Boolean Operations

[Anonymous]

Hi everyone,

some weeks ago I started to use Fusion 360 in order to create a breast model for my master thesis.

I have to realize a stratified model (each layer will represent single breast tissues, as skin, fat, gland, etc): 

at first I crated a homogeneous breast model, in order to have the correct shape, then I scaled this to obtain three models with the same shape, but different dimensions.

I have to include these other two models within the first one, to obtain the stratified model: the posterior planes of these three models overlap, so my question is how to work in order to obtain a perfect stratified model where the posterior planes are not overlapped.

I think that I have to use some boolean operations, but I don't know how to proceed.

Thank you so much,

Maria

[davebYYPCU]

Not totally sure what you mean, 

something like this, same body was copied and moved down, then pasted again and moved down.

Cut the inside one from its cover, then cut the base level.

File attached - step up the timeline to see the stages and settings....

Might help...

[Anonymous]

Hi,

thank you so much for your reply.

You understood very well what I mean; unfortunately I'm at the beginning with Fusion, so I don't understand what you said.

I create the three components as you suggested me, but then I'm not able to align these, in order to cut and proceed (I'm not sure if what I wrote now is clear...)

[davebYYPCU]

Ok, then it is 2 ways, 

I made one body, in place.  Copied it, and the copy is also in place, until I used Move Tool to slide it down,

(inside the original). 

Make another copy, and move it too.  So they are all aligned now to suit. 

I cut the inside out with the 2nd body, with Modify >  Combine > Cut.  Do that twice, or more etc.  Cut the bases off, with Split Body.  

The other way is not so different, make the Component bodies (not aligned), and then the placement is with Align / Move / or Joints.  To do it this way, you will need a consistent known point within the body of each Component, to make the positions coincide.  When in place, make the cuts as above.  So in my model, the centre point of all the cut faces will be in the same place when finished.

Might help...

[psych_uk]

I've made a basic model that shows the layers you require in 3 bodies, to adjust you can edit the sketch, and even add dimensions.

Seems if you want dimensions, sketches for each layer are the way to go.

On a personal note, I have never modelled a breast before, it's a great time to be alive.

[Anonymous]

Unfortunately I'm not able to open your fil, because I'm working with iOS, so I'm not able to download Fusion latest version which is needed to open it!

Anyway, thank you so much for your help!

[psych_uk]

Ok, this is what I ended up with.

One sketch, 3 revolves.

Just another approach.

[Anonymous]

Exactly, I have to create the same thing.

Now I have my three bodies, and I must insert each one in the other, in order to create the stratified model.

My issue is to perfectly align these objects, and then I don't understand very well why I have to split my body.

In attachment you can find my file.

Thank you so much,

Maria

[psych_uk]

Ok, I think I see where you are going with this.

This is what I got just by moving my bodies.

I see you prefer more complex bodies.

In order to cut out the 'parent'  body to accommodate the 'child' body, first move the child body into position (where you want it to end up), then use [Modify] [Combine]. Set the operation to [Cut], the 'Target body' to the outer body and the 'Tool Bodies' as the inner body.

Make sure to select 'Keep Tools' as if you don't you will lose your inner body.

Repeat this with the 3rd body, cutting it from the 2nd body.

[Anonymous]

I tried all the afternoon, but I was not able to find a solution.

The problem is that I cannot align each object which the other, in order to obtain a perfect cut.

I upload my file and my results.

Could you help me?

Thank you so much

[psych_uk]

Not surprised. I tried to as well, and I got very close.

Firstly, with reference to your file attachment, I firstly tried to move the bodies around the origin so I could slice the back with an offset plane to create a flat surface in which to sketch reference points (that's what you are missing). Once you have reference points you can simply move those bodies in and out, knowing you are always referenced.

However, you didn't create those bodies anywhere near the origin, at least that was my experience, I had to zoom right out so the bodies were specks on the horizon just to see where the origin was.

Having aligned the bodies around the origin, I find that the back of the bodies are not vertical to any plane. Now we are looking at angular planes and eyeballing the positions and angles.

That's where you lost me.

[TheCADWhisperer]

---

@Anonymous wrote:

...create the stratified model.

My issue is to perfectly align these objects,.

---

I have to go to class in a few minutes, but if you can't figure out the following steps - I will make a video later.

Shell

Offset surface

Thicken

Offset surface

Thicken

Bodies are modeled in position and no alignment needed.

[jeff_strater]

A couple of observations:

• do you really want this sort of faceted model?  I suspect that you don't.  I assume that the original data is mesh-based somehow.  There are ways to produce a smoother result using TSplines, if you have a quad mesh, or can convert to a quad mesh.  In this case, it might be easier to just use Pull in the Sculpt workspace to create a TSpline body that uses the existing data, but is much more of a smooth, organic result
• Please disable Contact Sets, unless you really need them.  They will slow down performance significantly.

[Anonymous]

I try to do what you suggested me, so I move the three bodies around the origin.

Then, how can I proceed? Do I have to create a plane aligned to my models and then...?

Thank you again!!

[psych_uk]

I would wait until @TheCADWhisperer gets back to you.

He's good. And he seems to know how you could do this more simply than my approach.

[davebYYPCU]

You might find the answer to use Section Analysis, with that active, and editing a few times, you can move each body to align with an internal cut, but the scaled edges are not exact.

Your file with bodies near the origin, and using move with section, have got it close.

Scaling each body, id not what I would do, I would do as the Whisperer says, make the outside skin, with surface body, and thicken.

Might help... 

[TheCADWhisperer]

What is the source of the geometry that you attached?

If you examine it closely - you will observe that it is entirely planar faceted triangles.

This is not representative of the real world.  How closely do you need to represent the real world, or is this for an idealized schematic/illustrative image?  (Otherwise I guess you could use a photo in place of modeled geometry.)

What is the purpose of this effort - I suspect that you will want better source geometry for the effort.

[Anonymous]

Hi everyone,

talking with you, I understood that my model has a lot of issues. 

I'm worried, because I need this model to proceed with my master thesis.

Maybe the better option is to rebuild the breast model, in order to create a stratified model in a easier way. What do you think?

Thank you so much,

Maria