text:
FreeStyle won't appear in Blender Render, pictures below?
It worked before but I can't seem to get it to work again, this is the model I was using this anime tutorial  I'm not using Makehuman like him though I'm using Fuse Mixamo. I've done this before and it worked fine I've tired this with 3 models and it won't appear for some reason.

These are my settings, I've gone through the video to make sure they were correct
I'm using blender 2.72, Blender Render not Cycles.

Welcome! Is the Line Set enabled (the checkbox is not visible in the screenshot)? Do you have the same problem with simpler scene like the default one?

You are allowed to post max two hyperlinks at a time in the question field as a "new" user. http://blender.stackexchange.com/help/privileges/new-user As the video is public on YT, I think that it's all fine.

Thanks for answering I'm not sure where is the Line Set enabled located?

Just above what you can see in the second picture you posted. Render layer tab >> Freestyle line set.

is the master "freestyle" checkbox enabled in the render options panel, is it?

Another issue is the render buffering. Try deactivating Performance/Save Buffers to force Blender to redraw the Freestyle overlay.
Make sure to turn this function off.


text:
My CPU is still faster than my GPU
When I render something with blender my CPU is faster than my GPU. Why is that?
My GPU is Nvidia Geforce GT730 2gb  and my CPU is intel i5

This is frustrating  I have a macbook pro but I bought a Lenovo pc  with intel i5 and nvidia GPU just for faster rendering but it is not.

This is related and may awnser your question: http://blender.stackexchange.com/questions/24272/gpu-slower-than-cpu

What rendering engine are you using?

@PGmath I'm using cycles render

The [tag:blender-internal] tag is for the blender internal (BI) render engine.

So you mean it works only with blender render ?

No, that's just what that tag on our site is for.

If I read the specs correctly, the GT730 is a pretty slow graphics card. It provides hardware acceleration for multimedia applications ("super-fast web browsing, plus incredible photo and video editing") but it is not meant for high performance calculations. They compare it to integrated graphics, which is like comparing a Smart to an old VW Beetle, while everyone else is driving Ferrari.

That explains a lot. I have never read its specs all I know that it is 2 gb. Now I know that I have to change it. Any recommendations?

There is a rendering benchmark on Blenderartists that lists rendering times for different grahics cards and processors. Maybe the spreadsheet can give you some orientation, then you will have to pick one that fits you budget.

Increase your tile size.

Your CPU is like Usain Bolt, and your GPU is a lot of turtles. Enough turtles will cover more total distance travelled than Usain Bolt going at full speed within the same time.
Likewise, your GPU will process more pixels at the same time, although slower, so increase the tile size.
You will need to experiment, though, with various values. You will need to find that sweet spot for your GPU and scene. If your values are too high, your GPU might not have enough cores to process an entire tile in one shot, so you might get that lag.
UPDATE
Your GPU has 96 cores running at 700 MHz. This explains why you may not be getting a very big GPU benefit no matter how you tweak the tile size.
In comparison, today's latest budget NVidia GPU is the GTX 950, which has 768 cores, running at a slightly higher 1024 MHz.
I advise you to upgrade your GPU.

I did that and it was kinda helpful but the cpu renders 4 tiles while gpu renders only one tile

Did you time your results? You may want to consider either sticking to your CPU or get a new GPU.

After increasing the size of the tiles the cpu became much faster than before but the gpu not that difference

GTX 950 , is it the in price and specs? Or is there a better one ?

GTX 950 is around the $135-$160 range. If you're willing to shell out around $500+, you can go for a GTX 980. Also, note that Blender Cycles may now support Radeon cards, but stick with NVidia (my bias).

source: Stack Exchange

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/3.0/

sort: votes


text:
Deforming a maze mesh into a hole
I'm trying to to get this effect :

with my maze.
So, the maze should fall into the hole. I have no idea how to go about it. Maybe get it to follow the surface of a torus? (but don't know how). Please help.

You intend to make a still image, or animate the fall into the hole ?

Still image is all I need

Tissue+Solidify
I would personally model a piece of the maze and spread it on a surface with Tissue add-on. Just pick the component first and then the generator and click "tessellate". From the add-on wiki:

Tessellate tool allows you to copy a selected object (Component) on the faces of the active object (Generator), adapting its bounding box to the shape of quad-faces.

Try to keep the faces of the generator (was made by slicing a torus) as square as possible to avoid distortion. You can improve the component (was made with Hilbert node from Sverchok) to make it more tileable than mine.
Then I'll add a solidify modifier to the geometry only after the spreading to be sure that the walls are perpendicular to the surface.

Finish with positioning the camera slightly upon the walls.

Wooow. Perfect solution!

Not so perfect as it is not appliable to any existing geometry, but only tileable's one. It requires to build the maze with the hole, and not before.

I was more impressed with this plugin at first sight than at second or third. Mazes are hardly tileable and there were issues with mesh density. No algorithm can do this, it has to be manual work.

You can use a few trick to make the tiles less visible, as enable randomize option on the plug in or apply a component only on some faces of the hole and another component on the other, and so on...the variety requires more work obiuvsly. About the density, you should try to keep the face of the generator mesh all of the same size by sliding or creating loopcuts.

Deform a rectangular maze
Another option could be to deform a starting flat maze with a sequence of simple deform modifier.
Start by creating the rectangular maze. In this example I imported a svg from mazegenerator, extruded the lines, solidified and than removed the upper vertices of the wall to get only the base contour)

Add an empty, rotate it on the X axis by -90 degree and add to the maze object a Simple deform modifier pointing to the previusly created origin. This way we can force the modifier to get the origin's Z axis as a bending axis. Set the deformation angle to something between 45° and 90°, you can tweak it later.
Above all modifiers I added a Subdivision Surface modifier (set to Simple) to get a quicker mesh resolution and so a better bending of the geometry.

Add now another empty, rotate it -90 degree on the Z axis this time, then add a second Simple Bending modifier pointing to the new empty. Set the angle to 360 degree and move the empty on the X axis till you find the right proportions.

Finish by extruding the walls with a Solidify modifier.

The proportion of the initial rectangular maze and also its density must be calculated basing on the final target shape to avoid any kind of distortion.

Why not simply using the proportionnal editing fonction ?
Here a basic shape (not a perfect maze, but some schematic one ;)
I've selected the center vertices

Press O, to activate the proportionnal editing. It allows modifications of the mesh, acting like a magnet, to smoothly deform the surface of the model.
You can activate it from the menu too, in 3d view/edit mode :

And you can adjust the falloff type :

(pictures from the blender Wiki)
Well, while in this proportionnal edit mode, select the vertices from the center of your mesh, where you want the hole. You can adjust the proportionnal edit influence by rotating you center-mouse button, and then you just have to move vertically the selected vertices :

Ok, his is probably as close as I can get with already modeled maze. Howerver, it doesn't give me a hole and I may need a view from the top into the hole. I would have to cut away vertices and it would be a mess.

You can also use a lattice modifier to deform non-destructively deform maze shape (or to animate it somehow)
here is a simple example: 2 dimensional cube arrays with an additional lattice to deform...

I ended up abandoning my maze model and modeling it from scratch on a torus by extruding faces. This gave me a clean result like so

that I couldn't get otherwise.

all_licenses: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/3.0/

all_licenses: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/


text:
How does Color Mix (Difference) node work?

How does the above node setup work, and what will happen when I change the Fac value (0-1)?  What calculation is the mix node doing here when set to Difference?

In Cycles a color is just a set of 3 numbers representing the red, blue, and green content of the color.  To perform a mathematical operation on a color Cycles splits the color up into its RGB channels, performs the operation on each channel individually, and then combines them back into a Color datatype again.
The Mix RGB node, when set to difference, returns the absolute value of the first color minus the second color.  Mathematically: Color = |Color1 - Color2|.
The Fac value controls how much this influences the output.  So if Fac is 0 the output is always Color1, if Fac is 1 the output is always the exact result of the mix operation chosen (in your case, Difference).  It basically just mixes Color1 back into the result of the operation.  Mathematically: Color = |Color1 - Color2| * Fac + Color1 * (1-Fac).

Shouldn't it be Color = Color1 - (Fac * Color2)?

authors: Дмитро Ганноцький


text:
Black faces when rendered

     Hey guys! I just started using Blender 2.76b and I'm encountering an issue when I render. I have a mesh and a light source set up but when I render, some faces appear black. I've done some research and found out about normals but when I checked, they all seemed to be facing the right way. Any help would be appreciated, here's a link to the .blend file. https://www.dropbox.com/s/5ebmmcrlc1gfce2/castle.blend?dl=0

Your light source seems to be directed down while you want it to light a castle, so rotate it towards the object. .

Mr Zak - It looks like that but I'm using a sun lamp that's positioned in front of the castle. Even with a spot lamp pointing directly at the wall, the render remains unchanged.

Looking at your scene, you need to select the sun lamp and press R to rotate it. Rotate the sun lamp to point the light in your desired direction, and try rendering again.

I was just looking at different light properties when I saw this comment, that's exactly the case! Thank both you and Mr Zak for helping me out!


text:
Importing an svg file doesn't work
I have bender version 2.76. I know this question has already been asked, I have have read the threads, but I still have the same problem. I have an svg file of a manta and I can't import it into Blender.
I understand an svg file off the net is not necessarily an svg blender can read. So I took my file, put it through inkscape, path- trace bitmap, saved it, and then imported the svg into Blender. But I don't see my image. I have tried scrolling in and out of the blender file to see if my image was on a smaller scale or something. but it still isn't there.

You mentioned tracing a bitmap, I believe blender can only import vector data from SVG files, not bitmap images.in fact raster data in SVG files is frequently pointless or unwanted. Can you post a link to the SVG file in questio? It is frequently of a very small or very large scale and you have to zoom selected to see it, try checking the outliner if there are any new curve object's after import.

If it has imported any vectors try hitting the period on the numpad. It may be scaled up really big or really small. If it is really big, then you should be able to scale it down 0.1 at a time until you see it. Assuming its there at all. Or instead of scaling you could adjust your view clip to be 10000. Worth a shot.

