is it possible / / how do i make an object give off "godrays" so that, for instance you can see it through slits in a wall?   I'm trying to make this, (an icosphere with a sphere inside, the inner sphere gives off a blue glow) into a sort of "disco ball" is the best i can describe it. but i'm fairly new to anything blender and have no clue how to achieve this.   I read somewhere that the only object that could give off volumetric light is a spot lamp, but the thread was like 3 years old.  Edit: thanks for the help, what you said to do worked, just can't have a material output and lamp at the same time apparently :D but that's fine it looks good now!
I'm trying to do a volumetric light on Cycles, and I've followed tutorials, but nothing has worked yet. How can I make a proper volumetric light in Blender, like the following one?    But to leave the light in the middle, like, almost a star, is this possible? I'm at the point to use an image plane besides the light which would be better... I need to use it moving the camera.  I'm actually trying to do this because I want to simulate the brightness of the Sun.  I tried the effect, but it still gave me an error:
Is everything in the physical world composite? In philosophy there is a principle that anything composite cannot have existed eternally, since it is preceded by its parts and whatever forces assembled it.  Is everything in the physical world composite in one sense or another or is there something not composite? Which part of speech is "Be assured"? Which of the spans in 1.1 is the stronger? Be assured, you are in numerous company if you pick the left one at first glance, where the struts and wires are doing nothing useful at all.   Could you please tell me what is "Be assured" here?  I mean whether it is an adverb, adjective, so on?  And, would you please show me some examples exactly like such the following, considering my original sentence?     Be assured, ... What is the trajectory of a photon moving through a vacuum? Since electromagnetic energy is carried by photons and moves in forms of waves, does it mean that a single photon when propagating through space doesn't follow the straight path but instead always moves up and down, up and down like a wave. If so another question arises the speed of propagation of light in vacuum is fixed meaning that it will always take the same amount of time for it to travel from point A to point B, but if a photon always moves up and down it will also mean that it travels longer distance than the distance between A and B and so it ill travel faster than light propagates, is it even possible, could you please clarify these concepts for me? Are there fewer positive integers than all integers? In our 6th grade math class we got introduced to the concept of integers. With all the talk about positive and negative, it got me wondering. Is the amount of elements in $\mathbb{Z^+}$ less than the amount of elements in $\mathbb{Z}$?  Here is how I thought of it. If we have $\mathbb{Z^+}$ and add one element to the "back" of it ($\mathbb{Z}^{\geq-1}$) there are certainly more elements in that new set, so there must be more elements in $\mathbb{Z}$ than in $\mathbb{Z}^+$ but on the other side if we try to express the amount of elements in them "numerically" (In a loose sense of the word) they both have $\infty$ elements.    So what is the right answer? Is there even one?  (Please note I am a bit of a layman when it comes to mathematics)  Edit: About the possible duplicate, I am not looking for a bijection between the two sets, I am looking for if they even have the same number of elements and why a bijection shows that they do/don't Meta's tag pages inaccessible due to self-redirect loop Are functions of independent variables also independent? Can I use B1 visa (Visitor-Business) to travel to the Canada without a business purpose? I got a B1 visa (Visitor-Business) for Canada in 2012 when I traveled to Canada for a business trip from my company. It expires in 2015 and I'd love to visit the Canada again, but for no other purpose than traveling, visiting family.  I want to know, If I can legally travel to Canada with B1 visa without a real business need (assuming I'm honest);  I live in India, and I have B1/B2 from US and used same Visa for Business &amp; Personal visits multiple times. Why doesn't a bike/bicycle fall if going with a high speed? given value of matrix, getting it's coordinate I have 13.04 installed from a DVD that I got on eBay but the application launcher is missing. I've tried CCSM but it won't work! Let's say we have one black hole that formed through the collapse of hydrogen gas and another that formed through the collapse of anti-hydrogen gas. What happens when they collide? Do they (1) coalesce into a single black hole or do they (2) "annihilate" into radiation?  One would expect (1) to be the case if the No Hair Theorem were to hold. So I guess what I'm really asking for is a modern understanding of this theorem and its applicability given what we know today. How to copy the complete folder structure one location to another location include all files and sub folders I have folder structure like in Shared documents/East using CSOM and C# Main Folder   Folder1   Folder2      File1      File2  I have to copy all folders with files to Shared documents/West .... Python idiom to return first item or None I'm sure there's a simpler way of doing this that's just not occurring to me.  I'm calling a bunch of methods that return a list.  The list may be empty.  If the list is non-empty, I want to return the first item; otherwise, I want to return None.  