Wikipedia:Reference desk/Archives/Computing/2016 September 5

= September 5 =

Autodesk Meshmixer: Creating a hole on a thin shell from a selection
I am using Autodesk Meshmixer to create a 3D printed face mask.

This mask has an outer surface and an inner surface. I am trying to cut two eye holes and maybe more holes for the mouth and nostrils but at first I need to have eye holes.

I have selected the area for one eye using the selection tool. I then tried Extrusion tool and input a negative value. Instead of creating a hole, the negative intrusion created a extended part inside the inner surface.

I then tried several other tools such as offset. They are not useful.

How do I cut a hole on this mask having inside and outside surfaces? I only need the name of the tool so I can look for related YouTube tutorials. If possible, I'd like to create two objects: the mask and the eyepiece. The eye object can probably be used elsewhere for Halloween.

I can use other free tools if I have to. -- Toytoy (talk) 00:37, 5 September 2016 (UTC)
 * The way I would go about it, (i have zero 3d printing and a little bit of 3d modelling experience), is to create a solid "cylinder" the shape of the hole you want, put it in the place you want the hole to be, and subtract it from the mask, leaving the hole. meshmixer boolean] tutorial looks like a tool that will do it. I don't think just selecting a portion of a face that you "don't want" and deleting it is the correct approach in 3d modelling, except in very specific cases. Think of it like a solid object you are actually modelling, rather than just a pair of "faces". Also keep in mind that most 3d printers have "invalid" shapes that are quite easy to create in 3d models, like steep overhangs, but won't print well or at all in plastic. Vespine (talk) 05:29, 5 September 2016 (UTC)


 * This mask has pretty evil eyes and eyelids. Maybe I'll say they look like the eyes of General Akbar of The Return of the Jedi. So I can't just cut off the eyes using a simple geometric shape. Thank you anyway. May the Halloween be with you! -- Toytoy (talk) 10:07, 5 September 2016 (UTC)
 * Well then you'll just need to make a "non simple" geometric shape? The principle remains the same. By "cylinder" I didn't mean it had to be a "circle": Premise 1) At some roughly "flat" plane on your mask there exists a "hole" (I don't mean that the eye or the mask has a flat spot, I just mean that there exists a plane where the hole, when viewed from one side, appears roughly "flat". . That hole has a "shape", draw that shape and extrude it into a cylinder. Place that cylinder perpendicular to the plane in the place you want he hole and subtract. If premise 1 is very incorrect, the shape of the hole is more complex you just need a more complex shape than an extruded solid.  Vespine (talk) 00:31, 6 September 2016 (UTC)

Best term for "website where you can buy something"
What is the best generic term for websites where customers can buy some specific goods and/or services, e. g. commercial online games or social media offering privileges? "Webshop", I think, is commonly restricted to traders of goods which work independently of the shop (e. g. music files), but this does not include aforementioned examples. What term may be used - "web offer vendor"? I haven't found any term which is actually in pracitcal use. --KnightMove (talk) 06:12, 5 September 2016 (UTC)


 * Online marketplace? E-commerce might have links that you might want to follow. Hofhof (talk) 08:47, 5 September 2016 (UTC)
 * Thanks, but "An online marketplace (or online e-commerce marketplace) is a type of e-commerce site where product or service information is provided by multiple third parties, whereas transactions are processed by the marketplace operator." - this is exactly the kind of restriction I want to avoid. I explicitly want to include websites that only sell "their own" stuff and services. --KnightMove (talk) 12:30, 5 September 2016 (UTC)


 * Then, it's an online store.Hofhof (talk) 14:00, 5 September 2016 (UTC)

Auto update page content
Can someone help me to write a program which can auto update all the content of a webpage to a wiki page, with "dest" as the destination website. Thanks! Wetitpig0 (talk) 06:42, 5 September 2016 (UTC)
 * See Bot requests for context to the question. If you are a programmer and seriously thinking about writing your own bot then see Creating a bot. PrimeHunter (talk) 12:44, 5 September 2016 (UTC)

