Collision Offset

Comments

• felis Posts: 5,721

  October 20 edited October 20

  In the surface settings, in the dForce group, there is a collision distance, and the simulation target to keep everything at collision distance.

  So if you have a mesh where parts of it the vertex distance are below the collision distance you will get that warning. If you have a smaller amount of warnings it is usually fine.

  But with many warnings there is a big risk the it will explode during simulation.

  You can lower the collision value in surface settings, just be aware that it will also impact e.g. collision with a character with a higher risk of clipping.

  If it is something you have modelled yourself, you should investigate in your model if the density is needed. You can have different collision distance per surface.

  Edit: what I call collision distance is formally collision offset.

  Post edited by felis on October 20
• richardandtracy Posts: 7,077

  October 20

  I have, with some Poser Dynamic Cloth conversions, resorted to scaling the characters up by 5x or 10x before doing the simulation as a number of entire facets were smaller than the collision distance and rather than fiddle with all the collision settings I just scaled the character. If the facets or collision distance are too small I fear that you can get into decimal point rounding problems. Anyway, it's just a different way of doing what @felis suggested.

  Regards,

  Richard
• crosswind Posts: 9,537

  October 20

  Whether it's bad or not depends on different case: 1) not really bad but just time-consuming with the dForce ready garments you bought... because vendors usually tested the produts; 2) more or less bad with the non dForce ready garments to which you added dForce Modifier ~~

  In your case, the vertices that have lower distance than preset Collistion Offset are preared to "sprung" to default 0.2cm... but you can reduce Collision Offset to 0.08 ~ 0.09 on dynamic surface(s), as well as increase the value a bit in Contraction-Expansion Ratio, to give it a test.

  Save your Scene beforehand ~ 
• richardandtracy Posts: 7,077

  October 20

  One should ALWAYS save the scene before any render, any simulation, any creation of an ultrascenery scene, basically any big operation in DS.

  Regards,

  Richard
• jmucchiello Posts: 599

  October 20

  felis said:

  In the surface settings, in the dForce group, there is a collision distance, and the simulation target to keep everything at collision distance.

  So if you have a mesh where parts of it the vertex distance are below the collision distance you will get that warning. If you have a smaller amount of warnings it is usually fine.

  But with many warnings there is a big risk the it will explode during simulation.

  You can lower the collision value in surface settings, just be aware that it will also impact e.g. collision with a character with a higher risk of clipping.

  If it is something you have modelled yourself, you should investigate in your model if the density is needed. You can have different collision distance per surface.

  Edit: what I call collision distance is formally collision offset.

  No, I've never made any clothing. This is a store asset. https://www.daz3d.com/dforce-radiant-dress-genesis-9-and-genesis-8-female

   
• felis Posts: 5,721

  October 20 edited October 20

  Hmmm, it is a fairly simple dress. I see no reason for it to have such high mesh density.

  How many faces are there in the dress? If you select the dress in the scene tab, and click info you can see mesh details.

  Have you tried to lower collision offset?

  Post edited by felis on October 20
• crosswind Posts: 9,537

  October 20

  dForce Radiant Dress Genesis 9 and Genesis 8 Female works well on my side. They can be instantly simulated with out-of-box settings on G8/G9 Base... with spring report for around 0.5 second.

  They should perform the same on other characters... even on heavily-customized ones ~
• jmucchiello Posts: 599

  October 20

  Primary Selection :

  Name :	G9 Base V3_8093
  Label :	Radiant Dress G9
  Class :	DzFigure
  Vertices :	32,089 / 8,093
  Triangles :	0 / 8
  Quads :	31,796 / 7,943
  Total Faces :	31,796 / 7,951
  Total Lines :	0 / 0

   

  I finally loaded the figure and dress/hair (and nothing else) into a separate scene. I set the collision offset to 0.080.

  Memorized Pose OFF: it took 15 seconds and there was pokethru. Not unexpected.

  Memorized Pose ON: 52 seconds and it looks great. There was only one spring note in the log file:

  2025-10-20 12:58:39.640 [INFO] :: Spring(0, 1) of node "Radiant Dress G9" extended: rest length < collsion offset (0.0234624 < 0.08001)

  2025-10-20 12:58:39.648 [INFO] :: Shortest spring had length: 0.0234624

  2025-10-20 12:59:28.811 [INFO] :: Total Simulation Time: 51.39 seconds

  Neither simulation with the new setting exploded. That solved the problem. 

   
• crosswind Posts: 9,537

  October 20 edited October 20

  Ah, that's great but odd ~   On my side, I only see a couple of springs in DS log: (ss1)

  I don't know why it performed differently on your side ~~ or that long report of springs might come from other dForce items....

  

  

  SNAG-2025-10-21-049.png

  2560 x 1392 - 507K

  Post edited by crosswind on October 20