Make Hole Tool (2)

[casey33]

ok, i used the make hole tool and cut out a specifically shaped hole in the front and back of my geometry. now that that is done, you can see inside the geomety. what is the best way to fill the new hole so that it still looks like a solid object?

an example of what i want it to look like is when you use a boolean-difference. the hole is cut and it looks like it cut through a solid object rather than a hollow mesh.

thanks for any/all help!

casey

[davvey]

Hi
One option is detach the faces not make hole then extrude the face into the poly. This will give you some poly faces which are same shape as your hole. Delete the faces used for the extrusion then Reverse the faces or normals and do a polyUnite to combine with original. You can then merge vertices and edges to ensure no starys.

A neater option maybe to select the edges of the hole and extrude them into the piece. This will give faces through the poly, use local transform and keep faces together.

[foxynutron]

I have a related question...

I was able to project quite a complex pattern onto a sphere and then trimmed it just fine. This created a sphere shell with a bunch of patterned holes in it.

Question: is there an easy way to give "thickness" to that cut out sphere / shell?
I've been trying to duplicate it / resize it and then creating a loft, but that didn't work too well.

and a process of creating Filet's between each cutout whole and its duplicate (sphere within a sphere) is a veeeeeery lengthy and tedious process, does anybody know how to do this in an easier way?

kind regards,

[davvey]

Hi
I assume you are working with a Nurbs Sphere as you mention projecting. If so just select the edges of the hole and extrude them in or out.

Another option is to duplicate the original sphere after trimming and scale down to say 0.9 0.9 0.9 or whatever thickness you want then loft only the trimmed edges of both spheres together.

If it is a polygon sphere with a hole then just extrude the edges. Or if you want depth to the whole surface select all sphere faces and extrude inwards or outwards to give depth required.

[foxynutron]

QUOTE(Davvey @ 04/03/07, 05:02 PM) [snapback]263476[/snapback]
Hi
I assume you are working with a Nurbs Sphere as you mention projecting. If so just select the edges of the hole and extrude them in or out.

Another option is to duplicate the original sphere after trimming and scale down to say 0.9 0.9 0.9 or whatever thickness you want then loft only the trimmed edges of both spheres together.

If it is a polygon sphere with a hole then just extrude the edges. Or if you want depth to the whole surface select all sphere faces and extrude inwards or outwards to give depth required.

that's exactly correct it's a NURBS sphere. Is there a way to project a flat pattern onto a polygon in a same manner?
what I'm essentially trying to do is to turn a flat 2D pattern into a 3D object, and the only way that I figured I can do this symmetrically is by projecting it onto a sphere.

I will try what you suggested, however I did try to loft the two spheres together (the only difference was that I did an offset rather than scale down to get a smaller sphere inside)

the problem is that the trimmed edges are composed out of a lot of sections, and I think you have to select them in the right order (on both levels... the smaller and the larger sphere) otherwise the loft gets all screwed up, and twisted etc. Now multiply that by 100 trimmed surfaces and you have 2 days of work

I wish there were an easier way to do this.

[foxynutron]

Here are draft renders to visualize what I'm trying to achieve.

[davvey]

Hi

Use a Polygon sphere and some Booleans. Image below made in ten minutes using two cubes to make a cross by Boolean Union then duplicate 5 times with 60 degree rotation (after Boolean the cubes pivot is at 0 0 0) so it was simple to duplicate then Boolean difference each cross from Sphere. Second image is after using a Boolean sphere inside the original to hollow it out.

[joojaa]

Loft the individual triim curves together,

Dawey if hes intentionally using nurbs then dont you think he has some deecent reason for it?

Heres a image that does the same,, offourse i do it as a outcrop not in. (note ies nurbs as doing this with polys is a extra hustle. As getting the normals to play ball i hard enough)

[davvey]

Hi Jooja

I had already mentioned using trimmed curves and lofting but He did also ask about doing something with Polygons

QUOTE
that's exactly correct it's a NURBS sphere. Is there a way to project a flat pattern onto a polygon in a same manner?

So if you Boolean a "Flat" cube surface with a sphere is the same effect as projecting a curve onto a nurbs surface.

[joojaa]

Well, yes thats what you'd expect but its not entirely true.

Polygons are well, not true to the shape of the object at hand so wehen you boolean something out of a curved polygon surface you get a boolean on the faceted surface which represents the samples of the apparent surface, so what your actually doing is making a exact change on something thats not exactly what its portraying.

