Created a gemstone using boolean and difference. The material is GlassBSDF (Green Cubic Zirconia). I have tried all the lamps and emmiting planes in a number of configurations and cannot achieve a realistic gemstone.  I tried a sky background and my clear gemstone became a blue gemstone. The best results so far is with  a background that is Gradient and Radial. The gemstone has distinct facets. It should be symetrical about the X and Y axes but it is not because of the gradient.  I tried a RGB background but the facets were not distimct like I get using a Gradient background.  What do I need to do to achieve a gemstone with distinct facets on a White background?
What would be the material or shaders node set up for a smooth gem in blender cycles engine?  I want a result similar to this image:
How to return only the Date from a SQL Server DateTime datatype The limit of a convergent Gaussian random variable sequence is still a Gaussian random variable I'm trying to prove this conclusion but have some problems with one of the steps.  Assume $X_1,\ldots,X_n,\ldots$ is a sequence of Gaussian random variables, converging almost surely to $X$, prove that $X$ is Gaussian.  We use characteristics function here. Since $|\phi_{X_n}(t)|\leq 1$, by dominated convergent theorem, we have for any $t$  $$ \lim_{n\rightarrow\infty}e^{it\mu_n-t^2\sigma_n^2/2}=\lim_{n\rightarrow \infty}\phi_{X_n}(t) = \lim_{n\rightarrow \infty}\mathbb{E}\left[e^{itX_n}\right] = \mathbb{E}\left[e^{itX}\right] = \phi_X(t) $$  this is the step that I cannot figure out: $e^{it\mu_n-t^2\sigma_n^2/2}$ converges for any $t$ if and only if $\mu_n$ and $\sigma_n$ converges.   Let $\mu=\lim_n \mu_n$, and $\sigma=\lim_n\sigma_n$, then $\phi_X(t)=e^{it\mu-t^2\sigma^2/2}$, which proves that $X$ is a Gaussian random variable.  Why can we get that $\mu_n$ and $\sigma_n$ converge? This looks intuitive for me, but I cannot make a rigorous prove. Recently my audio input, from USB headset and USB guitar cable have stopped working. Going into Windows 'Sounds' and enabling 'Listen to this device' outputs the audio as expected; the problem is not with the devices. However, as soon as I try to use them with any other program, discord, for example, no audio input is detected by discord.  I have tried everything I can think of and some suggestions from Googling around;   Updating everything - windows, drivers, all related software Rolling windows back to the last build Trying different USB ports Reinstalling drivers and software Running Windows troubleshooters Playing with device properties settings   But nothing seems to work, any suggestions? How to disable Ctrl+Shift+U? Ctrl+Shift+U is a combined shortcut in Eclipse. But when I press it, it shows up a u, just like input with an underline. I guess this shortcut has been declared by Ubuntu, so I can't use it. I used to solve this problem by typing Caps Lock first. Is there any better method? Excel text alignment with custom formatting Is there anything in a custom formatted formula which defines the text alignment?  I know the different parts of the formula is numbers, negative numbers and so on, but I need to set the alignment.  Example:  _*# ##0_;_*(# ##0)_;_*"-"??_;_@_ Batch convert 4 PDF pages to one PDF page Is it possible to create individual power settings for each hard drive? I have a number of different drives that I use for different purposes but I only use two of them frequently. I would like for the others to enter sleep mode when not in use, but never my main two.  Is there any way to edit power saving settings for individual drives? Apparently I inadvertently irked a moderator by creating a tag.  The moderator told me that my tag was "meta" and therefore not appropriate.  Having been a SO user for a long time (and a lurker on MetaSO), it was not clear to me what makes my tag "meta" and why meta tags would be inappropriate.  Many of the questions I see on SO aren't really about the topics in the title or the existing tag list.  For example, , isn't really about C++ or SetWindowText (or the Windows API as tagged).  It's simply somebody who had a bug, couldn't find it, and tried to outsource the debugging.  This seems to be a common category of question on SO.  So I started tagged questions like this with the label "findmybug".  Lots of frequent SO contributors regularly answer questions in this category rather than voting to close them as "Too Localized".  I took that as a cue that I should also try to answer rather than voting to close.  But leaving these questions open and tagged with "c++" and "winapi" even though the question isn't really about C++ or the Windows API seemed misleading.  Someone searching for answers on using SetWindowText from C++ probably isn't making exactly the same mistake and won't find that entry useful.  (In the end, the sample question was closed as "Too Localized", but this doesn't seem common for these types of questions.)  The Tags page says:     A tag is a keyword or label that categorizes your question with other, similar questions. Using the right tags makes it easier for others to find and answer your question.   It seems to me that the "findmybug" tag does group these similar questions together.  So from that perspective, it seems to fit.  Lots of users seem to enjoy answering these types of questions, so it makes sense they'd want a way to find them.  If you want to suggest that all the questions I would tag as "findmybug" should be closed as "Too Localized", that's fine.  But I'm trying to ask the more general question:  What makes a tag meta, and are meta tags inappropriate? Dodecagon Area Question The distance between two opposite vertices of the dodecagon is 2. Find the area of the dodecagon.  Is there any way to do this without trigonometry?  And could you include a proof also? :O How to deal with hierarchical / nested data in machine learning Option + click in iTerm In Terminal, Option + click allows me to place my cursor at any point on the current line-- great for editing really long commands.  