Seamless Hatches with Patches

More Working With Hash Splines

2000 By Jeff Cantin aka [TinCan] on IRC

In this short tutorial, I am going to reveal how I get seamless hatches for my mechanical models on curved surfaces. I'm gunna
tell ya right now, some of you are gunna say, "Dang! I knew that, I just didn't know I knew it!" ;-)

Step 1 "Plan Ahead"

In the image below, you see the spline I want to lathe (I made an arrow from splines to point to where I want to have the
hatch). You should notice the "hatch" part has more CPs to keep it's shape, whereas the tube section doesn't need very many.

Step 2 "Select Hatch"

As indicated in the screenshot below, select the CPs you want as the hatch. With your paste offset set to 0*, copy and paste
this section over the original. While it is still highlighted use the Zoom Selected Key Combo to, er, zoom in on it... LOL
(Hint: Ctrl-Sh-Z) You may notice minor differences from the first spline and the new one, so carefully adjust the new CP(s)
to align the shape to what you really want. DO NOT, as in don't touch the end CP because this CP is exactly where the
two mesh parts will come together. (The CP closest to my arrow pointer.) Next, select a CP on the tube section and
whack the (,) key, and then the (h) key and delete all but that end CP that made up the hatch. Un-hide and the screen
should look the same as before.

Step 3 "lathe"

Select one CP on each spline and lathe it. (Easy enuff...)

Step 4 "Test Render"

Again easy enough....

Add a bone to where you want the hatch to hinge from, create a pose slider or action and give it a test...

The things you should have learned from doing this:

1.) Copy with a zero offset places the CPs exactly over the old ones and therefore they will match up later.

2.) Your copied curve must have enough CPs to retain it's shape when it's copied.

* See my Basic Splinemanship II tutorial for more techniques....

If you learned something from this tutorial, please drop me an E-mail at Jeff Cantin
This is an important step, I track the number of visits to "thank you" notes, I need to know my time and my web space is well spent.

I have other tutorials linked from my hobby homepage. Give those a try too when you are ready.