Hi, You should output your colors with premultiplied alpha. Your code should look like this:
vec3 color = clamp(textureColor.rgb * lightWeighting.xyz, 0.0, 1.0); color *= 0.5; // premultiply by alpha gl_FragColor = vec4(color, 0.5); On Mon, Aug 6, 2012 at 4:21 PM, Tobias Reich <[email protected]>wrote: > I'm working on a new Galaxy S3 and found a problem that didn't occur on > other phones like my old Galaxy S1 or the Galaxy S2 - which has almost the > same GPU as the S3. > When drawing my OpenGL models on top of my camera image like this: > > mGLView = new GLSurfaceView(this); > mGLView.setOnClickListener(InputManager.getInstance()); GameRenderer > renderer = new GameRenderer(kamera, this); > InputManager.getInstance().currentActivity = renderer; > mGLView.setEGLContextClientVersion(2); mGLView.setEGLConfigChooser(8, 8, 8, > 8, 16, 0); setPreserveEGLContextOnPause > mGLView.getHolder().setFormat(PixelFormat.TRANSLUCENT); > mGLView.setZOrderOnTop(true); mGLView.setRenderer(renderer); > setContentView(new CameraView(this), new > LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT)); > addContentView(mGLView, new LayoutParams(LayoutParams.MATCH_PARENT, > LayoutParams.MATCH_PARENT)); > > So the GLRenderer should be transparent. It actually is. It works fine for > all the objects that are opaque as well as the background (where I see the > image of the camera) > > My problem is, when I make the pixels semi-transparent in the fragment > Shader I get a weird result. The brightest pixels seem overexpose when > "blending together". And it looks like they got clamped after so the value > that brighter than white - loosing probably the first bit - got dark again. > So only the brightest pixels are affected. It happens even if I use a > simple call like: > >> gl_FragColor = vec4(clamp(textureColor.rgb * lightWeighting.xyz, 0.0, 1.0), >> 0.5); >> >> > > So the actual GL-Fragment is clamped and I'm pretty sure it comes from the > camera preview itself. Here is an image that describes my problem: > > > <https://lh6.googleusercontent.com/-XhUolY4rNXA/UCBQnwRqb6I/AAAAAAAAAAM/YgzaE-KfGZs/s1600/glProblem.jpg> > > I get more and more convinced that it is an "overflow" for the values but > how can I change this? By the way - perhaps it helps - this effect gets > stronger the lower the alpha value of the fragment (the gl rendered one) > is. So somehow it looks like something is compensating/normalizing the > "semi transparent" values. > > Is there any way of "clamping" both values together since in the Shader I > can only clamp the actual rendered fragment somehow without asking for the > camera preview values. :-( > Thank you very much! I hope it is not a severe problem, > > Tobias Reich > > > > > -- > 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 -- Romain Guy Android framework engineer [email protected] -- 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
