[jitter] Re: Re: Re: erase_color with half transparancy works on one videocard, not on another

Quote: wesley.hoke at gmail.com wrote on Mon, 01 October 2007 15:39
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> Hi Mattijs,
> thanks for the patch.  I can only speculate right now that there is
> some difference in drivers between ato and nvidia causing this
> problem.  I could reproduce on my x1600 but my nvidia 8600 had no
> problems. 

Same here, nvidia geforce 7300 has no problems, ati radeon x1900 has.

> What erase_color with alpha is actually doing is not
> erasing the color buffer and drawing a fullscreen black quad with some
> blending over the scene so that it gradually disappears.  I've
> reproduced this effect in a shader which can be used as a drop in
> replacement for cases where you're using additive blending.  To use
> the usuall @blend_mode 6 7 blending, you'll have to modify the shader
> code a bit, but this takes care of the feedback network.

Thanks. I modified one line of the shader:

gl_FragColor = mix(framebuffer, current, erase_color.a);

And this seems to work. Thanks for the tip.

Btw what is the most convenient way to render multiple objects to the same texture? I was hoping that @capture scene could simply be applied to multiple objects, but it only seems to work with one at a time. 

Mattijs


Fuzzy btw that your jxs code appears broken on the forum, luckily it is back in the textarea once I press reply.


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SmadSteck - http://www.smadsteck.nl
Hard- and software for interactive audiovisual sampling