Classic Blowout Hair Collision with Other Objects

DarthD

I'm trying to create a scene with a woman, on her back, asleep on a bed. I start the simulation with her sitting up and end it with her lying down. The hair will not collide with the bed, it acts as if the bed isn't there. The bed is visible in the simulation and I've tried parenting the bed to the character. I also removed the bed and created a primitive plane with the same results. Another attempt is to leave her lying flat and move the plane up under her. I'm out of ideas.

 

 

Richard Haseltine

How many polygons in the mattress surface? How many divisions in the primitive you tried instead?

DarthD

The bed has a lot of polygons, the primitive only had one. I'm trying again with 1000. I just tried a different hair and have the same problem. I'm sure I was able to do this in the past but maybe I have a faulty memory. 

DarthD

https://youtu.be/bBVUpUxdEF0

 

Here is a video with two different types of hair. The plane has 1000 polygons

barbult

If you select the plane and look in the Parameters pane in the Display section, does the plane have Visible in Simulation turned on? In the Surfaces pnae, does the plane material have Visible in Simulation on?

DarthD

Yes it's on. I finally got it to collide by adding a smoothing modifier. Still working with it though. If I start with the plane far enough away so it doesn't intersect the hair then move it in until right behind the head, the hair collides at first then punches through about halfway to the head. I tried again rotating the character forward so the hair falls toward face, then move the plane to the back of the head and rotate the character on her back, The hair stops simulating before it reaches the plane. 

 

barbult

Have you tried changing simulation settings, like good, better, viewport? I think I have that hair. I'll try it when I'm on the computer.

DarthD

Yes i've tried all three The hair explodes with the lowest setting

barbult

OK, I tried it, and it works fine for me.

• I loaded the base G8F and loaded the Classic Blowout Hair fit to her.
• I put G8F into a reclining position (rotated on X axis to be nearly flat).
• I created a plane 6 Feet with 1000 divisions.
• I applied Linday's Simulation Settings that come with the hair, but I changed the Frames to Simulate from "Current" to "Timeline Play Range". Settings are:
  • Gravity 6
  • Air Resistance 2
  • Initialization time 0
  • Simulate from memorized pose unchecked
  • Timeline Play Range
  • FPS Multiplier 3
  • Subframes 8
  • Iterations per subframe 32
  • Collision mesh resolution Viewport
  • Collision mode Best
  • Collision iterations per subframe 3
• At frame 0, I moved the plane down below the hair.
• At frame 20 I set a keyframe with the plane moved up just below G8F's head.
• I used dForce Companion to start the simulation
• When I ran the simulation, at every frame, the viewport would show the hair poking through the plane and then actually colliding properly with the plane. It oscillated back and forth like that in the viewport for the entire simulation.
• When the simulation ended on frame 30, the hair was properly collided with the plane and looked lovely.
• Scrubbing back through the viewport shows the hair properly collided at every frame. I doesn't poke through at each frame anymore. That seems to just be an artifact of the simulation process.

I made screenshots. I'll try to upload them later, when/if the forum upload works.

barbult

I'm using a Windows PC with an NVIDIA graphics card. How about you?

DarthD

Same,  Windows with NVIDIA. What is DFORCE companion?

barbult

It's just a convenient way to access and change simulation settings. You can find it in the Daz Store.

barbult

Here are my screenshots of the finished simulation, and a render. I tried to attach the scene file, but it won't upload. The screenshots are from above, below, and the side.

barbult

I just had a thought. What tool do you have selected when you run the simulation? Some simulations behave strangely when a geometry tool is selected, like the Geometry Editor or Mesh Grabber.

Edit: No, I don't think that is the issue. The Linday hair is not Strand-Based. I tried the simulation with the Geometry Editor tool selected, and it still worked fine.

DarthD

I finally got it to work. I think the issue is I was using animate to move the bed, plane or character. I left her lying down and moved the plane in the timeline and it worked. Then I used the bed instead of the plane and that worked as well. The issue now is this is supposed to be an animation where she turns her head and when that happens the hair sticks through the bed again at that point. Her head movement is with a aniblock so I guess I need to move her with the timeline as well.

Richard Haseltine

Yes, AniMate can be a problem - the general advice is to bake to the Timeline. Sorry we didn't think of that.

barbult

The animate issue is news to me. That's good to know. Thanks, Richard.

DarthD

I hate baking because the character seems to always jump to some other location. I corrected it with the graph editor though. Just learning this tool