After Effects - Natural Lighting VFX Using Mattes

User avatarDecember 16, 2011 by Surfaced Studio

Creating A Lighting Matte For The Fire

The biggest problem with the above approach is that the shine of the light does not interact in any way with our base footage and thus appears to be stuck on top of it. One way to improve this would be to create many small masks on the FireShine layer to light up highlighted areas like face, arms, fingers, table and other elements that would be affected in real life by a light source at that position. However, there is a much simpler way: using a matte layer for the light.

A matte is a layer that is used to define the transparency of the layer directly below it. By creating a matte based on our footage and applying it to the shine of the fire, we can tie the lighting effect and the footage together organically

Duplicate the 'Footage Comp' layer and place the copy above our FireShine layer. Rename the layer to 'Light Matte'.

Notice that the new layer will hide the FireShine layer, but that is ok - we just want to be able to see the Light Matte while we make adjustments. Once we are happy with our matte, we will hide it and apply it to the FireShine layer.

After Effects Lighting Tutorial 04 - Matte Setup

We want to use the brightness of the footage to define how strongly the light shine will affect it. Bright areas will receive a lot of shine, dark areas will receive very little. Now I know that this is not how it works in reality, but we just want to blend the FireShine layer more organically into our footage. Additionally, keeping the dark areas dark will retain shadows and thus enhance the feeling of a real light source being present in the scene.

Now let's get to adjusting our matte so we can use it

Apply a hue/saturation effect to the Light Matte and fully desaturate the image. Now, add a brightness/contrast effect and increase brightness and contrast to bring out the bright and dark areas of the footage. Since the footage is a little grainy and fire glow is usually fairly soft, I have also added a fast blur effect to the matte to smoothen it all out a little bit. These are the effects on the Light Matte layer:

After Effects Lighting Tutorial - Matte Layer Effects

Your Light Matte (with the FireComp layer still visible on top of it) should now look so something like this:

After Effects Lighting Tutorial 04 - Light Matte

Now all that is left to do is to apply our Light Matte to the FireShine layer!

To do this, turn off the visibility of the Light Matte layer. Select your FireShine layer and set the track matte from None to Luma. 'Luma' means brightness and indicates that the alpha for our FireShine layer will be taken from the brightness of the layer directly above it, which is our Light Matte layer.

So wherever our Light Matte layer is black, the transparency of the FireShine layer will be 0%. Wherever the Light Matte is white, the FireShine layer will be fully opaque. Gray levels specify different levels of semi-transparency

You can quickly check how our FireShine layer looks now by settings its blending mode back to 'Normal'. I also turned off the FireComp layer to show only the FireShine affected by the Light Matte:

After Effects Lighting Tutorial 05 - Light Matte Solo

Now, this more sophisticated FireShine layer can be applied to our scene by setting its blending mode to 'additive'! The final scene looks like this:

After Effects Lighting Tutorial 05 - Light Matte Applied
After Effects Lighting Tutorial 05 - Matte Applied To Lighting

Voila, the candle light suddenly sits a lot more organically on your footage as the affected areas are literally defined by the footage While this may not be the most realistic way, it is fast and easy to do and does look a whole lot better than simply 'adding' a light layer over your shot!

Happy lighting!

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7 Comments

User avatar
Gideon
5 Years Ago
January 3, 2014 @ 8:47 pm

How to create lighting effect in dim light or in night time for muzzle flashes ??

User avatar
5 Years Ago
January 3, 2014 @ 17:40 am

You can use this technique no matter what the lighting situation is. You may just have to adjust the brightness of your lighting layer and the details of the masks.

User avatar
Inhaledcloud0
5 Years Ago
May 6, 2014 @ 6:56 pm

Can you please make a video tutorial on this? Pweeeasssee?

User avatar
Surfaced Studio@ Inhaledcloud0
5 Years Ago
May 6, 2014 @ 13:22 am

I am using this very technique in my Muzzle flash and Explosion tutorials so go check those out!

User avatar
joel
5 Years Ago
September 29, 2014 @ 8:19 pm

how did u made fire sparks at first plz give me the websute

User avatar
John
4 Years Ago
April 9, 2015 @ 19:40 am

Nice tutorial but is there away we can download your video so we can practice on after effect just like videocopilot

User avatar
4 Years Ago
April 25, 2015 @ 18:02 am

Hi, thank you! All my videos are available for free on YouTube, I don't have them as downloads per-se anywhere

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