i've been working on this Project for a while now and i am struggling with fireflies all over my metallic materials, I can easily get rid of them inside Photoshop but i would like to render an animation of the scene so i need cycles to render free fireflies frames.  I've tried: -Increasing my samples and no matter how high i go fireflies keep apearing, they even appear more one my frame has reached 4000 samples  -tweaking my material node  -deactivating my reflective caustics   -tweaking light (scene is iluminated by an hdri, a sun lamp and 2 point lamps)  I think it may have something to do with the roughness map or maybe lightpaths or max bounces since there are a lot of reflective materials inside the scene but im not an expert in either so i cant find a solution
I often use Cycles' built in Glass BSDF shader to achieve realistic refraction effects, but in many cases, it seems that Cycles' glass caustics creates an unfortunately large number of fireflies (pixels that are abnormally bright relative to their surroundings). In some models of mine, even when I render for 3000 or more samples/pixel, my final image is still covered in fireflies. While I can improve this in many cases by increasing the total amount of light available in the scene, this loses a lot of the potency of the refractive effects I'm looking for, especially in scenes with low light levels.  So my question is, how can I reduce the amount of fireflies while using Cycles' caustics without sacrificing the quality of the refractive effects?  Note: I am aware that Cycles' caustics will perform much better once Cycles has full support for bidirectional path-tracing, but it looks unlikely that that will become , unfortunately.
A short story about finding an inhabitable planet and meeting aliens So the story goes, humans in a spaceship search for an inhabitable planet, being surprised they found none in the vicinity of Earth. They find one, and it seems uninhabited. At the same time are observed by the aliens, who go down on the planet to meet them. The aliens sit them down and tell them a story about war and conflict that ruled the galaxy, and how all the sentient races in the galaxy got together and got rid of the race that tried to conquer all by blowing up their planets.  In the end you realise man is this terrible conqueror the aliens are talking about. Placement of the asterisk in pointer declarations I've recently decided that I just have to finally learn C/C++, and there is one thing I do not really understand about pointers or more precisely, their definition.  How about these examples:   int* test; int *test; int * test; int* test,test2; int *test,test2; int * test,test2;   Now, to my understanding, the first three cases are all doing the same: Test is not an int, but a pointer to one.  The second set of examples is a bit more tricky. In case 4, both test and test2 will be pointers to an int, whereas in case 5, only test is a pointer, whereas test2 is a "real" int. What about case 6? Same as case 5? in elisp's let, how do you reference a variable bound in the same let while binding another variable? How long is a 'block'? Difference between differential op amp and comparator What is the difference between a differential op amp and a comparator? I know a comparator can only give me two values (the supply values).  The differential op amp amplifies the difference between the inputs...but should a comparator not do the same then? What is the specific difference? WiFi problems (Atheros driver) with FreeBSD 11 With FreeBSD 10.3 my Atheros card worked fine and showed up as /dev/ath0. Now with FreeBSD 11 this is no longer the case, though the module is loaded and it seems the system recognizes the card:  root@igloo:~ # sysctl net.wlan.devices net.wlan.devices: ath0   Still, ath0 cannot be used:  root@igloo:~ # ifconfig wlan0 create wlandevice ath0 ifconfig: must specify a parent device (wlandev) when creating   What must I do to use the card? Is it possible to make a sequence of renders and give the user the option to cancel the process through the UI at any given time? I'm trying to make a script where I have to render several images of the same scene at the same frame, and write to disk with appropriate names. The problem is that although this works fine with a non-responsive UI, it doesn't work well when the render progress appears in the Blender UI.  I mean,  bpy.ops.render.render()   uses "EXEC_DEFAULT" when called from a script. This leaves a blocked User Interface until the render finishes, meaning that you can't cancel the process, except by killing Blender. The problem is that the render may be too big in resolution, and the user could want to stop the process when realizing that the render could take hours, so the idea is to cancel this process without losing the currently opened project.  If I call,  bpy.ops.render.render("INVOKE_DEFAULT")   I get a nice preview bar in the Info Window with a clickable "X" button. I want the user to be able to press that button to cancel the operation if needed, but for a series of renders (not animation).  The problem here seems to be when trying to loop this command with the INVOKE_DEFAULT context to write several renders. I made a lot of testing, and this way of calling the render operator seems to continue with whatever is next in the script, so it loops very fast and ends before the rendering actually finishes.  I think that I need some way to stop the script and make it wait until render finishes to continue looping with the next ones. I tried the "render_complete" and "render_cancel" handlers, but I can't use them to start a new render or even make the rest of the script wait until the loop of renders is complete. I tried threading and events without success either. Maybe I'm doing something wrong.  