Convert Body into a T Spline

[rwillardphil]

I would like to generate the basic shape with normal modeling tools, and THEN convert into a T-spline to manipulate and sculpt as needed.  Is that possible?

[Ndenekamp · Accepted solution]

You can, but only in direct modelling mode. To switch over, click on the little gear in the bottom right hand side, at the end of the timeline, and choose 'Do Not Capture Design History'.

Then go to Modify > Convert, and select one of all faces. Then switch to the Sculpt environment and edit to heart's content 

Niels

[gusspec]

I cannot see that this works at all, when I try this all I get is a large rectangular t spline face the size of the maximum extents of my model, and I can then manipulate that face but it not the model.

I cannot sculpt the 2 1/d shape,as it must be very specific

I also cannot use the extrude function in sculpt as it does not at all accurately follow the outline if my model

[luvmesweet]

@gusspec

Hello, actually you can do a conversion from BRep to T Spline at the parametric mode. You do not really have to stop recording. Just select "Create Form", then select "Convert" at the MODIFY menu and use the windows selection to select the whole solid. You can then modify the form.   The Extrude Command at the "Create Formm Mode" is doing something a little different from the Parametric Mode (without create Form). But there is a different kind of Extrusion that you can use. You might not aware of that yet. Select a vertex, an edge or a face or all the faces of one side. Then select Edit Form, and when dragging the arrow you should press and hold "Option" first in Mac. This will change into an Extrusion command and it behaves a little differently.  After that you can "Finish form" but beware, this way you ended up having the original body, which you might want to turn off the light bulb, and also a few unstitched planes. You can stitch them up by selecting Patch Mode and then select Stitch at the Modify menu and stitch up the unstitched planes. A few screen shots here. To modify more in TSpline mode you can try Crease, Uncrease, Insert edges, Slide edges etc.. Then perform a series of Edit form to get the shape you wanted.

1) A box is formed at the parametric mode, then select Create form, Select the whole solid and click convert. In the Convert box select "BRep". click OK

2) An Example of using Edit Form to extrude and edge. Select an edge, click edit form, press and hold "Option" then drag the arrow. You will extrude the edge.

3) Select all the faces of one side, and select Edit Form, Pressing and hold  "Option" then drag the arrow. A block of faces will be extruded out.

4) Then Click Finish Form. You solid is changed. But the Original Body is still there. You can play with the light bulbs. Just turn off the ones you do not want. The newly formed bodies are not stitched into a solid yet. Just unstitched planes. Select Patch Environment and select Stitch at the Modify Menu to stitch them together. A new solid is form. Your original unmodified one is still here. Just click the light bulbs right next to the bodies to understand the operatons more.

[gusspec]

this would be wonderful if I was starting with a cube or rectangle

I am starting from a traced outline of a JPG because I need that specific outline of an accurate shape for a machined part

I need to then shape the top surface which should be fairly easy in sculpt except i cannot create a t spline body in that shape.

convert simply makes a rectangular surface the size of the extents of the modeled body. I can push that around but it only modifies that 2 dimensional rectangular surface not the body it is on top of and in no relation to the edges of the body

I tried projecting in sculpt mode onto a plane created in sculpt and and then extruding from there which apparently is not a t spline body since it does not become selectable in any modify function

I do not see 'create form' if by that you mean under create, select form, as the menu reads box/plane/cylinder.....

[luvmesweet]

Hi , A wonderful way to improve your skills of using Fusion 360 is to join the AutoDesk university next month. Give that a try!

[luvmesweet]

I think you should learn to use "Replae Face:" after you modified a converted T Spline. To do a succesful "Replace Face" the target body or the T Spline plane converted back into BRep should be a little larger that the source face to be replaced. You can also experiment on the effects of different height between Source and Target Bodies.

You should change your preference to get into parametric mode as a default working envoronment, or right click on browser to start recording.

[luvmesweet]

@gusspec

some screens shots to show you.

1) In the preference: Select Design History to be " Capture Design History (Parametric Modeling)."

2) If you had Stopped recording, right click on Browser and turn it back on. Click "Capture Design History" will turn Parametric Mode back on.

Actually Fusion 360 is by far the easiest 3D program for designer that I had found. Others are actually harder to learn.

[gusspec]

I am in parametric mode. I have tried convert in both modes and the function is the same: worthless. It in no way creates a t spline body.

Forgive me but I do not see that you answers are related to my particular question

It would appear that it is not possible to convert a brep solid to a t spline. Every attempt does not in fact give me a t spline solid but a oversized t spline face overaid over my brep solid.