If you are able to share the .svg file, that might help us understand what the problem is and work around it.


text:
How can I use a game controller in BGE?
How can I use a Bluetooth game controller as an input device for a game in Blender. I have tried what I can think of but I can't get it to work.

It would help to know what kind as you may have other gamers that could answer. That being said if it remaps to keyboard keys, that would be the easiest, because then you could just use trap the keyboard events.

There is no native support to that kind of device.
If it comes with a joystick driver you can use the joystick sensor.


text:
Modeling low poly bush
I am planning on modeling a low poly nature collection, but I can't find a way to make a low poly bush like the one in the image below.

If anyone could mention the steps or make/find a video tutorial to the process of making a low poly bush like the one in the image, I would really appreciate it.
Thank you.

The following is my result with about 5 minutes of work. Note that I used Cycles Render, as it is much better for the scene showed in your question.

Modeling the Scene Minus the Berries
The key to this is Icospheres, which you can add using Shift + A > Mesh > Icosphere. Add an Icosphere. Key T to toggle open/close the Toolshelf and make sure there is only 1 subdivision.

I scaled all of my Icospheres down on the Z-Axis by a factor of 0.7 by keying S, then Z, then 0.7. I then rotated to Top Orthographic View through Numpad 7, then Numpad 5. From there, used Shift + D to duplicate, S to scale, and G to drag them around appropriately.
I also added an Icosphere of 1 subdivision, which I dragged behind the camera and out of view.
Lastly, I added a ground plane, scaled up just enough so that it fills the camera view.
Materials
The lone Icosphere behind the camera got a Diffuse BSDF with Hex: FF0000.
The bushes got a Diffuse BSDF with Hex: 57E746. Note that you can add the material to one bush, select all of the others, select the one with the material, key Ctrl + L, and select Materials to copy the materials from one bush to the rest.
The ground got a Diffuse BSDf with Hex: 296C27
Berries
Select one of the five Icospheres that should have berries on it. Go to the Properties panel > Particle Systems tab and add a new particle system. Use these settings, but note that Icosphere.010 should be the name of your red materialed Icosphere.

Select all of the bushes that should have berries, then select the one that you added the particle system to. Use this feature:

Lighting
Select the default Point lamp. Change to the following settings. Note that the Color: is Hex: FFFECC

Here is the .blend file:


text:
Why does a plane turn black in texture view after rotating?

Why did the plane turn black? I have added the texture correctly, but when I change the rotation on the X axis to 90° it becomes black.

I guess you could simply add another light source.

Or you could return to Solid shading mode and enable Textured Solid in Properties panel.

It's most likely not untextured, just shadowed or backfacing.
Either rotate the plane 180º so the it's normal is facing outside or add a lamp to light that face up

on what angle is it: X,Y,Z?

Any axis should work, what matters is that it is facing outside. In your case I would probably rotate 180 in Z axis

You can check your normal on that particular face in the properties panel > mesh display in edit mode.
It should show up as a blue line facing outwards (you can also see vertex and edge normals).
If the normal is facing inward, you can sometimes see the face as black depending on your view.
If you have a cube mesh, you can select it, go to edit mode, select the black face only, go to mesh > normals > flip normal (w -> f), or you can just go to edit mode, select all with 'a', go to mesh > normals > recalculate normals outside (ctrl-n).
If you have a plane, just make sure the whole thing is selected and you can flip normal by pressing the w key, and then the n key (or making the menu selection flip normal).
Hope this helps!

ok, so in the properties menu, if you scroll down to shading, there will be a tickbox for shadless, tick it and it will render

authors: Инны Таликина


text:
Mix shader not behaving as I expect
I'm trying to make sparks that fade out over time, and I'm pulling my hair out trying to get the nodes to work properly. It seems like the mix shader node is doing the exact opposite of what it's supposed to. This is my node setup:

Everything connected to the emission strength input is meant to control the spark's edge softness. I found it counterproductive to try to make a spark the edges of which you can see, so I set the brightness of the volume emission node to fade as it reaches the edges of the spark.
The mix shader node tree is where the problems are. Whenever I try to drag the factor slider on the mix shader node, nothing happens. I set the emission strength to be quite small, so that if it began to fade to transparent at all, I'd know. However, when I drag the slider, absolutely nothing happens until it hits 1. When it hits 1, the spark immediately goes from bright to invisible with no transition. I can get arbitrarily close to 1 (0.9999) and there's still no change. It only does anything when it hits 1.
This is exactly how the particle looks with a mix shader factor that's any less than 1:

This is what happens the second it hits 1:

This question is similar to http://blender.stackexchange.com/questions/49128/color-ramp-isnt-working-correctly-with-particle-info-node  .  Is it a repeat?

See answer below.  Your factor for the mix shader is set to zero.  That is fine for future flexibility ..... but at the moment you are getting one emission contribution and no transparency contribution.  Mix factor of 1 or 0 are the extreme mixes of only one contribution.

@atomicbezierslinger It's not actually a repeat. It's a similar problem I was having, but I'm not actually sure if they're connected. I get the feeling the problems are both based on the particle info age output not giving an actual age as an output. I think I'm going to delete the previous question, and this one too, and create a new one.

Did you understand my previous comment?  Did you try the proposed solution below?  Please try the solution and comment it as either .... difficulties are persisting ........ or the answer is successful.  Your image of nodes is a little difficult to read ... for some reason it is blurry.  Also you might consider changing the particle image to have a transparent background if you are trying to investigate transparency.

@atomicbezierslinger I know the mix shader factor is set to 0. That's not the issue I'm having. The issue I'm having is that when I manually adjust the factor, nothing happens. There is absolutely zero difference in brightness between a mix shader factor of 0, 0.5, and 0.999. But suddenly, the minute that the factor hits 1, it INSTANTLY goes from full brightness to completely invisible. I'm trying to get it to gradually lose brightness, but it won't.

Do you have a particle system?  Technically you have not stated you have a particle system.  In the proposed answer below are some sample images ... you may choose to provide similar images.  I am not sure what your goal is, even if it makes sense to you.  Is each particle to have its own fade?

I have created nodes not similar to yours with those particular results.  When I create nodes similar to yours I produce results  that are very undesirably sensitive to viewpoint and rotation.  If you have a particle system what is the shape of your particle? Square Plane?  Sphere?

Plug the Output of your Multiply Node into the Factor Input of your MixShader. You probably need to invert it before.

If all particles have a circular fade one could consider billboards of the texture.
For the nodes of the original question. I suggest a constant multiplier value for emission such as 2.
If one adds a weighted sum of the (age/lifetime) plus the value of intended (1 - opaqueness), that sum can be used as the input to fac of the mix shader.  It may be the poser of the question always wants a quadratic sphere texture style fade, with more opaqueness in the middle.
fac = x(age/lifetime) + y(1 - opacity)
The first time approaches 1 as age increases.
The second term has a more opaque center of the quadratic style sphere.
0 < x <= 1 and 0 < y <= 1.
If the sum is greater than 1, then zero clipping will occur, which may  be acceptable.
No effort has been made to preserve a bright center.
Image Below. Rendered image.

Problems encountered.  If the nodes focus on transparency and generated coordinates there are some undesirable traits for some scenarios.  If a spherical view is always desired than we can produce problems.  In the image below see the hemisphere shape from a certain viewpoint.  The two large spherical shapes use a different technique.

Alternative
Image Below. Rendered image.

A particle system with particles having the material below.
An alternative Material Node collection.


text:
Turn down volumetric smoke scale
I want to make some small smoke plumes using Cycles volumetric smoke. Think cigarette or car exhaust size. However, the default scale of smoke detail seems to be very large. Using default unit scale (1 unit = 1 meter), my smoke plumes have almost no detail at small sizes. I have to make them the size of buildings to have them look like I want. If I make the domain small, then I just get a tiny slice of low resolution.
Is there any way to adjust the whole scale down, or is this limited by voxel divisions? In that case, it ends up being easier to bake a giant oil well plume than a cigarette plume?

Here's my results, although not tuned perfectly, I feel they are reasonable.
For me the trick is in setting the Smoke High Resolution and bumping up the divisions.
There is some other things in here like smoke texture, and other minor things for you to look at to fit, so I've included a blend file as well.


text:
Loopcut not creating
So if you look a the image I extruded the side and filled a face at top, the bottom is empty and I wanted to create a loop around the 3 sides but it will only appear for one side any tips.

Have you tried pressing W > remove doubles

That worked thanks, is there any signs I can look out for to know I have a double.

I have not really paid super close attention to what makes double vertices.  I think they are just artifacts of some algorithms, when ever I have peculiar things like this happening I usually try removing doubles first.  If that doesn't work the problem is probably n-gons or non-manifold geometry (see the question stacker linked).


text:
How to create and animate the water reflection (Caustics) on an object?
What is the best method to create this kind of reflection and how to animate it?

These are known as Caustics. Unfortunately these are very computationally expensive to simulate, and cycles isn't very good at it. See http://blender.stackexchange.com/q/8645/599 and http://blender.stackexchange.com/q/10434/599. You might want to try a renderer with bi-directional pathtracing and MLT, e.g. luxrender.

A wave modifier can create the ripples in a surface.
If it is glossy and lit by a lamp, perhaps they will cast onto another object. Never tried it.

If it's just an effect, rather than physically accurate to the scene, is there a good way to do a procedural caustic texture?

There is a great tutorial at http://www.blendernation.com/2015/04/27/cycles-water-uber-shader/ (linked to Cycles | Water Uber Shader). And there has been an approach with Metropolis sampling.

The fake Caustics shader is explained in Part 1 starting from 18:03.

There is a new Add-on called Prism for caustics in Cycles. Though you have to pay a small fee for it.

A new material just was announced...

There is now Caustics support since Blender 3.1

Aaand there arrived just another "fake caustics" tutorial.

As @gandalf3 mentioned, Cycles is not great at this, if you want to make your render physically accurate; My approach can give you photo realistic results, which are not, however, physically accurate.