Verbose/non-verbose source file and executable size
If a source file is quite verbose (due to the choice of language, or just due to the programming style), will the resulting executable be shorter than one compiled from a terse source file? Hofhof (talk) 08:50, 5 September 2016 (UTC)


 * Not very reliable, but here  is someone claiming: "There is no correlation between the number of lines of code and size of the generated binary."
 * Think about it, a million lines of redundant definition can compile to tiny sizes, while just a few lines of procedural nonsense can generate giant binaries. Hopefully others can better explain/clarify/give better examples, but I agree with the StackOverflow poster that there is, and can be, no general trend. It gets more complicated if you want to talk about the "same" program (and how you define that), but even for one specific language and one specific task, I don't think you'll find an obvious relations between verbosity of source and size of binary. SemanticMantis (talk) 15:47, 5 September 2016 (UTC)
 * I'm guessing this is NOT what you mean, but it might be worth mentioning that there are things which a compiler completely ignores, the most obvious example being comments. So a program with loads of 'verbose' comments, and a program with no comments at all can "look" very different, but will compile exactly the same. Vespine (talk) 23:01, 5 September 2016 (UTC)
 * Another example is whitespace outside quoted strings. Line count or bytes are often used to describe the size of source code but most languages allow any number of spaces, tabs and newlines nearly everywhere. One programmer may use one line to write . Another may use seven lines (including blank lines) to write:

if a then b else c


 * Compilers don't care about the amount of whitespace. A third example is the length of identifiers like variable names, e.g.  or  . Many identifiers are used a lot of times. Many compilers will never store the identifier or only store it once. A different kind of example is source code which can never be executed, e.g. a never called function or the else part of a conditional that can be determined at compile time to always be true. Some compilers will detect some cases and simply not compile it. It is an undecidable problem to detect all cases, except for some languages which have limited power and are not Turing complete. PrimeHunter (talk) 13:22, 6 September 2016 (UTC)
 * To be more precise: some compilers for certain languages - free-form languages - do not care about whitespace.
 * It is not generally true that all compilers ignore all whitespace. Even some modern languages, like Python, interpret whitespace as part of the language semantics.  PEP-666, which may have originated as a humorous joke, was actually implemented, and made its way into my system's version of Python 2.7.10; I can actually cause Python to produce an error if any programmer makes "foolish" use of whitespace.  Nimur (talk) 17:49, 6 September 2016 (UTC)
 * In fact, some compilers depend on whitespace. For an extreme example, see Whitespace (programming language). --Guy Macon (talk) 01:19, 8 September 2016 (UTC)
 * Loop unrolling is an example where a compiler converts fairly terse source code (a loop) into rather "verbose" machine code (by explicitely "writing down" the steps in the loop). --Wrongfilter (talk) 13:32, 6 September 2016 (UTC)

Why is everything on my screen so big?
There used to be "100%" in the lower right corner on my old computer. When I finally find and click on "Zoom" it says it's at 100 percent. If I click on the minus it is 75 percent but everything is too small. I do know that my monitor was unplugged when I turned the computer on and I heard some weird noises, but I plugged the monitor back in. I have Windows 10 and Microsoft Edge.— Vchimpanzee  •  talk  •  contributions  •  19:45, 5 September 2016 (UTC)
 * I too recently "upgraded" to Windows 10 with Edge, and have noticed that the latter can look a little different to other browsers, possibly because it's more designed than others to work on mobile devices. I presume you're finding Zoom on Edge by clicking the "..." at top right [mouseover: "More"]? I haven't yet figured out how to make this use smaller increments than 25%.
 * There's also a Magnify function (or "App") in the 'Windows Ease of Access' folder that can be pinned to the toolbar, and whose increments can be adjusted down to 25% but apparently not less that that.
 * Have you also tried the effect of 'CTRL +' and 'CTRL –'? {The poster formerly known as 87.81.230.195} 90.202.211.191 (talk) 21:51, 5 September 2016 (UTC)
 * CTRL is what I was looking for. Actually, I turned the computer off, and when I turned it on everything appeared normal again. I didn't upgrade to Windows 10, by the way. It's a new computer which already had it.— Vchimpanzee  •  talk  •  contributions  •  16:17, 7 September 2016 (UTC)