Volumetric Lighting

We tackled another interesting/large endeavour in class today while learning about volumetric light. According to Wikipedia:

Volumetric lighting is a technique used in 3D computer graphics to add lighting effects to a rendered scene. It allows the viewer to see beams of light shining through the environment; seeing sunbeams streaming through an open window is an example of volumetric lighting, also known as crepuscular rays.

We set about by creating a new composition and reminded by Peter to try and name our layers/compositions for a better work flow. The clip would be 10 seconds long at 25fps set to 720p. We also had to make sure that we were working with the Classic 3D renderer, rather than the Ray-Traced 3D renderer.

First, we needed the logo we were going to work with – it read Magnetic North and looked quite cool. Dragging it into the timeline, we needed to make it a 3D layer so we could manipulate it in 3D space, and then reposition it in the composition so it was in the middle of the screen.

After that, we were going to create a background and floor, using solid shapes. The grey solid that would become our floor had to be a 3D layer as well, because we needed to transform it on its X axis and move it to underneath to logo (where we thought the shadows would be thrown under the logo if it were on a floor). The black solid that would be the background didn’t need to be 3D and would be the base layer of the composition. In the end, the logo not looked like this:


As we tread into new territory about lighting and shadows in After Effects, we needed to tell the logo to work with shadows and lights: we could do this by going to the Material Options and turning the options on or pressing A twice on the keyboard as the shortcut. From there, we needed to turn cast shadows, accept shadows, and accept lights to ON.


After that, we were going to add our first light. In this case, it was going to be a Point Light and we’d leave the colour as white. The most important thing we needed to do, when adding the light, was check the box so the light would Cast Shadows.


We just needed to move the light so it sat behind the logo (so on the Z axis in 3D space) until the logo started casting shadows. We could then add a spotlight at the front of the logo, but this time turn the Cast Shadows tick box option to off. This screencap was taken after some steps further down (where we added a white solid), but I thought it showed the effect of the lighting better than not having it.


Under the point light in the timeline, in its Light Options, we then had to change the shadow diffusion so the shadows would nicely feather, causing less harsh beams. After that, it was time to add a camera – we’ve done this in the past, so it wasn’t an unfamiliar process. It had to have a preset of 28mm as a one-node camera, while the Depth of Field needed to be enabled. Peter then said we had the option to use the Unified Camera Tool, which allows you to move the scene around in 3D space, so you could see more than if you were just looking at the scene straight-on.


As I’d shown/mentioned above, at this point we were going to add a white solid to put between the back light and the logo. Using the elipse tool, we could make it whatever shape we wanted (I just went with a circle); once again, it had to be a 3D layer, so we could move it across the Z-axis. Opening the material options for this, we wanted to make sure Accepts Lights was off for the layer.

Using Nulls as we have in many past projects, I created a Null Object that would be used as a Volume Control at a later point in the process. Finally, to achieve the result in the screencap below, I added an adjustment layer and a Radial Fast Blur, set to about 70. I thought it already looked even better than the plain logo we were given, but there was still more to do!


Under the new blur effect, we Alt-Clicked on the clock next to the Centre, then needed to pick whip to the Null layer. Before clicking off, Peter showed us a new code to add to the end of that line:


Moving the Null way, way, way back behind the light source (on the Z axis to about 3000), the goal was to see that the Null didn’t jitter much when the camera panned around. This caused less of an obvious blur and the reason to name the Null “Volume Control” made more sense.


While we’ve been shown colour correction in the past, I didn’t really utilise it that much. In this composition, we were going to use the effect to manipulate the progression of the colouring in the logo via the blurs. We were going to need two colour corrections: one before the blur on the adjustment layer and one after it.

On the one above the Radial Fast Blur, we needed to pull the line for the RGB channel so the left corner point was at about the middle of the grid. On the second one, place below the blur, we were going to manipulate each colour channel. The two graphs ended up looking like this:

I then changed the adjustment layer to screen mode and we moved on to add something like a smokey effect for behind the logo. Starting with a white solid, we added a Fractal Noise effect and changed the type (in the effect properties) from basic to dynamic. In the sub-settings, we had to change the rotation to about 200 and up the contrast to make it look more black/bleachy (set at about 220).

The look reminded me of something you’d see in a sci-fi film, which was really a neat effect. We then added an elipse mask shape and the feathered it out in the mask settings. Finally, to get rid of the milky white outer edging, we needed to fiddle with an effect simply called Channel; by going to Effect > Channel > Solid Composite and changing the colour to black, it softened the look of the outside edging.


Back in the settings for the Fractal Noise effect, I changed the blending mode to None and Alt-Clicked on the clock next to Evolution: this was going to animate the look of the noise, when I deleted the existing line and added the code “time * 175”.

Using a bit more of the colour correction curves effect, to add more blue/grey to the noise, we then needed to change the layer’s mode to Add before moving the layer below the logo in the timeline. It also had to be altered on the Z axis to place it in front of the colour correction light.

Meanwhile, after all this, we were running a bit low on class time so we didn’t quite finish the final look. On the logo layer, we added a Bevel Alpha effect and duplicated the layer, then set that duplicate slightly behind the first logo to add some depth. I managed to get a little more done before we all packed up for the day, which Peter just started to show us. I duplicated the back logo again, then added the CC Ball Action effect – I then changed the Scatter to its highest at 1024 and keyed it, before keying it to 0 at the end of the 10 second composition.

I think the end result looked awesome! Perhaps it’s not quite finished the way we’d set out to do it, but I still think the things we learn will come in handy for future projects. I always love learning about how to manipulate the different effects in After Effects and the CC Ball Action one might be a new favourite.


Posted in VFX

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