Technical Slop

Cannify Basic

A very long time ago, I was new to Adobe Photoshop. Hours and hours getting to know it. I remember very clearly, one fine spring day, setting a goal for myself. That goal was to be able to use Displace to warp a texture to a cylinder. After several years, it finally happened. Long road.

But... I'm going to show how to accomplish wrapping a texture to a cylinder using Shear and Spherize as the main tools. It's some what quick, and it works fairly well.

This is our subject. I don't know who he is, but I'm going to cannify him in the name of edification regardless of identity. Isn't that nice of me?

Since Shear works horizontally and I want to cannify him vertically, we'll have to Rotate Canvas 90° -- in this case 90° CW.

Not only rotated, but four guides have been placed that mark the boundaries of what is to be cannified.

Using those guides, we'll need two Alpha channels.

Alpha 1 is like so. The white on the left and right is to give us some room to play with.

And we have Alpha 2 like so. We'll be using this later for clean-up. Operating in tandem has benefits.

Now that the prep-work is done, time to get busy bending and shaping.

Go to the texture/picture Layer, load Alpha 1, and run Filter > Distort > Shear.

(Since we are using Alpha channels, I turned the guides off.)

Looks pretty good, but don't celebrate yet.

Keep Alpha 1 loaded and run Filter > Distort > Spherize.

Okay, there are two major things to notice here.

1.) The Mode is Vertical only. Look at the bottom of the Sherize dialog for the pull-down menu.

2.) Shear then Spherize. Yes, the order is important. Hmm... I'll try and expound on this later. For now, try flipping the order around and see what happens.

Oh, now that looks good.

So, how do we go about cleaning it up?

Well... remember Alpha 2?

Go to Alpha 2, make sure Alpha 1 is loaded as a selection, then Shear and Spherize. The settings for both filter should still be fresh in PS's memory, so use them.

Right. Time to Rotate Canvas 90° CCW and finish it up.

The rest is basically basic operations.

Load Alpha 2, Invert Selection, Delete.

For most applications, that's nearly it. All that's really left is Blending mode, Free Transform, extra layers for highlights/shadows, whatever. As an added bonus, I went ahead and did some extra Alpha operations for the top of the can.

Well, that was fun. Now, if you know your way around, you should be able to come up with a short-cut or two in the above. Around 2 weeks after I wrote it, I realized that some of the Alpha work wasn't exactly necessary. Live and learn.

Ready to move on and see what happens when we use some Displace? You knew I was going to do this with Displace, didn't you?