wip Real-Time Breast Physics for The Sims 4

[CPVC]

I'm making a mod that adds real-time breast physics to The Sims 4. It's not quite ready for prime time, so consider this a preview of what's to come rather than a finished product.

 

Really, this "mod" is more of a hack than a mod. It's basically a phony DirectX 9 DLL that acts just like the real deal, but injects a bit of extra code into the game loop (See https://en.wikipedia.org/wiki/Hooking).

 

I figured out how to detect when a sim was about to be drawn and modify the joint matrices before the rendering happened. I used the texture coordinates to find which vertices were part of the breasts then determined which joint matrices correlated with the left and right breasts.

 

With that information, I was able to add a rudimentary physics simulator to the breasts.

 

Please read the file "README" before using this mod.

 

I have included a cleaned up version of the source code for anyone that wants to know how this was done. Also, I'm ready to answer any technical questions.

 

QUICK INSTALL:

 

1.) Extract the files from the archive.

 

2.) Move "d3d9.dll" to your Sims 4 installation directory + "Game/Bin/".

 

3.) (Optional) If you'd like to send commands to the physics simulator to change certain things, move the folder "RTBP" into your mods folder. The README file has a list of all available commands.

 

4.) Use at your own risk.

 

Real-Time Body Physics

 

[Chipendale]

Looks interesting to say the least. Will definitely follow this for as long you decide to work on it.

Though the character portrait look frickin' hilarious, as if the tiddies are trying to escape the body ?

[Malcom Milton]

Good work. So this mod makes them bounce without the help of breast bones? unlike the 'Bouncing Sim Boobies' mod?

 

 

[Z0mBieP00Nani]

Nice! If this is possible then does that mean real time pussy physics are possible?.. Or maybe not, because I don't think The Sims 4 is set up for collision..

 

I don't know, I've asked before and always been told it's not possible.

[cableguy7uk]

Just one problem ( which i can live with) you get a strange elongated finger glitch.  The Boob bounce is now out of this world , well done!?

[CPVC]

5 hours ago, Malcom Milton said:

Good work. So this mod makes them bounce without the help of breast bones? unlike the 'Bouncing Sim Boobies' mod?

 

 

Yes, that is correct. It just modifies the positions of the b__CAS_L_Breast__ and b__CAS_R_Breast__ bones before rendering the sim.

5 hours ago, Z0mBieP00Nani said:

Nice! If this is possible then does that mean real time pussy physics are possible?.. Or maybe not, because I don't think The Sims 4 is set up for collision..

 

I don't know, I've asked before and always been told it's not possible.

That could potentially be done in the future. I should be able to modify the mesh vertices and add new bones at runtime, but I haven't tried yet.

3 hours ago, cableguy7uk said:

Just one problem ( which i can live with) you get a strange elongated finger glitch.  The Boob bounce is now out of this world , well done!?

Yeah, sometimes the wrong vertices are selected and glitches like that happen. I've seen cats with bouncing faces in my game. I'm working on coming up with a solution to this problem.

[Z0mBieP00Nani]

Quote

That could potentially be done in the future. I should be able to modify the mesh vertices and add new bones at runtime, but I haven't tried yet.

Oh, this is good news indeed..

 

This feels like Lovers Lab Skyrim circa 2013-2015 all over again, lol.

[CPVC]

56 minutes ago, parzysty said:

Could the same be done for butts?

Yeah, I think it could. After I get the breasts working satisfactory, this is what I plan on working on next.

[millionserved]

I like this.  While it is buggy there is a lot of potential.  It worked for me in CAS, and with the older WW animations done by animators that hadn't implemented breast movement.  Will you be able to make this compatible with Reshader?  I'm guessing that since this is a different d3d9.dll file it removes the Reshader mod.  Also do you think that this will be a way to introduce more bones to the game for things such as dynamic hair and clothing movement?  If so, you should talk to Redfaction.

