Hi Artaud, wow that is a fantastic result for your first MoI model, it looks really great!

I'm glad that the workflow is good for you!

Your questions:

> - I did not found a "curve/surface" rebuilding tool. Sometimes,
> it is necessary to simplify a curve or a surface, reducing the
> number of control points;

Yeah this is definitely on the list to be added, I just have not quite had enough time to get to it yet.


> - Rail revolve seem to work only with 2D rails;

The way that rail revolve works is by a kind of scaling out from the center axis, I'm no so sure that it is really well defined on a non-planar rail.

If you could please post some example models that are using a non-planar rail from other software that would help me to see what you are looking for more specifically and what might be possible here.

I do want to add another option for rail revolve in the future to make it work with multiple profiles which will use a somewhat different mechanism which is more like sweeping rather than the "exact" combination of 2 curves that the standard rail revolve (sometimes called "swung surface") uses. That method will probably work more easily on non-planar rails rather than the exact method.


> - with complex shaded models, directx is not so fast. 3D navigation is slow.

This doesn't really have a lot to do with directx, but rather the meshing settings.

By default MoI is set to produce a dense display mesh which makes for a very smooth look in the viewport but which will generate a really large number of polygons if you have many small curved parts, especially stuff like long twisted skinny tubes like you've got in your model here will generate a really really large number of polygons with the default settings.

You can switch the settings to be better for a heavier scene by going to Options / View / Meshing parameters, and change "Mesh angle" to be 20 degrees, and uncheck "Add detail to inflections".

That will make the meshing be coarser which will look slightly more jagged in the viewport but there will be many many fewer polygons generated which should help out quite a bit.

I'm going to try to do some work in version 2 to manage this a little more automatically and try to avoid making such high density meshes on things like really small fillets.

But currently you have to alter that setting manually.


> - Some deformation tools would be useful.

Yes, definitely! Unfortunately NURBS solids that are made up of many pieces that touch at trimmed edges rather than natural surface edges do not tend to lend themselves very easily to being deformed.

It's probably going to be a while before deformations like bending or twisting objects will be in MoI. Currently the best way to do this is to use Rhino in combination with MoI - in Rhino version 4.0 there are several new deformation tools added and you can use Copy and Paste between MoI and Rhino to move objects back and forth between them.

- Michael