Curves across multiple textures

[Relayer91 2]

So, I'm getting to grips with making new liveries - currently mostly GA - and one of the problems that seems to be causing me a real headache is getting the angles correct when a curved shape (i.e like you see here - https://murmerair.com/wp-content/gallery/paint-schemes/pilatus-pc12-scheme-2.jpg ) runs across multiple parts of a texture sheet, or even an entirely different sheet. I can line up the two shapes (with a hefty dose of trial - error - shift it down by 3px etc) but whenever I try to make a new shape to continue a smooth bezier curve on another part of the sheet, I just can't quite seem to get the angles 'right'. 

Is there some tip / trick to getting this right, other than just 'git gud'?

It probably isn't helping that I'm using Carenado / Alabeo aircraft just now, as I've gathered their unwraps are pretty horrid to work with - but people like Ron seem to manage absolutely fine with them.

Edited June 30, 2020 by Relayer91

[Chock 17,769]

Let's imagine you have a jet airliner which uses three texture files along its length, of which (just to make the maths simple for this example), comprise three textures, each one being 1024 px wide. We'll ignore the height for this example.

So, first up, what you need to do is to create an image file which is 3x1024px wide, so that would be and image file which is 3072px wide of course. Then you do the complete repaint of the entire side of the aeroplane on that file. Now what you have to bear in mind here, is that depending on the aeroplane you are doing a repaint for, and how the texture projection has been applied, the three individual 1024px wide textures used on our hypothetical finished model could either butt up against one another, or they might overlap somewhat. Some models are textured one way, some the other way. So we'll cover both ways.

If they butt up against one another, this makes life easier, because all we have to do is create the livery in one go on our 3071px wide file, and then chop it into three to get our three 1024px texture files and the height of the files should mean everything aligns okay. If on the other hand you have three files which overlap somewhat, you will have to create some registration target marks to assist in aligning stuff (do a search for target marker for print and you will find one you can copy if you don't want to draw them yourself), then use those to help you align things.

So you might paint something like the image below, and simply cut it up into three equal sections, or you might cut it into three slightly wider segments which include the target markers, and then use a partially transparent layer in your paint program to help you align the target markers up over the ones which are visible on another layer. when everything is aligned, you can then resize the image file to the appropriate width and name the file the same as your required texture file.

The other tricky bit is using Bezier Curves if you are not used to them, but the trick here is to understand exactly how Bezier Curves work. So here is a little practice exercise to help you with that. When you understand this, you will be able to create any curve you like very accurately, so if you did want to create three individual Bezier Curves (not that this is the best way to go about it as we can see in the above example), then you will be able to do that accurately. So here goes (This is in Photoshop, but the technique is the same for other image programs).

First, create a blank image file with a white backdrop in your paint program. Then create a bright yellow circle:

Next, get your Pen Tool and click on all four cardinal points of the circle to create four anchor points, then click again on the first one you drew, to close the shape, creating a circular path:

Next, choose your Convert Point Tool, click on the top most point, hold the mouse button down and drag the top-most anchor point out horizontally (you can hold down Shift to keep it straight if you like), until it looks like this:

Now, do the same thing on the next point at the 3 o'clock position, but pull vertically this time (depending on which way you drew the circle, this will require you to either pull up, or down, if the line bows back on itself, try pulling the opposite way). Get it looking like this:

Repeat this for all other points and you should be able to create a perfect circle path which exactly matches the yellow one by fine tuning things. If you can create a perfect circle, then you can create any other curve easily enough. The point of this exercise is to note the following:

The two control points I have drawn red boxes around both affect the first section of the curve I've marked alongside in red. So the trick with getting Bezier Curves to go where you want them to go, is to understand that sometimes it is more than one anchor point which controls where the curve goes, and to create that perfect circle, you need TWO control points to be in the correct position for each of the four sections of the circle. Once you understand this, you will understand exactly how to create perfect Bezier Curves, exactly where you want them. 

Don't get frustrated if you are not instantly brilliant at this by the way, it does take a bit of getting used to, but the above exercise along with 15 minutes of practice on it, should have you well on the way to understanding how to create perfect Bezier Curves for your paint jobs.

Have fun. 🙂

 

 

Edited June 30, 2020 by Chock

[Relayer91 2]

Ah superb thank you for that!