Water Movement
You can use a Displace modifier, a Stucci procedural texture and an empty for Texture Coordinates in order to simulate the water movement. Do keep in mind that you'll need a lot of samples in order to get a usable image and a build with the Metropolis patch.
To do this, first add a subdivided plane (Shift + A>Mesh>Plane); then, go to the Modifiers tab in the Properties editor and add a Displace modifier and press the New button to add a new texture. After that, go to the Texture tab and select Stucci; you can later tweak this setting for better results.

Then add a Empty, go back to the Modifiers of the plane and select Object in the drop down list for Texture Coordinates; after that, set the object to be the empty you created earlier.

You can then animate the position and/or rotation of the empty, in order to "animate" the water movement.
Then you can simply add some glossyness to the plane point a lamp at it and render.
Caustics Simulation
A better way is to simulate Throw Patterns on a Spotlight.
Add a Spotlight (Shift + A>Lamp>Spotlight); then add another plane, in the location of the spotlight, and move it down. After that, parent the plane to the spotlight, by selecting the plane first and then the spotlight and pressing Ctrl + P>Offset (Keep Offset). Now, go to the node editor and add a material to the plane, wich looks like the following node tree:

In order to animate the caustics, you can use a Vector Mapping node.

Here, you can animate the X and Y values, for the location, in order to move the caustic pattern around.
Now you can point the spotlight at your objects and git it a test render. Make sure the strength of the spotlight is rather high - I used 2000 - otherwise, you'll not see the light on your object. Also, you can control the softness of the throw pattern by adjusting the distance of the plane to the spotlight or the Size field found in the Lamp tab, on the Properties editor, when the Lamp is selected:

This gives me this result:

The ocean modifier is also good for this. However this answer doesn't really explain the caustics part (which seems to be the focus of the OP's question)

Thanks for the great solutions man! I've animated the rotation  and contrast value of the Voronoi Texture (using Mapping Node and Color Ramp) and the reflections look amazing!

First:
There is now Caustics support since Blender 3.1
Second:
There is a great tutorial at blendernation.com (linked to Cycles | Water Uber Shader). The fake Caustics shader is explained in Part 1 starting from 18:03.
Third:
There has been an approach with Metropolis sampling.
Fourth:
There is a new Add-on by Eric Edelo, a "Fast & realistic glass shader for Cycles" called Prism.

One of its main features are:

Super-fast caustics with colors, dispersion & absorption

You have to pay $6.99 for it, but it should close this gap... This Post is not intended to be an advertisment and I'm not affiliated with Blender Market, I just found out about this news on blendernation.com and think, it might help you solve your question.
Fifth:
There is a new "fake" method for the effect you're looking for with Geometry Nodes: https://www.youtube.com/watch?v=C9iQKsShYIM

I've been playing around with prism and from why I can tell it mainly does transmissive (refractive) caustics.  Not reflective caustics like in the OP's picture.

At least they advertise it as that it "lets you build virtually any glass-like material, be it diamonds and gems, water bottles, fluids, lenses, ice and so on". To be honest, I didn't try it out on my own, but it should be possible. And it's probably possible to position a non-rendered (camera ray invisible) mirror below to achieve it...

See my comment on the cgcookie market page you linked, he did confirm that it only produces refractive caustics.

Yeah - so it might still be working by only using refractive caustics and a camera-invisible light source from below the water surface to fake this effect using Prism. Should be worth a try.

As of today, November 2018, the second and the third ways don't work: Metropolis sampling addon became unmaintained in 2016 (as I understood, the creator had no time/desire to continue it), and the Prism realistic glass addon became unavailable too – the creator removed from Blender Market (it's very sad, I've seen it several months ago and wanted to try when I'll become more skilled with Blender – i.e, now).

https://www.blendernation.com/2019/11/04/free-download-water-caustics-material/

Is it has to be done in Cycles? If not, check Yafaray as an option for this kind of effects.
The trick in the scene below is the reflecting material which is 50/50 mix of Water and Mirror (shiny diffuse with 0% diffuse and 100% mirror reflection). You can adjust the proportion as per required brightness of the effect.. or should I say "realism"? :-)
It is also quite important to have fairly large caustical photon radius (1 or higher) and quite small number of mixes (50 or less) to produce sharp lines.
Also equally important to create not too sharp and not too soft edges on reflective surface, so carefully watch the number of subdivisions on the surface -- too many of them will blur the result.

To do caustics, I stepped to Luxcorerender  and ended up with Appleseed-Render for Blender 2.8.
I did this with Blender 2.8 + Appleseed Render Add-on in a few minutes (just 200 Samples without denoising):

Blenderfile: https://drive.google.com/open?id=1dBlC4ulL06xoMoZKYBtfs4DaEb3G3oqF
Add-on (Appleseed beta for Blender 2.8 on Discord server under: #builds): https://forum.appleseedhq.net/t/how-to-download-latest-build/808
The Appleseed-Render is already included in the Add-on

While it's correct that LuxCore is able to achieve correct caustics (which was mentioned in comments to the very question 4 years ago) you could include more information about how you did that, at least a screenshot of the scene layout with lights and render settings. This site is not a forum for posting pictures of results

OP was using Appleseed for that image (as mentioned), most likely with the help of the following  (IMO pretty bad) tutorial: https://www.youtube.com/watch?v=G-uV4NPlggo @MrZak

Is this a windows-only solution?

It's for Windows, Linux and Mac

authors: Миша Мякишев


text:
Why is one face on my model gray instead of orange in edit mode?
I'm relatively new to Blender and mainly use it for viewing 3D geometry in various formats (such as OBJ). Currently I'm writing my own mesh voxelizer, and my program has support for outputting the resulting voxel array to an OBJ file containing a cube for each voxel. It's not incredibly effective, but I found it to be useful for quickly checking whether or not my voxelizer produces adequate results.
I have a three-dimensional voxel grid; every voxel that is a 1 (instead of 0) is represented as a simple cube, and all these cubes are stored in an OBJ file. The OBJ file contains only the vertex positions and face definitions, there's no MTL mentioned in the OBJ file (and no MTL file is generated, accordingly). Here's an excerpt from a typical OBJ generated by my program:
v -1,20000004768372 -1,20000004768372 -1,19999957084656
v -1,20000004768372 -1,20000004768372 -0,899999618530273
v -1,20000004768372 -0,900000095367432 -1,19999957084656
v -1,20000004768372 -0,900000095367432 -0,899999618530273
...
f 1 2 3
f 2 4 3
...

When I open it in Blender, I see that all geometry is correct, but one triangular face (always the first one in the list of faces!) is highlighted differently by Blender. Here's a screenshot (imported the OBJ, selected the whole mesh, didn't touch anything else):

(It's not a representation of any meaningful geometry yet, just a randomized voxel grid, for those wondering)
I'm not sure what Blender is trying to tell me here. How is this face any different from all the other ones (except for being the first face in the file)? What is wrong with the OBJ file my program generates? There's no color assigned to vertices or faces, there's no material specified, all vertices and faces should be the same.
Here's the file in question, if you want to examine it:
https://www.sendspace.com/file/wlrva9 (171 kB)
It's actually a re-created file so the random cubes might be different here and there, but the problematic face in question is still there: look for the corner vertex at (-1.2, -1.2, -1.2).

That is simply the active element.  The active element changes all the time when you change the selection.  It is usually the last element you selected.
It is used for various types of things.  For example, the most common use is if you have the transform pivot point set to active element, it will use the active element as the center of the transformation.  You can change it to another element by selecting that piece of geometry last.
In object mode, the active element will be an object, it will have a slightly lighter orange boundary around it.  It is more significant in object mode, since when you change most settings in the properties panel (or go into edit mode) it will only affect the active object.

As pgmath said, this is the active element. It is mostly used as a reference for blender. Operators usually use it as a special pivot point by changing the pivot to active. Also may be used in union with snapping.


text:
Is a Toon Ramp material with image textures possible?
Is it possible to set up a Toon Ramp Material that would use image textures instead of flat colors?
I usually do a Toon with Ramp checked, interpolation set to Constant, and input set to result to get a hard edge transition with full control over the "shadow" color.
In Maya you can plug image textures into the color slots on a ramp so you can cheat a cel shadow over an image texture by having a "normal" colored image transition to a "shadow" colored image.
Is there a node set-up for this? Is there another way to get this effect?

I have always wanted to use shaders as a factor . . .

@NoviceInDisguise Related: http://blender.stackexchange.com/q/2612/599

You need to create 3 materials:

Toon with your setup with white and black colors
A shadeless material with texture you wanna use on lit areas
A shadeless material with texture for areas in shadow

Then you will combine them in 4th material using nodes like this:

Brilliant! Thanks so much... exactly what I needed.


text:
How to blur background image.?
I am rendering a image in cycles.The question is how to blur background in blender cycles?

You can use dept of field to blur the background. It is located in the camera properties panel.

There are many ways of doing this, here is how I would do it.
First, go to the render layers tab of the properties view and enable an environment pass under the passes rollout.

Then make sure you have checked transparent under render properties > film rollout.

Then you can blur just the environment pass in the compositor and mix it into the render using a mix node based on the alpha.


text:
How to compile a stop motion movie in the VSE with python?
I have a ASCII text file, which holds the data for combining images into a stop-motion movie as follows.
Length_in_second/100|filename.ext|x|y in pixels
50|ImagePhoto.jpg|0|0
100|NextPhoto.jpg|0|2

How can I load all photos into Blender's VSE?  I need to show ImagePhoto.jpg on screen trought 0.5s (first photo)
next for 1s. ... etc.
If it is possible I would like to save the images back to a similarly syntaxed ASCII file when I edit length position etc. in Blender.

