VFX – Volumetric Lighting

This week in VFX we tackled looking at volumetric lighting. This is a lighting technique used in rendering which allows the viewer to see the light in the environment, the best example would be light beams shining through clouds or a window.

As usual with my VFX posts this will be a blow by blow description so I have reference in the future. As always apologies if it’s a little dry.

So new composition, 720p, 25fps and 10 seconds long. However as a first we were instructed to name the first composition to start aiding good habits. AE’s renderer was to be set to Classic3D as well.

First of all we needed to import the artwork that would be used as the ‘hero’ object in the scene (a term I’ve now picked up from Peter and will continue to use). The artwork/logo reads magnetic north and like most of our assets for these exercises, was vector. It was dragged onto the timeline , 3D layer turned on, pushed back in the Z axis and positioned centrally.

To be able to cast shadows later on the scene would need a floor and a background. A grey solid was used as the floor and a black solid was used as a background to the scene and set as the lowest layer on the stack.

capture

Here is something important to remember for the future. We need to tell our 3D object to be affected by lights and cast shadows. If you hit aa on the keyboard on the selected layer it will open material properties. From here you can turn on accepts lights/shadows and cast shadows. As you can see from below we set everything to ON.

Now we needed a light, Layer > New > Light, light type set to point light and casts shadows check box ticked to on.

light1

This new light needed to be placed behind the logo so it was cast shadows towards the camera. So translate back in the Z axis. A second light was created to illuminate the front of the logo, this time a spot light that didn’t cast shadows. To get the image below there was one more step, within the light options for the point light we had to increase the value of the shadow diffusion to feather out the edge of the shadows to make it look more natural.

capture6

Now to create a camera rather than rely on the default viewport for the composition. The camera was a 1-node camera with a 28mm lens, and DOF enabled. Using the Unified Camera Tool we could now pan around the scene in 3D space and reset the camera to default position when required.

To begin our light effects we created a new white solid that would be placed behind the logo and used to mimic an intense light source. The ellipse mask tool was used to shape this new solid to size. Turn on 3D, push it back in the Z axis and in material properties turn off accepts lights.

A new Null was now created, made 3D and named volume control. We’d come back and use this later. An adjustment layer was created at the top of the stack and had a radial fast blur applied set to a strength of 70 and its blend mode set to brightest. This really lost detail in the logo but we’d fix this.

capture9

Under the radial blur effect we parented its Centre to the Null layer we created (Alt-click on centres clock and drag the parent tool). We added an expression to this as well.

pickwhip-code

The null was now offset behind the logo in the Z axis which gave us the beginnings of our volumetric lighting effect.

capture11

Two colour corrections were added above and below CC Radial Fast Blur. These were to help the colour of our fake lighting mimic the colours of the logo. The effect can already be seen above as the light has taken on a cooler blur hue.

The adjustment layer was then set to screen mode for full effect. We now moved onto creating an animated effect that would be used behind the logo but in front of the light source. We created another white solid and added a fractal noise effect to it, the effects type was changed from basic to dynamic and in its sub settings its rotation was changed to 200 and its contrast ramped up to around 220 to give its blacks a little more clarity.

comp1-6

I’ve used difference clouds in Photoshop before to create various effects and this seems to be exactly the same thing. An ellipse mask was added over this and feathered out in the mask settings. To soften the edges we used a new effect called ‘Solid Composite’ and changed its colour to black.

Returning to the settings for fractal noise the blending mode was changed to none and we added an expression. Alt clicking on its clock next to ‘Evolution’ we added time*175. This would animate the noise over time. The end result had a curves colour correction added and was tinted blue. The layer itself was changed to an Add blend mode and in the layer stack it was dropped below the logo.

As with most of these in depth exercises the three hours of class time was running short and we had to dash to get something resembling a finished product. The logo layer was bevelled, duplicated and the duplicate offset in Z axis slightly behind the original to add a little bit of depth and to crisp up the outline.

That was it for class instruction but for anyone that had reached this point in the class, Peter instructed to play with the effect CC Ball Action Effect to add further spit and polish to the end result. I added this to another duplicate of the logo layer and animated the effect to maximum scatter on frame 0 and minimum scatter at frame 240. I also did the same for the opacity and faded the effect out at the end.

volumelightfinal

The final result was a little dashed and not how Peter’s example looked, however it was an interesting exercise and these in depth composition tutorials are really pushing me to get the hang of After Effects. I’ve mentioned it before but week after week I feel myself getting more comfortable with the interface and manipulating assets and effects.

 

 

 

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