WT: Animation blending and root motion UI

[Nickelony]

[Sezzary]

TEN-exclusive features.

Details:

Animation blending

• Can be used to transition seamlessly between animations, eliminating the need for many pointless transition animations, expediting the creation process of new assets, and overcoming some annoying restrictions I currently face with implementing modern controls. Blending is strictly cosmetic and doesn't affect mechanics in any way.
• Left menu requires two new boxes, perhaps in a new row below the box labeled Framerate:
  • Blend frames for numeric input.
  • Blend curve for a modifiable bezier curve with some handy presets available. Maybe clicking the box can open an expanded view of it?
• In the State changes window, rename the Next frame column label to Next low frame.
• After the Next low frame column, three new columns:
  • Next high frame for numeric input. Having a low and high frame will allow dispatches to be "mapped" to a range of frames.
  • Blend frames for numeric input.
  • Blend curve for bezier curve.
• Some way to preview blends.

Root motion

• Can be used as an accurate and modern alternative to the current linear velocities, eliminating the need for many pointless animation splits, having to eyeball whether a movement cycle treads the ground correctly, and allowing for a less miserable asset creation pipeline.
  • 7 new checkboxes needed somewhere on the main screen:
• Whole group labeled Root motion.
• Single checkbox labeled Cycle.
• Subgroup labeled Translation with X, Y, and Z checkboxes.
• Subgroup labeled Rotation with X, Y, and Z checkboxes.

Bonus: bezier curve fixed velocities

• An idea I had in the past was to improve fixed motion velocity by updating it to use a bezier curve for finer control. This way, there would be a modernised system allowing for two movement methods:
  • Fixed motion, driven by velocities derived from 3 curves corresponding to X, Y, Z.
  • Root motion, driven by velocities extracted from an animation.

Animation blending and root motion already have 100% working (as far as I can tell) implementations in TEN on a branch in the repository. All we need is a way to write data to the wad. :)