1 Use consistent naming and hierarchy

One of the main causes of animation pops and glitches is the mismatch between the naming and hierarchy of the bones or joints in the different animation states. For example, if you have a walk state that uses a bone named "Hip" and a run state that uses a bone named "Hips", the blending will not work correctly and the character will snap or jitter. To avoid this, you should use consistent naming and hierarchy for all the bones or joints in your character rig, and make sure they match the ones in your animation clips or states.

2 Adjust the blend duration and curve

Another factor that affects the smoothness of the animation blending is the duration and curve of the blend. The duration is the time it takes to transition from one state to another, and the curve is the shape of the interpolation between the two states. If the duration is too short or the curve is too steep, the blending will look abrupt and unnatural. If the duration is too long or the curve is too flat, the blending will look sluggish and unresponsive. To avoid this, you should adjust the blend duration and curve according to the context and the desired effect of the animation. For example, you might want a shorter and sharper blend for a fast and sudden action, like a dodge or a punch, and a longer and smoother blend for a slow and gradual action, like a turn or a crouch.

3 Use additive or subtractive blending

Sometimes, you might want to blend two animation states that have different root motions, such as a walk state that moves the character forward and a jump state that moves the character up. In this case, simply blending the two states might result in a pop or glitch, as the character will suddenly change its position or direction. To avoid this, you can use additive or subtractive blending, which are techniques that combine or cancel out the root motions of the two states. For example, you can use additive blending to add the upward motion of the jump state to the forward motion of the walk state, creating a realistic jump forward. Or, you can use subtractive blending to subtract the forward motion of the walk state from the upward motion of the jump state, creating a realistic jump in place.

4 Use masks or layers

Another way to avoid animation pops and glitches is to use masks or layers, which are tools that allow you to control which parts of the character are affected by the blending. For example, you might want to blend only the upper body of the character, while keeping the lower body in a fixed state, such as a walk or a run. In this case, you can use a mask or a layer to isolate the upper body of the character and apply the blending only to that part, while leaving the lower body untouched. This can create more complex and varied animation combinations, without affecting the stability and consistency of the character's movement.

5 Test and tweak

Finally, the best way to avoid animation pops and glitches is to test and tweak your animation blending until you are satisfied with the result. Animation blending is not an exact science, and different situations might require different solutions. You should always check your animation blending in different scenarios, such as different camera angles, different lighting conditions, different speeds, etc., and look for any pops or glitches that might occur. Then, you should tweak your animation blending parameters, such as the naming, hierarchy, duration, curve, blending mode, mask, layer, etc., until you eliminate or minimize the pops or glitches. You should also get feedback from other animators or viewers, and see if they notice any pops or glitches that you might have missed.

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?