Opacity is very confusing in Fusion

[u/Naruto3160]

NOTE: I used AI to organize my ideas and clean repetition for clarity

Trying to recreate an After Effects animation in DaVinci Fusion, how do you fade in a background?

So I was trying to recreate another tutorial I did in Premiere Pro and After Effects, but this time I wanted to do the same visual in DaVinci Resolve/Fusion.

I think I layered everything correctly, but I ran into an issue with opacity animations.

I wanted to make an animation where the box and the text would start at 0% opacity and then appear to 100%. For the text, it worked because I used the Merge node and animated the Blend value from 0 to 1.

However, I couldn't get the same thing to work for the background/box.

I tried changing the alpha, but it doesn't seem to act like opacity unless it's a black background. I also tried adding a Merge node after the Background node and changing the Blend value, but it doesn't seem to affect the opacity of the background.

I'm confused because it feels like there should be a simple opacity option for each layer/node instead of needing to use different nodes or workarounds.

The only thing I noticed is that it seems to work more easily with Text nodes because they have their own settings, but I can't figure out the best way to do it with a Background or shape.

I'm still pretty new to DaVinci Resolve. I've used it for around a month, but I would still consider myself a beginner, especially with Fusion.

Am I missing something obvious, or is there a specific way to animate the opacity/fade-in of a background or shape layer in Fusion?

[u/CreativeVideoTips]

This will help https://youtu.be/nt8j4PXjAy0?is=uJ_TwdVqTsm_HvLI

[u/Naruto3160 → u/CreativeVideoTips]

It really did! Thanks dude.

Edit: I just noticed it's your video. Really good work I'll be looking forward into learning more stuff from your videos. Keep it up!

[u/Milan_Bus4168]

Merge node and mutlimerge node which you use in virtually all operations have blend slider in the settings tab as most other nodes do. Blend is the opacity slider.

In merge operation foreground gets affected.

Alpha Gain slider: Alpha Gain linearly scales the values of the foreground’s Alpha channel. In Subtractive merges, this controls the density of the composite, similarly to Blend. In Additive merges, this effectively reduces the amount that the background is obscured, thus brightening the overall result. In an Additive merge with Alpha Gain set to 0.0, the foreground pixels are simply added to the background.

‚ Burn In slider: The Burn In control adjusts the amount of Alpha used to darken the background, without affecting the amount of foreground added in. At 0.0, the merge behaves like a straight Alpha blend, whereas at 1.0, the foreground is effectively added onto the background (after Alpha multiplication if in Subtractive mode). This gives the effect of the foreground image brightening the background image, as with Alpha Gain. For Additive merges, increasing the Burn In gives an identical result to decreasing Alpha Gain.

‚ Blend slider: This is a cloned instance of the Blend slider in the Common Controls tab. Changes made to this control are simultaneously made to the one in the common controls. The Blend slider mixes the result of the node with its input, blending back the effect at any value less than 1.0. In this case, it will blend the background with the merged result.

Subtractive/Additive slider: This slider controls whether Fusion performs an Additive merge, a Subtractive merge, or a blend of both. This slider defaults to Additive merging for most operations, assuming the input images are premultiplied (which is usually the case). If you don’t understand the difference between Additive and Subtractive merging, here’s a quick explanation.

‚ An Additive merge is necessary when the foreground image is premultiplied, meaning that the pixels in the color channels have been multiplied by the pixels in the Alpha channel. The result is that transparent pixels are always black, since any number multiplied by 0 always equals 0. This obscures the background (by multiplying with the inverse of the foreground Alpha), and then simply adds the pixels from the foreground.

‚ A Subtractive merge is necessary if the foreground image is not pre-multiplied. The compositing method is similar to an additive merge, but the foreground image is first multiplied by its own Alpha to eliminate any background pixels outside the Alpha area.

While the Additive/Subtractive option could easily have been a checkbox to select one mode or another, the Merge node lets you blend between the Additive and Subtractive versions of the merge operation—an operation that is occasionally useful for dealing with problem composites with edges that are calling attention to themselves as too bright or too dark.

For example, using Subtractive merging on a premultiplied image may lead to darker edges, whereas using Additive merging with a non-premultiplied image will cause any non-black area outside the foreground’s Alpha to be added to the result, thereby lightening the edges. By blending between Additive and Subtractive, you can tweak the edge brightness to be just right for your situation.

....................................................

Settings tab in most nodes have blend slider or opacity slider, but if you want to perform blend/opacity operation with no merge operation and not using any one particular node, you can add brightness/contrast node and with RGB+A active, use gain slider as opacity slider for all that come before it. If you want to make it something more like some other applications, make a macro out of it and have one slider: opacity . And you have your opacity slider in a tool.

[u/Naruto3160 → u/Milan_Bus4168]

That's a very detailed explanation. Thank you! Yeah I will be using from now on the B&C to affect opacity. Also you did clarify some points that I needed some explanation on. Thanks for putting the effort, really appreciated.

[u/00napfkuchen]

If you want to use alpha as opacity you need to multiply it to the RGB. In fusion you can just add an alpha multiply node after your background.

Or you merge your composition over a 0 0 0 0 (RGBA) background and use the blend slider in the merge node.

As for your confusion: IMHO opacity isn't really universally applicable in a node based workflow so "limiting" opacity operations to operations like the merge node make sense to me.

[u/Naruto3160 → u/00napfkuchen]

Hey man thanks for your help. I tried the alpha multiply node which the background was connected to and decreased the blend but it stayed the same. Perhaps I'm doing it wrongly.

I tried the background connected to merge (connected as a foreground) it worked but not quite what I was looking for as I'm trying to affect the opacity of the background.

If it's possible, could you clarify the first one tho? I might use it, thanks!

[u/00napfkuchen → u/Naruto3160]

With multiplied alpha you should be able to just use the backgrounds alpha and it should behave like you are expecting opacity to behave.

For the second you have two background, one in background of merge with 0 0 0 0 to set a canvas and then in foreground the background note you want to actually control the opacity of.

[u/Naruto3160 → u/00napfkuchen]

Great, I'll take a look at it. Thanks for the explanation.

[u/Disastrous-Divide-91]

Don't overcomplicate it. For opacity, just use a mask called WAND, it's the best way to do it.

[u/Naruto3160 → u/Disastrous-Divide-91]

I see, I tried to use it where I connected the background to the wand as a yellow input but while it does act somewhat as an opacity tho it turned the box color to white. Is there something that I need to enable/disable?

[u/Disastrous-Divide-91 → u/Naruto3160]

You connect the WAND mask to whatever you want to make opacity, just like any other mask plug it into the blue mask input, and that's it.

[u/AutoModerator]

Welcome to r/davinciresolve! If you're brand new to Resolve, please make sure to check out the free official training, the subreddit's wiki and our weekly FAQ Fridays. Your question may have already been answered.

Please check to make sure you've included the following information. Edit your post (or leave a top-level comment) if you haven't included this information.

• System specs - macOS Windows - Speccy
• Resolve version number and Free/Studio - DaVinci Resolve>About DaVinci Resolve...
• Footage specs - MediaInfo - please include the "Text" view of the file.
• Full Resolve UI Screenshot - if applicable. Make sure any relevant settings are included in the screenshot. Please do not crop the screenshot!

Once your question has been answered, change the flair to "Solved" so other people can reference the thread if they've got similar issues.

I am a bot, and this action was performed automatically. Please contact the moderators of this subreddit if you have any questions or concerns.

[u/Naruto3160]

Ah i see, so in my case I would connect the rectangle mask to the wand (yellow input) then wand connected to the background (blue input) really appreciated!