The following script reads your control file (extended so that # is used to mark comments):
#Length_in_second/100|filename.ext|x|y in pixels
50|0001.png|0|0
100|0002.png|0|2

The script read the file names from the control files and add image strips to the VSE
import bpy
directory='X:\\New Folder\\'
filename= directory + 'control.txt'

# adapted from blender.stackexchange.com/questions/6101
old_type = area.type
area.type = 'SEQUENCE_EDITOR'

start = 0
for line in open(filename):
    line=line.rstrip("\n")
    # skip comments
    if line.find("#") == -1:
        time,image,x,y = line.split("|")
        # / 10 because 50 eq. 500ms; * 25 for 25 frames per sec
        duration = float(time)/10*25
        end = start + duration
        bpy.ops.sequencer.image_strip_add(directory=directory, files=[{"name": image, "name": image }], frame_start=start, frame_end=end, channel=1)
        start = end

area.type = old_type

Something like this should work to get the values to update an edited file:
for s in bpy.data.scenes[0].sequence_editor.sequences:
    print("%d|%s|0|0" % (((s.frame_final_end- s.frame_final_start)/2.5), s.name ))

In order to print to a file see my answer here:How to export list of prop values as txt to a certain folder? And how to import them back?


text:
Why is my camera pan not rendering
I am a beginner in blender and I made a quick animation of an object that does not move and the camera pans around it. When I press the play button in the camera view, it pans around fine. But when I render it, all the frames are the same. Every object is there and all but the camera does not pan. Please help as soon as you can.
http://pasteall.org/blend/33664

You're rendering out an animation, correct?

yes i am rendering an animation with all of the frames rendering the same

It does not work here either... Renderer Pro + eGPU. Works with Eevvee and eGPU


text:
Viewport background images disappeared when .blend file closed and opened
I loaded my background images to my model and placed them where I need them to be. I could not finish my project at that moment, so I saved it in hopes that I could return to it later. I opened the saved file and both the front view and side view images weren't there. However, all my settings stayed the same. My background images were still saved as datablocks in the blend file, but they wouldn't appear anywhere in the 3D view port. Why are my background images not displaying?

background images only display in orthographic view (press NumPad 5).

I`ve pushed "/" button twice and images appeared. Maybe it will help somebody.

Some things to check for that would impact the visibility of your background images, besides being in the proper type of view (orthographic, as distinguished from perspective view) include the following.
If you used the background images panel in the properties shelf of the 3D viewport, are the background image files still on your computer in the same place as they were when you loaded them?
If the images are in the same location, is the background images panel activated in the new instance of Blender into which you loaded your previously saved file?
Are you looking at the right view in the 3D viewport? An image is only visible if Blender thinks it is looking at the same view, so that if you used the facility to rotate the image in any direction from one of the six background image views, even if you rotate it back to the original view, Blender will still think it's in a user view, and the image will not be visible. Try pressing the numpad keys for the view for which you have background images located: for example, if you have a top view, press the  Numpad-7 key; a left view, press CTRL-Numpad-3 .
It might expedite getting an answer if you upload your blend file to blend-exchange.giantcowfilms.com, and edit your question to provide a link to the blend file.


text:
How to achieve animated handwriting with variable thickness?
There's a nice tutorial here showing how to get such an effect by tracing a real text object and creating a cruve from it.
https://www.youtube.com/watch?v=QUVUR9jupMY
The problem is this makes all the text lines be the same thickness which is unnatural for handwriting.
There's a trick mentioned in the tutorial which is having a plane behind the text curve and moving the sections of the curve you don't want to see behind the plane which could also be used to make same section of the curve less thick but that would take very long to prepare. Is there a less time consuming way to do it?

We managed to create a script which parses several fonts and recreates the exact thickness of each letter.
You may take a look here: https://www.youtube.com/watch?v=uvL-ZqG5aVo


text:
Missing Shadows
I have a problem:
In material mode, this little medium-poly Miata casts a shadow on the ground.
When I press Render, the Miata's shadow disappears.
Is there any way to get the shadow back?

Disabling the "shadows" option in the rendering panel under "shading" behaves like that (also in 2.76) ... maybe?

This could have quite a number of reasons (animation on light source or other objects, various render settings and natural differences between openGL preview and actual render). To preview a scene properly, its best to use the render preview mode (Shift + Z). If you're still encountering problems, please load a blendfile to http://blend-exchange.giantcowfilms.com/ and edit your question to add the link.


text:
No audio output in rendered video file
I am trying to render a video (that is not a .dvd file) with audio using Blender. So far, I haven't had any success; all of my rendered clips have had the audio missing from the playback. I've tried a couple of different encoding and output options but nothing has worked so far (except for a .dvd file that I rendered originally).
What are my options for rendering a video with working audio?

Can you please elaborate? How did you add audio to your scene? Which audio codec did you tried, in conjunction with which video codec?

In addition to what was already asked by Polosson, which player do you use? Have you tried VLC (http://www.videolan.org/vlc/) it would probably best to add a screenshot with all settings.

@Polosson So the audio was included with the video clips that I imported into Blender. I didn't import the audio separately from the video.
Here is a link to some screencaps displaying some of the output/encoding options I tried out (it goes to a deviantart page; just an fyi): http://sta.sh/0pb1dwup78

OK, but... where did you import that video? in the VSE? in the MCE? as a input node in the compositor? as a background animation in the 3D viewport? Please tell us more about your setup, and add some screenshots if you can.

@Polosson I imported the video using the VSE. As for my setup, I'm not entirely sure what sort of information you need (I'm new to Blender and new to video editing so I'm not sure what kind of information is needed). As to why I'm using Blender for video editing...It's free.

When you add a movie with audio in VSE, you should have 2 tracks appearing : a blue for video and a light blue/green for audio

Had the very same issue. I was keying a green screen video in Compositor and was wondering, why my render was void of audio despite having it properly configured in the settings. Loading the raw video (into frame 1 & ff) in VSE and deleting the image strip, then switching back to Compositor solved the issue. It is kind of unintuitive that audio gets lost in anything but the VSE. On the other hand this precisely what the VSE is for and if I used a professional workflow with multiple video and audio strips, I probably would not have even noticed as I would have intuitively used VSE for the final

Open a Properties Pane.
Scroll down until you see the "Encoding" dropdown tab.
You'll see Audio Codecs. If "None" is selected, there will be no audio.
Here is an example.

Ayyyy is that Yugioh?

Actually, the MLP CCG.

As someone who has some experience with encoding video, I couldn't believe how hard it was to find a solution for this.
What worked for me was:

Add the video as an image texture in the Emission material - basically follow the Olav3D tutotrial.
Open the image using the picture button of the mountain and sun, in UV Editing (not the Open file)
Wrestle with getting the image on to the surface I wanted. This consisted of rotating the image and moving the corners of the UV map to where the image was.
Adjusting the correct frame start and end
Switch on MP3 Audio in the Rendering tab.

This is where I figured it out...

Add the Video Editing menu, by pressing the "+" on the menu bar.
Add the video, and moving the sound and video strips, to start at 0. Just drag and drop.
Delete JUST the video strip, leave the sound strip.
Check the video plays in Render View, adjust cameras etc.
Wonder why no one explained this ever on the internet and post to Stack Exchange.

I hope this works, if not I can post pictures. Good luck.

because they would get downvoted into oblivion :) you just need to start a new Video Editing file, drop your video in the sequencer, select a video and audio codec and hit render

I don't mind deleting this if you think it will lead people astray - especially if there is a nicely documented guide available.

maybe? up to you really. since the question is just about enabling audio (and to be fair that's already been asked and answered multiple times on this site), I doubt many ppl will come across your answer when trying to import video, which is the part of your answer that's convoluted. My comment was just to make your life easier next time you import a video :)

The solution comes from Richard Antalik, at developer.blender.org
Enable Sequencer in Output Properties > Post Processing panel.
In Blender 3.0 the Output Properties (tab) is where you define the size of your output, where to output your file to, encoding for video and audio, etc. You will also find in the same tab the Post Processing panel with compositing and sequencer check boxes. Put a check on the Sequencer.

Hello and welcome. Please don't post the same answer more than once, if the questions are the same instead vote to close them as duplicates, thanks.

Running Blender from the terminal with --verbose I was notified that the audio fails because of a problem with ffmpeg (I'm using ffmpeg from packman repo on opensuse leap 15.4 instead of from the opensuse repo).


text:
Moving complex object along bezier path
I am fairly new to blender and am using it to model things that I am loading into OpenGL. I am modeling this logo:

I am also animating the gears, which I have done already. I modeled the gears in Blender, which turned out awesome!
Now I am moving onto the chain... The chain is something that is going to be too hard to animate using OpenGL, and so I am hoping I can do something tricky in Blender. What I am hoping to accomplish is modeling the gear 4-5 times in Blender and then just showing different models at different times to make it look as if the gear is moving. So what I am hoping to do here is to model the gear once, export the obj file, move it a little, export the obj... ect.
Is it possible to do something like this in Blender?

Did you consider using OpenCollada. In theory it should be possible to export object, meshes and animation and import it into your OpenGL application (there is library for loading OpenCollada files). https://collada.org/mediawiki/index.php/OpenCOLLADA

Well, you could get the chain to wrap by applying an Array mod, set it follow the curve, then you could just move it everywhere you needed and it'd all follow.


text:
How can I save memory in cycles when I have a lot of duplicates?
I have a scene I'm working on which requires a large amount of duplicates which I was planning to use an array for.
I recently heard if you use Shift+D instead of Alt+D and wondered if there was a way to do the same with arrays as it's going to take forever otherwise!

You'll want to use dupli objects. See my answer here for details on how to use them with the array modifier. Dupli objects are more memory efficient than Alt D (which is more efficient than Shift D), as Alt D still creates a separate object, but with linked data. Dupli objects are instances of the entire object, so the object is only stored once and all the duplis are just references to it.

Woop Woop!!! Thanks for that!!! I've got about 2,000 of them so that should save me quite a bit of memory!! :D

Instancing
Use instanced geometry (and objects) - instanced duplicates won't consume memory.

Alt+D will link the mesh data and save memory (Shift+D will not). You can have different materials applied to objects with the same mesh (link the material to object not to mesh)
Use Dupliverts/Duplifaces or Group Instances - this links whole objects (groups). This will save the most memory.
Use linked object (groups) from another .blend (Ctrl+Alt+O) multiple times - same memory savings as previous.