It would appear that fusion is designed that t splines be created from blobs and pushed pulled slid etc into shape, which is incredibly tedious when you already have the shaped defined in the cad system, as in it is going to take hours for a complex shape that took 5 minutes to draw. The PDF document for sculpt shows this on a simple shape and makes no mention of converting from brep

As to replace face, ok, how does this relate to what I am trying to do?

I am not finding Fusion particularly difficult to learn, but the documentation is practically non existent, and when you are trying to get a particualr thing done, the hit or miss nature of replies on forums is frustrating. While having a 2000 page manual seems so 1978, a well indexed manual is very helpful when trying to locate one particular function.

in the end I think I can fake it with some regular modeling tools

[Oceanconcepts]

Could you post a screen shot so we could better understand your goal? 

If you are wanting to just edit a single face of the solid model, while keeping the precise shape of all other faces, then entering the direct modeling environment and using the Edit Face tool will allow T-spline editing of a single face. The t-splines will display as a large rectangle, but that’s just the tool being used to modify the face. Note that if you want to maintain your history you could copy the component (Save Copy As), work on it in another document, then re-import. 

Converting the entire form to T-splines and editing faces will definitely lose your precision on the editied faces. How easy it is to hold precision on other faces may depend on the shape you are working with and what you need to do with it. The oversized faces you see on the converted form are just representations of the tools. When you finish the form they should resolve back to the actual solid. 

When I have needed to do more extensive sculpting on a body, while keeping some aspects precise, I have often made a copy and converted that into the Sculpt environment, done the modifications, converted back to a solid, and used a chain of boolean operations to create tools with which to modify the original part.

Replace face could work if you can sculpt the face contour you want using t-splines, convert that to a surface, and use it to replace the face you want to modify. 

There are probably many ways to do what you want, having a clearer idea about what you are working on would help us make better suggestions.

[luvmesweet]

Dear @gusspec

I am sorry that my suggestion might not work for your case. But we learn from disccusions in these forums. We picked up lots of tips, solutions, workflows from the users' input in these forums. In the last few years that I had been using Fusion 360 I made that as a habit to read these discussions a few times everyday. I would say that if your project is not a classified one maybe you can post a few screen shots or attach your files here.  The AutoDesk Community Board Members in the US will be on holidays for Thanks Giving so you might have to wait a little longer for their replies. 

Hope it works out for you soon!

Thanks for joining this forum! You actually helped me to refresh some of the ways that I had not been using for sometimes. 

[gusspec]

this is basically what I am working with

2 1/2 D object that needs the top surface contoured.

turning it into a t spline would be perfect

My attempts at doing this do not create something worth manipulating, you cannot see through the extra overhanging material, or select the sections to modify easily

It would not appear that this is something that it is designed to do, which is fine

[Oceanconcepts]

OK, that helps- I think this is exactly the sort of thing where Fusion excels. 

Using Edit Face would be one option- depending on how complex and what shape the face needs to be, other workflows might be better. 

For the Edit Face workflow, you need to be in direct modeling.  Select the Edit Face tool (still in the Model workspace). 

You are presented with a face to edit- you can adjust the number of divisions to give the level of detail required. 

Use the manipulators, just as in the Sculpt workspace, to get the shape you want. 

Finish with the tool, and you have the solid body with the edited face. 

There are other tools available in the full blown Sculpt workspace, like bridging and creasing. So for some shapes reworking as a full on t-spline body and using Combine might be needed. 

[luvmesweet]

Dear @gusspec

Ron's suggestion is good. If you wanted to stay at the Parametric Mode, the" Replace Face" command works exactly the same. You select "Create Form" then select the face and to convert. Be sure to click "Brep". after the conversion you click "Finish Form" and then select "Replace Face" from the "Modify" Menu. The original face is the source face, the newly created face is the Target Face. 

The good thing about this mode is the T-Spline plane is still there. You can work on the light bulbs to show that or not. This operation can roll backwards and you can edit your the T-Spline Plane. I also suggested tools like creasing, uncreasing, insert edges, slide edges. The original "Source Face" is still there too. You can roll back on the timeline to edit as well. I was a bit against the Parametric Mode when they first changed to this feature but now I really like it and I just stay with this mode. 

On the precision part, you can always limit yourself in your edit form. The good thing about edit form is you can select the area to be affected by your editing and the Falloff. You can also form a box around your model with the precise dimension you would limit your model. Sketch the box and I suggest you to right click on the lines and select to change them into Construcion Lines. They will change to dotted lines. You can also select that from the Sketch Tool Box that will come out. Easier to distinguish. Then you can edit your form not to exceed the boundary box.

