Pinching issue with clip curve

[AlexanderTheGreatest]

I have been trying to do some hard surface sculpting using extraction and then by refining with the clip curve brush to straighten out the edges.

Unfortunately no matter what I do I get some ugly pinching near the sides or the edges of the mesh which is driving mad.

I have been trying to find a work around, tried using edge loops. or group loops and the likes, but no matter what I do I get this ugly issue which sometimes even ruins the consistency of the meshes thickness.

How do you guys deal with this issue?

[musashidan]

This is the nature of the clip brush. It’s physically mashing all that clipped Geo flat against the clipline. So this is the artifacting you’re experiencing. It’s not a good technique for finish Geo, but is more for building forms/shapes, which you would then clean up with trimDyn/polish/etc brushes and retopology.

There is also the Trimcurve brush. This behaves slightly differently, and also slices the mesh and fills the hole rather than mashing the Geo - exactly the same as doing a: slicecurve>hide>delete hidden>fill hole.

[AlexanderTheGreatest]

This is the nature of the clip brush. It’s physically mashing all that clipped Geo flat against the clipline. So this is the artifacting you’re experiencing. It’s not a good technique for finish Geo, but is more for building forms/shapes, which you would then clean up with trimDyn/polish/etc brushes and retopology.

There is also the Trimcurve brush. This behaves slightly differently, and also slices the mesh and fills the hole rather than mashing the Geo - exactly the same as doing a: slicecurve>hide>delete hidden>fill hole.

Thanks musashidan for the reply.

I have an issue with the Trimcurve as well. It sometimes trims it sometimes doesnt. It seems to work only on low poly models for some reason in my case and I dont quite understand why.

[musashidan]

Yes, the trim/clip curve brushes take some experimentation to get the feel for what they can and can’t do. Not sure why you’re getting the impression that the trim brush works better on low-poly. It should be just as effective on high poly.

As I say, it’s really just a matter of getting a feel for them, and their limitations.

[AlexanderTheGreatest]

Yes, the trim/clip curve brushes take some experimentation to get the feel for what they can and can’t do. Not sure why you’re getting the impression that the trim brush works better on low-poly. It should be just as effective on high poly.

As I say, it’s really just a matter of getting a feel for them, and their limitations.

Well when I use the trim, most of the times it doesnt seem to do anything. I am not sure if it does something which is not visible to me.

I have a tutorial on hard surface techniques from EAT3D and it drives me mad how he does almost all the work with mask extraction and then the clip brush without creating countless pinching errors

I run his tool file on Zbrush to check it and it is pretty much flawless. It boggles my mind

[musashidan]

If you like I could take a look at the ztool that you’re having a problem with?

[AlexanderTheGreatest]

If you like I could take a look at the ztool that you’re having a problem with?

Ok something I just noticed. Does the trim curve work only if it is a straight line? I mean, if I curve an angle, or make a curve it doesnt work?
I just noticed that this is why it didnt work. But this isnt helping me in making more interesting shapes.

edit: When it doesnt trim an area it creates a new polygroup exactly where the line has passed. Its like it sometimes works like a trim curve and sometimes like a slice curve.

[musashidan]

The thing about the Trim brush is because it’s slicing and recapping the mesh rather than just mashing it together, it has to make some pretty complex calculations to figure out how to cap that hole. So if you try to slice shapes that are at hard angles it can’t figure out how to cap the hole, so you will notice it leaves behind a convex area of the area you trimmed.

It’s hard to explain but if you have a look at my vid tutorial I explain some of the things to understand about how the slice/trim brushes function. It starts at about the 13min mark:

//youtu.be/Xg8FRbqSNt8

[AlexanderTheGreatest]

The thing about the Trim brush is because it’s slicing and recapping the mesh rather than just mashing it together, it has to make some pretty complex calculations to figure out how to cap that hole. So if you try to slice shapes that are at hard angles it can’t figure out how to cap the hole, so you will notice it leaves behind a convex area of the area you trimmed.

It’s hard to explain but if you have a look at my vid tutorial I explain some of the things to understand about how the slice/trim brushes function. It starts at about the 13min mark:

//youtu.be/Xg8FRbqSNt8

My apologies for not replying sooner. I was very busy.
Thanks for the video. I am checking it right now