[CPVC]

9 hours ago, millionserved said:

I like this.  While it is buggy there is a lot of potential.  It worked for me in CAS, and with the older WW animations done by animators that hadn't implemented breast movement.  Will you be able to make this compatible with Reshader?  I'm guessing that since this is a different d3d9.dll file it removes the Reshader mod.  Also do you think that this will be a way to introduce more bones to the game for things such as dynamic hair and clothing movement?  If so, you should talk to Redfaction.

I can definitely make it compatible with Reshader. I just have tell it to load the Reshader DirectX 9 DLL instead of the system one. I'll work on this tonight.

 

And yes, this could lead to dynamic hair and clothing. Basically anything about the mesh can be changed on the fly.

[IfYouOnlyKnewMe]

Now we just need physics for Male and Female Sim balls and penis. Helicopter penis all day long!

 

@REDFACTION This may be a solution for the problems you are facing!

[IfYouOnlyKnewMe]

I wonder if there is a way to add weight paints to the bodies of Sims and animate using those ?

[millionserved]

Will this override any breast bone movements created in animations or will it add to the breast movements done causing them to be thrown off slightly?

 

[modella]

Oh this is perfect ☺️!!! Can’t wait to test it out, thank you!

[Super anal fucker meiko]

I expected the shim to be able to perform physical movements such as MMD and dynamic bones. This adjustment is quite innovative.

 

ネタバレ

 

Some people said there was a strange bug, but I didn't know what it was. It is like this. This changes the location where the bones bounce off each time you change your outfit and can cause your belly to move, depending on your shim. The bones that are instructed to bounce do not exist on any bones except the female shim, so they seem to have chosen it randomly. Make exceptions for non-female sims. Or if I could give the swing to a male sim, the problem might be solved, but I'm not sure about the program.??

 

I mean, I'm looking forward to the completion, and I'd love to help with anything I can do about this.... ?

[CPVC]

On 8/15/2020 at 7:49 PM, ColonolNutty said:

I wonder if there is a way to add weight paints to the bodies of Sims and animate using those ?

There is! Check it out, butt bones! I have successfully added new bones to a sim at runtime.

 

20 hours ago, millionserved said:

Will this override any breast bone movements created in animations or will it add to the breast movements done causing them to be thrown off slightly?

 

It will add to any animation targeting the breasts. This mod does its magic after the sim had been animated, but before rendering. I imagine that this, combined with manual breast animations, is going to look pretty bad.

6 hours ago, Super anal fucker meiko said:

I expected the shim to be able to perform physical movements such as MMD and dynamic bones. This adjustment is quite innovative.

 

  Hide contents

 

Some people said there was a strange bug, but I didn't know what it was. It is like this. This changes the location where the bones bounce off each time you change your outfit and can cause your belly to move, depending on your shim. The bones that are instructed to bounce do not exist on any bones except the female shim, so they seem to have chosen it randomly. Make exceptions for non-female sims. Or if I could give the swing to a male sim, the problem might be solved, but I'm not sure about the program.??

 

I mean, I'm looking forward to the completion, and I'd love to help with anything I can do about this.... ?

Yes, sometimes the wrong bones get selected. I'm working on a better way to find the correct bone indexes. One that doesn't rely on the texture coordinates. Also, I need to find a way to distinguish female, male, and pet vertex buffers from each other so I can target only the female ones.

[IfYouOnlyKnewMe]

11 minutes ago, CPVC said:

There is! Check it out, butt bones! I have successfully added new bones to a sim at runtime.

It will add to any animation targeting the breasts. This mod does its magic after the sim had been animated, but before rendering. I imagine that this, combined with manual breast animations, is going to look pretty bad.

Yes, sometimes the wrong bones get selected. I'm working on a better way to find the correct bone indexes. One that doesn't rely on the texture coordinates. Also, I need to find a way to distinguish female, male, and pet vertex buffers from each other so I can target only the female ones.

Now we just need Sims with limp arms that flop around behind them as they run naruto style.

