Skill Level Intermediate
- [Narrator] In the next few episodes of this weekly series we will see how to create this cool effect which is a spark gap transformer, commonly known as a Jacob's ladder. Along the way, we will learn several techniques in 3ds Max. This week we will learn to use the linked X form modifier as an animation tool. Last week we used linked X form as a non destructive modeling tool. Now we'll link sub objects to animated helpers to achieve complex deformations. In the spark gap example we'll create a spark object.
It'll be a chaotic, noisy spline with end vertices linked to these point helpers. Later we'll animate the helpers with path constraints. The helpers are currently positioned over their respective paths. These two electrode objects on the left and right are actually editable splines. With linked X form we can be sure that the end points of the spark always touch the electrodes. Let's create the spark object. We want to snap to the pivot points of these point helpers.
Go up to the main tool bar and right click on any one of the magnet icons, and in the snaps tab of the grid and snap settings dialogue turn off everything except for pivot. We want to snap to pivots only. Close the grid and snap settings dialogue and then enable three D snaps. We're going to create a line object. Go to the create panel, shapes, splines, click the line button.
Then hover the cursor over the spark helper on the left until you see a big yellow cube and that's actually the snap icon. Click the mouse and then drag over to the center spark helper, click again, and then drag over to the right hand spark helper. Click a third time, then right click to exit that line and right click again to exit the tool completely. Turn off three D snaps and with that object still selected go to the modify panel and rename it to spark.
Convert all of the vertices to smooth. Go into vertex sub object mode. Select all three vertices, right click, and in the quad menu choose smooth. Now we've got a nice arc there. Turn off sub object mode and go into the rendering roll out. We want this to generate geometry both in the view port and in Arnold. Turn on enable in renderer. Turn on enable in view port.
Turn on use view port settings so that they will always match, and then very importantly down here choose the view port radio button and under these conditions the settings down here will control both the geometry and the renderer. Let's set the thickness here to one centimeter. And we can leave the number of sides at 12. Also go into the interpolation roll out and turn the number of steps up to its maximum of 100.
Now we will have a lot of detail on that object. Now we're ready to link the spline object to these point helpers. So in the line objects modifier list let's add a new modifier. It's going to be spline select and we see some red dots there representing the vertices. We'll select the one on the left. Just drag a rectangle and now that vertex is selected and we can pass that up to a linked X form modifier.
From the modifier list choose linked X form, click on pick control object, and then click on the spark helper oh oh one, and then we can test that. Select the spark helper. Maybe get in a little bit closer here and we can move that around just to test it and indeed it's working. Undo that with control Z. Just repeat that process for the other two point helpers.
Select the spark object, add a spline select, and then go into vertex sub object mode if you aren't already. Select the center vertex and if you're having difficulty seeing you can turn off shading. You can go into F three wireframe mode. We can see that that vertex is actually selected. Go back to the modifier list, add another linked X form. Once again click pick control object and select spark helper oh oh two in this case and then we can select that and move it and test whether it's working.
Seems to be working, so undo that with control Z. Back to the spark object. Add another spline select. Select that end vertex. Add another linked X form. Click pick control object and finally click on spark helper oh oh three and now we can back out of all of this. We can deselect the object and we can try these all at once. We can select a few of these, two or three of them maybe, and see if they work.
Everything seems to be working just as planned. I'll undo all of that. Now we want some noise on this, but we want the noise to be only within the volume inside these two electrodes and to do that we're going to use a volume select modifier and volume select will only work if this is actually a true mesh object. So reselect the spark and we want to clear out any selection. So go to the modifier list and choose mesh select and just don't select anything.
Make sure that there's nothing over here indicating you're in a sub object mode. Then convert this to a mesh object. From the modifier list choose turn to mesh. Here it is, turn to mesh. Now we can use our volume select. So go back to modifier list. Do a volume select, and the stack selection level will be vertex. Scroll down a little bit. In the select by section we want to use a mesh object and I've got one already in the scene.
It's hidden on a hidden layer. So go into the layer explorer and unhide the geometric helpers layer. If we open that up you'll see there's a selection pyramid in there and it's transparent, so we normally can't see it. But there it is. Once I've selected it it's visible. Okay, so back to our spark. We've got our volume select in vertex mode and we want to select by mesh object then click on the none button and we can click on the selection pyramid in the layer explorer and now we've actually selected just the vertices that are inside that pyramid's volume, and the vertices inside that selection will be affected by the subsequent noise modifier.
I'll close the layer explorer and to get a nice transition here at the ends let's enable soft selection and give it a low fall off value. Maybe give it a value of 1.5 just to play it safe and now the effect of the noise modifier will fall off gradually. We can go ahead and add that modifier now. So go to modifier list one last time and add a noise and in its parameters we want a scale of one and let's turn on fractal here and set it to two iterations and increase the strength in X, Y, and Z.
I'm going to set the X strength to 2.5 centimeters. Press the tab key. The Y strength also 2.5, press tab, and the Z strength to five centimeters, and now we've got a nice effect there. We want this to be animated. So in the parameters down here we want animate noise enabled. It's got some keyframes on it already, but we want to change that up just a little bit. Let's go into the curve editor with that object still selected.
Open up modified object and noise. Scroll down if you have to, and we're looking for phase and we can frame horizontal and value extend so we can see the entire curve here. Let's cause this to change phase linearly so it won't speed up or slow down. Right click on phase and choose assign controller. In the assign float controller dialogue choose linear float. Click okay, and then we'll change up the animation here.
We're got a keyframe on frame one over here and if we click on it we can see its values. On frame one it has a value of one. We've got another keyframe here at the end. Select that. We'll make the noise move twice as fast by doubling the phase amount on frame 600. We'll give it a value of 1200, and now it's twice as steep. We can close the curve editor and then play our animation, see what it looks like. So that's our first attempt at the animated noise effect and in the following movies we will move these point helpers along their respective paths and animate the Jacob's ladder, and that's how to use linked X form to set up a rig for an automated animation.