ok ;)

draw 2 separate line to figure the borders of the crack

draw a small arc to join the 2 borders of the crack ( not flat ) in a perpendicular plan

select the small arc and choose the sweep command

select the 2 rails ( borders of the crack )

so you'll get a crack with a volume

place this on your curved surface

boolean union if neccessary

i try also Nsided command but it gives unpredictable results sometimes fun sometimes crap ;)

the borders of the crack can be distorted with a script " distortcurves"

with this script you can add deformation ( just a little bit 0.1 on one or 2 axes )

look at the right

here you go

http://moi3d.com/forum/lmessages.php?webtag=MOI&msg=8440.1

place files in moi3d command folder

Hi Tony, curve to curve flow won't work for that because it does not know how to align itself to the surface normal. That might be possible to add as an option in the future.

Surface-to-surface flow might work for you here though, check out this thread for an example:
http://moi3d.com/forum/index.php?webtag=MOI&msg=7516.1

- Michael

Tricky methods!

Thanks Michael excellent I try now .... if I can post here another problem I have with Flow .... I would like to place those two screws on the red curve to the gray surface but I can't ... I don't know if I'm wrong.

I tried with orient but it doesn't position me well ... how can I do it?

Sorry here are the files

Hi Tony, how are you wanting to place them, should it be like a projection? But with a projection onto an angled surface or with Flow, the result will have deformation in it like getting stretched out.

Do you want it something more like projecting the center point of it onto the surface and then having the knob not be deformed but only rotated to align with the surface normal?

- Michael

Surfaces have a "Normal" snap. So I can draw a line in the normal.




I then can use copy with origin and PastePart to set my object on the surface, facing the right direction.

Do you want it something more like projecting the center point of it onto the surface and then having the knob not be deformed but only rotated to align with the surface normal?

Yes Michael

Hi Tony, I'd probably draw a line down the projection direction like this:



Now select the line and the surface and then use Construct > Curve >Isect. That will generate a point at the spot on the surface you want to snap on to using Orient:



To use orient, select your knob, run Transform > Orient, place the base point onto the bottom of the knob, right click since you don't need to set any base rotation. Then for the target point place it on the point that was made with the intersection, and then right click to finish since you don't need to do any rotation there either. So that's 4 clicks total, left click on the base point, right click to end rotation picking, left click on the target point, right click to end rotation picking there.

Note that it will initially look like the knob isn't on the surface, but that is just a display artifact since the surface has a rough display mesh in that particular area. If you export to a polygon mesh format you will be able to see it better. Here is a screencap video:



Note that the bottom of the knob is planar but the surface is curved. If you plan to cut a hole in the surface you would probably need to push it in a bit further so it fully intersects with the surface.

- Michael

Thanks Michael

How do you view that sideways mesh view command you see in the video?

Hi Tony,

re:
> How do you view that sideways mesh view command you see in the video?

I have a keyboard shortcut set up to save to a polygon mesh format, the shortcut is set up like this:

SaveAs c:\test.obj

- Michael

Thanks Michael

Michael what kind of settings do you recommend for eportation for surfaces that are regular enough for rendering?

Hi Tony,

re:
> Michael what kind of settings do you recommend for eportation for surfaces that
> are regular enough for rendering?

Well it depends on the particular geometry involved.

The main thing to use is the angle parameter - that measures the angle between surface normals at polygon vertices and if it is beyond that angle value it will subdivide it further. So for example an angle value of 5 will subdivide until surface normals are less than 5 degrees apart. This will make a denser mesh in areas with tighter curvature.

However, a surface that is pretty large but also only shallowly curved (like you have here for example) can not get enough refinement from the angle measurement alone. For that case then you want to introduce additional dividing by using the "Divide larger than" parameter. That takes a distance value and subdivides polygons that are larger than that distance across. So you want to put in some value proportional to your overall object size like if your object is 10 units across try a "divide larger than" of 0.1 and see if that gives you enough refinement or not. If not go lower in steps.

But generally start by moving the slider around which controls the angle parameter.

- Michael