Technical Slop

Table of
Contents

Displace
Considerations
Solid
Channels
Circle Grads
Gradients
PSD
Curve It
Tweakables
Scans
Broken China
Bulge
Math 1
Math 2
Heat Waves
Reflection Maps
Power Distort

Other
Cannify
Extrude
Whispies
AMP
Brush Making
Picking Colours
13 Revisited
Levels
Pixel Shuffle
UVW 2
Pui Pui
Light Rig

E-Mail

Heat Waves

This is a variation on Mahjqa's Fire, Fire II, and Fire III. I highly recommend reading it and playing with it. Not only is it a fun technique, but it will help you understand the ground work that goes into Heat Waves. Thank you, Mahlqa.

This is about simulating heat wave distortion. Sounds like fun, doesn't it? Heat wave distortion is the waviness you see just over the top of a hot object, like a car engine that has been running for hours on a hot summer day. The hot air rises and causes the light to be distorted as it passes through. The lower air pressure in the hot air has an index of refraction (IOR). Hence, photons get moved around while passing through. Unfortunately, I don't know what the IOR is for various conditions. Fortunately, this can be faked anyways with Mahlqa fire technique to build an animated D-Map.

I think I'm getting goose bumps.

.

Let's start with a subject. I know, how about Biker Chic? Let's make some heat rise off of her and distort the background. After all, she's one hot Biker Chic.

Dimensions are arbitrary.

Okay, first thing is a "mask". For this, I used some Quick Mask and the Airbrush. Not the greatest mask, but it will do. Later, this will be used as a mask over the pattern and set to Colour Burn.

This is was painted in the same doc as Biker Chic. Then I cut and pasted it into a new doc. This new doc has the same dimensions as Biker Chic and will eventually become the D-Map.

Time to build the D-Map.

Start a new document. This one has dimensions of 256x256 so that Clouds/Difference Clouds will be tilable. It's a neat trick.

Make sure that the Default colours of black and white are on. Hit 'd' just to make sure.

In the Red channel, run Clouds followed by any number of Difference Clouds to taste.

In the Green channel, do the same thing.

Just to smooth things out, I also used a Gauss of 3.

Normally, I like the Blue channel filled with 50% grey, but I made an exception in this case for visual reasons. Have Black in the Blue makes this easier to see.

So, why have different cloud patterns in the seperate R and G channels? Well, if the channels are the same, then the D-Map Grabitude is limited to a diagonal line defined in the Displace dialog. See: Channels. However, the IOR in a heat wave grabs from all over the place. You don't have to do them seperately since the fakery will largly go unnoticed, but I like seperate channel work.

Got a good, tilable pattern? Good. Drag-n-drop it into the doc with the mask. It will be a different size, so Edit > Tranform > Free Tranform (ctrl + t) and make it fit. Don't worry, it will still be tilable.

Now the pattern needs some room to move. Grab the Move tool (m), and move it up some. Copy it. Grab the copy of the pattern and move it down until the top of the copy meets the bottom of the original pattern. Then merge it down (ctrl + e). On the merged pattern, move it down until the top meets the top of the canvas. You should now have a pattern that repeats twice with half of it off of the bottom of the canvas.

Put the pattern underneath the mask. Set the mask to Colour Burn. Almost there. Just a few things to clean up.

Now, all that Black has got to go. However, the integrity of the Clouds/Difference Clouds has to be mantained. Kind of a pain in the ass.

On top of it all, add a Curves Adjustment Layer and do it like so.

What I did was enter Arbrary mode, the little pencil in the Curves dialog. The I dragged just a tad on the left at the 128 mark. Then I went back to Smooth mode, the little curve icon thingy next to the pencil. After that, tweaked the points a bit.

On the left, make sure that the point is Input/Output : 0/128. If it's not at 0/128, then the whole target pic will shift, and that's bad.

With all of the bits and pieces in place, the Layers palette looks something like this.

And this is what the composite looks like. Just for fun, grab the 'messy colours' with the Move tool and move it around.

Exciting, isn't it? Yeap, I've got goose bumps.

Okay, the height on both documents is 218 pixels. I want 8 frames, so divide 218 by 9 and get 24. Divided by 9 because the last frame will be the same as the first and have to be deleted leaving 8 unique frames. Tada.

So, save the D-Map as is. Go to Biker Chic, copy, and Displace. Back to the D-Map, nudge the pattern up 24 pixels, and save. Back to Biker Chic, copy, and Displace. Et cetera until done. Gotta nudge the pattern in the D-Map with the cursor keys because Offset won't work - it just won't.

.All that nudging, saving and stuff. Sounds like a job for an Action. Personally, I keep a Temp Junk folder in my Action palette for just such an occassion.

Okay, only the D-Map and Biker Chic documents are the only documents in PhotoShop. Start with the D-Map active. Then, Start recording.

On the pattern layer, nudge it up 24 pixels, which reads as -24. Save it.

Select the Biker Chic document. Select the bottom layer, mine is "Layer 1", duplicate/copy it, bring the copy to the front (Layer > Arrange > Bring to Front), Displace it, and select the bottom layer, "Layer 1".

Tada! One throw away Action all set and ready to do my grunt work.

When I was recording the Action, I ran into a problem with the Bring to Front command. Because Biker Chic only had one layer, and, when I copied it, it was already in the front. That means I had to toss in a junk layer to bring the copy in front of. Once it's recorded, toss the junk layer and call your girlfriend in from the kitchen to tell her about your cleverness. Of course, Bring to Front doesn't have to be used, but that's how I like it. Personal preference that taught me something that I didn't know about.

.Action recorded? Good. Now use it as many times as needed. From ground zero, I thought I would have to run the action a mere 8 times. Something messed up somewhere and I had to run it 10 times. I have no idea what went wrong, but it did.

Save out Biker Chic as a PSD and head on over to Image Ready (IR). Time to get busy again.

On the first frame, only one frame on.

Add a frame. Turn a layer on. If you are like me, turn the previous layer off.

Add a frame. Turn a layer on.

Add a frame. Turn a layer on.

Until you are done. You *might* be able to record an Action for this, but I haven't tried. I'm only doing 10 frames, so it's no big deal. Still, I might try it someday just to know.

Add any final touches and save out the animated GIF. Wouldn't be a bad idea to save out the PSD with a different version numuber, either.

For a reason or two, I had to take it easy on the file size. This final GIF is a mere 16 colours.

Looks pretty crappy, don't it? Well, it looks better with more frames and more colours, but the file size sky rockets.

That aside, I should have used smaller numbers in the Displace step. Perhaps 5% / 5%. Maybe even slow down a bit more.

Well, that was fun.

play.fiddle.learn