Naturalis v1.3-alpha2 (53.var)

Ok, I think I've made enough progress now to release another alpha. (Still no v1.3 Hub post.)

I'm gonna ramble a bit about the pressure implementation for anyone interested:

The internal pressure system, called Mesh Pressure in the main UI window and in user preferences, is basically fully functioning though possibly somewhat unpolished. The implementation very much depends on the morphing system to produce the changes in shape that you're used to seeing. Mesh pressure is just a layer on top of that that compensates for volume loss in collisions.

When it comes to breast morphs, there's some volume compensation built into the morphs that result in slightly too large breasts in certain poses when there is no collision removing volume from the mesh. This was a compromise I made back in the day, and the morphs will need some editing in this regard. With the mesh pressure we can finally make the volume consistent across the board in all poses and whether there is collision happening or not.

It feels like there's a lot more that could be done with the concept of applying custom forces on the soft joints. Pressure is just one possibility. Some of the possibilities might be too computationally expensive for real-time simulation, but I have a hunch that there are feasible ways to move more responsibilities from the morphing system to the force system. The pressure system takes care of the issue of volume loss due to collision, but what about the changes in shape caused by other factors like movement or gravity?

If the soft physics mesh was more fine-grained and covered a larger area, it could open some possibilities.

For example, a mesh that covered the chest around the breasts would allow spreading the base of the breast when leaning back without requiring morphs for that. Or, skin wrapping around a finger when pushing the finger into the mesh - a "wrap force" that pulls nearby soft joints to fill the gap left by the joint that is pushed in. These would be very interesting to try to implement, and a better soft physics mesh could substantially increase the simulation's quality as well, so a proof of concept of a custom soft physics mesh could be the next step.

Changes in v1.3-alpha2

Main UI

• Soft physics toggle moved to the top and center given how central it is to everything, and how it's a prerequisite for the Breast Softness (Soft Physics) slider as well as the stuff in the Advanced Soft Physics section
• Soft physics self collide toggle is moved to the Physics tab

Advanced Soft Physics section

This term differentiates between the advanced soft-physics-only features of Naturalis from the basic soft physics of VAM. Adv. soft physics includes the dynamically adjusting soft physics (depth and local distortion) as well as the new mesh pressure implementation. (Collider friction and specifically adaptive friction can be considered a part of it as well.)

You can now toggle any of the features without requiring calibration! The only exception to this is if they are all disabled and the plugin has only gone through the quick "non multi directional" calibration. In that case, a multi directional calibration is needed when toggling on any of the advanced features. But once that's done, you can just keep toggling them off/on at will.

Updated depth physics implementation

• Updated the calculation of soft joint depth, it requires a bit higher effect slider value to produce the same change
• Depth Compression Effect is now called Depth In Effect
• Depth Compression Sensitivity is now called Depth In Sensitivity
• new parameters Depth Out Effect and Depth Out Sensitivity for when the joint moves further away from the center of the glute/breast

As a result of these changes, depth physics values saved in alpha 1 are ignored when loading plugin parameters.

Mesh pressure

When mesh pressure is enabled, the soft physics mesh expands as soft joints are pushed towards the center of the mesh. It's very performant, there's barely any effect on frame rate - depth physics and local distortion physics are more costly. It works great for glutes as well.

You can configure the pressure using a new soft physics parameter called Fat Pressure Multiplier. This is just like any other soft physics parameter in the UI, should be pretty easy to use.

Like other soft physics parameters, you can set the value along a gradient and dynamically adjust it using depth physics and/or local distortion physics. Whether those dynamic adjustments make sense for this parameter, not sure - but worth experimenting with!

It's a multiplier on how much pressure force joints can receive, not how much force they contribute. By default, the the outer multiplier is low and center multipliers are high, so the pressure force degrades towards the edges of the physics mesh.

The pressure multiplier base value is 0.40 in TittyMagic and 1.00 in BootyMagic, and these currently don't change with softness or mass. Might fine tune these later.

Changes to soft physics defaults

Since the new mesh pressure implementation will expand the mesh and move joints further away from the center, this can trigger depth physics to adjust parameter values using the Depth Out effect. Some of the physics parameters take advantage of this by default, but I guess it's going to be hard to see the difference because individual joints aren't going to move away from the center that much. The pressure spreads pretty evenly across the mesh.

Depth physics:

• Fat Spring - increases with depth in, slightly decreases with depth out
• Fat Mass - increases with depth in, slightly decreases with depth out
• Fat Collider Radius - increases both with depth in and depth out (since collision typically deforms the mesh in a way that gives it more surface area)
• Fat Collider Friction - increases with depth in (base value needs to be low for the depth adjustment to have much of an effect, e.g. use adaptive friction with glossy skin; even then it's hard to tell the difference)

Other:

• Fat Mass gradient - outer multiplier is now 0.65 (was 1.00), so fat mass decreases towards the edge
• Fat Distance Limit - in TittyMagic, it now has the same base value whether local distortion physics enabled or not, and no longer adjusts with local compression/stretching

User preferences UI changes

In the previous update I split the user preferences into sections. The Dynamic Soft Physics section is now called Advanced Soft Physics, reflecting the same named section in the main window.

• New toggle for whether the mesh pressure should be enabled by default
• In TittyMagic, toggles for glutes are not shown
• In BootyMagic, toggles for breasts are not shown

The update rate only applies to the depth and local distortion physics. The mesh pressure force is always applied at the full physics rate.

Other

• Changes to monitored morphs are now detected instantly and there's no overhead (morph values are not actively checked, instead they trigger a callback)

I will be taking a few days away from my plugin duties soon, but will try to be active apart from that. Happy holidays!