antialiasing iPhone OpenGLES

Question

I need in antialiasing in iPhone 3G (OpenGL ES1.1), NOT iPhone 3Gs with OpenGL ES.2.0. I've draw 3d model and have next: pixels on the edges of the model look like teeth.

I've try set any filters for texture, but this filters making ONLY texture INSIDE look better.

How can i make good antialising ? May be i should use any smooth for drawing triangles ? If yes, then how it possible in OpenGL ES1.1 ?

thanks.

score 8 · Answer 1 · edited May 23 '17 at 12:31

As of iOS 4.0, full-screen anti-aliasing is directly supported via an Apple extension to OpenGL. The basic concept is similar to epatel's suggestion: render the scene onto a larger framebuffer, then copy that down to a screen-sized framebuffer, then copy that buffer to the screen. The difference is, instead of creating a texture and rendering it onto a quad, the copy/sample operation is performed by a single function call (specifically, glResolveMultisampleFramebufferAPPLE()).

For details on how to set up the buffers and modify your drawing code, you can read a tutorial on the Gando Games blog which is written for OpenGL ES 1.1; there is also a note on Apple's Developer Forums explaining the same thing.

Thanks to Bersaelor for pointing this out in another SO question.

epatel · Accepted Answer · 2010-02-11T22:31:18.347

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You can render into a larger FBO and then use that as a texture on a square.

Have a look at this article for an explanation.

edited Feb 11 '10 at 22:31

answered Feb 11 '10 at 15:51

epatel

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Thank you very much for this link! And i'll try "render into a larger FBO". – Sergey Kopanev Feb 12 '10 at 17:49
I've posted a new answer: the concept is the same but there is an easier way to do it in newer versions of iOS. – benzado Nov 04 '10 at 23:40

genpfault · Answer 3 · 2010-02-11T15:46:02.887

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Check out the EGL_SAMPLE_BUFFERS and EGL_SAMPLES parameters to eglChooseConfig(), as well as glEnable(GL_MULTISAMPLE).

EDIT: Hrm, apparently you're out of luck, at least as far as standardized approaches go. As mentioned in that thread you can render to a large off-screen texture and scale to a smaller on-screen quad or jitter the view matrix several times.

edited Feb 11 '10 at 15:46

answered Feb 10 '10 at 14:22

genpfault

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Thanks, but openGL on the iPhone has no support eglChooseConfig(). Or am I mistaken? But when i set GL_LINE_SMOOTH and use glDrawArrays with GL_LINE_STRIP i have SUPER antialiased line. But when i set GL_TRIANGLES then this effects is disappear. – Sergey Kopanev Feb 11 '10 at 15:17
Looks like you're right. Odd. Anyway, found a thread with some alternative approaches and edited the answer. – genpfault Feb 11 '10 at 15:46
genpfault, may be. i've googled more sites and feeling that there is only one way - try to use this http://www.gamedev.net/community/forums/topic.asp?topic_id=548956 or similar. – Sergey Kopanev Feb 11 '10 at 17:28

score 2 · Answer 4 · edited Apr 18 '16 at 07:17

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We found another way to achieve this. If you edit your textures and add for example a 2 pixel frame of transparent pixels, the colored pixels in the texture are blended with the transparent pixels when necessary giving a basic anti-aliasing effect. You can read the full article here in our blog.

The advantage of this approach is that you are not rendering a bigger image, or copying a buffer, or even worse, making a texture from a buffer, so there is no impact in performance.

edited Apr 18 '16 at 07:17

Dreamwalker

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answered Mar 12 '11 at 01:02

Rula

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This link to [our blog](http://agileroute.com/blog/how-to-emulate-anti-aliasing-in-opengl-es-1-1) is broken – Andres Bucci Feb 01 '13 at 09:35

antialiasing iPhone OpenGLES

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