Multiple Renderlayers
Divide your scene objects into multiple render layers and combine them into a single image in the compositor. This way you can defer the memory load across multiple rendering sessions.
Texture optimization
For Blender 2.78 and up: Bindless Textures are now supported on GPU, which means only limit is now VRAM and a CUDA limit of 256 textures. Cycles now has support for single-channel textures - therefore no need to pack textures.
For older Blender versions: pack your black & white textures (masks, influences, specular maps, etc.) into channels of color textures (1 color texture with alpha - tga/png - can store 4 BW textures or 1 RGB and a mask). This can save the GPU memory in texture heavy scenes significantly. Old Cycles does not use single-channel for BW.

"Array modifier produces also instances". I don't think that's correct. It looks to me like it copies the mesh for every repetition, which is very inefficient (but allows for further manipulation with modifiers).  See http://blender.stackexchange.com/q/7235/599

@gandalf3 you are right I reverted the edit.

Massive thanks to peeps for the answers... I'll have a look into saving tip #3... mostly going to be using procedural materials but I think there may be a few which aren't! Just got a 2nd gfx card to which will help! Cheers guys! (+ Gals!! just in case!)

it looks like linked duplications and instance groups save about the same amount of memory, is it right? is there a preferable method? is linked duplications as fast as instance groups when the file is open? I personally prefer linked duplications as it's much more convenient than instance groups... any information on this topic would be appreciated!

@moonboots yes, they save exactly the same amount of memory. It should be also same fast, this I didn't test so thoroughly, but it would make no sense why one should be slower or faster. The data just comes from different files, that's all.


text:
Part of the geometry disappears when in edit mode
I need to seperate the bars from the cells in this model.

But when i go in the Edit Mode, the bars disappear.  I am using an array modifier, but I think the problem is not with the array.

Could you post a .blend file? Thanks!

This question and answer is better than in the one it's a duplicate of. Can we reverse the marking as duplicate so that that is a duplicate of this?

It looks to me like you have hidden the bars.  To hide something, select it and press H.  If you are in object mode this will hide the objects that are selected, in edit mode this will hide only the geometry that is selected.  You can also press Shift+H to hide everything but the selection.
To unhide everything, just hit Alt+H.

Oh yeah, i forgot. Now it works, thanks mate!

@CookieFresh Glad I could help!  If this solved your problem you can hit the accept answer button next to my answer.


text:
How to change highlight color for icons in outliner panel
I'm quite colorblind and can't easily see the orange highlight behind the icon of a selected item in the outliner.  I've been all through the themes preferences but the color doesn't seem to come from the outlines sub-panel.  I would be very grateful for any guidance.

The colour in the outliner seems to be linked to the outline colour of the active object in the 3D view.
You can change this colour in User Preferences> Themes> 3D View> Active Object:

Also the color behind the selected items in a multi-item selection can be set by changing User Preferences> Themes> 3D View> Object Selected.
It is usually set to a lower alpha, which makes it hard to see on lighter theme backgrounds.


text:
VSE: How to render a video with audio?
I want to play a music strip with a video in the video editor but the video has no music when I play it.  I've rendered it but it still doesn't have sound.  How can I render and play the video with the sound track.

Welcome to StackExchange. We need more information in order to solve your problem. For instance: do other sound clips play properly? Have you tried reencoding the sound clip in a different format? Maybe you could provide a screenshot of your sequence and settings? These, and any other details, will help people to give you a helpful answer.

Please add at least a screen shot of you render settings / output. Which audio codec do you use? Do you hear the music when played in Blender? Did you try to play the video in another player like VLC?

In blenders preferences under system you have a few options for the software used for sound, this may help playing sound from blender's VSE.

For the output video you need to check that you have selected an audio codec in the encoding options.

Any idea why I can't get sound even after setting the audio codec?

Where can I find the second image, how do I get to the "Output" options?

@Michael the output settings are part of the render output settings which you can find in the properties editor

In video Editor, in the left side. Edit Strip / Sound.
volume. now volume is 1. go up to 100...

Please expand/clarify your answer. Screenshots can help future viewers as well.

volume max is 1.0  not 100.


text:
How to bake in Cycles without hidden objects affecting the bake
I have a clothing piece over a model and I am trying to bake the clothing piece in its location.  There is also a hidden object underneath the clothing, and i think this is affecting my bake.

Are you talking about baking materials/textures or physics simulations?

talking about materials.

You can exclude an object from baking calculations by moving it to another layer from the object you are baking with M.  Then just uncheck the layer you have moved it to in the viewport footer before baking.

Thank you for the reply: This is how i normally do it myself :) But my blender is giving strange errors and crashes when i move my mesh to another layer. i decided to put that question apart from this because else it would be 2 questions in 1. here is a link: http://blender.stackexchange.com/questions/46478/no-valid-selected-objects-preventing-me-from-baking-material

@ChoCho  Well, AFAIK there is no other way.  This is how you exclude objects from baking.  You'll have to resolve the error so you can do it this way.

alright i figured that would be it. but its better to ask :)


text:
Can I replace an object with another object and keep animation?
Is it possible to use an element, in this case a ship, in a blender scene and progress through animation and then easily replace that ship with a different one? A replace command?

replacing the ship during the animation or the same animation with another ship?  2.spin maybe? https://www.blender.org/manual/modeling/meshes/editing/duplicating/spin.html

are there any simulation in the animation " physics , cloth, hair, particles "?

Please include more information in your questions, it makes it much easier to see what you are asking. Screenshots help as well. Also, never include two questions in one. Please edit one out and post as another.

I have edited you question down to just one question (the one with two answers already) to avoid this getting closed.  Feel free to post the other question as a separate question though.  We just like to have one question per post to keep things from getting too confusing.

The best way to replace a "replace" button. :)
Create a proxy object that will be animated. Create as many ships as needed. naming them as object and mesh can be useful.

change the mesh of the proxy object with another ship.

The same animated object can be any ship you like with the same animation.
The resulting object is a linked duplicated, same as AltD. They share the same mesh. If you need an independant duplicate (same as ShiftD), press the button beside F (normally 2, counting objects sharing the same mesh) to make it a new object independent of the original. Use F button to give the mesh a fake user before changing it if you want it to be saved in the .blend even if no object use it (else it will disapear when you reload your .blend file).

You can copy and paste keyframes in the dope sheet using Ctrl+C/Ctrl+V.

This way you can animate one object, and then copy and paste the keyframes from that to any other objects.
Note (as Greg Zaal mentioned in the comments) that only objects with some kind of animation will show up in the dope sheet.  A sort of mickey-mousey way to fix this would be to add a temporary keyframe to the object so that it will show up in the dope sheet, paste the new keyframes in from the other object, and delete the temp keyframe.

Note that the other object won't show up in the dopesheet unless it already has some animation. You might want to add a keyframe to it temporarily, copy the animation, and then remove that temporary key.

@GregZaal Good point!

Also, start by setting the current frame to zero to have the animation copied and pasted to the same frames.

Furthermore, seems like the keyframe transform must be of the same kind, for example, I used "disable in renders" state as the temp keyframe, but then when pasting location transforms, the location was not keyframed (?). So if you are pasting transforms (location, rotation, scale) make sure the temp keyframe also is a transform.


text:
How to add shortcut for 'Only Render'?
How can I add a shortcut for the 'Only Render' checkbox in the Display section of the Properties pane?
I use the function a lot to get a better view on things and would save time if there was a shortcut for it.

As an aside, the Amaranth Toolset addon adds a ton of useful things, including a shortcut to show only render.

In ⎈ Ctrl⎇ AltU> User preferences > Input, navigate to 3D view > 3D view (Global), then scroll to the bottom of 3D view > (Global) and click add new.

Put wm.context_toggle as the operator.
This is an operator which toggles a property given by a datapath parameter.

Put space_data.show_only_render as the datapath parameter (you can put stuff there even if it appears grayed out). You can get the datapath for any checkbox by right clicking on it and selecting Copy Data Path. The datapath can then be pasted with ⎈ CtrlV.

Assign a key combination which doesn't conflict with an existing shortcut (e.g. ⇧ ShiftQ)

Now pressing ⇧ ShiftQ (or whatever you assigned as the shortcut) in the 3D view will toggle show only render.

What is this: ⎈ symbol... and why is it next to the ctrl key... Is it a windows thing? I know on mac these: http://cdn.osxdaily.com/wp-content/uploads/2010/11/mac-keyboard-symbols.jpg are the notations for each symbol

@10Replies because it's the ISO keyboard symbol for 'control'

Hmmm, strange that I have never encountered it before. I use (and troubleshoot) with windows all the time.

@10Replies Perhaps since it seems relativly few keyboards actually have it on their ctrl keys.. Mine is one of the few I've observed it on, or at least it has something that resembles it.


text:
Render pass that output center of object of each pixel
I am looking to create a render pass that takes a scene and outputs, for each pixel, the 3D world coordinate of the center of the object to which that pixel belongs. In other words, all pixels that show the same object should have the same value.
Now, what I could do, is render a separate pass for each object where only the pixels of that object are white, and then set the values manually, but I was wondering if there was a better/quicker method.
Thanks a lot!

You can do this by using a Material Override and a special material to give the objects' positions.
First create a new material with an emission shader (you can add it to any object, it doesn't matter).  Add an Input > Object Info node and plug the Location into the color of the emission shader.

Now you can create a fake user for the material and remove it from whatever object you added it to.
Then add a new render layer and set the Material Override (under the Layer rollout) to the material you just created.  It would also be useful to override the samples to 1 as well to reduce rendertimes and effectively disable antialiasing.

In the resulting RAW rendered image the red, green, and blue values of each pixel will represent the location of the object rendered on that pixel.