This code works:  my_list = get_list() if len(my_list) &gt; 0: return my_list[0] return None   It seems to me that there should be a simple one-line idiom for doing this, but for the life of me I can't think of it.  Is there?  Edit:  The reason that I'm looking for a one-line expression here is not that I like incredibly terse code, but because I'm having to write a lot of code like this:  x = get_first_list() if x:     # do something with x[0]     # inevitably forget the [0] part, and have a bug to fix y = get_second_list() if y:     # do something with y[0]     # inevitably forget the [0] part AGAIN, and have another bug to fix   What I'd like to be doing can certainly be accomplished with a function (and probably will be):  def first_item(list_or_none):     if list_or_none: return list_or_none[0]  x = first_item(get_first_list()) if x:     # do something with x y = first_item(get_second_list()) if y:     # do something with y   I posted the question because I'm frequently surprised by what simple expressions in Python can do, and I thought that writing a function was a silly thing to do if there was a simple expression could do the trick.  But seeing these answers, it seems like a function is the simple solution. WI-FI Nic showing 3 different transport id {Device id} There was a problem with my network controller so i opened up cmd and started to check for interfaces. I noticed a strange thing that my Wifi network controller had 3 different Device ID (Transport id's) When i tried to disable the wifi card the different id's went away. On my other computer i tested the same thing and it only shows 1 id? Device\NPF_{4A45A363-6346-48DA-8D28-13DD9C9C1E6A} Device\NPF_{E6994972-C66C-4ABF-BE27-17BAC7C1C971} Device\NPF_{B6394772-H66C-4ABF-HRE27-17JLC0H9C971} I am using snort to check for available interfaces. Can anybody explain why i am seeing this? WLC model: intel dual band wireless-ac 8265 running default settings on the adapter however i have hyper-v open Finding the distribution of the sum of three independent uniform random variables If temperature makes particles vibrate faster, and movement is limited by the speed of light, then I would assume that temperature must be limited as well. Why is there no limit? Summary table with a field that shows components of each summarized record I have a table with 2 fields the first is for community and the second for the main community that it belongs to, as in the image  I want to summarize the second field (Belongs_to) but with an extra field (multiple value field) that shows components of each main community, as in the image  Could anyone help me please? Random errors on various sites when viewing main page Occasionally (very occasionally) when returning to the main page of a site by clicking on the logo I get the following message:     It was not possible to perform this tag search at this time due to an unexpected error.   This is odd because I'm not performing a tag search.  So far this has happened on both Movies &amp; TV and Cooking.  I have heard that others are getting this same message. Can't login using ssh as root I am trying to virtualize an old linux server, and the PtoV software requires a password login as root via ssh. However, the root login is being prevented with a "Permission Denied" error on the client end, and a "Failed Password for root" on the server end (when sshd is running in debug mode).  I HAVE set PermitRootLogin yes in /etc/ssh/sshd_config.  This is an old RedHat 7.3 server that has had hardening scripts like Bastille run on it years and years ago, and has many remnants of old OS's (like ipchains - no longer supported by the kernel) lying around. All to say I have little idea what has been altered from the original system, but there is a lot.   I can log in fine as root from the console I can su to root fine from within the console or ssh session I can ssh fine as a regular user.   My question is: What else could be preventing my root login on this server?  More information: /etc/pam.d/sshd   auth       required     pam_stack.so service=system-auth  auth       required     pam_nologin.so  account    required     pam_stack.so service=system-auth  password   required     pam_stack.so service=system-auth  session    required     pam_stack.so service=system-auth  session    required     pam_limits.so  session    optional     pam_console.so   /etc/pam.d/system-auth  auth        required      /lib/security/pam_env.so auth        sufficient    /lib/security/pam_unix.so likeauth nullok auth        required      /lib/security/pam_deny.so account     required      /lib/security/pam_unix.so password    required      /lib/security/pam_cracklib.so retry=3 type= password    sufficient    /lib/security/pam_unix.so nullok use_authtok md5 shadow password    required      /lib/security/pam_deny.so session     required      /lib/security/pam_limits.so session     required      /lib/security/pam_unix.so     Can anybody tell me if the hashing algorithm could be the culprit?  Keeping in mind that I can log in as an unprivileged user. Clarifying question on meaning of derivative of a linear transformation In my analysis class, my professor (and the textbook) reference the fact that $\mathbf{D}T(\bar{x}) = T$ for any $\bar{x} \in \mathbb{R}^n$ where $T \in \mathcal{L}(\mathbb{R}^n,\mathbb{R}^n) $. I'm wondering about the precise meaning of this statement. Is it that the differential of any linear transformation is also linear? Or is that the differential of any linear transformation is itself (and therefore also linear)? The second seems confusing to me because the derivative of a function is often not itself. For example, $f(x) = 2x$ is a linear transformation but $f'(x) = 2 \ne 2x$ for all $x \in \mathbb{R}$.