text:
Curved arrow of variable thickness to connect to objects
I have two objects that I want to connect using a curved arrow whose thickness should be variable. The following picture illustrates my intention:

The grey boxes have to be imagined as cylinders. I assume that I would have to create some curve that is attached to the two objects and extrude the curve accordingly, but I can not figure out how to achieve this.
Thank you very much for your help!

I thought the intention was to have a scriptable solution?

I think you're looking for a scripted solution which allows you to define two points and the direction of the Curve. Remember; the thickness and colour of such Curves can be animated at a later stage, and the Arrow or 'direction indicator' of the Curve is another matter.
The concept is each box you want to connect has an edge which will be a terminal for the Curve.

Exactly how you determine the length of these virtual guide lines is up to you, it could be some factor of the relative distance between the two terminals on the boxes -- really that's down to taste.
The script would create something like this, if you give it two terminal coordinates, and a direction for each.

If you look at the source of the TubeTool addon you'd get a fair idea of how to script it, but the core of the code is this snippet.
import bpy
from mathutils import Vector

def add_curve(medians, normals, curvename, amp=2):
    curvedata = bpy.data.curves.new(name=curvename, type='CURVE')
    curvedata.dimensions = '3D'

    obj = bpy.data.objects.new('Obj'+curvename, curvedata)
    obj.location = (0,0,0) #object origin
    bpy.context.scene.objects.link(obj)

    polyline = curvedata.splines.new('BEZIER')
    polyline.bezier_points.add(1)
    #   polyline.use_smooth = False

    # obj.data.fill_mode = 'FULL'
    # obj.data.bevel_depth = 0.1
    # obj.data.bevel_resolution = 4
    point = polyline.bezier_points[0]
    co = medians[0]

    point.co = co
    point.handle_left = co - (normals[0]*amp)
    point.handle_right = co + (normals[0]*amp)

    point = polyline.bezier_points[1]
    co = medians[1]
    point.co = co
    point.handle_right = co - (normals[1]*amp)
    point.handle_left = co + (normals[1]*amp)

    polyline.order_u = len(polyline.points)-1

medians = [Vector((-2, 0, 0)), Vector((2,3,0))]
normals = [Vector((0, 2, 0)), Vector(( -2, 0, 0))]
add_curve(medians, normals, "curvename", amp=1.2)

And that gives (with the extras commented out, like thickness) this:

medians: Absolute coordinates, Vectors. (Location)
normals: Relative to the median they're associated with. (Direction, and Distance away from Location)
amp:  'push factor' for the control point. The amp parameter pushes the control points along the normals, effectively scaling the control points to be further away or closer to the terminal)

Thank you for your answer, I like this idea really much! I thought that I should first create all arrows and later script only the change in thickness, but your solution is much more elegant since I need quite many arrows. I experimented a bit with it already, and it works good!

hopefully  the additional link at the top of the post gives enough information to also script the arrow heads. I think once you make the one single function to add the arrow head + spline and keep track of the object names, you'll be able to easily move on to the materials and animation

I actually think about using the tubes alone without the arrow heads since I feel it looks better this way, and the direction of the flow does never change so should be clear in either way. I can still add them if I get the feedback that it would be mandatory.

There is an addon you can get, it's called "Tube Tool", this will make what you want for you very easy and give you much control over it.
More information here: http://blenderaddonlist.blogspot.com/2015/05/addon-tube-tool.html?m=1

Thank you really much for your answer! But in my case, I think the scripted solution is more applicable.

You simply can model those cubes and arrow.

Creating base - rectangles. I switched to Top View by Numpad 7. Added 2 cubes, scaled them, selected the face pointing to me and used inset tool by I. I scaled new face so it to be roughly the same rectangle:

I flipped normals of the boundary faces so them to  create a knid of border (may be not the best way, depending on your scene you may rather use materials). I did the same with second cube.
I added a curve and positioned it, extruded new points and rotated them to get that shaped arrow:

I duplicated that curve, moved it by X and Y so it to be located roughly the same as the first. I made actual arrow and made curve cyclic.

