[Solved] Dforce and Cloth Surface Spikes
James
Posts: 1,036
After retopoligizing, my cloth has spikes again after sim.
Last time, I get rid the problem, by increasing the number of polygons. It was using Marvelous Designer and quadrangulated.
But this time increasing using the same method for my retopologized cloth in Blender doesn't help. It keeps spiking everywhere.
On certain poses the spikes even more prominent.
What to do?
Post edited by James on
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Hi, so I have a bit of clue with these spikes problem.
I did some experiments.
After I deleted some of the bottom part of the dress, the spike is gone.
(I didn't clean too much of the mesh just for experimenting)
But what's on the bottom part area effecting the occuring of the spikes?
Maybe.. is there a certain type of edge flow, that Dforce doesn't like?
I don't think it is the lower part casing the spikes. Then it should set traces towards it.
Spikes can happen, and I don't know a certain way to avoid them.
But how are you simulating? Single frame or animated?
I usually always use animated, then I can see changes along the timeline, or let it run longer if something needs to settle.
You can also increase number of subframes, to give it more time to find a solution.
Well, I gave more tests, and the more dense the lower part is, the crazier and bigger the spikes are.
https://prnt.sc/d6R70UIwoM18
I used Single frame.
I tried double the subframes, still the same.
Pfff, maybe it's just the way current Dforce works.
All I can do currently is reduce the density of the lower part, to minimize the trouble.
During a sim every polygon pushes against the one next to it, and that pushes the polygon next to it - continuing out to the edges, similar to when you put a ball into a ball pit, they all push against each other until there's room for all the balls. Lots of little balls will have lots of movements, larger balls will settle quicker.
You will definitely get better results with lower resolution polygons (use subd in DS to get higher res looking mesh) and you will get better results with square polygons because it pushes out evenly against the polys next to it.
Avoid triangles as much as you can, especially along cutlines. It will cause weird issues when you turn on smoothing, especially if its long thin triangles.
The same answers we gave you before: Your mesh is too dense and you should stick to quads for dforce. Mada gave a good explanation of why.
@Mada
Which one is better retopologizing the mesh or use the quadrangulate automation from Marvelous Designer in term of making a product for consumer?
Do you have a link to her explanation as I haven't seen it.
I agree about quads as the tri's seem to have issues in DS.
Whichever method works for you - using quadrangulate in MD gives good mesh but often the loop flow is not as good. Some vendors retopo with ZBrush and that works fine too. Blender seems to be popular too.
I retopo by hand in Modo since I can control the loop flow and mesh density - but its very much whichever method clicks with you.
It is in this thread just above.
Thanks I thought you meant another thread...
@barbult
The mesh is in quad. If it's imported to DAZ it gets triangulated automatically.
It's normal.
This current mesh is a different mesh. Although the same shape.
I retopologized it in Blender.
Last time it was from Marvelous Designer, which already has no spike problem using your settings.
But this current mesh, even with less polycount compared to the last one, I got the spike problem.
And If I go too low with the polycount, I got skin poke through problem.
So, either with high density or low density polycount, with the current mesh, I got the spikes.
Long story short
I found the source of the problem. It's the bottom area.
If I cut it, I can go with high density polycount (If I want to) without any spike problem.
Somehow the bottom part of the dress causing the spike effect.
As an experimentation I added more polycount only specifically to the bottom area to test my hypotesis.
The result, the effect gets stronger.
Thus, what I do now, is to reduce the density of the bottom part to reduce the effect. Not the whole dress like before.
So this is a different case with simillar symptoms.
That can't be remedied with the same answers you all have helped me before.
Daz studio does not triangulate, that is hapening on export. Daz Studio will not adjust the mesh.
@Richard
Mmm..
I tested to open the exported obj files from blender and marvelous designer in Maya.
The exported files don't look triangulated on export.
To make sure,
I also cheked DAZ starter content Dforce outfits .
They are triangulated too on base resolution.
What am I missing?
That is not how they load for me - you have lost the SubD (no faint edgs btween the edges of the base mesh) and added triangulation. Check that that is the current version, and try reinstalling.
Okay I figured out the difference. I have also reinstalled as suggested.
And it turns out it's not the version difference.
It's the Drawing pane settings. There's a dial called "Triangulation Wireframe Opacity".
Mine is at 100%. Probobaly yours is at 0% (default value)
At 0% my mesh also looks quad.
But the fact that every mesh has triangulation (appears at 100% Triangulation Wireframe Opacity), DAZ must has triangulated it.
Because in theory without triangulation, Daz would cost a lot of computating power when doing things.
Quads are harder and power intensiver to calculate than tris.
At least that's what I know why game engines triangulated all meshes in the game.
That is, I think, a preview of how the object will be triangulated at render time - it isn't triangulated now.
That triangulation also affects dForce. There is a Daz video tutorial on rotating triangulation of selected polygons to achieve a smoother dForce drape.
Yes, I think the recommendation about having a quad mesh is esentially about having something that will behave nicely when processed.
Triangles do work, but they can have issues, but so can quads.
If you are having issues, try lowering the Collision Offset value; it defaults to 0.2, but I rarely leave it at that and generally set it to 0.1 and on occasions lower - which can also (very occasionally) cause issues.
Soooo... for anyone who have similar problem.
The solution is pretty simple: I delete one horizontal loop at the bottom.
Somehow it solves everything..