[REDFACTION]

Amazing skills. Outstanding discovery.

 

Congratulations !

 

Thank you @millionserved and @ColonolNutty for the lookout.

 

On 8/17/2020 at 10:01 PM, CPVC said:

Check it out, butt bones! I have successfully added new bones to a sim at runtime.

Did you add those bones on top of the 180 bones cap or were you still below the cap ?

 

On 8/17/2020 at 10:01 PM, CPVC said:

This mod does its magic after the sim had been animated, but before rendering

Does it mean that we can't animate the new bones in blender as usual ? It must be animated by a real-time physics mod ?

 

I wish you all the best for your future research !

[CPVC]

2 hours ago, REDFACTION said:

Did you add those bones on top of the 180 bones cap or were you still below the cap ?

I was still far below the cap.

 

2 hours ago, REDFACTION said:

Does it mean that we can't animate the new bones in blender as usual ? It must be animated by a real-time physics mod ?

You could probably do animations in Blender and get them to work with this mod. You'd just have to make sure the matrix indexes match up. It's difficult to tell which matrix index corresponds to each bone. There doesn't seem to be any pattern to their numbering and it's different for each mesh.

[cableguy7uk]

Just copied rtbp file into mods, how do I  access and please could you give us a few numbers to test.

[CPVC]

9 hours ago, cableguy7uk said:

Just copied rtbp file into mods, how do I  access and please could you give us a few numbers to test.

The RTBP mod allows you to communicate with the physics simulator in game. Here's the list of all the commands from the readme file:

 

'rtbp.command "test"': Tests all currently running simulations.

 

'rtbp.command "reset"': Resets the translation and velocity of all simulations.

 

'rtbp.command "printpos"': Prints the translation of the left breast of all simulations.

 

'rtbp.command "setMass X"': Sets the breast mass for all currently running simulations. Replace "X" with the new value. Default value is 0.9.

 

'rtbp.command "setDamping X"': Sets the damping for all currently running simulations. The damping is how quickly the breasts stop jiggling after being moved. Default value is 10.0.

 

'rtbp.command "setSpringK X"': Sets the spring k constant of the spring physics for all currently running simulations. Google "Hooke's Law". Default value is 150.0.

 

'rtbp.command "setMaxLength X"': Sets the maximum distance between the breasts' target vector and simulated vector for all currently running simulations. Default value is 0.2.

[2cool4u_1]

35 minutes ago, CPVC said:

The RTBP mod allows you to communicate with the physics simulator in game.

I really appreciate that. Being able to change the settings on the fly lets me see exactly how it affects the game. Thanks.

[CPVC]

Another preview of what's to come: Butt physics. I set the damping value super low for this demonstration.

 

[cableguy7uk]

5 hours ago, CPVC said:

The RTBP mod allows you to communicate with the physics simulator in game. Here's the list of all the commands from the readme file:

 

'rtbp.command "test"': Tests all currently running simulations.

 

'rtbp.command "reset"': Resets the translation and velocity of all simulations.

 

'rtbp.command "printpos"': Prints the translation of the left breast of all simulations.

 

'rtbp.command "setMass X"': Sets the breast mass for all currently running simulations. Replace "X" with the new value. Default value is 0.9.

 

'rtbp.command "setDamping X"': Sets the damping for all currently running simulations. The damping is how quickly the breasts stop jiggling after being moved. Default value is 10.0.

 

'rtbp.command "setSpringK X"': Sets the spring k constant of the spring physics for all currently running simulations. Google "Hooke's Law". Default value is 150.0.

 

'rtbp.command "setMaxLength X"': Sets the maximum distance between the breasts' target vector and simulated vector for all currently running simulations. Default value is 0.2.

To change my original question  where in game can you access these?? is it in cheat mode ?

[2cool4u_1]

1 hour ago, cableguy7uk said:

To change my original question  where in game can you access these?? is it in cheat mode ?

Yes. <ctrl>+<shift>+c, and type them in.