Join Brian Bradley for an in-depth discussion in this video The importance of pivot points in animation, part of Animating in 3ds Max: Constraints, Controllers, and Wire Parameters.
- [Instructor] When animating in 3ds Max, whether that be with the simplest or most complex of objects or rigs, there will always be one element of the setup that will have a huge impact on our project's success and that is the placement of pivot points in the objects that we are rigging or animating with. In this video then we want to take a couple of minutes to discuss just what pivot points are and to demonstrate the important role they play in the rigging and animation process. So, what is a pivot point? Well, when animating in Max, we are typically going to find ourselves working with the transform tools of move, rotate and scale and the pivot point is the point in 3D space around which these transforms will occur.
For instance, in our simple scene here, we have three standard Max primitives all created in the top view port and they have all been set to a roughly equivalent size. Now, from this top view they all look to be fairly uniform in every respect including their spacing in 3D space but when we use the alt and W keys to reveal the other three view ports, we can see that this is not actually the case even though as I select through the objects with the move tool active, we can see that they all have Y and Z axes values of zero set.
This discrepancy in placement occurs because of the default placement of the pivot point. For the cube and the teapot this has automatically been set to the base of the object whereas for the sphere, it is in the center. If I enable the base to pivot option on the sphere though it joins the other two objects in perfect alignment. The pivot then is the single point in space where 3ds Max reports an object as residing. The software is aware that these objects have volume as we can see if we jump into the Utilities tab and use the Measure tool but for any and all transform operations, be that modeling, rigging or animating, Max will be using just this single reference point in space which will oftentimes mean as animators and/or riggers that we are much more interested in where the pivot point is than we are in where the actual visual mesh is in the view port.
For instance, let's say that I wanted to create a very quick animation of our sphere orbiting around the teapot here coming back to its starting point as the animation ends. Well, selecting and rotating the sphere around its Z axes in the top view port clearly won't work as it just sits and spins which it does because the local pivot point is perfectly aligned to the poles on the geometry. What we need to do then is either move the object pivot to a different location or create an animation rig that forces the object to use a different pivot point for animation purposes.
Now, whilst the latter is generally speaking the way we would always want to do things in a production situation, for demonstration purposes I'm just going to show you the brute force effect of using the actual pivot from the sphere. With the sphere selected then, let's jump into the Hierarchy tab on the command panel and from inside the Pivot section, enable Pivot Only mode. From up on the main toolbar, let's grab the Align tool and then select the teapot geometry. In the Align Selection dialog that pops up we only need to align to the X and Y positions in this particular instance although we do want to make sure that we are aligning from pivot point to pivot point after which we can click OK and then disable Pivot Only mode.
When we come to the top view port and rotate the sphere around it Z axes now, notice that Max is no longer interested in where the visual mesh object is, only the pivot point as this is the point around which the transformation will take place. Another option we could use here besides creating an animation rig that is, if I just undo that pivot move, would be to use what 3ds Max calls the working pivot for the sphere which is a temporary pivot point around which modeling and animation operations can be performed.
If we enable Edit mode for the working pivot then, and again, align to the teapot using the same options, we can enable the Use Working Pivot option and in the top view port get the same kind of motion that we had earlier. Now, ultimately of course the ideal solution when creating animations in 3ds Max is as already mentioned to create an animation rig even if that is as simple as adding a point helper to the scene around which these types of transforms can be performed, although having said that, you will see me violate this good piece of advice a few times throughout the course just for the sake of keeping the lessons moving along.
One final word of warning here and gotcha that can catch even the most experienced of Max users unawares is the need the bear in mind the effect that our choices in the transform coordinates system and use center fly outs can have on just how 3ds Max uses pivot points in a transform operation with different combinations here being capable of producing very different transform results.
- Reviewing the importance of pivot points in animation
- Accessing and working with controllers in the UI
- Creating reaction animations
- LookAT controllers
- Wire parameters