I making a digital sign for a restaurant in Blender. The theme is winter and I animated falling snow and make stacking snow on the ground/floor(plane) and the font. But I got the problem with the shadow catcher. I am using sun for the the lighting type and i rendered by Eevee but the shadow doesn't show in rendered as like in the view port. I tried to click every &quot;shadow&quot;- related boxes but it never worked. And I attached my file in this link.
I want to know is there a way to render Shadows only in Blender's new EEVEE Render Engine. I want my objects in a separate collection and a ground plane on a separate collection(to receive shadows from the objects collection).I want to render the shadows only and not the objects.
Recursively replace string in files I want to replace the backslash in the string page_path\example_filename.txt with a forward slash.  I also want to be able to run this on a large file system and have it recursively search all directories.  I found someone on the web who said to use grep, xargs, and sed but I wasn't able to get it to work. I've been trying different variations on delimiters and escape characters, but didn't get it.  Here is the command I was trying to run: grep -lr -e 'page_path\\' * | xargs sed -i 's/page_path\/page_path//g'  Thanks in advance. Why do we say that irreducible representation of Poincare group represents the one-particle state? Only because   Rep is unitary, so saves positive-definite norm (for possibility density), Casimir operators of the group have eigenvalues $m^{2}$ and $m^2s(s + 1)$, so characterizes mass and spin, and It is the representation of the global group of relativistic symmetry,    yes? Typesetting 144...4 with "n times" under the 4's is easy, but what about \sqrt{144...4}? Inspired by  on the math StackExchange, suppose you want to typeset the square root of the number 144...4, that is, 1 followed by n 4's. If you write $\sqrt{1\underbrace{44\ldots4}_{n\ \text{times}}}$, as in the current version of the question, you get a huge radical sign that reaches down to match the "n times" text below the number. Is there an elegant way to typeset this so that the radical sign looks like it would with $\sqrt{144\ldots4}$, but also keeping the underset text in the right place? Adding tags to files in OS X: How to use, where are tags stored, and will they work on a network? I've heard it is possible to add tags to a file's meta data in OS X, and have Spotlight search through such tags.   In a nutshell, how would one access this feature in Finder &ndash; not Spotlight (Command+Space) &ndash; but the adding of tags themselves? Where are these tags stored?  Do they go in .DS_Store (I tend to delete those!) or elsewhere in the filesystem? Does this tagging mechanism work on removable drives?  What are the requirements? Does this tagging mechanism work over a network share?  I have some Windows SMB network shares at home that I frequently store files on.  Would it work on those or is another configuration required? Aside from Spotlight, are there any command-line tools for searching through or accessing the tag data for files?   Thank you! How to NOT show keyboard layout chooser popup when changing language in GNOME 3 Interpretation of mean absolute scaled error (MASE) How to create a progress bar? How do I get a substring of a string in Python? Is there a way to substring a string in Python, to get a new string from the third character to the end of the string?  Maybe like myString[2:end]?  If leaving the second part means 'till the end', and if you leave the first part, does it start from the start? How does item level and rarity affect the possible attributes? Error installing virtualbox-dkms on Ubuntu 20 Ubuntu 20.04. I installed virtualbox using package; it worked, I created and ran a RM. But then stopped to work after software update. I cannot run the VMs, message says : Kernel driver not installed (rc=-1908)  The VirtualBox Linux kernel driver is either not loaded or not set up correctly.  Please reinstall virtualbox-dkms package and load the kernel module by executing  'modprobe vboxdrv'  as root.  I managed to disable secure boot, so this is not related to this. Now I try to reinstall virtualbox-dkms package as requested : sudo apt remove virtualbox-dkms sudo apt install virtualbox-dkms  But then I get the following error : Préparation du dépaquetage de .../virtualbox-dkms_6.1.10-dfsg-1~ubuntu1.20.04.1_amd64.deb ... Dépaquetage de virtualbox-dkms (6.1.10-dfsg-1~ubuntu1.20.04.1) ... Paramétrage de virtualbox-dkms (6.1.10-dfsg-1~ubuntu1.20.04.1) ... Loading new virtualbox-6.1.10 DKMS files... Building for 5.8.0-34-generic Building initial module for 5.8.0-34-generic Error! Bad return status for module build on kernel: 5.8.0-34-generic (x86_64) Consult /var/lib/dkms/virtualbox/6.1.10/build/make.log for more information. dpkg: erreur de traitement du paquet virtualbox-dkms (--configure) :  installed virtualbox-dkms package post-installation script subprocess returned error exit status 10 Des erreurs ont été rencontrées pendant l'exécution :  virtualbox-dkms E: Sub-process /usr/bin/dpkg returned an error code (1)  If I look at /var/lib/dkms/virtualbox/6.1.10/build/make.log I see : /var/lib/dkms/virtualbox/6.1.10/build/vboxdrv/linux/SUPDrv-linux.c:760:38: error: ‘cpu_tlbstate’ undeclared (first use in this function); did you mean ‘cpuhp_state’?   