After that I switched it to 2D curve and made Fill option to Front.The result:

There are a lot of ways to do that, it depends on animation needs. If you want to animate that curve's thickness then I think you might want to convert it to mesh and use Shape Keys.

Thank you really much for your answer! But in my case, I think the scripted solution is more applicable.


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Retopo Sculpt Selecting Unwanted Vertices
I'm having issues with blender selecting vertices that I can't see and projecting them through the other side.  Is there a setting where I can make it not allow selecting through my sculpt during the retopo process?
Here is an example of what this is doing. Of course, I can't work in wireframe because its too hard to see my vertices.

is your mesh supposed to be symmetrical?

Yes its symmetrical.

if only 1 side has been damaged, you can try to symmetrize it on the +/- axis

I don't have issues with the damage I can fix that -- I just want to know if there is way to change the reference model's wireframe color.  I can barely see what I'm doing in wireframe mode because the dynotopo is so cluttered.

open user preferences (file menu or Ctrl+Alt+U) go in theme tab, select 3D View and change the colors

OMG Thank You Purple on Purple was killing me!!!

source: Stack Exchange

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

sort: votes


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I'm using a high number of samples. Why is my render coming out in low quality?
Can someone help me determine why my render is coming out in such low quality? I have Cycles up to 500 Render Samples, but I have no idea why it looks like it's only using one.

could you detail the lights and materials you are using here ?

Possible duplicate of How to avoid noisy renders in Cycles?

Does it look the same if you keep everything set as it is except render it with the CPU?

Here's the next piece of information we need in order to help answer your question: Render it with only one sample. Then render it with 100 samples, and post all three results (including the one you have now) here.

...if you don't have enough rep to do that, post links in the comments and someone (or me) will edit your question to add the images.

Maybe, you should check under dimensions, Resolution. I suspect it is 25% or 50%. Make it 100% and render it again.

Oh, good catch @cegaton. I'd forgotten about render layer overrides.

EXCELLENT!!! >:-) evil hand wringing

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


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Why is Blender so popular for 3D printing?
In a recent news by i.materialise I saw that Blender is the most popular 3D modeling software for 3D printing (complete ranking here: http://i.materialise.com/blog/top-25-most-popular-3d-modeling-design-software-for-3d-printing).
Personally I have the feeling that it's quite hard to turn a Blender design into a 3D print. Am i missing out on something? Do you guys know any easy tricks/tools to make a Blender model 3D printable?

Wasn't this was based solely on popularity in social media score and usage in the 3d printing community?

One obvious advantage is that Blender has a bundled addon called 3D Printing Toolbox which lets you easily check for errors like non-manifold edges, faces too small to be accurately printed, overhangs, intersections; and measure statistics like area, volume, dimensions.
Go to File > User Preferences > Addons,  type 3d print and check the 3D Printing Toolbox.

And possibly the best reasons of all, blender is free, and modeling is easy.

Most popular =/= best nor most used (which seems implied by this statistic). Statistics is a tool that I can use to show you any result I want by carefully picking the categories.
Paid software does have better tools and is much faster (volumetric booleans, highpoly performance, etc..), so why didn't it win in popularity?
Know-how in paid-software communities is very guarded, most had to pay for tutoring/tutorials and not so many people are willing to share it for free (usually they gladly tell you when you ask them, but they won't post it online on their own). Between professionals if you are the only one that knows something in the world, you are worth all the money for a company. It is similar how companies guard their know how or they licence it to others for money.
You will find that Blender and SketchUp got all the winning points in the Forums/Youtube/Google category. Free software is available to everyone and they share. On the web, on social medial, everywhere. If this is the key metric no surprise it won.

Enough of this now.. So what tricks blender offers for 3D printing?

Many Import/Export format options - which gives you great flexibility. You can bring models from professional CAD or sculpt software and export as STL, OBJ, X3D, Collada or VRML97/2
Solidify modifier to make it hollow inside
3D Printing Toolbox Addon - this is a nice tool to analyze your mesh if it will print nicely

You want to check minimal wall thickness
If the mesh can exist in real world (is manifold)
Check overhang geometry
Check normals if all pointing out

Powerful modelling tools to fix any errors
Average/Good_Enough_If_You_Have_Time sculpting tools
Python scripting for automation and customization
Tutorials everywhere and great community
And it is free :) The only cost is your time.

