Technical Slop

Gradients

Ah... gradients specifically. This is where things start to get to be real fun.

Again, Biker Chic! I just love her. Her current dimensions are 256 x 256. For this particular chat, her dimensions are for convenience.

This is our D-Map. Fairly simple and still Greyscale (one channel).

We will be doing vertical only with this and Stretch to Fit.

Let's run it with 0% / 50% and see what happens.

(Slight re-size on the result.)

Her face got stretched! That's right, buddy. How the? Glad you asked.

The White at the top of the D-Map grabbed from 64px down and brought thos values onto itself. The Black in the D-Map grabbed from 64px above. Everything inbetween is inbetween. The Grey didn't grab from anywhere at all except on itself. Remember: Grey in the D-Map is neutral and stays the same.

Using the same D-Map, this is what happens with a vertical percentage of -50% and Wrap Around.

The White along the top of the D-Map is told to grab in a vertical, negative direction, ie from above. Since it's the top of the picture, it wraps around the bottom and grabs from there.

Same thing with the Black along the bottom of the D-Map. It wants to grab from below, but gets wrapped around to the top.

That's all well and good. Now let's play with the horizontal values. For this given D-Map, playing with horizontal will skew.

There you go. Two examples and they got skewed. See those yellow lines? They should be straight, but they are slightly bent. I can't figure out why they are getting bent like that. I tried quite a few examples, and they all came out like this. If the lines weren't there, you probably wouldn't even notice. Hmmm...

Addendum: A little wiser, I know why those yellow lines are bending. When I laid down the gradients in the D-Map, Smoothness was set to 100%. Smoothness set to 100% is bad, as you can see. Should be set to 0%. See: Considerations.

Anyways, back on track.

Okay. So with this D-Map, you can squish (expand/contract) in one direction. You can also skew. But again, in case you didn't notice, only one non-zero value was used in the above examples. Try some mixing it up. Skew and squish.

Here is a bender for ya. If you Invert the D-Map, all of the above example will be backwards. Try it. I highly recommend it. Please, don't underestimate Inverting the D-Map for edification. The light just might go one.

That D-Map was fun. Let's play with a different, yet similiar, D-Map.