Saturday, October 4, 2014

Con-fusion, pro-fusion

I am liking Autodesk's "Fusion 360" more and more. Finally figured out how to use proper spline curves (the tutorials were no help there). The major item in the "con" table right now is the cruddy documentation. I joined several other people on the comments page asking for a real manual. Watching someone zip through a tutorial without explaining how they made a selection, how they got to a tool or a sub-menu...(or that, in at least one place, what they were showing was actually impossible unless you'd turned off a preference in a totally different place, then re-started the application).

I'm up to about try 4 or 5 on the Jubal Early. Got through the basics of the upper receiver in Carrara but I'm dumping that. Doing it native in Fusion is going to make all the following stages much easier. And now that I understand their spline curves, I have half a chance of getting those weird curves right.




Yah; like a lot of things. The Fusion tutorials pretty much assume you've got a sketch, you want some curves, you'll adapt the design as you work. Replica prop making means someone shoved a chunk of stock into a band-saw, cleaned up the edges, handed to the actor -- and you are forced to try to replicate the result exactly, working from nothing but screen shots and dimensions off third-party casts pulled off a maybe/maybe-not screen-used original.

So most of the fancy modeling techniques in Fusion are of no use in roughing out that form. I need to reproduce those exact curves. And it has taken me most of a week to finally figure out where (and what) are the appropriate tools.




I'm going to laud the software in a moment, but first, one more con. 3d aps, for me, fall or shine based on how smooth it is to manipulate the view camera. Outside of Occulus Rift and a few other high-end bits of tech, we are viewing our 3d models and scenes through a 2d window. The only way to truly grasp the parts and their relationship is to be able to manipulate the view.

I turned off "use gestural control" again as it was useless. The only thing it did was dolly move and pivot. Pivot? Who puts pivot high on the view menu? There's no point at all in pivoting the view. Orbit is what you want. And orbit would have been so simple to code...! But, no, you get pivot. Which means you are constantly re-setting the resulting Dutch Angles. Oh, and the application breaks the GUI standard -- no space bar drag. Why? The spacebar isn't coded to anything else. They could have allowed spacebar drag. Instead you have to mouse over to a little widget, drag the viewport, mouse back up to the selection tools, go back to clicking. It breaks the flow.

This is why, sad to say, Carrara is still useful. Because you can navigate and select and manipulate practically simultaneously, just by holding down different combinations of command and control while you move the mouse.

In everything else, of course, Carrara basically sucks.

Fusion almost gets a pass for the slower viewport manipulation due to render tricks that make it vastly easier to see what the hell you are doing. It uses a translucent, fully-shaded object, with reference images (when you want them) floating on planes and also translucent.

But here's what else you get:

Fully parametric modeler. You specify lines and curves mathematically, meaning they are infinitely smooth, scaleable, and editable. It also has parametric methods to model along mirror planes, work on multiple clones simultaneously, generate topologically complex objects such as screw threads, and so forth.

It is an integrated environment. You can check dimensions on (mostly!) arbitrary points, generate fixed dimensions and even generate complete printable plans.

You can also check clearances, set standard clearances or interference fits, create and animate mechanical motion, and do a lot of other useful little functions for 3d print and CNC such as making a volume check.

It will also generate and edit CNC tool paths. I don't believe it slices for 3d printing, but oh well -- that's easy enough. Although I haven't gotten far enough to see if it can export in formats that are readable by standard slicers and other manufacturing prep software.

I also haven't gotten far enough to see how clean the meshes are if you export in OBJ format. So I may need to turn to Blender, still, for Poser product creation. But then, Fusion has as far as I can tell nothing resembling UV mapping tools.




So the gunsmithing continues. Prop-gun-smithing. I've cleaned enough of the slag from the Suomi receiver to start messing around with welding. Current plan is to install a fake bolt machined out of aluminium; that will hold the pieces aligned, and give it some extra strength. It will also fill the empty space visible through the ejection port.

(I'd be about willing to skip the welding at that point and go for Liquid Weld or similar. Except that I purchased a couple cans of Gun Blue and that's only going to look right on real metal).

A pair of Pachmayr grips arrived in the mail and I'm measuring them to fit the Jubal Early to them. That's going to be a little while yet; I have to finish the model, prep that for CNC, and order a rather pricey amount of metal (the Jubal's upper body is a slab-like 26mm thick.)

I've been posting images of the evolving 3d design for the "flash hider" of a "King of the Rocket Men" gun, which may possibly be turned in aluminium. If I get design approval I may be borrowing a (real!) luger P-08 in order to take detailed measurements.

And, yes, I still have the pirate pistol. When my head can't take learning new 3D software anymore, I'll switch gears and go back to learning how to parse sensor data in Processing.




Oh, yeah. Switching out my old desk chair for a piano bench is doing me a world of good. I'm able to spend a lot longer at the computer without pain in my legs. Getting rid of the chair, setting up a proper tool area in the kitchen and putting my keyboard controller out also makes the place feel a lot more spacious and clean and also is bringing my spirits up. Now I just have to reserve enough time to repair more audio gear and start creating sound effects for Poppins!

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