Hi Richard Thanks for your reply but I don't want to use frustumM I want to use orthoM. I want a 2D projection not 3D hence the -1 to +1. I have use frustumM and it works ok, I can see the triangle. What is the negative aspect ratio about? I don't understand that. It should really work like the old glOrtho function but I guess it doesn't which is a shame. Steve
On Friday, September 14, 2012 9:46:58 AM UTC+1, RichardC wrote: > See: > > android-sdk\samples\android-10\ApiDemos\src\com\example\android\apis\graphics\GLES20TriangleRenderer.java > > for Matrix.frustumM(mProjMatrix, 0, -ratio, ratio, -1, 1, 3, 7); > > which is similar. > > There is a lot of information out there on OpenGL projections, I suggest > you read some of it. > > Note that: > * near and far should both be +ve as they are distances in front of the > camera in the direction the camera is looking. > * if your triangle is at 0 on the z-axis you will need to move your camera > position (which defaults to [0,0,0]) so you can see it. > > > On Friday, September 14, 2012 9:27:35 AM UTC+1, reaktor24 wrote: >> >> I have a very simple application which draws a triangle at zero on the >> z axis. I want an orthographics view but for the life of me this >> function won't work. It just shows a black screen with no triangle. >> How exactly do you use this function? I did the obvious thing which >> is: >> >> Matrix.orthoM(projection,0,0,width,0,height,-1,1); >> >> >> Although seeing some peoples source code they are doing all sorts of >> stuff which I would of expected to be inside the orthoM method (like >> calling tan functions and dividing etc). So how exactly are you >> supposed to use this function? >> >> Steve >> > -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