760 |     RTCCUINTREG uOld = this_cpu_read(cpu_tlbstate.cr4);       |                                      ^~~~~~~~~~~~ ./include/linux/percpu-defs.h:318:9: note: in definition of macro ‘__pcpu_size_call_return’   318 |  typeof(variable) pscr_ret__;     \       |         ^~~~~~~~ /var/lib/dkms/virtualbox/6.1.10/build/vboxdrv/linux/SUPDrv-linux.c:760:24: note: in expansion of macro ‘this_cpu_read’   760 |     RTCCUINTREG uOld = this_cpu_read(cpu_tlbstate.cr4);       |                        ^~~~~~~~~~~~~ /var/lib/dkms/virtualbox/6.1.10/build/vboxdrv/linux/SUPDrv-linux.c:760:38: note: each undeclared identifier is reported only once for each function it appears in   760 |     RTCCUINTREG uOld = this_cpu_read(cpu_tlbstate.cr4);       |                                      ^~~~~~~~~~~~ ./include/linux/percpu-defs.h:318:9: note: in definition of macro ‘__pcpu_size_call_return’   318 |  typeof(variable) pscr_ret__;     \       |         ^~~~~~~~ /var/lib/dkms/virtualbox/6.1.10/build/vboxdrv/linux/SUPDrv-linux.c:760:24: note: in expansion of macro ‘this_cpu_read’   760 |     RTCCUINTREG uOld = this_cpu_read(cpu_tlbstate.cr4);       |                        ^~~~~~~~~~~~~ make[2]: *** [scripts/Makefile.build:290 : /var/lib/dkms/virtualbox/6.1.10/build/vboxdrv/linux/SUPDrv-linux.o] Erreur 1 make[2]: *** Attente des tâches non terminées.... make[1]: *** [scripts/Makefile.build:519 : /var/lib/dkms/virtualbox/6.1.10/build/vboxdrv] Erreur 2  What I am missing ? Clearing Recently used coordinate reference systems using QGIS? After using some non usual SRC for demonstration purpose, I wish to clear my  "Recently used coordinate reference systems" list for the sake of praticity.  Is it possible?   I am using QGIS 2.10.1. A Light is shone out the side window of a spaceship ( moving close to light speed ), will the light still travel at the speed of light in the B axis? "did shoot" vs "shot" I normally use the iPhone timer to sleep the device after I've dozed off to some music or podcast. Unfortunately this means that when I ask Siri to set a timer for some cooking, Siri waits the allotted time and turns off the phone rather than notify me that the time is up. Any solutions to this? How can I explain how to play D&D to new players without them falling asleep from boredom? Some of my friends just started playing Dungeons &amp; Dragons [5e] for the first time and don't know anything about how to play. I have tried explaining to them the things that are completely necessary and teach them the rest while playing but I could not get them to understand. None of them have a players handbook and they can't afford one and they really want to play. I really want a simple way to explain the basics and since I have a habit of explaining things in ways that are much too complicated. I have already told them the basic rules so all I need to know is a simple way to explain how to play. Can a ring of positive characteristic have infinite number of elements? Near-universally applicable alternative to "sanity check" The phrase "sanity check" is  as it implies that there is something wrong with people who have mental illnesses and the word "sanity" has been used to discriminate against such people.  Therefore, it should should be avoided.  What is a better alternative in the context of software?  Example usage:     _: if this is not what it should be, we have memory corruption (a fatal   error) and should terminate the program. Just read this which basically says you can freeze and thaw food in the fridge any number of times.    I'm still unclear on one point. If I had food which would be good in the fridge for 4 days and i put it in the freezer after 3 days, when I put it back in the fridge is my food good after its thawed for another 4 days or 1 more day? Anti-Cheat for MMOs issues and solutions? Most online games suffer for this problem and there are some  out there to cover this but recently from what I've seen most companies are trying to avoid those programs creating their own system (blizzard with warden, aion with their own checking, etc...) but it is a very difficult case to prevent such ...  Just wanted to say i made another question topic as community wiki specific for posting applications and it is features and the ideas behind this question here is not to list those but instead to know more about what were your attempts, issues along the road and possible solutions, piece of codes if application and so forth.  What sort of protection do you guys use in order to (try to) prevent such acts:   Anti-cheat Software ? (please state which, why and possible problems you faced, for example aion stopped using GameGuard at beta stage due to a huge amount of compatibility problems and complains from their users) Your own code ? (what sort of verification do you usually run to make sure of the bad-faith players, for example speedhack, verify new location against speed+last location, etc...) None, i dont care ? (any personal reason or input you did like to share ?)   Any interesting piece of code related to the issue you would like to post ?  Feel free to rework my text my english inst that great  ?** Complete residue system proof I was given a proof of this in class, but it does not make sense to me, can someone provide a better proof, or explain the one I have provided, thanks.  Suppose $\gcd(a,n) = 1$, where $a$ and $n$ are natural numbers. Prove that $0$, $a$, $2a$, $3a,\ldots, (n-1)a$, is complete residue system modulo $n$.  Proof given in class:  \begin{align*} ka &amp;\equiv ra \pmod{n}\\ &amp;\Rightarrow  k \equiv r \pmod{n}\\ &amp;\Rightarrow  \text{$k-r$ divides $n$}\\ &amp;\Rightarrow \text{$k=r$ because $0\leq k\lt n$, $0\leq r\lt n$} \end{align*}