The Direct Modeling mode is important to me too. After I created my model and when ready to be sent to mold designing/making, I always saved a Parametric Version of my file in the Fusion cloud and my own hard disk. I then "Stop Recording" and saved a DM version. I will delete the hidden files, and generate a smaller and cleaner stp file to mold designers/makers to build the molds.

Parametric Files seems to have a lot of hidden files inside and the resulting STP file could be too large. One thing good about Parametric Mode is the ability to roll back in time, edit something and what's after could be changed too. I said "could be" because not everything could be changed afterwards. Most of the things at the parametric mode could not be deleted otherwise there will be yellow icon on the timeline. If that happened, I will change to Direct Modeling mode.

Your file is not a very complicated file and could be relatively easy to modify. Play around with the commands and you will be able to do things the way you wanted.

One advice, copy and paste a few of your files in the cloud. Rename them to something like  nnn v1., nnn v2  and so on. Just in case you made a mistake you can always have back up files available.

Have fun!

@Oceanconcepts Ron, Thanks for joining! Thanks for refreshing my mind in the DM mode. Oh by the way Ron, this is your old friend Kingson. I changed to MAS account two months ago due to problem in HK licensing.

Regards,

Kingson

PS Ron, "LuvMeSweet" is my registered trademarks in a few countries, thanks to Fusion360 that set me up in this business a few years' back!

[luvmesweet]

@gusspec

BTW T-Splines are not solids. Only Breps are. You change to solids when you hit" Finish Form". But your T-Splines have to be created correctly to change to solids. Like I suggested before, to edit all the faces of your Solid files, you can use the first method I suggested. Select all faces and hit convert at the Mody Menu in the "Create Form" environment. I already posted the screen shots for them. After the conversion you do not need to "Replace Face". You T-Splines will change to Planes (Unstitched Planes, meaning only planes, not joined together, a hollow model). You just play with the light bulbs to show them or not to show them. You should "Switch" off your original solid to be modified. Then select Patch Mode, select "Stitch" at the modify menu, the select all the faces in new modified form. Click OK. That will stitch the planes together into a solid. 

That is the correct workflow for these kinds of operation. The Patch Mode is for those purposes. Patches are planes. But you can thicken planes in Patch Mode to becomes solid planes with thickness.

So now it is clear. Both Ron's and my suggestions will work for you. We are just using different methods. You can create your own workflow that is comfortable for you too!

Hope these work for you and your solid could be built successfully now!

Kingson "LuvMeSweet".

[Oceanconcepts]

Hi Kingson,

I think your suggestion is much better overall, since by using the "Create Form" option in parametric mode you both keep history and have access to the full range of sculpt tools, like bridge, so you can make things like this. The Replace Face tool can be confusing, since without clues it's difficult to know which is the "source" face and which the "target". 

I think the point about limited documentation for new users is apt, and in particular we should have more on how to combine sculpt and precision modeling, since that is an area where Fusion is very strong. 

[luvmesweet]

@gusspec

This is a double reply. Something is wrong while doing this.

[luvmesweet]

@Oceanconcepts

Hi Ron, yes the tutorials of Fusion 360 have to be more precisely organized. I did write something about this at the forum. Fusion360 changed many times since four years ago and now it has so many functions and also evolving very fast. It is hard for new users to understand that. Could be very frustrating too. Catching up might be easy for us as early adopter but very hard for new users to really understand the "New Things" because first they have to understand what the "old things" were!

We grew with Fusion 360 from its early days and would understand it more. But we might forget some of the early functions, for example "Pressing Option to Edit Form" will change into "Extrude" and so on.

In fact I totally forgotten about "Edit Face" at the DM mode as well. Thanks for refreshing my mind!

I lost my "Early Adopter" status when switching to MAS version but fine. I do not need 5 AXIS Maching anyway!

Thanks for joing again!

[radradish]

It's really an absurd design choice. It' should work just by switching to sculpt mode without having to convert body to anything. Why there is no simple conversion to a mesh or something so you can sculpt it later? Please rethink your strategy and hire UX specialists.

[Oceanconcepts]

This is a very old thread, but maybe if you could be specific about what you are trying to accomplish we could help. Modeling solids and t-splines are fundamentally defined differently, Fusion makes it possible to work back and forth with both methods. If you are looking for mesh tools Fusion is probably not the right place, it's much more oriented towards workflows that end up with a need for precise modeling.