GearHeads Corner

Michael;

I thought I heard the problem in using these formats was licensing,  but I can't say for sure, so I'll have to bring it up with Art when he gets back.


Cheers
Bob

Bob:

When is Art expected back?

Michael

Hes back if you use the other way to bring .dxf into fusion it is not so bad, through the inset menu.

it come's in to scale but circles and arcs are still short lines.

Hi:

  Im back. Im be doing behind the scenes code for the next while with occasional releases as new abilities
get completed.

  I constantly look into those other file formats, but each time I do I find their complexity or
cost to be prohibitive.. but as Im doing DXF coding at the moment, Ill look into the current
state of those formats..

Art

Art:

Thank you!

Michael

Wanted to add another vote for this, if I may.

Belt pulley DXF exported from Gearotic crashed Fusion360. Even dwg and dxf's that went through AutoCAD and saved there crashed Fusion. And the svg saved from dxf at online converter crashed it.

Interestingly enough, the 35 tooth one survived in Fusion, 42 tooth crashed.

I am pretty sure it is actually Fusion's fault, but as there was already talk about changing the dxf's somehow, so maybe that helps.

Viljo I posted a work around for you on the fusion forum what works quite well.

Art if you want I can poop a tot here so anyone else has this problem will know how to get around it.

it's the sort lines doing it fusion still blows with imported .dxfs

Hi DanL:

  Sure, drop anything you feel helps. Im not sure I understand the issue , is it that Fusion needs
less resolution or something? Hard to understand that being the case.. Anyone know WHY the dxf's
crash fusion? If I can massage something I will. Do the dxf's from Auggies vector also crash fusion
or is it only Gearotics output?

Art

Art it's the way fusion deals with .dxf, it a silly way.
what happens is every sort line, line, arc or circle has a point at each end and a constraint at each end. if the circle has 100 sort lines it will have 200 points and 200 constraints.

so a gear may have 5000 sort lines so 10000 points 10000 constraints the bigger it get it will kill fusion.

it's not gearotic at all doing it, it's fusion it happens with all .dxf's.

I will pop a vid in here.

Sounds almost like its making everything into a bezier...

pretty much art,
one of the fusion staff ran the file through Adobe illustrator and put it out as a 2010,11 and 12 .dxf and it was fine.

but I don't think many of your user's would have that program it's a bit expensive per month and there's that hackability in it what they have not fixed yet.

the pick is a corner of a tooth imported as a .dxf into fusion what is Viljo gearotic .dxf you can see how many points there are you double the count of points and add the lines the count of objects gets in the 0000 very fast.

Dan:

  I suspect the end point is their software really wants beziers for long contours.
I belive its all about architecture. One of the reasons I keep saying I don't want
to write a cad program is architecture. A drawing program's underlying architecture is
something almost locked in from start of development, which is fine if you know
exactly where your going, if not, you get into a situation I fond myself in a few years
after I start anything, I often dont know the end destination so I code in directions
that lead me into odd places. Had I KNOWN for example, that flourishes and drawing
would begin to play a fundamental part in Gearotic, my internal databases would be better
suited to drawing, unfortunately, since I deal in Gears primarily, my databases
are more setup for chains of points, not arcs and lines.

  Things like this are good and bad at once.  Chains of data points are hard to query
as to things like adding lines and arcs to drawings, but very easy to do other operations
such as extruding and manipulating data. Fusion, probably requires drawing entities to be
nodes that have a lot of information in them, so each line has an entry in the database,
and since the dxf's from gearotic are outputting poly lines, it likely breaks them into
individual lines. That would get heavy fast.

  The lesson here is that poly-line entities are probably getting out of favor at autodesk,
with a preference for bezier curves. This makes sense to me as I suspect they use
3d beziers to effect solids for algorithmic reasons. Clever mathematicians can do algorithms
on beziers to join them in space and manipulate them in fantastic ways for 3d work
and meshing where lines and arcs are more difficult to work with for 3d op's.
 
  I have pondered all of this for several months in the background since Ive heard
of the trouble. My conclusion is that I will have to effect a bezier output in the future.
I'm not there yet though. Gearotic doesn't like entities much like lines ,arcs etc.
  It prefers to think only of points in series. While Ive added arcs and such for next
release, they , in the end, will devolve to chains of points internally as you work with them,
trimming them and such.

  Were I to do a Gearotic from scratch, my database would look quite different.

All that having been said, chains allow for special ways to process internally that
give me some power entities don't have. The next version has French curves for example,
a tool that allows one to use a selectable ( and even user drawable )french curve cursor
to trim an object, something unusual because its very hard under normal cad databases. 

  So Ive decided most things in Gearotics drawings will devolve internally from lines
and arcs to a single polychain when a user interacts with them. At some point I will
add a tool to reconvert them to lines and arcs if one wishes, OR, to save them as
beziers, which would likely make Fusion very happy, as it would then only have 1
entity as a chain, which is how gearotic holds them.

  So I think Fusion wants not a contour, but a bezier, which is odd
as you'd think they'd just convert from one to the other..but it doesn't look like
it to me.  So instead of having one bezier entitity with perhaps a hundred control
points, they get thousands of individual lines, each requiring their own entry
in their database.

  So at some point I will add a bezier output, and a proper bezier class,
as that would allow me to attempt a Nurbs command in Gcode for a smoother
way of doing massive small point moves in GCode. Thats likely a summer
project though as its very complex to do Nurbs in a trajectory planner
respecting jerk and speed limits. Doable though I think..maybe.. :)

  So Ill keep in mind this issue, and will issue tweaks as I can to help,
with the aim of adding proper b curve outputs that I "think" would solve
the issue permanently.

Thx
Art

Do it when you have time Art, we are hammering them over .dxf now a lot of the guys need proper .dxf not .dwg for laser's, water jets and plasma.

I think they are trying to move to there standard and it's not working most of the contract deisginers need .dxf for there customers.

once I remember to do the conversion vid it will be fine it takes 10 mins first time, then after that a person will get faster at doing it, one of the other fusion user's use's gearotic, it was him tallying A fusion staff member off (young guy just started) that gave me the idea what to use to do the conversion so it keeps the gear to speck.

the first 5mins is deleting chunks of the gears.

anyhow have fun in the snow

Dan:

  Would it help to simply reduce the point count? I could experiment with a settable resolution like the old days.. on the output, something to limit the distance between points.. though gears are so curvy it can lower the resolution..

Art

I would not bother Art it would make the Gears ruff.

.dxf from Vcarve pro are fine, running the gearotic .dxf through vcarve pro does not fix them. it may work with a gearotic .crv that something I should try.
can I have one in .crv and .svg just so I can test them.

the dxf from rhino are fine in fusion, I just got sent a gear from rhino to test.