"Know-how in paid-software communities is very guarded" ...That's funny since while those so-called communities are busy creating a scarcity of knowledge Blender will just be expanding its user base more and more. The other guys are betting on a business model based on lack, while Blender is based on abundance and openness. Anyway, good call-out about the 3D Printing Toolbox add-on!

@Mentalist That's true but till blender will have usable tools and workflows on the same level as paid software, the openness is for nothing and blender will stay mostly between hobbyists. There comes time when blender is not powerful or fast enough and that paid software actually saves money because it saves time for the companies/you. So in the end the expensive tutoring is also worth it because you will get nice paycheck when you are good.

I get what you're saying, but consider that Blender could easily get more of those features if the community did more to support development costs. We get more when we invest more. And depending on how you're using it Blender may be all that you need, for example if you're doing archiviz or game assets Blender can be totally sufficient, but if working on Hollywood VFX maybe not so much. There are also areas where Blender outranks paid alternatives and there are plenty of people switching over to Blender too. Don't pay for other software until you're sure it can't be done in Blender.

@Mentalist That's very true. For the community financing I wish Blender Foundation would make at least same effort for getting money to hire new devs as for getting money for making movies. Sure some things got coded along but I would rather see all that go into development. My unpopular opinion is that in the end it would help blender more than a movie.

blender is not freeware.

@deusexmachina fixed

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


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Optimal emission strength for lightbulb
I am making a cone with a lightbulb in it, and I am not very good at modeling yet, so my "lightbulb" is just a sphere.  I added an emission property to the material, and I made a cone that has a diffuse and translucent property, and the RGB value is 0.74 for all of them.  If I am making a regular lamp, what should I use for the strength of the emission for the lightbulb so I can get regular lighting?  The lamp is supposed to be the key light, and I do not want the cone to be completely white.

I am using cycles.

I also don't know how to upload an image from my computer.


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Scene Eventhandler: bpy.app.handlers.scene_update_[pre|post]
In a quite large addon I have enabled some event handlers to check some things and everything works fine so far. But I'm struggling a bit with scene updates. They get triggered continuously and repeating relatively fast even if nothing obviously (like deleting an object) is changed in the current scene. Even if the mouse didn't move they get triggered multiple times in a second (I'm assuming something with draw cycles is happening here or some kind of time properties in the scene got changed).
I would like to know if this is an expected behaviour and how to determine if something of interest is happening? My goal is to hook in if a camera, a light, an object  or a material has changed (if possible without iterating over many or all objects). Thx.

Related  Those handlers are called upwards of 2000 times per second.  I recall seeing something about this being looked into for 2.8.  I would look into running a modal timer operator (see templates for example) that you can turn on and off with boolean property update.  Example

@batFINGER Puh! Than this EventHandler is useless and I can't understand why it exists for sripting. Anyway, the Relatet link has some good information. Thx.


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Adding a 'SUN' via lamp_add() actually adds a 'HEMI'. Bug?
If I fire the operator afterwards from a button, it doesn't work properly. I've other operators with other lamp types and those are working quite well as expected. But this one stole me a hour or two. Before I open a bug report I would like to check with more experienced developers (I'm quite new to Python) if I'm doing it wrong. Details are given in the following code:
class RfB_OT_OBJECT_AddLightDay(bpy.types.Operator):
bl_idname = "rfb.object_add_light_day"
bl_label = "Add DayLight"
bl_description = ""
bl_options = {"REGISTER", "UNDO"}

def execute(self, context):
    #
    # FIXME:  Adding the lamp as type 'SUN' here from operator, will add
    #         the lamp as 'HEMI'. Changing C.data.type to 'SUN' direct
    #         afterwards explicitly doesn't work, have to do it a few
    #         lines later. See QUICKFIX.
    # DATE:   2018-01-21
    # AUTHOR: Timm Wimmers
    # STATUS: assigned to self
    # BL_VER: 2.79
    #
    bpy.ops.object.lamp_add(type='SUN')  # BUG?: will be added as 'HEMI'
    _tmp = {'material': None, 'lamp': bpy.context.active_object.data}
    bpy.ops.rfb.node_add_nodetree(_tmp, idtype='lamp')
    bpy.context.object.data.renderman.renderman_type = 'SKY'
    # QUICKFIX: change late explicitly
    bpy.context.object.data.type = 'SUN'
    return {"FINISHED"}

