Comments on: OpenGL ES Tutorial for Android – Part III – Transformations

By: OpenGL ES Tutorial for Android – Part III – Transformations | Per-Erik Bergman

Wed, 01 Feb 2012 17:52:01 +0000

[...] (function() { var s = document.createElement('SCRIPT'), s1 = document.getElementsByTagName('SCRIPT')[0]; s.type = 'text/javascript'; s.async = true; s.src = 'http://widgets.digg.com/buttons.js'; s1.parentNode.insertBefore(s, s1); })(); TweetThis tutorial is original posted at Jayway’s Developer Blog and can be found here: Jayway’s Developer Blog [...]

By: koupoo

koupoo — Sun, 11 Dec 2011 01:46:34 +0000

the picture rotation showed is not fit:
gl.glRotatef(90f, 0.0f, 0.0f, 1.0f); // OpenGL docs.

By: Adrian May

Adrian May — Mon, 05 Dec 2011 09:34:35 +0000

I’m playing with ES 2.0 on a Desire and I find that the coordinate system is left handed, not right handed. X points to the left, y to the top of the screen, and Z points INTO the screen away from your eye. This is contrary to what all the bloggers say, but it’s definitely true on my phone. Is this something strange about ES 2.0?

By: lokesh

lokesh — Wed, 16 Nov 2011 12:20:45 +0000

Very useful tutorial..Make a idea in Opengl…

By: Forbidden things and tricks of OpenGL ES 1.x programming(Android) | Software development support, software risk,bugs for bugs, risk analysis,

Mon, 07 Nov 2011 07:56:11 +0000

[...] followed this tutorials and tested code on Samsung Galaxy Ace and it lagged a bit. Some code of that [...]

By: x

Thu, 27 Oct 2011 20:43:33 +0000

The best tutorial I have seen about OpenGL until now, thanks very much!

By: Chris McManamana

Chris McManamana — Fri, 21 Oct 2011 18:12:28 +0000

Absolutely fantastic job! You have set the standard for online tutorials.

By: Research (Done by Lai Chin Wang) « ifyp

Research (Done by Lai Chin Wang) « ifyp — Fri, 16 Sep 2011 11:13:52 +0000

[...] http://blog.jayway.com/2010/01/01/opengl-es-tutorial-for-android-%E2%80%93-part-iii-%E2%80%93-transf... [...]

By: Praveen Mehra

Praveen Mehra — Fri, 16 Sep 2011 10:31:07 +0000

thanks a lot it is very owesome…………

By: ZiN

ZiN — Sun, 28 Aug 2011 10:12:56 +0000

Your tutorials are fairly good, they helped me remember a few things and work out where I was going wrong. I followed someone elses tutorial in which there was a few mistakes, I had a funny feeling about it but didn’t test it till last thing.

Anyway minor mistake with your picture of your left hand. It should be your right hand as OpenGL uses the right hand rule. Thumb is always X and first, second index finger finger is Y and middle finger is Z. Just remember right hand rule, use right hand, starting from thumb working your way around through x,y,z.

That might clear up confusion a bit when people come across left hand rule systems in which you just use the same procedure but with your left hand. I hope this helps someone.

By: jitendra verma

jitendra verma — Wed, 24 Aug 2011 07:41:50 +0000

very nice

By: Eldar

Eldar — Sat, 20 Aug 2011 05:49:15 +0000

Great tutorial. Thanks a lot!

By: Hangfire

Hangfire — Fri, 19 Aug 2011 07:44:10 +0000

Thank you for these tutorials, they’re proving to be more helpful to me than a number of books I’ve bought.

Just one question…

At the end of the onDraw method you restore the the last 2 matrices. But at the start of the onDraw method we load the identity matrix. My question is why restore? My guess is to keep the stack of matrices to a minimum preventing the hundreds of stacked matrices from building up.

By: waikin

waikin — Thu, 18 Aug 2011 19:23:20 +0000

hey great series of tutorials.

i’m having trouble trying to move a few objects towards the screen on loop. Can anyone help me out with the code to that? lets say make the cubes move into the screen again and again?

i’ve been playing around with gl.gltranslatef (0f,0f,-5f) but to no avail.

Sorry if this is too noobish. Help would be very much appreciated!

By: thai

thai — Fri, 12 Aug 2011 02:49:14 +0000

Really usefull^^

By: Sheddy Bear

Sheddy Bear — Sun, 31 Jul 2011 22:13:14 +0000

xFaTE: Push and Pop are correct in this tutorial. You use a stack of matrices, and you are performing the translate/rotate/scale on the matrix on top of the stack. Push adds a matrix to the top of the stack (copies the top matrix then adds it to the top, so the top TWO matrices are the same immediately following a push), and pop takes the top matrix off. Most glPushMatrix are eventually paired with a glPopMatrix

Also GREAT tutorial!! I took a computer graphics course 3 years ago but I haven’t done any since, this was a brilliant refresher course.

By: shobha

shobha — Fri, 29 Jul 2011 12:17:33 +0000

This tutorial is very helpful for a beginer.Thank you ..

By: xFaTE

xFaTE — Sat, 09 Jul 2011 18:14:27 +0000

popMatrix is mixed up with pushmatrix
just a hint
but everything else GREAT!!!

By: karim

karim — Tue, 21 Jun 2011 13:51:58 +0000

everything is well explained except for one thing ,
there is an implicite loop somewhere , but i really cant find where
the whole thing is looping after we increment the angle but how is it doing it ?

By: Guillermo

Guillermo — Wed, 01 Jun 2011 20:05:57 +0000

Thanks again! it was really easy to read

By: AVEbrahimi

AVEbrahimi — Tue, 24 May 2011 05:49:51 +0000

Thank you for quick tutor.

By: lattimore

lattimore — Thu, 14 Apr 2011 05:52:15 +0000

Excellent!
Great Tutorial!

By: GC

GC — Sun, 10 Apr 2011 18:30:21 +0000

This is a very simple but powerful tutorial.
Many things become clear now for me.
Many thanks.

By: qoole

qoole — Fri, 08 Apr 2011 05:41:03 +0000

Thank you for your tutorial, it’s very clear.

By: dpk

dpk — Tue, 08 Mar 2011 04:46:42 +0000

Let’s say you wanted to show the object at a different rotation in different frames. Like, the first frame, you want it to be 10 degrees rotated in some direction, and the second frame you want to apply a new rotation on top of that 10 degrees. How would you you “save” the current matrix so you can “load” it again the next frame (w/, say, glLoadMatrixf?)? There’s no corresponding glSaveMatrixf function. Do you have to do the math by hand, outside of OpenGL?