Distorted Glow Tutorial

This is one of those effects you won’t be using very often (if ever), but it’s use­ful to learn more about the com­pos­i­tor and open to new ideas. This tuto­r­i­al is based on 2.68 and uses Cycles (but can also work with BI).

The Setup

Delete that wimpy default cube and add a Monkey to the scene. Rotate it so it’s fac­ing the cam­era, then rotate on the X axis so it’s look­ing slight­ly down­wards. The lat­ter is a mat­ter of style, you can do what­ev­er you want. Now, we need dark­ness to appre­ci­ate light so go to the prop­er­ties pan­el and set the world back­ground col­or to pure black.

Select Suzanne and give her a default dif­fuse mate­r­i­al. Now go into edit mode, select the faces that make her pupils, add a new emis­sion mate­r­i­al and click the assign but­ton. Set the emis­sion mate­r­i­al to a large strength (I used 200) and an orange-ish col­or (#E74800). Don’t for­get to check the Render Layers pan­el and enable the Emission pass.

We’ll add a sim­ple light set­up to make more of our mon­key vis­i­ble, this is also a style choice and you can skip this if you want. Grab the default lamp and light Suzanne’s face from below. We want a very dif­fuse and sub­tle light to fill in the shad­ows, so let’s set the size to some­thing big like 8.0. Play with the strength of the emis­sion node, I left mine at 50.0.

Add a new light and put it behind Suzie. This will be our rim light and will help our char­ac­ter pop from the back­ground. Set the size to 2.0 (still sub­tle), and a strength of 150. To add some vari­ety we’ll change the light col­or to the com­pli­men­ta­ry of our  glow’s col­or. And since our glow will be orange-yel­low, our rim light will be a sub­tle green-cyan (#E7FFF1).

Here’s our ren­der before compositing

Base Glow

The com­pos­i­tor is where all the mag­ic hap­pens, so make space for a nodes edi­tor and acti­vate the “Use nodes” option. Add a Glare node, set the type to Fog Glow and the qual­i­ty to High. Increase the size to 9 and set a low thresh­old (I used 0.0). Add a Viewer Node, and plug both the Viewer and Composite nodes into a Reroute Node (This is in Add > Layout > Reroute). Plug the out­put of the Glare node into the Reroute.

Distorted Glow

Add anoth­er Glare node, but this time plug the emit pass into it. Set the type to Streaks and the qual­i­ty to high. Increase iter­a­tions to 5, low­er thresh­old to 0.0 and set the streaks to 2 so the glow goes side­ways. The Fade slid­er will con­trol how long the streaks are, I used 0.98.

We don’t want the pupils along with our glow, because we would be dis­tort­ing them too. Add a Mix node, set the mode to Subtract and plug the emit pass and the out­put of the glare node into it. Make sure the Factor is set to 1.0.

Plug the out­put of the mix node into a Displace node (Add > Distort > Displace). The dis­place node can use an image or tex­ture to dis­place an image, so we’ll add a Texture node (Input > Texture). Click on the tex­ture but­ton in the nodes pan­el and add a new tex­ture. Plug a clouds node into the out­put. Set it to Improved Perlin and Hard, then set the size to 0.5 and Depth to 24. Now give it a name and hop back to the com­pos­i­tor. Plug the out­put of the tex­ture node into the dis­place node Vector input and increase the scales to 150.0 (or some­thing big like that). You might want to add anoth­er Viewer node to check the result of our set­up as we go along.

Let’s make our glow curve (since we are look­ing down). Add two more Displace and Texture nodes. Create a new tex­ture and use a Blend node, set it to Spherical and leave every­thing as it is. The cir­cu­lar tex­ture will make the glow buldge up, since we want it to go down we’ll use neg­a­tive scales in the Displace node. I used ‑100 and ‑250.

Now, we got the glow going but chances are the dis­place nodes also moved it from where it was. Let’s add a Translate node ( Distort > Translate ) to move our effect. Just play with the slid­ers until it’s cen­tered on Suzanne’s eyes, and a bit down (remem­ber she’s look­ing down). In my case I had to use 25 on the X axis and 140 in the Y axis. Up Next: more glowy-ness. Add a Blur node, set it to Fast Gaussian (because wait­ing sucks) and set the scale to 50 on both slid­ers. Add a new Mix node, plug the out­put of both the Blur node and Translate. You can use the Factor to con­trol the strength of the blur (I used 0.6).

We can final­ly mix our effect with the rest of the image. Add one more Mix node, set it to Add and plug the out­put from our first Glare node and our the out­put of the pre­vi­ous Mix node.

Return of the pupils

We’ll add our pupils back. This is anoth­er a style choice, but I think it looks kind of lack­ing oth­er­wise. Add a Hue-Saturation-Value node and increase the val­ue to 2.0, plug into a Mix node and set it to Add. Don’t for­get to con­nect our pre­vi­ous result and the out­put into the reroute node!

Take it further

This con­cludes the dis­tort­ed glow tuto­r­i­al. But think of the pos­si­bil­i­ties! You could try ani­mat­ing the glow, add hue-sat­u­ra­tion-val­ue nodes to give slight­ly dif­fer­ent tones to the glows or try dif­fer­ent inputs for the dis­place node. You could also add more dis­place nodes to cre­ate small­er details in the dis­tor­tion (and ani­mate those as well). If you have any cool ideas, share them in the comments.