Thank you,
Timm

Update method on renderman.renderman_type
Setting renderman_type to SKY sets the lamp type to 'HEMI' See renderman code
    if light_type in ['SKY', 'ENV']:
        lamp.type = 'HEMI'

This is not a bug.  bpy.ops.object.lamp_add(type='SUN') adds a lamp object of type 'SUN' named "Sun",  which is pretty easy to test.


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I get a "baking map saved to internal image, save it externally or pack it” message when baking textures
For some reason, when trying to bake a texture, I sometimes only get that message (on the bottom) and the image editor only shows a blank/black image. Sometimes it works, sometimes not, no idea why. The mesh is a simple deformed plane. All I'm trying to do is to have the texure (made procedurally) as an image file, so I can add it to a displace modifier. Not sure what else should I include in this description.
Here's the .blend file:
https://drive.google.com/file/d/1-XIVXZJZnasZ9okJYllfRBpfjvg0QsjA/view?usp=sharing

Your 50k verts plane has a Subdivision Surface modifier with 3 & 5(!) levels. In the viewport, this bumps the vert count to 600k, in render mode it's a few million.  Do you really need this? You can't bake Metallic (and Subsurface Scattering). Set it to 0 for the bake and reset it for the final setup.

The warning message in the title is a reminder that you must save or pack the baked image. Else it's lost when you quit Blender.

Mr. Blunder, I deleted the subdiv surface modifier, but I still only got the message, without the image actually showing up in the image editor.

To bake the image you just need to set Metallic of the Principled BSDF node to 0.000. If you don't do this the image will be black. Subsurface must be 0.000, too. (just saying). After you have baked the image restore the Metallic value.

The warning message "Baking map saved to internal image, save it externally or pack it” is a reminder that you need to save the baked image to a file (=external data) or pack it (=embed it into the blend file) after the baking process.
If you choose File you need to save the image explicitly Alt+S every time you change it (bake, paint, etc). It's not saved with the blend file!
Select Image > Save or Image > Pack in the Image Editor:

Sometimes there is an update glitch. If the image doesn't look like it should, try Image > Reload to reload it from disk just to be sure you see what you get. And after you saved it the first time, of course ;-) else it's discarded.

Thanks for your time dude, this helped.

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


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Can you assign a Masked area (in the Sculpt mode) as a Vertex group?
Watching a ZBrush tute, a guy uses a mask to block in an area and then deletes the rest of the mesh (keeping only Front faces of the Masked area)..
https://youtu.be/7wjK4axInhc?t=8m25s
That would be an amazing workflow for Blender... do you think it is possible? Maybe if I could assign the Masked area as a Vertex group?
Cheers for checking...

Perhaps you will find what you need here in the sculpt tools addon http://jayanam.com/blender-sculpt-tools-ui-mask-extract/

If it works for you, maybe include a rundown of how you used the addon to get your result and maybe a screenshot or two. That way it serves as an answer for the next person.


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Best way to model these ears
I recently started 3D Modeling. Trying to model this chair and having the hardest time figuring out how to model the shape of the ears just right. Any tip would be appreciated.

Welcome to Blender Stack Exchange! This question is kinda broad... There must something in specifics that's making you ask this question. Something that you can't get quite right.

You also seem to have already answered your own question with the second image showing a pretty good topology for the geometry in question


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Fix face collapse when subdivide
I'm trying to cut out a piece on my object like this:

But when I go to subdivide, my object gets distorted. How do you go about fixing this?

When you subdivide an object, the degree to which an edge gets smoothed out depends on how far away the next edge is. You'll notice that the right side of your cutaway is completely devoid of edges, so this edge is getting pulled a long way off. Meanwhile the edge at the back of the cutaway has another edge loop close behind (where the selected vertex is in the first screenshot), and is therefore much sharper in the subdivided mesh.
Here's a simpler example to illustrate what's happening:
Plain mesh before subdivision:

After subdivision. Notice how the edge is more rounded on the right side of the cutaway.

