tag:blogger.com,1999:blog-6042417775578107106.post6053561090458898397..comments2023-08-05T11:30:32.754-04:00Comments on The Hacks of Life: Perspective Correct Texturing in OpenGLChrishttp://www.blogger.com/profile/14648675681957285299noreply@blogger.comBlogger10125tag:blogger.com,1999:blog-6042417775578107106.post-33808196028559007442013-02-28T12:05:23.745-05:002013-02-28T12:05:23.745-05:00Definitely not! See the comments above about the ...Definitely not! See the comments above about the limits of affine transformations, etc.Benjamin Supnikhttps://www.blogger.com/profile/04886313844644521178noreply@blogger.comtag:blogger.com,1999:blog-6042417775578107106.post-47123826758420688462013-02-28T04:05:37.743-05:002013-02-28T04:05:37.743-05:00Might it be possible to achieve the middle image b...Might it be possible to achieve the middle image by rotating a quad within an orthographic projection?namuolhttps://www.blogger.com/profile/14169116211426610867noreply@blogger.comtag:blogger.com,1999:blog-6042417775578107106.post-32324540853194815252010-07-27T06:23:18.526-04:002010-07-27T06:23:18.526-04:00Thanks a bunch. I have been googling for exactly t...Thanks a bunch. I have been googling for exactly this.<br /><br />I have a GL_QUAD with a texture. On top of that i have a freely adjustable 4 corner polygon that user can change to choose texture coordinates for mapping the same texture on a rectangle.<br /><br />At the moment i see wrongly interpolated textures. I will probably have to use a pixel shader then.Tõnuhttps://www.blogger.com/profile/01268071829349334574noreply@blogger.comtag:blogger.com,1999:blog-6042417775578107106.post-68880398439541214762010-06-20T16:52:59.796-04:002010-06-20T16:52:59.796-04:00Thanks for your reply of the Mac OpenGL mailing li...Thanks for your reply of the Mac OpenGL mailing list. This is just what I needed. I couldn't reply on the list because my copy of the email wasn't delivered. But, I was able to pull your reply off of the archive.<br /><br />Thanks so much!Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-6042417775578107106.post-63698407724953183272009-10-27T08:50:19.818-04:002009-10-27T08:50:19.818-04:00Sorry, bad news - the middle trapezoid distortion ...Sorry, bad news - the middle trapezoid distortion isn't available via hw texture interp...because it's not an affine transformation. At least, I think...Benjamin Supnikhttps://www.blogger.com/profile/04886313844644521178noreply@blogger.comtag:blogger.com,1999:blog-6042417775578107106.post-12396092287457262172008-11-06T20:26:00.000-05:002008-11-06T20:26:00.000-05:00hi guys. i really need to make a radial stretch of...hi guys. i really need to make a radial stretch of an image. like an ultrasound picture. are fan strips the way to go? i need to get rid of the perspective. according to this blogpost opengl will never give me that midde image (http://bp1.blogger.com/_TrRVoYy3Itc/SFF1aDGquZI/AAAAAAAAAUY/rPV86rOPljw/s1600-h/perspective.jpg). never? or never automatically? how do make a trapeziod like the middle one?Pål Driveklepphttps://www.blogger.com/profile/10554208074938757308noreply@blogger.comtag:blogger.com,1999:blog-6042417775578107106.post-82479107102604190042008-08-11T16:49:00.000-04:002008-08-11T16:49:00.000-04:00I've just been looking at the XNA documentation.It...I've just been looking at the XNA documentation.<BR/><BR/>It looks like one could create a custom texture coordinate format using a Microsoft.Xna.Framework.Graphics.VertexBuffer and the flexible vertex format (VertexDeclaration, which uses multiple VertexElement structs to describe the format, each of which has a VertexElementFormat (like, 2d float vector, 3d float vector etc), and a VertexElementUsage (position, normal, colour, tex coord etc)). Now, I've no idea whether that would let you create a 4D texture coordinate but if it did then one might assume that one could place the Q value in the fourth dimension there. Might work!haowanhttps://www.blogger.com/profile/09624266567898334086noreply@blogger.comtag:blogger.com,1999:blog-6042417775578107106.post-69172560112818482472008-08-11T13:54:00.000-04:002008-08-11T13:54:00.000-04:00Might be pushing my luck here, but I don't suppose...Might be pushing my luck here, but I don't suppose you know the equivalent for Direct3D?<BR/><BR/>I'm using OpenGL from now on, but if you did, I could go back and fix some XNA things.Bezhttps://www.blogger.com/profile/08296337066041438209noreply@blogger.comtag:blogger.com,1999:blog-6042417775578107106.post-51571855938895768782008-08-11T13:53:00.000-04:002008-08-11T13:53:00.000-04:00Ditto. I'm a friend of hao's, and this has been bu...Ditto. I'm a friend of hao's, and this has been bugging me since I did a radial menu system with fan strips (so lots of quads in the shape you've shown). Putting textures onto them looked horrible. Now I might have a chance of fixing that!Bezhttps://www.blogger.com/profile/08296337066041438209noreply@blogger.comtag:blogger.com,1999:blog-6042417775578107106.post-75475964572025804892008-08-11T13:42:00.000-04:002008-08-11T13:42:00.000-04:00I absolutely love you for explaining this to me. I...I absolutely love you for explaining this to me. I've been looking for this solution for ages!haowanhttps://www.blogger.com/profile/09624266567898334086noreply@blogger.com