import bpy  render = bpy.context.scene.render path = render.filepath = "/tmp/" shots = ["one", "two", "three"]  for x in shots:     render.filepath = path + x     bpy.ops.render.render("INVOKE_DEFAULT", write_still=True) # this doesn't work      # but if I use:     # bpy.ops.render.render(write_still=True)     # without the INVOKE thing, images are written as expected,     # but losing the possibility to see the progress and cancel rendering $\exp(A)$ is orthogonal iff $A$ is skew symmetric Let $A \in M_n(\mathbb R)$ and $\exp(A)=\sum_{i=0}^{\infty}\frac{A^i}{i!}$. How to prove $\exp(A)$ is an orthogonal matrix iff $A^t=-A$?  I can get that $\exp(A)$ is an orthogonal matrix iff $\exp(A^t)=\exp(-A)$, but how to get $A^t=-A$ from it?  What's more, is $\exp(A)$ injective or not? How do I do a search in File Explorer that includes subfolders of zip archives? In File Explorer, I can enter search terms in the upper-right search box to search the current folder and all subfolders. I can also navigate the folder tree of zip archives like any other folders. However, if I want my searches to include files in a zip archive I have to navigate to the specific folder in the zip archive where the file is located. My searches never include files in zip archives if I'm not in the archive, and when I am in the archive my searches don't include files within the archive's subfolders.  Is there a way for my searches to include zip archive subfolders? What's the easiest way to use a linked list in python? In scheme, a linked list is defined simply by '(1 2 3 4 5). Python's lists, [1, 2, 3, 4, 5], and tuples, (1, 2, 3, 4, 5), are not, in fact, linked lists, and linked lists have some nice properties such as constant-time concatenation, and being able to reference separate parts of them. Make them immutable and they are really easy to work with! Data recovery from an accidental format on ext4 partition When I was installing Mint Debian edition unlike the classic edition, the installation automatically formated my home partition when I did not specify to format.  So the formatting previously was ext4 as is now. I believe the data is still there as it was a quick format.   I have now booted the computer up on a live USB to prevent writing on it.  Ran testDisk. Is there anyway to recover to a previous superblock so i can recover my data? I'm trying to remember the name of a series of books about a boy who works with dragons.  Dragon's blood (or maybe it was slobber?) is acidic, and the children who wrangle these dragons often end up with deep pock marks.  On this world, days are like ours but nights get very cold, requiring anyone stuck outside to find a shelter until dawn (not the false dawn)  The other thing I remember is that in one of the books by slicing open a dragon and spending the night, the character emerged with special dragon powers. Using a wi-fi and an ethernet connection at the same time thus having more bandwidth? Restoring a backup to an older version of SQL Server Is it possible to determine the exact date and time (if possible) of creation of an Apple ID?   Is there any official or unofficial way to establish this if you don't have the initial sign up information recorded? Is there a way to insert Keyboard Glyphs in Google Docs? Here on the StackExchange framework we have a nice feature, which is apparently called "Keyboard Glyphs" (cf. ):     CTRL+Z   Is there a way (e.g. with an Add-On) to do the same in Google Docs? I browsed the Add-Ons but did not find anything, maybe it's hidden somewhere different (e.g. in a Code Formatting Plugin). I'd like to write something in the shape of this "coat of arms".    I'd like to have the text filling the coat but with a hole roughly in the shape of the sword. I know there is the \shapepar command to create paragraph shapes so I tried to , a patch for XFig that allows you to draw the shape you want but it never worked on my computer (Mac OS X). I also know I can build the shape by myself with shapepar syntax but it seems really complicated and I don't think I'll make a lot of shapes. So if anybody has ShapePatch working on his computer or knows shapepar syntax very well, could he give me the code? Ubuntu does not offers me "install alongside Windows" Any of the partitions makes in Windows was not recognised by Ubuntu, or Zorin OS, or LinuxMint. It's like a blank hard disc, 250 gb free. I'm a new Linux user, but what confuses me is that I was able to install Ubuntu alongside Windows on my laptop with no problems, but on PC... no way! Crash adding comment How to figure if it is safe to travel to the area I am interested in? When planning a trip, I like to make sure I will feel safe enough (I am talking about war/terrorism risk, not pickpockets), or at least I like to have an idea about the risks. I know the risk could be subject to political views (for example the political stability of a region might not be acknowledged by every country) and therefore I am mostly interested in a Western country view.  In order to figure that, I thought about checking travel operators offers. I suppose if they do not organise trips to a specific region, it might be due to political instability risks. But it might be due to a lack of tourist interest too. As I tend to travel without their help, I am not really considering this kind of source as very helpful.  So I am interested in one (or two, for cross-checking) source(s) of information with a western view (I mean I understand the view could be biased) regarding the security of ideally any area in the world. My expectation is that, the same way I can browse a tour operator's catalog of visited areas, I could browse through the areas and see if it is recommended or not to travel there.