Modeling with the animation Snapshot tool

- [Instructor] The Snapshot tool lets us create copies or clones of an animated object. We can use this as a modeling tool, and in this case I'll make copies of a chamfer box to create the steps of a spiral staircase. I've got a scene set up with a single chamfer box, which will be the first stair step. I've also got a tape measure helper to indicate the total height of the staircase, which is 12 feet. Sorry to all of our international audience, I'm using feet and inches, which is the standard for architecture.

For a spiral staircase, I want to rotate around a point which is outside the step itself. And to facilitate that, I can move the pivot point of the chamfer box. Select it in the top viewport, go over to the Hierarchy panel, click Affect Pivot Only, choose the Move tool, and over in the Snaps, click and hold on the 3D Snaps icon and choose 2.5D snaps.

That way when I move the pivot point in the top view, I won't change its elevation. The stair step is not actually flush on the floor. So I don't want to place the pivot point on the floor, which is what would happen if I used 3D snaps. All right, so I'll get in a little bit closer with the mouse wheel. Grab that and move it in the Y axis, maybe move it down a little bit more here. And I've got that at a position of negative four feet in Y.

And then we can exit out of Affect Pivot Only. So we're going to have a pretty wide diameter circle in the center of the spiral staircase. If we wanted to have, for example, a single pole, then we'd want that pivot point to be closer to the object. Now I'm ready to figure out how many steps I need, and that will determine the number of frames in the animation. I know that the height of the staircase will be 12 feet, or 144 inches.

I've chosen a step rise of six inches, that's the difference in elevation between steps. Each step will be six inches higher than the one before it. And of course, six inches is half a foot. The number of steps is the total height divided by the step rise. 144 inches divided by six inches is 24. I'll have 24 steps in my staircase. Another way of looking at that is that I'm going up 12 feet and I'm going up half a foot with each step, and so 12 times two is 24.

Let's go to frame 24 in the timeline. Turn on Auto Key, and with the Move tool active and 2.5D Snaps enabled, go over to the Front view and select the Z axis and move the step up and snap it to 12 feet. Release the mouse and then check your work, which should see a value of 12 feet in the Z axis, or that object's position. We've got Key Frames in the timeline now.

Let's also do the rotations. Activate the Rotate tool, and also enable Angle Snaps to precisely rotate the object. Go over to the top view and right-click to activate that view. Click on the rotate gizmo to rotate around the Z axis. Drag the mouse over to the right until you see the pop-up display read out -360 degrees. Release the mouse, and now we have both position and rotation key frames.

Let's disable Auto Key. Dolly back in the perspective view. And we can go back to just the Select Object tool. Rewind and playback, and we see that the object is moving in the correct pattern, but its velocity is changing over time. It's got a default slow out/slow in key frame interpolation. Let's fix that. With the object still selected, go to the Curve editor, and choose the Z Position transform.

Select both of the keys, set them to linear. Go to the Z Rotation, and once again select the keys, and if you can't see them, you can just simply click Frame Horizontal and Value Extents, and then select those keys. Set them to Linear. Close the Curve editor, rewind and playback, and we don't have a slow out/slow in anymore, we've got perfectly linear interpolation for both position and rotation.

Stop and rewind. Before invoking Snapshot, we want to make sure our key frames are on the right frames. We actually want the first key frame to be on frame one so that we will have exactly 24 samples in time, from frames one to 24. Right now both of my key frames are selected, so I'll click in the timeline to deselect them, click on the first key frame at frame zero and just drag it over to frame one. Now we're ready to open up the Snapshot tool. Go to the Tools menu and choose Snapshot.

We don't want a Single copy, we want a Range of copies, so enable Range. And we'll sample starting from frame one, so type in one in the From field. We'll stop sampling at Frame 24, so set the To field to 24. We'll have a total of 24 Copies and we want these to be Instances so that we can make changes to all of them at once. Click OK, and now we've got a spiral staircase. I can toggle around or orbit in the Perspective view to take a look.

If we scrub in the timeline, we can see how this works. The selected animated object is still highlighted, and on each frame it's in a different position. In our final scene we would probably hide that animated object to avoid any problems with rendering. I'll show you one last thing which is that, of course, since these are Instances, we can edit them all at once. I can select any one of these objects, go over to its Modify panel, and play around with its parameters, such as its length, and they all update automatically.

And that is how to use the Snapshot tool for Modeling in 3ds Max.