Fantastic PGmath, exactly what I needed! Perfect!


text:
How to set Blender to use identical controls as Unity?
I am used to Unity's controls and would like to mimic them to Blender to make transitions between the two easier. If you know how, please let me know.
Edit: I apologize, I should have been more specific. Is there a way to import Unity control preferences(key mappings) to Blender? If not, can I remap the basic (by default) left click to rotate view instead of placing crosshairs?

Keyboard shortcuts, operators behavior or what exactly?

@Alex, you can change anything that's possible to change with user preferences, but ultimately, these are two different programs and will never be exactly the same.

Yes, you can remap the controls. Press Ctrl + Alt + U, or go to the Info Header>File>User Preferences, to open the User Preferences; Then, switch to the edit tab and edit away!
You might also want to take a look at existing presets; However there isn't any for Unity controls...

authors: Алексей Тюлин


text:
Low-res texture blurry
I unwrapped a simple plane and applied the following 80x80 pixel picture:

Yes, it's quite small. The problem is, the result is all blurry, like so:

How do I make it accurate to the pixel?

Cycles or blender internal render engine? By tiling the image a couple of times in both U an V direction would get the image to it's original resolution on any given polygon surface.

Pixelation

Materials, Texture, Image Sampling.
Select all the settings on the right hand side as indicated by the arrow.
MIP Interpolation Filter FELINE Filter Size
Assuming Blender Render.

If you are using Blender Internal Render Engine:
In the Properties Window > Texture Tab > Image Sampling Panel > Filter
change it to Box.
Have in mind that this will not have any effect in the viewport preview, but it won't appear blurry in your final render.
If you are in Cycles/EEVEE Render Engine:
In the Node Editor, under your material node tree navigate to your image texture node and set the second pull-down menu Interpolation to Closest

Using Blender Render, go into the Materials/Texture//Image Sampling and deactivate the Interpolation checkbox.
For the Filter you probably want Box, FELINE, or Area.  I'm not sure exactly what the algorithms behind them are, but the results from EWA are not even remotely sharp.  They only differ when a rendered pixel is on the boundary between two pixels of the texture.


text:
Subdivide in only one direction?
Say I have the top mesh in the image. If I subdivide it, I'll have the second mesh in the image. But what I want is the third. It has vertical subdivisions, but not horizontal. Is there a way to do this?

Related: http://blender.stackexchange.com/q/3259/599 and http://blender.stackexchange.com/q/6415/599


text:
Is it possible to repeat modified Shape Key actions?
so I'm trying to sync a Taurus mesh with some music to mimic the thumping of a bass and have found this video: https://www.youtube.com/watch?v=RWebgsyuaNg (starts around 1:20) which describes using the shape key mixed with a Sine wave modifier that restricts the keyframes I'm using so I can isolate my "wub wub"'s to when the song does the same.
There's a few issues with me doing it this way. For each set of "Wubbles", as we'll call them, I have to add a new modifier (and restrict keyframes) each time.

Now this wouldn't be a huge issue, but I'd like to copy all of this data and repeat its usage when the song itself repeats, but I can't seem to select the Sine wave to Shift+D it and move it down the frame line. Is there a way to do this? or am I just missing the easier way of animating my Taurus altogether?

Have you considered using the NLA editor? eg, have one wub_wub action starting at frame 1, then use the NLA to position in your timeline.

I have not, I'll check it out and see if that'll work better for me :) thanks for the insight.

As an alternative to the NLA Editor, you should also be able to bake those curves. If you post your .blend maybe we can take a look and see why it can't be selected too.

Blender includes the ability to convert sampled f-curves to keyframes, but doesn't include a way to use it without a python script. Luckily someone already has made an addon to make it easily accessible. Save a copy of this addon then install and enable it.
Now you can bake the f-curve with ⎇ AltC, delete the sine wave modifier and convert to keyframes with Channel->Convert to->Keyframes from Samples.
Now that you have a f-curve made of keyframes, you can delete any parts you don't need and duplicate the remaining as many times as you want.
With a graph editor and VSE open with a waveform displayed you can change the current frame by clicking in the VSE so that it is at the start of a "wubble" and this will also be visible in the graph editor, then use ⇧ ShiftDX and move into position visually.

Awesome, I'll have to check this out and give it a go. this sounds like exactly what I need to be accurate and specific with my f-curves. thank you VERY much!

Using the NLA.
The NLA is used to position,  repeat, scale (etc) actions as strips in tracks.  The fcurve modifiers can be retained and tweaked etc enabling you to keep one "master action".  Moving and positioning the strips is simple as is scaling their time and repeating.
Note For convenience I've added the action (Wubble.001) to Cube.001 to show it in graph editor, as it gets confusing having both an action and NLA tracks / strips on same object.

Thanks for going through the extra work to give me more feedback on this batFINGER :)

authors: Александр Журавлев


text:
Blender renders my material incorrectly

All the black object have the same material but only the outside floor renders it correctly, what can I do to change this?

Under the "Color" settings within the "Surface" panel, what happens if you change "Flat" to "Box"? Does your mesh have a UV map? Are you able to post a .blend file?

In your screenshot it is not really rendered (in Cycles), it is in material view mode.  Material view mode basically tries to convert the material to a texture, which does not work very well in Cycles.  Try shifting to Rendered View mode.  It also looks like you may not have a UV map on the black object.

authors: เจตริน เมินดี


text:
Is knowing the Blender internal renderer settings for materials and textures important for using the Cycles renderer?
I have been learning Blender for the past several months, and I just discovered the Blender 3D: Noob to Pro wikibook. Although I'm not a complete novice, I have started from the beginning of the book to fill in the holes in my knowledge (since I have used various tutorials until now). If I plan on just using cycles render from now on, would I be wasting my time to go through the "Section 2C: Materials and Textures" part? I have a basic understanding of materials and textures, but as I said, there are several holes in my knowledge there. Is knowing the Blender internal renderer settings for materials and textures important for using the Cycles renderer?

Short answer: nope.
Cycles and BI work very differently, consequently materials are completely different for the two, both in the way they are defined and calculated.  I think learning BI first often does more damage than good when switching to Cycles.
I should note that some people do say new users should start with BI since it is (arguably) simpler than Cycles.  I heartily disagree with this view though.  Cycles may be a little more complex to some people due to it's much greater flexibility, but I don't see any reason why starting with BI would help one learn Cycles.
I think the idea that BI is "simpler" is a misnomer though, it's just different.  Personally, I find Cycles's nodes to be a much more intuitive way of defining materials than BI's wall of settings for everything under the sun.  Which one really is simpler is a matter of opinion, so neither one comparatively blows the other out of the water and should.

In  fact I would argue that cycles is simpler to learn and understand, as the same concepts can be applied to pretty much all aspects. BI is.. shall we say, more "specialized". For example BI uses ray-tracing for reflections, while using scanline techniques for diffuse, etc. Or the perhaps confusing way BI material nodes work (quite different from cycles).

I concur with the answer that PGmath gave for the most part, but I think there needs to be just a bit more nuance there, because the answer to the original question depends to a significant degree to your intended use of Blender. If you are making stand alone Blender renders and animations, cycles is the way to go.
However, if you are making content for use for export to other platforms, Cycles is probably not going to be very useful at the moment, as to my knowledge, none of the external platforms, such as external game engines, support cycles, so anything done for that will need to be in Blender Internal. Also, as far as I know, as of the writing of this answer, if you want to export a decorated object, anything that is going to be exported to a different modeling platform will not be able to make use of cycles. Of course, it is possible this might change, as it seems to me that a node, or family of nodes, could be devised so that an object in which cycles is used could be exported for platforms in which it is not.

I think the OP is asking not whether they should use BI or Cycles, but whether they should learn BI before moving to Cycles.  They did state the intention to end up with Cycles.

You're right. But the answer still depends upon what his use will be. For example, if he's only making game content,  there's no need to learn cycles at all.


text:
Fire itself does not show in final render
Just followed the campfire animation. Fire, smoke, and embers all show in Alt+A view and also in F12 render.  But when going to full animation all I get is the plane, the sticks and a glow. no fire, smoke, or embers.

What render engine are you using?

blender 2.76b. i know i saw on one topic, it was switching between cpu and gpu. But mine does not give that option

Are you using Cycles or Blender Render for the render engine?

i am using cycles.

!http://postimg.org/image/6nbotlm7n/7728b292/

and transparent film is turned off

If your GPU does not meet requirements GPU rendering will not be an option.

The flame property shouldn't be capitalized; that's why there's no fire (at least one of reasons). However this doesn't explain why the smoke isn't seen. Make sure you played animation until smoke was emitted.


text:
Object turns dark when using normal map in Cycles
I have been using Blender for a while, however up until recently I have only used Blender Render. I started to get interested in Cycles, and somehow it worked fine like Blender Render, up until i noticed a problem when I used a normal map. It took me some time, but i was able to narrow the problem down. Though now i hit a wall and don't know what to do now.
Here is an example:

This scene has no light source other than the background set at white and strength at 1. If i add a light source it doesn't change the problem at all.
The blue cube is just for an example of a normal Diffuse with nothing whatsoever special about it. No normals in none of the images.
The gray objects have an Anisotropic(same problem with glossy material) material on it.
Nodes can be seen here:

Top left are the gray objects with normals, the jacket with the ball behind it.
The other three do have a Normals setting on it. And here comes the problem.
As you can see, if you view it from behind(top right) it looks fine, the details of the Normals appear as they should, everything is dandy.
Bottom left you can see some dark shadows appearing.
And bottom right is completely black.
And the crazy part is, this happens when there is a lightsource as well(i have tried variations with no "background" light source as well)! I could add a lightsource with the strength of 10000 right in front of it, it would still appear pitch black in the bottom right perspective
I've already tried inverting the faces, checking to see if the vertices are correct(thus the ball in the back), with different normal textures etc. same effects happens all the time.

Related - http://blender.stackexchange.com/questions/16443/using-a-normal-map-together-with-a-bump-map. Don't plug image with normal map directly into Normal input socket rather than use Normal Map node (if you really have normal map, i.e. image in blueish hues). The blackness is most likely because of too high and wrong effect of normal map.

