I’m developing a game with an Alien Shooter style control (http://youtu.be/0lQhV2dkzxE - Alien Shooter gameplay). Since I’m not good at 3D modelling, I used Epic Games AnimStarterPack to animate my character. Here is a brief how-to I implemented an AimOffset asset.
AnimStarterPack provides an animation sequence Anim_Space_Hip, which is simply a sequence of 9 poses. Those poses cover 180 deg. yaw and pitch angle. To make a character to aim its weapon smoothly, those poses must be blended according to two given parameters: yaw and pitch angles.
Export Aim_Space_Hip animation somewhere and import it 9 times, each time choose the frames range which correspond to the pose. The editor doesn’t allow to import a one frame animation, so choose 2 frames and then delete one frame in the editor. Note, that some poses have a one frame “extremum” and if we don’t want a quivering pose there must be only one frame in a pose animation.
Importing the “centre-up” pose.
Give proper names to the pose animations, like CC for “centre-centre”, LU for “left-up” and so on. After importing, open the animation and change Additive Anim Type to Mesh Space, Base Pose Type to Selected animation frame and choose below Idle_Rifle_Hip asset. Right-click on the Sequence Editor and Remove from frame 1 to frame 2. Finish up with 9 poses in this way and proceed to creating an AimOffset asset.
To create an AimOffset asset and get a basic idea of it, check the documentation page https://docs.unrealengine.com/latest/INT/Engine/Animation/AimOffset/index.html. Along the X axis determine the yaw angle, along the Y axis - pitch angle. Set -90 … 90 deg. range and 4 divisions for both. Put all the “down” poses on the bottom row, i.e. “left-down”, “center-down” and “right-down”. On the middle row put “center” poses and, finally, on the upper row put “up” poses. Change Preview Base Pose to Idle_Rifle_Hip to check what’s done.
Final AimOffset asset.
Check out the Content Examples demo to get an idea how to aim your character run time https://docs.unrealengine.com/latest/INT/Resources/ContentExamples/Animation/index.html. In my case, the yaw and pitch angles are defined by a point in the world the cursor hovering over.