Hi Danny,

> It seems we've got different interpretations and experiences
> in what we think a traditional layer system is.
> Unigraphics (NX) was first developed in the '70's so there was
> no influence from Autocad which came out in the '80's.

The AutoCAD layer system tends to be the one that is much more commonly used by quite a range of PC CAD software...

Certainly a system that originated off of a PC will tend to have a different history, and although there is nothing necessarily wrong with that system that you are showing there, I think it would be hard to incorporate that exactly since it is just not what the much wider majority of people would expect when you use the term "layers".

Here are some examples of layer systems from other CAD-ish programs currently on my machine:

Rhino:



SketchUp:



DoubleCAD XT:



ViaCAD:



Alibre 2D drawing module:




Notice how they all general fit the same pattern where a "layer" is an entity that has a name, and certain properties such as color and linetype.


It's just by far the most common thing that is done...


One big problem that would prevent me from adopting the system that you are showing there would be having colors assigned as an individual object property, rather than the color coming as a kind of named entity.

That's because one big purpose of setting this up in MoI is to translate that into material assignments. It is easier to control materials when there is a list of available named materials, and you can assign an object to belong to one of those rather than just a color value directly, because you may want to do things like set up materials like "Spaceship hull damaged", "Spaceship hull 1", "Spaceship hull 2", to have things arranged into different categories but not necessarily mess with having different actual colors set to them quite yet, until later when you are altering the materials in your rendering program.

So for instance it would not be unusual for someone to have set up 3 "styles" in MoI all of which are black currently but still have a separate identity. If all things that were Black had the same "material identity", it would prevent that kind of workflow...


At any rate, the Groups mechanism is meant to be a kind of container system, it may more closely align to the layers that you are accustomed to.

- Michael

Hi Michael,

I understand what you are trying to do with MoI and I agree that the layer systems you're showing there are restrictive, the reason why I couldn't understand where you were coming from, is because I was used to a whole different system.
The layer system that most other cad vendors have followed is from Autocad, which I don't think has ever evolved from the 2d world of past. I wonder how Autodesk handled Mechanical Desktop's layer system.

> At any rate, the Groups mechanism is meant to be
> a kind of container system, it may more closely align
> to the layers that you are accustomed to.

No doubt when Groups are implemented, MoI will be flexible enough to accommodate different ways of object organization, keep up the good work.

Cheers

Hi Danny, yeah they are kind of restrictive which is why I didn't want to jump right into having only that system for organizing objects and nothing else...

However on the other hand, those kinds of layers are pretty simple and easy to understand, and also are very widely used to control color.

It's that common connection with color that I was trying to demonstrate with those screen shots from various other programs.


So anyway, that's why mapping styles in MoI to layers in certain CAD-type export formats seems to be a good matchup.

- Michael