Modeling in detail a Teak tree in Fusion 360

[Anonymous]

Hi Fusion 360 Community,

I've been using the fusion 360 software on and off for a few months trying to create a model of a Teak tree in detail but I am having quite a few issues with my model. I think it has to do with my way of modelling that might not be quite right. 

I'm looking for advice in order to create a model that I can export as obj afterwards. For the moment the model throws quite a few error messages about star connections and t connections. This leads me to be stuck on the step of meshing the whole model.

I would really appreciate the help of someone that would know a bit more about modelling in Fusion.

Here is a link to my model if you would like to have a look at the kind of error messages I am getting:

https://a360.co/2PaTZQf

It's the first time I use this forum so please let me know if something needs changing.

Cheers,

Thom

[TrippyLighting · Accepted solution]

The mesh structure/topology is fine. In general it is preferable to stick with quads. But T-Splines also deal well with 5 sided polygons. But, again, that is not the problem here.

I also looked at the mesh in box view mode and did not see anything obvious.

You already used the "repair" tool, but likely have not tried the "make uniform" tool. That does the trick in this case.

However even then, in rare cases these tools do not manage to fix a mesh that otherwise should be OK.

In such cases, export the T-Spline control cage as a .obj and reimport that mesh and convert it to a T-Spline. That forces Fusion 360 to completely rebuild a T-Spline form a mesh.

[Anonymous]

Thank you for your answer @TrippyLighting! I've tried the make uniform on the whole shape and you were right that solved all my issues with star points and T intersections. 

I don't quite get your last sentence. How do you export the t-spline control cage? Do I have to stay in the create form menu or exit from the modification before doing so? Do you mean I should export the shape when it is in box mode?

[TrippyLighting]

---

@Anonymous wrote:

I don't quite get your last sentence. How do you export the t-spline control cage? Do I have to stay in the create form menu or exit from the modification before doing so? Do you mean I should export the shape when it is in box mode?

---

While still in T-Spline mode, right click on the body in the browser and select "Save control frame as .obj. It does not matter whether that is in box view mode or smooth view mode 😉

[Anonymous]

That's great, thanks a bunch @TrippyLighting.

I'm trying to create an accurate-ish tree model of a teak tree. For the moment it's quite basic and I think it will only start coming to life when I start adding secondary branches and roots. Would it be the right steps to finalise the main branches and when I am happy with them to select all the shape and subdivide all the current shapes to help me get smaller faces to extrude out? Would that be the right steps to follow?

I am also struggling to add an additional main root right underneath the tree where there is a star point. How would I go about to create a new face right in the middle?

If these do not make sense I can explain further with a screencast perhaps?

[TrippyLighting]

There is no reason to model all of that as one single connected T-Spline. The trunk, branches, twigs etc can be all individual meshes.

[Anonymous]

How would I go about connecting them all together afterwards? Could they all be open t-splines that I connect at the end? I think I have a fundamental lack of comprehension of this software.

[TrippyLighting]

Why would they have to be connected ?

What is your end goal with this model ?

This isn't essentially a software problem. You'd run into this using any other Sub-D modeling software 😉

[Anonymous]

The end goal with this model is to create a detailed illustration of the teak tree to use for a large format drawing for my studies. I will try and represent how the tree connects the ground and air together through additional simulations using Realflow to simulate the groundwater interaction with the roots and Autodesk's CFD to simulate the wind moving around the canopy, that is the end goal at least. 

As you mentioned it probably doesn't need to be connected as I am modelling it but the final output will need to be as I will be using the model as a whole. For the illustration I am drawing my inspiration from Macoto Murayama's botanical blueprints. 

I've been using Zbrush to remesh the T-splines shape to output that finer squared grid then using illustrator to edit the line weights.

[TrippyLighting]

So if yo already know how to use ZBrush why would you not simply sculpt the tree with the tools in ZBrush and then re-mesh it?

That is the entire purpose of the re-meshing tools in Zbrush, to remesh the triangulated sculpt meshes. Sculpting in Fusion 360 is really NOT sculpting. Is very similar to polygon mesh modeling or Sub-D mesh modeling.

I personally would NOT use Fusion 360 for this at all. Not because it could not be done but predominantly because of its clunky sculpt UI make it unpleasant to create such models. 

Something you should be aware of is that these FEM software packages usually don't work with meshes. They need NURBS based geometry o BRep. There are a few traps here!

[Anonymous]

I don't actually know the Zbrush software, I only used it as it is the one I found could closer output the geometry shape I was trying to get at which is a grid of lines closer matching the curves created in T-splines.

I ended up using T-splines because I started using it with Rhino as a plugin but then had to go to fusion to continue modelling the shapes first started in rhino. This was more a default option and a quick check on internet of how easy it would be to make the move. 

---

@TrippyLighting wrote:

I personally would NOT use Fusion 360 for this at all. Not because it could not be done but predominantly because of its clunky sculpt UI make it unpleasant to create such models. 

I have to agree, it is not easy at all to model the tree I am trying to do with Fusion 360. I'm open to suggestions if you have a better idea of software I could use to do this more efficiently and still achieve the output I am trying to get to. In the first place, I was trying to get a Nurbs model so I could use it in Rhino to "make2D" of the tree but it sounds like I might be making my life harder for nothing. I didn't really question the process I was going through up to now.