Login | Register 

Audio Reactive Image Opacity

Still a little green? Ask your beginner's questions here

Audio Reactive Image Opacity

Postby chromasy » Sat Jul 20, 2019 7:49 am


I've been reading up a lot about TD on and off for a while and have decided it's time to start learning. So far I've gone through a bunch of the introduction tutorials and have slowly got comfortable with the interface and basic node structure. I come from a background in AE / Nuke / Ableton and a little Python knowledge, so can't wait to really get stuck in.

Anyways, my first issue that I can't seem to figure out is:

Having an audio signal drive the opacity of an image.
I've been using a MovieFileIn (is this best for a still image - png specfically?) and have been watching many similar tutorials, but they all seem to be based on sending the signal to Geo/SOPs.

Essentially, I want my still image at 100% opacity when audio signal is strong - and to have 0% opacity when it's quiet/silent.

A simple task, but one of those moments where I've been scratching my head long enough - it's time to ask!

Look forward to talking more in the community, thanks in advance!
Posts: 2
Joined: Sat Oct 06, 2018 12:48 pm

Re: Audio Reactive Image Opacity

Postby nettoyeur » Sat Jul 20, 2019 8:28 am

You can use an Analyze CHOP to get the RMS power of the audio signal, and use that to drive the opacity parameter on the Post page of a Level TOP.

simple example attached below- change the volume parameter on the Audio File In CHOP to test

Also see this (old but still very useful) tutorial about using references in TouchDesigner:
https://matthewragan.com/2014/06/01/und ... hdesigner/
which will teach you how to use the output of any node to control parameters of any other node
(3.84 KiB) Downloaded 32 times
Idzard Kwadijk | freelance TouchDesigner consultant | IdzArd.com
Checkout ChopChopChop.org - the TouchDesigner marketplace!
Posts: 1151
Joined: Mon Oct 15, 2012 12:00 pm
Location: Amsterdam, The Netherlands

Re: Audio Reactive Image Opacity

Postby chromasy » Sat Aug 03, 2019 12:41 pm

Thank you for the response and example file!
The tutorial was super helpful also.

I managed to achieve the look I was after, by adjusting the Multiply and Post parameters.

Thanks again!
Posts: 2
Joined: Sat Oct 06, 2018 12:48 pm

Return to Beginners

Who is online

Users browsing this forum: No registered users and 17 guests