> result[15] = 1;<br />}Unknownhttps://www.blogger.com/profile/17722363995092826471noreply@blogger.comtag:blogger.com,1999:blog-1048411582271228135.post-82460595901355208772010-02-15T00:30:05.286-08:002010-02-15T00:30:05.286-08:00Good tutorial... for someone like me who is using ...Good tutorial... for someone like me who is using it just to refresh some concepts. Thanks.Kenraehttps://www.blogger.com/profile/06965898436269567894noreply@blogger.comtag:blogger.com,1999:blog-1048411582271228135.post-88341280151483797582010-02-07T02:55:20.907-08:002010-02-07T02:55:20.907-08:00I'm get frustrated because EVERYONE on the web...I'm get frustrated because EVERYONE on the web give infos and tutorials, but nobody put a decent piece of code as real-world sample. And the best of all is that nobody write the last part of what is telling (now you do simply this and that... without explaing how).Unknownhttps://www.blogger.com/profile/06051531711970728922noreply@blogger.comtag:blogger.com,1999:blog-1048411582271228135.post-81678667755958873602009-09-21T14:06:53.099-07:002009-09-21T14:06:53.099-07:00Excellent tutorial! I've already seen several...Excellent tutorial! I've already seen several people asking about this and I'm glad that you posted the code to be able to do it correctly.<br /><br />Thanks!Unknownhttps://www.blogger.com/profile/06342374188639459405noreply@blogger.comtag:blogger.com,1999:blog-1048411582271228135.post-44462215475312018702009-08-06T12:03:21.397-07:002009-08-06T12:03:21.397-07:00Thanks.
But I asked that how do you find out the ...Thanks.<br /><br />But I asked that how do you find out the ray vector if the camera position is not located at (0, 0, 0) in case of using gluLookAt() method??<br /><br />Assuming the eye point is placed anywhere but looking at the origin (0, 0, 0)??Cody Nghttps://www.blogger.com/profile/11652549735499816855noreply@blogger.comtag:blogger.com,1999:blog-1048411582271228135.post-20187407265342639752009-07-31T15:58:29.734-07:002009-07-31T15:58:29.734-07:00Thanks for the tutorial. It s been very helpful.
...Thanks for the tutorial. It s been very helpful.<br /><br />Cody Ng:<br />The camera position in eye coordinates (camera coordinates, basically) is always (0,0,0). That s why the ray has to be transformed to world coordinates before it can be used to hit-test objects in the scene, for example.<br /><br />This tutorial is very ready-to-use, thanks again.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-1048411582271228135.post-34732365085750832322009-07-31T15:56:00.518-07:002009-07-31T15:56:00.518-07:00This comment has been removed by the author.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-1048411582271228135.post-91153762554487380102009-07-19T02:53:41.019-07:002009-07-19T02:53:41.019-07:00Thanks for share.
What about if the camera is not...Thanks for share.<br /><br />What about if the camera is not located at (0, 0, 0)??Cody Nghttps://www.blogger.com/profile/11652549735499816855noreply@blogger.comtag:blogger.com,1999:blog-1048411582271228135.post-41435712870369698332009-03-23T03:04:00.000-07:002009-03-23T03:04:00.000-07:00Hi, i would like to know the procedure for tapping...Hi, i would like to know the procedure for tapping one image on another image using opengl es in objective c. As i m working on a game for iphone.Anand Saurabhhttps://www.blogger.com/profile/08131019428994921247noreply@blogger.comtag:blogger.com,1999:blog-1048411582271228135.post-53461914614087220202009-02-17T10:02:00.000-08:002009-02-17T10:02:00.000-08:00Someone already asked this, but do you have any so...Someone already asked this, but do you have any source for this tht you can share?zidjianhttps://www.blogger.com/profile/05125357172177255841noreply@blogger.comtag:blogger.com,1999:blog-1048411582271228135.post-45933761181686918222008-12-21T08:49:00.000-08:002008-12-21T08:49:00.000-08:00Hi, how are you building up the ray vector once yo...Hi, how are you building up the ray vector once you got ray_start_point' and ray' ?papillon68https://www.blogger.com/profile/06004380132180077560noreply@blogger.comtag:blogger.com,1999:blog-1048411582271228135.post-11099062214397701502008-12-21T03:49:00.000-08:002008-12-21T03:49:00.000-08:00Hi, I followed your instructions but couldn't make...Hi, I followed your instructions but couldn't make it to work. Do you have a working Xcode project that you could share ?papillon68https://www.blogger.com/profile/06004380132180077560noreply@blogger.com