Try including a normal map node between the image texture and the normal input of the anisotropic BDSF.

Also include a texture coordinate node to tell blender how to wrap the texture onto a mesh.

The Normal Map solved it, the Texture Coordinate didn't seem to do anything though, as it was already binding to the UV

In addition to the previous answer, Image Texture should be Non-Color Data.


text:
Can Blender be used on an Android device?
Can the software be downloaded on an Android device?  If yes, then what is the process?

You may be interested in this answer: http://blender.stackexchange.com/a/33062/599

STEP 1: install GNURoot Debian and Hacker's Keyboard.
STEP 2: Launch Virtual Machine (computer button)
STEP 3: Touch the 3 dots button and switch to Input Track pad
STEP 4: Install blender by click the terminal and type: apt-get install blender
STEP 5: type:Y
STEP 6: When the install finished click at the wall screen and select exit
STEP 7: Launch again then click main screen and go to App >Graphic>Blender
STEP 8: Wait until it display frame placing, just click and wait until it in.
If nothing happen, you can uninstall and install again.

You can also use it from cloud: https://www.rollapp.com/app/blender . Or Remote Desktop with your own PC.

the simplest and easiest way to run blender 2.79b in android device https://youtu.be/9SedjSEv_iI

i think this video should it worked for me
http://www.youtube.com/watch?v=W_LW1M9ljj4

Sorry, there is no Android support at this time, and probably not ever. It would involve a massive coding effort for support and because blender is very cpu/gpu intensive, the devices that run it would make for a poor experience indeed.

Well said. Plus, one would need to pair a keyboard with it for it to be usable in any practical way. Maybe doable with a tablet, but with a phone it would be ridiculous. Just one more reason among many.

I think I heared of an Android Test Build... So I'm not quite sure if this answer is correct. But I think it wasn't fully usable due to the lack of a keyboard.

Hey, but there's a blenderplayer for Android. http://www.blendernation.com/2012/06/26/blenderplayer-for-android

I hadn't heard of this but it looks like quite an old project and not a version of blender but a port of the game engine player. Interesting though.

In fact they have a version for Android.
Check this out.
https://www.blendernation.com/2015/02/12/using-blender-for-android/

I'm running Blender 2.76b on KitKat Galaxy Tab 3 lite
8GB internal 1GB Ram
A little slow, but it's sufficient for simple designs.

Go to Google Play Store and install GNURoot Debian. You can download apk. Just make sure your internal memory free about 850MB to install.
Install Hacker's Keyboard
Launch Virtual Machine (computer button)
Touch the 3 dots button and switch to Input Track pad mode.
Install blender by click the terminal and enter apt-get install blender
Press Y.
When the terminal back to receive input state (install completed) click at the wall screen and select exit
Launch virtual machine then click main screen and go to App -> Graphic -> Blender
Wait until it display frame placing, just click and wait until it in.

If nothing happen after install blender and reboot the machine, or can't boot the virtual machine, you can uninstall and install agian (sometimes got unknown error)
You can install inkscape by entering apt-get install inkscape


text:
Sub-models in scenes?
I have never used Blender before. Is it possible to create a hierarchical super-model or "scene" that contains the lighting, camera and so forth, and have it reference multiple sub-models stored in separate files? What I mean is, I want to be able to edit the sub-models separately and have the changes automatically be reflected in the hierarchical super-model. How do I set this up?
Let me know if you need me to explain this more clearly.

Yes, this is possible through linking objects.
In the master scene file simply go to file > link or hit Ctrl + Alt + O, choose the file you want to link an object from, go to object and select the object.  Then when you change the files containing the objects they will change in the master file.
Linked objects will be highlighted with light blue.

Something to keep in mind is that you can't edit the linked objects in the master file which makes it cumbersome to make small adjustments.

You can't nest objects in hierarchical trees it seems, which is a big drawback for me. :(

@posfan12  Do you mean across files?  Within a file you can use parenting.

I mean, nesting models within models nested in other models nested in other models, and so on.


text:
Node noodles getting cut when I change image for image node
The attached GIF files below explain what's happening exactly, whenever I open a new image in the Image Node, I lose all connections between output points in the Image Node and their adjacent input points, check first GIF.  The weird thing is that it doesn't happen always, only with some files, check the second GIF.I double checked, all loaded images are Multilayer EXR, with the same amount of passes.I think there's a simple explanation to what I'm doing wrong, but I can't find it!

It might have to do with the layer names or order, or type, if they are not exactly the same blender may not know what to do with them or how to correspond the existing connections to the new layer socket names so it disconnects them. It might also be a bug, and if so it's worth reporting to the bug tracker.

I don't think it has anything to do with names, or Blender version, all images are renders of the same file, using the same amount of passes, using Blender 2.78 CR1, the only thing I can point to, is that it didn't happen with images that I rendered as images, while it's happening with images I rendered as animation (using Animation batch render)

@Georges When you render as Image, how do you save them to disk? Using the save as command or a file output node? Are the file format settings (bit depth, RGBA output, etc.) EXACTLY the same when you do that compared to what you set in the Output section for rendering?

@aliasguru the settings are the same, as I said in my previous comment, I noticed that when I'm changing in between images that I rendered them using (Render) button and saved them using (F3), the noodles are not cut, but when I change the image to another that I rendered using the (Animation) button, the noodles get cut, I'm sure I haven't change the output settings though.

I agree with Duarte, this is a case for the bug tracker at https://developer.blender.org/

There must definitely be something being done different when saving from an Image Output Node or directly from an animation. Now whether this is intended behavior, something you unintentionally missed, or an actual bug I cannot tell. If no one else knows maybe report the bug and mention this thread in the description?


text:
FPV camera inertia/movement
I'm trying to make a sci-fi short movie. I have a camera inside the cockpit of an helicopter, and I would like to have some inertia or a small movement when the helicopter moves. Right now I have a camera parented to the helicopter, but it stays fixed as you see here:
https://www.youtube.com/watch?v=L-lN1HLvJDk
I like to have some movement when the helicopter turns or banks, like in this Star Citizen trailer:
https://www.youtube.com/watch?v=-rQDDc7Pxlc

All you have to do is animate the camera too. You're already animating the helicopter to displace the camera. Now animate the camera to give it the desired details, as if the person inside was moving its head.
There might be a script or something to do it automatically, but seems to me like it would be actually more complicated.


text:
materials rendered as black in BI
suddenly all my objects are rendered as black, i'm in Blender render.
any tips?
cheers

Can you include a screenshot of material panel ? Are material nodes used for this material ? (check in Node Editor with object selected).

it looks like there is no lamp in this layer but... as @MrZak said, that could be useful to have at least the description of the material

I accidentally hid the lamp.

That's why all of the objects turned black.


text:
How to set all selected vertices to height of another vertex?
Let's say i have selected all these vertices which you can see in this screenshot, and i want to set the height to the same height as the marked vertex (see red arrow in screenshot)

I always copy the height from the target vertex, then i select each vertex one by one and paste the height into it.  But this takes a very long time, especially if you have big models. Is there an easier way to do this?
Result should look like this:

One way to do this is to set the pivot point for transforms to be the active element, by choosing Active Element for the Pivot Point in the bar below the 3D View:

If you have Pie Menus enabled, you can press .>7 instead.
Then select all the vertices you want to affect making sure that the one whose height you want to copy is the active one (i.e. select it last) and just Scale in the Z axis direction to 0, by pressing S, then Z and then 0.

I don't want to scale to 0, i want all my selected vertices to be the same height as my target vertice. If i do it like you describe, then the position of all my vertices is changed and i have to adjust everything again.

Try it first. You can undo (Ctrl Z) if this is not what you want

Still worked in blender 3.6.2

Open the properties shelf (N key), select the vertex with the desired height, place the cursor over the "z" box in the transform panel of the tool shelf, and copy (CTRL - C) the value in that box. Then select all of the vertices you want to be the same height as the original vertex, and scale (S key) them constraining the movement to the z axis by pressing the Z key, and setting the scale factor to zero. Then, without deselecting the vertices, move the cursor over the "z" box in the transform panel of the properties shelf, and paste (CTRL - V) the Z value. This applies the height characteristic of the original vertex to all of those selected.


text:
Actual speed of object on curve
It is possible find the actual speed of object animated along a curve at a specific frame?
The object has a follow path constraint and it is animated by offset. I'm making a car animation and it would be useful to know this.
I can get the curve's length by Curve Length Add-on it's in the description of this tutorial.

I figured it out, I must measure the distance between one frame and multiply it by (scene fps)*60*60/1000, the result is in km\h (one scene unit is one meter).
An automatic solution would be better though.


text:
Adjust number of digits displayed for timer property?
I want to make a nice timer in Blender Game. I used a timer property, but it doesn't look right because it has way too much digits. I only want it to show the number of seconds and 2 decimal digits.
I checked the source code of the property but I'm not sure what to change.

There is an option with quite a few Logic Bricks, but
formatting.py:
def propertyToText(controller):
    sensor = controller.sensors[0]
    propertyName = sensor.propName
    owner = controller.owner
    value = owner[propertyName]

    formattedValue = "{:.2f}".format(value)

    owner.text = formattedValue

Usage:
Have a Property (e.g. timer)
Property Sensor [enable True Level Triggering]
Mode:Changed Property: your property
--> Python Controller Module:formatting.propertyToText


text:
Create hi-res screenshot of node tree?
Is there a way to export (as a high-resolution image or vector file) the node setup of a given material? As I'm setting up some tutoring material I would prefer to avoid screenshots for material with approx. 15 nodes or more.


text:
Texture Painting and Uv: how to control Target image?
I am working on 3 objects: eyes, face and chest armor.
I have them on different layers and each one has a separate material and UV map. I have texture painted the eyes/face and when I switch to the UV mapped chest area and try to texture paint, it automatically switches the UV map to the one I used for the face and has the face texture on the chest.
If I switch to the UV map view and try to change the texture image to the blank chest one, it doesn't actually change on the model. I've tried setting up the nodes in cycles to assign the UV / texture I want to paint to, but it still stays at the face texture on the chest.
I'm sure I am missing a step / not setting it up right. What do I need to do?
Thanks.
Here are some images to help explain better:
This is the UV map and texture I want it to use:

And this is the UV map and texture it auto applies:

Instead of editing the question you can mark your question as solved by accepting the answer that helped you.

sharing some pictures and the .blend file could help a lot
(since i don't have enough rep to comment your question i said it here)
anyway i show you the steps hope it helps:
first you have to set up a few different uv maps:

one for the texture and a few more for sides, back, top, etc.
you can use ALT+B to cut the mesh so you only select the vertices that are visible from that angle
like this

then align the uv with pictures you want to copy from

after that go to texture paint mode and create a texture for the face
(explained in the picture)

hope it helps

and also be sure to save the face texture (or any other) after you create it        otherwise you lose any painting you did (i have lost hard works before cuz of this not saving)

Oh, you beautiful person! Thanks so much, changing those two sections on the "Slots" tab is what I needed!

