Curve Hair Interpolate Density strange issue

Support Modeling
1

When use a scale smaller size object -Apply scale and add curve.
Then enable Interpolate by default set, the curve is gone.
The density need set several ten thousands of can get litte curve.
Its even hard to get little toy fur. Whats wrong here? Why happened. Troubles here couples of days.
Create plane and scale to 0.5m, Apply scale
Attached defaut curve fur
Change Density to 10
Object only show 4 curve
Enable or disable interpolate ,no change

issue1
issue12713Ă—1373 245 KB

Edit mode show many curves

issue2
issue22756Ă—1269 272 KB

issue3
issue32121Ă—1204 2.31 MB

Set 10k density only get few hair.
Set 2M density can get liitle more.
It is not right.
CurveFur_Density issue.7z (739.9 KB)

1 Like
2

That Interpolate GN culls the guides based on density which depends on size of mesh. So your example is expected behavior.

For the hat you can check the following:

  • does the “surface” object and UVMap in the modifier panel match the surface adn UVMap in the Curve Data panel?

image
image

  • Is the UVMap unwrap good or broken? - if the unwrap has a issues (e.g. overlap) then the hair will have issues.

Alternatively consider making your own interpolate GN which doesn’t cull the guides… maybe something like this where the density is determined by the resample length:

image
image925Ă—772 85.9 KB

Or copy the Interpolate GN and customize it to your needs.

Good luck.

2 Likes
3

Thanks for your kindly reply.
I checked Surface/UVmap is same.
UVmap checked ,there is should be ok.

issue4
issue41513Ă—1179 2.41 MB

issue5
issue52390Ă—1511 1.34 MB

Any scaled and applied scale objects all have the weird fur.
Upload the hat file, could you help check .
Modeling_Potato.7z (1.2 MB)

4

I can’t open 7z files but I have some ideas about what is going on…

Your hair curve isn’t parented to your mesh so when you apply the scale the settings go out of sync. You also would need to apply the same scale to the hair curves (ctrl-a). When you apply the scales all the settings of the modifiers after the interpolate are way too large and will cause more than half your fur to go inside the model… The Distance setting for both Hair Curve Noise and Frizz need to be very small ~ 0.0001m or most hair will go inside the mesh.

So, its not the interpolate that’s the issue, its the modifiers after the interpolate that’s the issue.

Hope that helps.

1 Like