Character Swap & UMA systems finally done! | August 2023

Hi everyone! Has been a while.

As we pointed out in our previous post, we’ve been working tirelessly on a universal character system to support additional character models, and in doing so we had to temporarily remove Estelle from the game; putting new release builds temporarily on pause.

Since you’ve all been waiting for the next version of Lustbound in anticipation, we feel it’s important to show you guys why it’s been taking so long.

Due to the complex nature of 3D character models, and the fact that every model has so many unique aspects that make them all fundamentally different from one another, making a system like this can be quite challenging. Because of this, we had to rewrite many of our dynamic sex scripts from the ground up.

Our system needs to accommodate this wide range of variation by taking into account completely different bone hierarchies, unique bone names, changes in bone orientation, and different blend shapes; and it has to do all of this automagically while the game is already running!

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Before getting to the major changes we had to make, we want to share a bit of the magic going on under the hood when a character swap is initiated during gameplay in our new revised system. Here is a simplified step by step breakdown. (Lots of technical info below)

• 1. Basically every character, including custom imported characters will be an UMA. When a character is loaded, an UMA dynamic character avatar is spawned
• 2. Bone offsets are calculated (more on this major change below) and placed inside the original IK targets, allowing the new character to use IK poses that were created using other characters
• 3. Once the new UMA is fully built, its bone structure is analyzed and a full body biped IK is created on top of it; setting up all of the appropriate IK targets and bend goals. This gives our animator system the ability to control the character movements by positioning their hands and feet
• 4. On top of the full body IK, two additional effector are created
  A. The head effector which gives control of the head separately from the body, allowing for precise blowjob movements
  B. The pelvis offset effector which gives more precise control of the hips, allowing for accurate cock riding
• 5. The new hand IK system (which we’ll detail a little further down) is created, allowing for hands that grip, grab, rub and more
• 6. Animation motors are populated and positioned according to the new characters bones; allowing for all the juicy in and out, smooth rotational movements you see in the game
  

• 7. Vertex based sensors and dynamic bones are placed and activated to give our characters natural and fun jiggle in all the right places, including breasts, ass and tummy
• 8. Shape drivers are added if corrective blend shapes have been specified for the character, allowing more natural bending of joints including knees, elbows and shoulders
• 9. Look and eyes animators are added, allowing the eyes, head, neck and spine to gracefully look towards the camera or any other object the character is focusing on, as well as enabling a natural blinking behavior

• 10. Collision meshes are set up and appropriate layers are given to them, allowing for raycasting to know when the character is interacted with via mouse or controller. In the future these same collision meshes will be used to land cumshots and other fluids on character bodies.

• 11. Particle effects for moving the character mesh around the apartment are spawned and given reference to the new character mesh and its own set of colors
• 12. Blend shape overrides are added, allowing the system to use the blend shapes of the new character in place of the ones used in our original Estelle character, including breast size, labia and vagina open states etc
• 13. IKy Sticky is reinitialized, taking into account all the new character data and reconnecting itself to all the vital parts that were just created beforehand
• 14. Finally, our SexFX Audio Manager and View Manager are reconnected to the new character
  

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The first major change we had to make was to our animation system. Since our entire system is based on inverse kinematics rather than relying on a more traditional animator based system, special attention was required.

(in case you don’t already know, our IK based sex system (IKy Sticky) which moves via motors, is what gives Lustbound complete control over the depth, length and speed of strokes during sex animations, perfectly synchronizing every character movement to your bluetooth sex toys, allowing Estelle to follow along with porn videos via funscripts, serving dynamic movement based sound effects, and allowing characters to follow custom patterns or beat based gameplay)

Until now, hand posing was the only part of the system that wasn’t based on IK, and hand poses used Estelle’s unique bone names and hierarchy specific to her character model. Unsurprisingly, when we introduced a new character with different bones, hand posing was completely broken and had to be reconsidered.

The solution? More IK! Rather than posing her bones in a more traditional sense, we now simply pose finger targets and the fingers naturally bend to follow their position and rotation.

The biggest change we’ve had to make thus far, and which we’re still working on right now, is the bone offset system. Since the orientation of each bone varies so much between different characters, we’ve had to come up with a new way to initialize each one in a way that each character follows IK poses the same.

Basically we now  initialize every character in an identical neutral t-pose, zeroing out offset objects within each important bone.The original target is moved to the same global position, while the offset is placed within it. Then we can animate using the original IK targets, while the offset object becomes the actual solver targets, keeping all the bones oriented properly.

Unfortunately there is one shortcoming of the new offsets, being that we will have to remake the animations. The good news however, is that we already anticipated this would be an issue, and that is the primary reason we haven’t been adding new animations up until now.

Luckily remaking the existing animations should be quick as we can reference the old and new animation motors side by side. After that we can finally start adding new animations on a regular basis!

We know this has taken a long time, and we’re so grateful that people have kept their faith in our vision.

 We don’t quit, we always make it work, it just requires time and patience to do right. We can’t wait to share the next version as soon as possible!

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If you skipped a majority of the text above and landed here. Don’t worry we can understand! (It's quite technical after all!)

We wanted to show you all just how much work we’ve been putting into this, and why it’s taking so long. In short though, we’re nearly done with the transition, so you can hopefully expect a new version soon-ish.