I've managed to render PNGs which have my machine on a transparent background, but I want to have a video of it.  I've tried lots of settings to no avail....the film/transparent setting doesn't seem to do anything.  Every vid I've rendered, whether it be straight from Blender Render or Cycles Render or via creating a film strip from the PNGs via Video Editor and creating a vid from there, turns up with a black background from my scene.  Whats the trick?  Thanks!
Does anyone know if there are any video formats (besides the HUGE uncompressed avis) that you can render in that maintain the alpha channel? (i.e. for after FX etc.)   I used to use quicktime, but that's no longer an option.  I know you can render in png. or other image formats, but video is significantly smaller, and I often work on machines with less space &amp; resources.
Say we have a rod with a fixed axis of rotation. If we give it a push at some point other than the axis, it will start to rotate. Say our force is $F$, then we might write: $\Delta P=F\Delta t$. I’m wondering how to incorporate angular momentum here. We know that for a single particle it holds that $L=r\times p$. And for an extended object with a fixed axis of rotation, we generally might write $L=I\omega$. However, can I write $L=r\times p$ too for the extended object? I would think that I would need to integrate. So we have $p_\alpha=m_\alpha v_\alpha=m_\alpha r_\alpha\omega$, where we consider an infinitesimal mass $\alpha$. So should I write $L=\int r^2\omega\,dm$? I’m confused whether to work with this integral, or just use $L=r\Delta P$ at once.  The reason I'm asking, is because I'm trying to calculate the sweet spot of a baseball bat. So this is my attempt at solving the exercise. How do I calculate $\lim_{x\rightarrow 0} x\ln x$ I was thinking about the reasons behind $0^0=1$ and I remember one of my friends studying math arguing about the continuity of the function $x^x$ in $0$. But when I write as $$x^x=e^{x\ln x}$$ I am now looking at $$\lim_{x\rightarrow 0} x\ln x$$ Graphically I can see in Mathematica that it goes to $0.$ But I can't calculate by using a Taylor expansion, because I can't expand log around $0$. How do you prove that? How to typeset subscript in usual text mode? Why is the Yang-Mills gauge group assumed compact and semi-simple? What is the motivation for including the compactness and semi-simplicity assumptions on the groups that one gauges to obtain Yang-Mills theories?  I'd think that these hypotheses lead to physically "nice" theories in some way, but I've never, even from a computational perspective. really given these assumptions much thought. How do I pre-install Ubuntu for someone (OEM install)? What does the plus sign do in '+new Date' Show that $S = \sqrt{S^2}$ is a biased estimator of $\sigma$ given a random sample from a normal distribution ... Suppose $Y_1, \ldots, Y_n$ is a random sample from a normal distribution with mean $\mu$ and variance $\sigma^2$. Let $S^2$ be the sample variance, which is unbiased for $\sigma^2$.  GOAL: Show that $S = \sqrt{S^2}$ is a biased estimator of $\sigma$.  I realize that $(n-1)S^2/ \sigma ^2$ is chi-square with $(n-1)$ degrees of freedom.  I am given that $$E(S) = E\left[\frac{\sigma}{\sqrt{n-1}} \left[\frac{(n-1)S^2}{\sigma^2}\right]^{1/2}\right] = \frac{\sigma}{\sqrt{n-1}} \int_0^\infty v^{1/2} \frac{1}{\Gamma[(n-1)/2] 2^{(n-1)/2}} v^{(n-1)/2} e^{-v/2} \, dv$$  Can anyone help me understand why they have $v^{1/2}$ and $v^{(n-1)/2}$ (combining them $v^{n/2}$ as I think it should be $v^{1/2}$ and $v^{\frac{(n-1)}{2}-1}$ (combining both terms give $v^{(n-2)/2}$ since the pdf for chi-square distribution is $$ f(v) = \frac{v^{(x/2)-1} e^{-v/2}}{2^{x/2}\Gamma(x/2)},$$ where $x$ is degree of freedom?  Could anyone please tell me which one is the correct answer with explanation?  Thank you What form of the verb is used with compound subjects containing "or"? Recently I downloaded Pokemon GO but when I try to sign up with google account,the option isn't there. Help please. I use a LG G2 mini I'm working with Beamer and I would like to create boxes with round corners. I use \ovalbox, but I would like to control the thickness of the line. How can I do this? I also tried \thinlines, but I still not understand the sintax since I didn't find a minimal example. How to unzip a zip file from the Terminal? Just downloaded a .zip file from the internet. I want to use the terminal to unzip the file. What is the correct way to do this? When a divination wizard character uses their Portent ability:     Starting at 2nd level when you choose this school, glimpses of the   future begin to press in on your awareness. When you finish a long   rest, roll two d20s and record the numbers rolled. You can replace any   attack roll, saving throw, or ability check made by you or a creature   that you can see with one of these foretelling rolls. You must choose   to do so before the roll, and you can replace a roll in this way only   once per turn.   ... to replace a roll, can a player with the Lucky Feat:     Whenever you make an attack roll. an ability check, or a saving throw,   you can spend one luck point to roll an additional d20. You can choose   to spend one of your luck points after you roll the die, but before   the outcome is determined. You choose which of the d20s is used for   the attack roll, ability check, or saving throw.      You can also spend one luck point when an attack roll is made against   you. Roll a d20, and then choose whether the attack uses the attackers   roll or yours.      If more than one creature spends a luck point to influence the outcome   of a roll, the points cancel each other out; no additional dice are   rolled.   ... use the Luck Roll to replace the result? Or does the Portent trump all rolls and simply give you the final outcome?  This question spun off from  on .  Some relevant points:  .  Mike Mearls tends to believe that luck can triumph in some cases, but admits this is , and further seems to conflate the question with .  I would suggest reading the linked discussion before formulating an answer. There's some good thought there. I already derived a QM expectation value for ordinary momentum which is: $$ \langle p \rangle=  \int\limits_{-\infty}^{\infty} \overline{\Psi}  \left(- i\hbar\frac{d}{dx}\right) \Psi \, d x $$ And I can read clearly that operator for momentum equals $\widehat{p}=- i\hbar\frac{d}{dx}$. Is there an easy way to derive an expectation value for $\langle p^2 \rangle$ and its QM operator $\widehat{p^2}$? Is there a RegExp.escape function in JavaScript? What TV show has kids entering a video game of some sort? I've been searching the entire Internet for this show about 4 teenagers that enter a video game world where they have to fight monsters that looked like insects. Every time they had to enter the world, they'd go down in the sewers and one of the guys had a skateboard, a girl had a scooter and that's what I can remember. There was also one guy that always stayed behind to check their "health" in the game and pull them out in case they took too much damage to avoid them dying inside the game. I don't know if it was animated or not so there's not much to go on at all but hopefully someone might know what show it is? sudo apt-get upgrade installs all updates, not just security updates. I know that I can use Update Manager to select only important security updates, but is there a way to do this from the command line? Rising edge pulse detector from logic gates The circuits I describe are entirely made of 7400 series logic gates (7402, 7404 and 7408 ic). I'm trying to build a rising (positive) edge pulse detector using logic gates.  The following circuit should work in theory:   (see )  I do not expect the short output to be seen through a LED so, to test it, I make it trigger an SR latch to its up state:    However, it doesn't have effect on the latch. So I added an inductor to delay the input to the NOT gates in the pulse detector circuit and it worked:   But now I can see the short flashing output through a LED which I should not because it would mean it is too long to work with a circuit like that:   Which intends to toggle the D Latch output on each clock rising edge (Note that this is a D Latch not a D Flip-flop)  And anyway there is no place for inductors in integrated circuits so there must be a way to do this only with logic gates. Can someone solve this mystery?  BTW It does not show in my schematics but I did put 10K pull-down resistors where there might be floating pins. Is it acceptable to use "is become" instead of "has become"? In the King James version of the Bible there is a verse like this:     The Lord is my strength, and my fortress, and my song. And He is become my salvation.   Is it still feasible to use "is become" instead of "has become" and what is the semantic difference? Let $\{f_n\}$ be a sequence of analytic functions on a region $\Omega$ with $|f_n| ≤ 1$ on $\Omega$. Let K be compact and contained in $\Omega$. Suppose $\{f_n\}$ converges at infinitely many points in K. Then is it true or false that $\{f_n\}$ necessarily converges at every point of $\Omega$? Entering U.S. exactly on the day of visa "expiration date"