Edgblend help

Ricardo's icon
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Hi. I'm trying to use a video-plane in such a way that it has the option to be transparent in some areas. I want to be able to overlay one plane on another and being able to do some opperations which leaves parts of the video-plane transparent. I'v manage to do this, but I also want to be able to edge blend the the video-plane, but this does not seem to work. The point is that i do not want to blend two videos in one plane, but the videoplane's them selfs.
Point me in the right direction?

Rob Ramirez's icon

the problem is that the edgeblend shader creates it's own alpha channel, overwriting any existing alpha channel.
a simple solution could be to multiply the alpha channels of both the alphaglue and edgeblend.

a better solution would be to modify the shaders to include the multiply in the actual shader code.

Max Patch
Copy patch and select New From Clipboard in Max.

also, make sure you have @depth_enable 0 on any geometry that you want to have transparency blending (ie your videoplanes).

Ricardo's icon

Thank you. I'll look into this. This was very helpful.

Ricardo's icon

I'v been looking at the tutorial for writing Shaders but I was wondering, do you mean that I shoud make a shader witch includes the edgeblend and the multilpy?

Andrew Benson's icon

You can add the following line to the edgeblend shader to preserve your alpha channel:

    wiped.a *= a.a;

This should go directly before the line that starts with gl_FragColor...

Altering existing shaders is a great way to get oriented with writing your own. Most of the ones included with Jitter are pretty simple.

(ab)

Ricardo's icon

I have been looking at the different shaders and the tutorial "your very first shader", I think this is really interesting .
Thanks for all the help. :)