Ok, just finished another boolean tune-up for the next beta - Boolean difference now works well when using surfaces instead of only solids.

This combined with auto-extrude means that this is now possible - given this setup:



Doing a boolean difference of the box with curve as a subtraction gives this (pieces moved to illustrate):



Where each piece is a solid. Here's another example - the results are all solids:




So quite a bit of boolean stuff for the next beta coming...

- Michael

Very cool stuff!

I think this spring I will get a new release of all the apps I use!
AutoCAD, Revit, Maxwell, MoI, etc...

Hi Michael,

What happens when group of curves will be inside of solid or intersect the one?

Petr

Hi JTB, AutoCAD is released each spring... I think it is rather embarrassing then worthwile... -Petr

> What happens when group of curves will be inside of solid or intersect the one?

Hi Petr, I may need an image of this to be certain that I understand your question.

But if I understand correctly, it doesn't matter where the curves are located, they can be anywhere along their plane normal and have the same effect.

This is because the solid doesn't interact with the curves directly - instead imagine that the curves are
moved along their plane normal to be placed just a little bit outside the bounding box of the solid (or surface), then extruded so that they push through to a little bit more than the other side of the bounding box of the solid.

This produces the same extrusion part no matter where the curves are placed along that normal direction.

Then the solid actually interacts with that extrusion.


I've now finished Union now to work properly with surfaces.

- Michael

All that is not in the beta of the 26 / 2 feb 2007?

> All that is not in the beta of the 26 / 2 feb 2007?

Hi Pilou, nope - all this new boolean stuff will be for the next beta which should be ready pretty soon.

- Michael

Just an update - I'm trying to get the new curve boolean stuff to work on open curves as well instead of only closed curves. I'm making progress but it is taking a while, maybe a day or so longer before the new beta is ready with all this new boolean stuff.

- Michael

Feature Suggestion: Min/Max Range Values for Offset & Shell commands

If you're not particularly paying attention to the scale of your model, then you don't know where begin when plugging in values for "Offset" and "Shell"... I often have to try several values just to get one that successfully displays a result on the screen.

Would it be possible for MoI to display the Upper and Lower Limits of possible offsets by default, or perhaps provide a "Calculate Min/Max" Offset button? (Obviously you would need to cap the MIN/MAX values well before infinity for very simple surfaces that have virtually nothing limiting how far they can go.)

Also, if MIN / MAX values are present, perhaps a range "slider" could be provided at the bottom of the keypad so one can simply slide between the values to evaluate different distances or thicknesses. With a range slider, you would probably need to provide a little "Calculate" button so that MoI didn't try to calculate the offset or shell operation each time you nudged the slider...)

Hi Justin, I guess this would involve a lot of different calculations, some on detecting the curvature of surfaces, and others trying to analyze the interference between different adjacent surfaces.

Unfortunately these calculations are really complex, it would be really hard to actually implement this, even harder than doing the shelling operation itself...

But I do want to figure out some way to improve this in the future though.

In the meantime, there is an alternate method to entering a numeric distance - you can pick 2 points in a viewport, and the distance between those points will be used. This can help adapt to the scale of your object for example by picking the 2 points snapped on to a piece of your object...

- Michael

That's very helpful! I didn't know you could specify a distance for an offset or shell that way... Here's another idea based on whay you have going already: simply let the user set a own Min/Max slider on the fly. Instead of the two clicks defining a set distance which is applied immediately, the two clicks define the Min (always 0) and the Max. Then as one slides between the two points, the offset, shell or fillet shrinks and grows.

Anyway, just a thought. Being able to pick a distance in the viewport definitely gets one in the ballpark for finer tuning with the keypad. Thanks!

Hi Justin - that same thing (pick 2 points for distance) also works for fillet and chamfer by the way.

Re: Slider - I've had a couple of thoughts along this same line. I was thinking that once you have a distance (I guess I could default to 1.0 instead of no default, especially now that you can cancel and update parameters dynamically) I could put a couple of grips on the model, along some surface normal lines.

If you grabbed on one of those grips you could drag it and it would be another way of tweaking the distance - the current "distance between any 2 points" method would still work if you clicked somewhere not next to one of those grips.

But it is going to be a while before I'll be able to experiment with this.

- Michael

Curve booleans with open curves have proved to be pretty challenging, but I'm getting there.. Just finished difference. (note that this is for the next beta, not the current one).

Given this initial setup, with a grid of simple line segments and a closed region:



Doing a boolean difference with lines difference closed region gives this:



Basically just automatic trimming of the lines.

But somewhat more interesting is the closed region difference the lines:



This takes the lines and sort of imprints them into the closed region to form a bunch of new diced up closed regions (shown slightly separated for illustration).

Still have a some work left to do on the other operators for open curves though.

- Michael

> Must be a little headache for code that :)

:) Yes...


> Some aeras have some priority to other?

For closed regions it works like extrude - a closed area that is contained inside of another outline will become a hole inside the outline.


> Order of selection make some differrence?

It's not supposed to...


- Michael

Michael,
One feature that would be nice is that when a vector is highlighted, the dimensions would show up somewhere. Possibly in the same area that shows the dimensions when drawing them?
When I work with many small circles, etc. it sometimes becomes difficult to remember what the dimensions are.

Hi Michael,

Are you sure MoI's users will be able to learn all those boolean stuff? What about analogous command to Rhino's _Boolean2Objects?

Petr

> Are you sure MoI's users will be able to learn all those boolean stuff?

Well, there are no additional commands so there is not too much to learn - there are just more interactions available between different types of objects with the same commands.

I have probably spent a bit too much time struggling with the curve booleans with open curves though... But it is pretty cool and it's another thing that I'm not sure if anything else out there can do.


> What about analogous command to Rhino's _Boolean2Objects?

I believe this command was created in Rhino due to people getting confused about doing booleans with open surfaces and having the result be different depending on the surface normal orientation. That means that you need to be aware in advance of your normal direction and possibly flip it with the Dir command before doing the boolean - well a lot of people don't know about doing that part in advance and get surprised by results different than they intended when using open surfaces, so this was a fairly frequently asked question.

With Boolean2Objects, it will step through different surface normal orientations for open surfaces, one by one, so you don't have to worry about the normal directions in advance of doing the command.

In MoI I have solved this in a different way - when you do a boolean using a surface, MoI will just generate a couple of different objects for you and if you don't want one you can just delete it. I think this is easier to understand, and it is yet another instance of building more stuff into a single command rather than introducing an additional specialized command.

As another benefit it works well to handle multiple surfaces in one shot, as in this previous example:




In contrast, Boolean2Objects can only handle well, 2 objects at a time...


For solid/solid booleans, the regular operations are well defined - I don't really see why it is necessary to have a separate command that steps through all the different possibilities for this, just pick the proper operation at the start and you're done.

- Michael

Hi Ken,

> One feature that would be nice is that when a vector is highlighted,
> the dimensions would show up somewhere. Possibly in the same
> area that shows the dimensions when drawing them?

What I have been thinking of for this is to have an "object properties" panel that appears in the top portion of the side bar, where command options normally go when you are running a command. Somewhere on there would be a way to see probably width and height of an object, and some additional information for certain special objects like the length of a line or the radius of a circle.

However, I have don't expect to have time to work on this until after V1 is finished.

- Michael