Creating a mask in After Effects.

[cg_Butler]

Morning all.

 

I'm used to using Fusion for comping but am trying to use after effects as i don't have Fusion at my new workplace.

 

I want to desaturate a certain material in after effects and would like to create a mask/selection using the VRay wire colour channel I have rendered out. Before people start suggesting or asking why i didn't save out an object id or material id or multimatte elements, I didn't have time to setup everything and i ca'nt re-render as i don't have time either!

 

So, using my limited knowledge i have tried to do what i want but as i'm still new to aftereffects and how it works (regarding layers etc) i'm getting rather confused.

 

I tried to follow this previous thread but as it's closed i couldn't ask directly!

 

Here is what I have tried.

 

I've created a new comp and added an EXtractoR to get the wire color channel. Then I added a Color Key to choose the color i want to create a mask from and then i added a Hue/Saturation to in crease the contrast if it to make it black and white.

 

So, I'm happy with this as a mask......but how can i use this to mask out a Hue/Saturation on my main comp? I'm very confused!

 

If this doesn't make sense please let me know and I will elaborate!

[cg_Butler]

Hmmmm. Perhaps it's something to do with using after effects and the wire colour elements to create a mask but I too, Like Crazy Homeless Guy did, have solved the problem myself with perseverance and trial and error!

 

So I just popped my mask precomp as a layer on the top of my other comp, ticked the adjustment layer box, added a Hue/Saturation and voila, problem solved.