XGen inverted Grooming brush

[Parmenides]

Hello, while using Xgen and the grooming brush sometimes it has no effect because the brush tries to paint on the inside of the model. The image below shows the direction as painting inward which is of no use. Is there a way to invert this? Xgen allows to "Flip to the other side of a surface" in the primitives but that only affects the fur/hair somewhat like a reverse normals. I don't see any settings for the brush.  I have tried all of the options under Mesh Display and done a Cleanup under Mesh, but nothing seems to change it. This only happens on certain models and not all. 

[slimboJoe]

I think your geometry is inside out.  Go to MESH DISPLAY menu and choose REVERSE.

[Parmenides]

No, the normals are not reversed. I have tried reversing them and then the guides, texture and hair switch to the inside (and the brush is still inverted). 

[slimboJoe]

Weird.  I tested a on a simple sphere.  When I reverse normals from the MESH DISPLAY menu, the hairs continue to point outward, but the grooming brush reverses, producing no effect like you experienced.

When I turn on FLIP TO OTHER SIDE OF SURFACE, strange things start to happen.

Try using Houdini.

[tony.su]

Could you zip and upload your scene file? I'll test it.

[Parmenides]

Zipped scene file.

[tony.su]

Sorry, I tested. As you said, it don't work. And I don't know why. I'll report our development team.

[tony.su]

My ccolleague tested. And give me a solution. Select the mesh and go to Mesh Display > Set to Face. It's like the normals are corrupt or something.

[tony.su]

I have a question about it. Where you get this model, or which tool you use to make it? My ccolleague want to know it.

[Parmenides]

Thanks Tony, I had tried Average, Conform, Reverse, Set to Face, and set to Vertex Normal before I originally posted as well as Mesh Cleanup. I just tried again but it still doesn't work (hair faces inward).  This model was originally created in FormZ. Thanks. -Derryl

 

[tony.su]

I test on the model you uploaded. Set to Face is works. But I'm not sure why on your new model it don't work. Could you upload this new model?

[Parmenides]

I tried 'Set to face' many times using the regular Xgen and the newer Groomable splines (which doesn't show the direction of the brush). I have included the scene. The mesh has also been used in other programs without issue (including ElectricImage in the render below). 

[tony.su]

Normals issue. The normal of this model are inside. Use Mesh Display - Reverse to reverse the normals. 

[Parmenides]

Tony, you are correct this is a normals issue. I mistakenly used this as an example thinking it was one of the problem meshes. With those I can assure you that I tried everything in Mesh Display menu before posting. If I am able I will create a small video showing the problem exactly. As noted by others reversing the normals on the ones in question will flip the fur to the outside but still leaves the control splines inside among other strange things. Thanks for your help. 

[tony.su]

Thanks for your report. If the tools is not good enough, our development team want figure out why. So they ask me to collect those model. We want to help our customer!

[Parmenides]

Thanks Tony. Here is an example video showing what happens to some models. The abdomen mesh is fine, but the thorax and head refuse to let me brush them because the control splines are on the inside. When using "Groomable Splines" you can't see the splines for some reason but when you use the older XGen method you can see that that is the issue. Even though I used Mesh Cleanup and Set Face, I will rebuild them from scratch from now on. I thought there may be a simpler solution like flipping the control splines because they appear to function independently of the normals. 

https://www.dropbox.com/s/76fkj7ixfsqanlh/BrushNotWorking.mp4?dl=0

[Parmenides]

Hello Tony, I'm back.  I deleted my prefs, rebuilt my models from scratch and XGen still isn't working correctly. Here is what I have discovered:

- If I create a sphere, select it, and in the XGen Interactive Groom Editor menu/Create/Interactive Groom Splines I will have fur and it will be groom-able.

- BUT, if I create anther sphere, add another description the same way, the second sphere is not groom-able. 

- If I delete the first description, I can then groom the second sphere. 

I have done this many times and only the first description works and the second will not work unless you delete the first one (only one at a time).  Can you confirm this? Thanks.  -Derryl 

[tony.su]

It's fine on my computer.

[mspeer · Accepted solution]

Hi!

I can confirm this for Maya 2018.2 on windows.

Without further adjustments (see below) some Grooming Tools work on both spheres, like Density and Place and

some others only work on the first sphere, like Length and Noise.

What you have to do is to click on Edit in the Sculpt Layer of the description you want to work with, if "Edit" is red this description works with all Grooming Tools correct.

[Parmenides]

Aha! Thanks, that is what I was missing. I have rebuilt the meshes, installed on different computers, etc. and that was the problem. I was starting to think it was a Mac thing but I was just missing that step. Thanks.  -Derryl