How can I do this in iTerm2?  Update: According to , the feature has been around since 0.7.0 (2003). I've also noticed that if I hold Command+Option, the cursor changes into the familiar cross like in Terminal...  but clicking still does not reposition my cursor. Don't display pending edit counter if you've exhausted your suggested edit votes Check for missing fonts/characters in XeLaTeX? Because I began to use many Unicode characters (Japanese, some unusual diacritics, etc.) I switched from LaTeX to XeLaTeX to render my documents. Unfortunately, if a font is missing, the letters are simply left out (for example, when I had forgotten to specify the font for Japanese) without any error (and I can't seem to spot a warning either). I will read the result, but I prefer to get some early warning if some character isn't available. Is there any way to get a warning about characters that have not been rendered? An error would be even better. Run apt-get without sudo youtube-dl unable to download audio how to resolve that issue? series of young adult science fiction books from early 1980s about last of a race of martial experts that sees the destruction of his home planet I remember that the main character is trying to find the group that destroyed his home planet while he was on a mission. His planet was very difficult to live on and the people became expert in martial arts and were the best soldiers in the galaxy. They were mercenaries and often helped against tyrants. There was a very memorable section in at least one book about an initiation task that the main character had to do in that he had to survive in their wilderness for days. He was at some point surrounded in a old building by thousands of poisonous worm/snake creatures that he managed to survive until rescued by the leaders. Fantasy series with Celtic overtones, intermittent stone magic, and ongoing slow magic I checked this series out of the library during college, maybe 15 years ago now.    It was based around 'stone magic' – magical stones that granted their bearers enormous power.  Unfortunately, the power of these stones is intermittent, they'll fade out for a long time then fade back in.  The main characters dealt with a 'master' stone of some sort, the first to restore, last to die.  It's also the key to granting other people access to their own powers – I think seals had magic fish they swallowed, which keyed off the master stone, and in the last book I think the character created magic staves for another race. It also had 'slow magic' – longer to set up, less apparently potent than stone magic, but the slow magic, given time to work it, could still be powerful and dramatic.  It just took time and preparation instead of brute force. In one book, the main character faces off against the source (or something like that) of magic, and is about to win when it's discovered she's pregnant.  The source – a dragon? – isn't allowed to harm anyone who doesn't come to it freely, so the main character is forbidden to finish the trial.  In the sequel, her daughter repeats the trial, and becomes immensely powerful by winning, but there was a cost of some sort, something that transformed her A lot of the naming made me think it had a Celtic root. Bash File Unable to locate package when new line is added When building a bash file to execute I keep getting an error after adding a new line. I have tried moving some lines around or removing some of the packages but it will results in the same error. In the file if I was to remove 3 and 4 it there will no longer be an error.   E: Unable to locate package &lt;package&gt;   The bash file looks like this   #!/usr/bin/env bash sudo apt update &amp;&amp; sudo apt install -y python3-pip build-essential python3-dev python3-setuptools gcc sshpass sudo apt-get install apt-transport-https lsb-release software-properties-common dirmngr sudo apt-get update   The output with the error  Hit:1 http://us.archive.ubuntu.com/ubuntu bionic InRelease Get:2 http://security.ubuntu.com/ubuntu bionic-security InRelease [88.7 kB]                                                   Hit:3 http://archive.ubuntu.com/ubuntu bionic InRelease                                             Get:4 http://us.archive.ubuntu.com/ubuntu bionic-updates InRelease [88.7 kB]         Get:5 http://us.archive.ubuntu.com/ubuntu bionic-backports InRelease [74.6 kB]                                       Fetched 252 kB in 1s (189 kB/s)     Reading package lists... Done Building dependency tree        Reading state information... Done All packages are up to date. Reading package lists... Done Building dependency tree        Reading state information... Done E: Unable to locate package sshpass Reading package lists... Done Building dependency tree        Reading state information... Done E: Unable to locate package dirmngr Hit:1 http://us.archive.ubuntu.com/ubuntu bionic InRelease Get:2 http://security.ubuntu.com/ubuntu bionic-security InRelease [88.7 kB]                                                   Hit:3 http://archive.ubuntu.com/ubuntu bionic InRelease                                             Get:4 http://us.archive.ubuntu.com/ubuntu bionic-updates InRelease [88.7 kB]         Get:5 http://us.archive.ubuntu.com/ubuntu bionic-backports InRelease [74.6 kB]                                       Fetched 252 kB in 1s (209 kB/s)     Reading package lists... Done Do we need a global test before post hoc tests? SSL certificate for a public IP address? I just tried buying a Comodo Positive SSL but it was rejected due to not supporting a public IP address, but instead they only support a domain name.  Does anyone know any SSL certificate provider that supports public IP address instead of a domain name?  My company has a dedicated server hosted with a web hosting company, which is used for running a bugtracker for multiple projects (for multiple clients). Since it's only used for a bugtracker, we don't need a domain name (our clients access it by typing the public IP in their browser).