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PeterO
Posts: 5085
Joined: Sun Jul 22, 2012 4:14 pm

OpenGL gotchas !

Thu Sep 03, 2015 9:31 am

When all you get is a blank screen, don't assume nothing is being drawn.

The camera might be looking the wrong way ! "IT'S BEHIND YOU " :D DO'H !!

PeterO
Discoverer of the PI2 XENON DEATH FLASH!
Interests: C,Python,PIC,Electronics,Ham Radio (G0DZB),1960s British Computers.
"The primary requirement (as we've always seen in your examples) is that the code is readable. " Dougie Lawson

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panik
Posts: 369
Joined: Fri Sep 23, 2011 12:29 pm
Location: Netherlands

Re: OpenGL gotchas !

Thu Sep 03, 2015 9:54 am

I feel you :)

Similar things that happened to me:

- backface culling is on, and the camera is *inside* the model.
- model is outside the clipping plane.
- model is *way* too big or too small (1 pixel is hard to spot on a blank HD screen)
- model has a fully transparent texture.

I'm sure there are more...
Microcontroller addon boards and software for Raspberry Pi A+/B+/Pi2:
- ARMinARM: ARM Cortex-M3 (STM32)
- AVRPi: ATmega32U4 & ATmega328 ("Arduino")
http://www.onandoffables.com

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PeterO
Posts: 5085
Joined: Sun Jul 22, 2012 4:14 pm

Re: OpenGL gotchas !

Thu Sep 03, 2015 10:08 am

Yes I'm sure there are many more, but this one wasted me a several hours yesterday :(
PeterO
Discoverer of the PI2 XENON DEATH FLASH!
Interests: C,Python,PIC,Electronics,Ham Radio (G0DZB),1960s British Computers.
"The primary requirement (as we've always seen in your examples) is that the code is readable. " Dougie Lawson

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