@ORYG1N you're welcome, well if my answer was useful hitting that tick mark next to my answer is appreciated :) i want to get enough rep to comment

In the tools settings panel you can change the painting mode to image which is compatible with cycles.


text:
How can i move a set of meshes to a new layer?
how do I move a set of meshes to a different layer?

You hold Shift in order to multi-select many objects. After you selected all your objects, you can move them to a new layer by pressing M to select the layer you want them to be in.
Or use  M folowed by the layer number,  for example: M3 will move the selected objects to layer 3

There is an alternative method for moving one object at a time from one layer to another than the method detailed by WhovianBron3. Select one of the objects you want to move, open the object context button of the properties editor window, and in the "Relations" pane (illustrated below),
[
select the layer(s) in which you want to appear.
With both this method, and the one by WhovianBron3, the same object can be assigned to appear in multiple layers at the same time. One difference between the two methods is that the mesh can be reassigned in the properties editor window while in edit mode; to use the M key shortcut, one must be in object mode.


text:
How do you try different random seeds for noise texture node?
Using Blender 2.76 and cycles, I'm trying to color an object with the Noise Texture node, among others. The resulting object looks like this:

I'm happy with the basic colors, but I'd like to try different random seeds, to see different distributions of the green and blue.  But I don't see a field for such a seed on the node.

Is there a way to do this? I tried putting some things into the Vector input, but it only zeroed out the noise. I don't understand that input yet.

Check out my explanation of texture mapping here.

This doesn't really change the seed, but you can get a different noise pattern by translating the whole texture by a significant amount.

The Suzanne on the left uses a noise texture with default settings and mapping coordinates.  The Suzanne on the right uses the same noise texture, but uses the below nodes to shift the texture coordinates to get a different noise pattern.

For the sake of space i am using my homemade translate node but you could just as well use a mapping node as well.

Perfect, that's what I was looking for. That's even better than a seed, actually, because you can make minor adjustments too.

You could introduce an object info -> random node to this setup, to have it, well, more random.

@MSchmits  The Object Info node's random output is per-object.  I believe the OP wants to manually adjust the seed to adjust the pattern on a single object.

I added a node Input > Object Info,
and linked the Random value to the Location value of a Vector > Mapping node
Your texture UV (or simply Input > UV) goes into the Mapping node's Vector value,
and the output of the Mapping node goes into the Vector of my Noise Texture.

That worked very nicely and I didn't have to make my materials single user - just cloned my objects and it worked.
The Random output generates a value in the 0 - 1 range for each object.  If you want to increase the random range you can use a Math > Multiply node.


text:
Can viewport playback be improved by moving elements to other layers?
I am currently working on project that is made entirely of 2-D elements, images-as-planes.  I have the whole scene on one layer right now and the viewport playback speed has slowed down badly.  I have changed the fps to 24 and have checked "frame dropping" but the best it can do is 15 fps.  If i moved parts of the scene to different layers and then made them invisible would I be able to improve viewport playback speed? All of the elements are images-as-planes and are being loaded from an external hard drive; is there a way to bake an image-as-plane so it does not have to be loaded over and over?
Would packing all the external data into the Blend file reduce the problem?
And finally, if 15 fps is the best I can do with the viewport, is there any problem with rendering the final project as 15 fps ?
Thank you!

Blender viewport performance is known to degrade with many objects, and frame rate can decrease significantly depending on scene complexity.
The rendering system is a bit archaic and doesn't currently take full advantage of high end hardware, it's planed to be overhauled in the near future, but unfortunately there is not much one can currently do to to overcome the underlying problem until then.
Where your images are loaded from (external hard drive, local disk, or packed in blend file) as little effect on viewport performance, except when reading them for the first time, before they are loaded into memory.
That being said, hiding objects that are not needed has a huge influence in viewport performance, you can either hide unneeded objects, move them to different layers, or even organized them into several distinct groups and use the Outliner to toggle viewport visibility en-mass. All those should have a positive impact in performance.
Additionally depending on what render engine you are using, (if you are in Blender Internal or Game Engine) you can switch to GLSL viewport shading mode which is said to have slightly better performance. N Properties Panel > Shading > GLSL
If you have an nVidia graphics card you can also try to turn on VBOs in the user preferences, which generally give quite a considerable performance bump in many cases. You can find it in User Preferences > System Tab > OpenGL Column > VBOs Checkbox.

Thanks you!  Where do I find the Outliner?

In the default Blender screen layout the outliner is the editor area on the top right where you can see a list of yiur scene objects. If you wish to use groups for toggling visibility you should switch it's mode to "Groups"


text:
Making all points meet in the middle using inset
I have a cylinder that I want to close the tip by making all the points meet in the very middle. Kind of like what I have here but further inward meeting to one point in the very center. When I press I and then 0 (which I thought would bring them all to meet in the center) nothing happens.

You want to use the Merge at Center operator.  You can find it on the menu, or by pressing Alt+M or search for it using Space.  You will see more options.

In the exact case shown here, that works. But in general unless you want a single vertex merging is not the answer. For example if you want to make a blade edge, you need an EDGE in the middle of a flat face, not a single vertex. In that case the inset tool would seem to be the best, but it has no way to stop it going through itself. So how would you merge that?


text:
What are these black axes lines on my model?
I am trying to deconstruct this mess of a file I downloaded from TurboSquid, I think it was made in Blender Render, in order to reconstruct it in Cycles and I just do not know what these things are.

These are Empties. Learn more about them here: https://www.blender.org/manual/modeling/empties.html

My first guess is that they are used in some form of rig for the mesh

"Empties".. hmm. They are very bizarre. I don't get it. Because when I turn the eye icon to off nothing happens... the object it's attached to still shows up in the modeling window... but if I right click on the name and choose delete, then whatever part it's attached to deletes.  So obviously they aren't THAT empty because they somehow hold an object. :) Sorry. Thanks for the link. I'll try to make sense of it.


text:
Separate object rotation values
Sorry but I don't know how to explain my problem. I am start working with blender.
I separate faces from cube.001 (black arrow) and set origin to center of mass of this new object(blue arrow). Than I try to get new transform location and rotation of this object. Unfortunately rotation is always 0 degrees. Can I somehow get world space values of rotation? Maybe some vector with euler angles between normals of this face and global axis?

I just separated this face from cube in Edit mode with P > Selection. Then in Object mode I set changed origin of the face with Set Origin > Origin to Center of Mass on the Toolshelf.

If your object was rotated in Object mode, separated face would have rotation values of the original. However from your screenshot it looks like your cube doesn't have rotation values changed; so the question is a bit unclear.


text:
Physical interaction between objects
Is it possible with Blender to have a physical interaction (dealing with contacts) between objects?
For example:

I would like to make a sphere scratch another object and imprint a permanent plastic deformation on this object.
I would like a sphere enter inside a cylindrical part (with an elastic behavior) and expand it from the inside.

Is it possible to do this with Blender, or by combining Blender with external tools?

I believe what you want to look at is dynamic paint.

Yes, Blender is absolutely capable of doing this.  The feature you are looking for is called dynamic paint.

To do this simply select the object you want to deform, go to the physics tab, click on dynamic paint, and choose canvas.

Then just scroll down to the dynamic paint advanced rollout and choose displace under surface type.

Next, select the object you want to use to inflict the deformation and set it as a dynamic paint brush (just select brush instead of canvas).
Then you can animate the brush object to scratch across the canvas object and it will deform it.
A few tips for using dynamic paint:

You will want the canvas object to have plenty of subdivisions so that it has enough geometry to get deformed.
You may want to enable anti-aliasing and add some sub-steps on the canvas object for a smoother deformation, particularly if the brush object is moving fast.  This makes Blender sample the motion of the object between frames for smoother painting.

You can easly achieve physically believable results by running physic simulation, dynamic paint, keyframed shape keys, molecular add-on, fluids... a mix of all... but remember that Blender is an animation-focused software, so don't expect to be asked just about some real world phisical parameters and let the software do all the work.
First example:
An interesting way to imprint plastic deformation by using a "static" cloth simulation can bee seen in this video https://www.youtube.com/watch?t=267&v=wJFE2pb0Ri4
The object to be deformed is a highliy subdivided, cloth physic enabled, with structural stiffnes set to 0 in order to keep the deformation caused by a second object that has collision physic enabled.
Second example:
No smart idea about.
Maybe a fluid simulation (if I have well understood what is your concept about). The cilinder act as a boundary and the sphere emit big fluid particles in both direction...but the interface will never be smooth as an expanding sphere has.


text:
Bones are unresponsive after closing and reopening file
I was doing this perfectly well, but when i saved and opened it, the bones do not work well for some reason. I probably skipped something. I just followed this tutorial and the end result when i saved was perfect; now, the bow is not distorting with the string.
https://www.youtube.com/watch?v=jpsd0Aw1qvA
The file: http://www.filedropper.com/levercrossbow

It seems the String bone is working, but the Limit Distance bone constraints in left_limit and right-limit aren't working.