Edit property of opacity without mouse

[Roei Tzoref]

Ctrl+Alt+ minus or plus keys. add shift to move in X10 Increments.
also Ctrl+shift+o will open the opacity dialog

it’s all here: https://helpx.adobe.com/after-effects/using/keyboard-shortcuts-reference.html

Roei Tzoref
After Effects Artist & Instructor
♫ Ae Blues Tutorials

[Remus Hosu]

For the opacity you can use an expression that fades in and/or out. The expression still work if you trim or extend the layer. It fades in and out over the duration of 10 frames. You can just copy paste the expression to other layers then. Here’s the expression:

fadeInTime = .5; // time (seconds)
fadeOutTime = .5;

Math.min(linear(time,inPoint,inPoint + fadeInTime,0,100),linear(time,outPoint – fadeOutTime,outPoint,100,0))

If you’re not sure how to use it or nor really familiar with expression, here’s a more detailed take on this expression:

https://bluefx.net/how-to-add-opacity-to-layers-footage-after-effects

https://bluefx.net

[Steve Bentley]

You can also stick a slider in the effects tab and link it to the attribute with the whip tool (look ma, no code to write!)
You are still using the mouse but you don’t have to enter values and you can set the resolution of the slider so when you drag it can be very very fine grained unlike the clicking and draggin on the actual attribute value.

You didn’t mention why you wanted to do things this way – that might help us help

[Michael Müller]

I’d also like to be able to do that. sure for some things you need a mouse but shortcuts are there for a good reason! They make the time you need for getting things done, wait for it… SHORTER! I mean why are we using tons of shortcuts when we can click on all the frickin buttons in the user interface!? Computers use mice, don’t they?? It would make roto-ing values much much easier if you could just switch between the value edit mode and the frame with page up/down.

This would be a great feature to add. I have not found a shortcut yet.

[Steve Bentley]

I think what the OP is after is the paradigm used in Pshop – you can just bash the number keypad and change the opacity of layer without any mouse interaction.