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MadMapper Syphon Input colors inaccurate.
Posted: Sun Aug 04, 2019 5:30 am
by ProjectileObjects
Hello, I'm trying to understand why Madmapper is showing a syphon input darker than the source. If you look at the photo example, the window is sending out a white area. Syphon Recorder shows a white area, but MadMapper shows the same source as grey.
Does someone know why Madmapper's syphon is not pulling in the correct color values?
Re: MadMapper Syphon Input colors inaccurate.
Posted: Mon Aug 05, 2019 12:39 pm
by mad-matt
Hi,
That's because of Alpha channel. MadMapper supports Alpha channel by default, if the source stream transmits an Alpha channel and the alpha channel is not fully opaque, that would be different in MadMapper than in Syphon Recorder.
Please choose "Ignore Alpha" in the blending mode of the Quad, it should now show the same image than Syphon Recorder. Can you confirm this ?
Cheers
Re: MadMapper Syphon Input colors inaccurate.
Posted: Mon Aug 05, 2019 7:06 pm
by ProjectileObjects
Hi,
That's because of Alpha channel. MadMapper supports Alpha channel by default, if the source stream transmits an Alpha channel and the alpha channel is not fully opaque, that would be different in MadMapper than in Syphon Recorder.
Please choose "Ignore Alpha" in the blending mode of the Quad, it should now show the same image than Syphon Recorder. Can you confirm this ?
Cheers
Yes, worked perfectly. Thank you.
Re: MadMapper Syphon Input colors inaccurate.
Posted: Mon May 09, 2022 6:54 pm
by dfreeds1
Having the same issue. Ignore alpha isn't fixing it when attempting to send my image to LED panels over ArtNet.
Any leads appreciated.
MadMapper 5.0.5, Windows, Incoming texture is coming from Max MSP over Spout.
Re: MadMapper Syphon Input colors inaccurate.
Posted: Tue May 10, 2022 10:42 am
by mad-matt
Having the same issue. Ignore alpha isn't fixing it when attempting to send my image to LED panels over ArtNet.
Any leads appreciated.
Ignore Alpha is fixing it for video surfaces, but there's no "ignore alpha" on fixture (you could do it by multiplying color levels by the invert of alpha in glsl expression but it's tricky)
The solution for a video projector loopback to LEDs is to put a black "solid color" layer in the background of the video projector used for loopback. Then alpha will be 1 in the loopback visual.
Re: MadMapper Syphon Input colors inaccurate.
Posted: Wed May 11, 2022 5:42 pm
by dfreeds1
Thanks, this was exactly the info I needed!
For any Maxers that may experience this:
Andrew Benson's alphaglue fragment shader set to a -1. threshold on my outgoing texture did the trick.