Theres a additional problem regarding this. Because it does exact splits on the surface it also has the possible sidde effect of making nGons out of predictable edge flow meshes. That is unless your boolean hits the exact edgeloops but then why not extrude. This causes horrible problems on the mesh itself, because theres nolonger a predictable normal interpolation path to use. This can cause all sorts of very hard to fix artifacts on the object.

This is why you don't use polygon booleans, in general, because they do not work on the representation of the geometry but quite literary on the geometry, which is NOT what the surface is displaying itself to be.

In your picture out of fluke this works out quite well but theres absolutely no guarantee that will ever happen if the normals try to change over the surface by more than a few degrees. Especially whan you start working on it further.

[joojaa]

ok this question gets orbited around alot so i drew a picture to make above statement a bit clearer

fisrt in series shows in black the surface that you think the polygon in pink is. Second shows the poly boolean with normals in black and apparent surface in pink (note it can asses a number of relatedly shaped surfaces too due to its rather abgstract nature), third is comparrasion between what you want to get in blue and what you apparently do in pink.

Not quite what you guys expect eh! This is even worse in 3d.

Ok so its BIG tessellation gaps but on small scale this does not actually get any better its just easier to interpolate less data by hand This is why booleans on ploys are evil incarnate. Offcourse poly bolean away if your polygon does not abstract a a surface curvature. Also you might luck out, untill you start smoothing normals.

[foxynutron]

first of all, I'd like to thank you for your help with this. I'm a newbie, that tries to do something that's above my current skill level.

1) the reason I'm trying to use NURBS sphere is because I have a quite a complicated pattern (red image below) that I'm trying to "wrap" around a sphere, and the only tool that I found so far that would allow me to do it is the project surface tool.

what I've done is I trace the image above in CorelTrace, and then exported it as DXF. Imported into Maya as lines. Projected it onto a NURBS sphere and then used trim tool to cut out the wholes, leaving a nice 3D shell in place. so far so good.

next step was to give that shell some thickness. so I figured I'll just use offset or duplicate the outer shell and scale it down, and then use loft to create these sections between the two shells. Unfortunately each trimmed space (or a whole if you would) is not a simple regular shape (such as cube etc.) and is made of multiple line sections making it hard if not impossible to loft. just take a look at the flat image above, and see how many trimmed spaces it creates when wrapped around a sphere.

so far I was able to create the interconnecting sections (between inner and outer sphere) using Surface >Filet tool. but it's a very tedious process of selecting each trimmed space (which in turn is made up of multiple line segments - you can't select them as isoparms, because it doesn't see them as isoparms apparently). all of this has to be done in the right sequence otherwise the Filet surfaces can cross and make a mess.

I'll post a screenshot later on today to show you guys what comes up step by step when I try lofting these as well. I'll upload the source maya file as well, so you can try it your self.

[foxynutron]

Joojaa,

I forgot to mention thanks for your very informative explanation. I guess I landed with NURBS by the virtue of finding the project surface tool. Even though I know how to do boolean operations on polys, I could not imagine how to even attempt to use that in conjunction with my complex pattern that I'm trying to

Is my approach the right one? (projection on NURBS sphere and then trimm + Filet with a duplicate copy of the scaled down sphere?) do you have any suggestions how to make this process easier?

I spent hours doing this Filet manually, and the larger wholes worked out ok. (see the two images I initially posted, showing one [white] section between the spheres that I created using the Filet tool. The problem started when I started to connect the trimmed faces that have a lot of curves. I experienced that the filet started creating crossed walls (might've been my mistake, as the process is tedious, because you have to select all these lines in the trimmed spaces in a sequence... matching both the inner and outer sphere.) that is just insane...!

There must be an easier way to do this in Maya
... such as select the trimmed object and extrude it in both directions a bit to give it thickness.

[foxynutron]

ok guys.... here it is... I uploaded the binary here Trimmed sphere's - Maya Binary.

take a look and see if you can extrude, loft or whatever to connect these two shells in order to create a thick 3D cutout sphere.

I tried regular bevel, and Maya crashes as it uses up all 2GB of memory on my pc

so I tried bevel of fewer trimmed spaces on the sphere, and that came through, but the bevel is skewed to one side... and I don't know how to fix it. here's how this looks.

I guess I'll try to bevel this piece by piece, and then try to Boolean unite with a smaller sphere inside (because bevel created obviously the sides only)

[joojaa]

do you need them extruded straight or by arc?

[foxynutron]

by arc I guess (if that implies they'll be round at the ends of extrusions) in preparation of Boolean Unite with the inner sphere. If you'll open up the binary you'll see that there's a second scaled down sphere inside the outer sphere. the goal is to get a uniform "thickness" with the extrusion, and cap it with that smaller sphere.