If you want all the edges to have the same amount of rounding, add edge loops at a constant distance from both side of each edge in the existing mesh (by hitting ControlR in Edit mode)
Here's the same mesh in edit mode with extra edge loops:

And this it what it looks like after subdivision:

If you want the edges to be more rounded, move the additional edge loops further away from the existing edges. And if you want sharper edges, move them closer in.
Alternatively, try using the Bevel tool instead of a subdivision modifier.

Thank you so much squeamish. Learning Blender has been frustration and a test of patience.


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Connetcting Vertices While Retopologizing
When I first learned how to retopologize a model, I wanted to connect two vertices to finish one of my faces.  However, I could not find any obvious tools to connect to vertices, and the book I was using did not mention connecting vertices.  How do I connect these vertices?

pls clarify the question a bit, best with a picture what and how you want it to connect. 2 vertices do give you an edge but no face. So what you asked is "How I finish face with creating an edge."

Well let's say I'm making a square face, and I already have 3 out of 4 vertices for it, and I want another vertex to finish the face.

There are dozens of ways you can create the 4th vertex and connect a face when you have already 3, but most of them will be slow for retopo.
To work fast you want to enable the F2 addon (and while you are at it also have a look at BSurfaces):

With this your F shortcut gains new features, these ones help your case:

Make polygon by selecting corner vertex and hitting F:

Then you need to snap them to highpoly mesh. The addon has Auto Grab option which is great for this case - it let's you place that 4th vertex precisely.
Make polygon strips from an edge (extrude all the needed vertices with E, select edge, hit F couple times):

The F2 addon takes into account the position of your mouse cursor, when there is no clear direction where to put new face from the surrounding geometry:

If you mean merge vertices then, AltM, should do it, you can choose to merge your vertices in the center, at first, at last, at cursor and also you can collapse them.


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Adding Ngons to Meshes
I heard about this thing called ngons, and adding ngons to your mesh.  I am wondering about how to add an ngon to my mesh, and what it looks like.  There are no obvious tools for adding an ngon.  How do I add an ngon?

related and worth reading: http://blender.stackexchange.com/questions/89/when-should-n-gons-be-used-and-when-shouldnt-they/95#95

An N-Gon is simply a face with more than 4 vertices.

Notice how there aren't any edges going across it, it's all one face.
To add one, just select more than four vertices, and press F. An N-Gon is just another type of face.
Now, an N-Gon might seem great, but let's look at what happens if we pull of of the virtices from the last image up in z space a bit.

It might look okay, but notice how you don't see any shading from the raised vertex. Now let's look from another angle.

It might seem okay, but notice how the shading is the same all around. There's no change in color throughout it. To amplify the issues even more, let's run this through cycles.

3D view (for a point of reference) The selected Vertex is the raised one.

Notice how odd the shading is when it's rendered, especially when you compare to how it's rendered in the 3D view.
To understand what's happening here, we'll have to take a quick look at how faces are rendered, or prepared for rendering.
Tris are the only thing that the GPU can render, so that means that every face you make, has to be split up into a Triangle. What's happening here, is that the Blender is having issues splitting up the face, because it has no way of knowing how to split it up effectively. This is where the real downfall of N-Gons are.
But there couldn't be an explanation of N-Gons without mentioning their issues with subsurf.
Take a look at this example of a cylinder that is capped with an n-gon.
Normal

Subsurf

As you can see, there are lots of distortions.
Pro's and Cons of N-Gons?
Pros

They allow you to connect more than 4 vertices to a face.

Cons

They are extremely unpredictable when it comes to shading
They cause lots of distortion when deformed or subserfed.

I thought it was a face with an infinite amount of edges.

Nope, it's a face with more than 4 vertices.


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change the sscene before deleting an object
How can I perform some actions before deleting an object.
If I have an object that has a relation with some other objects in the scene. and the object was selected in the screen then deleted.
How can I perform some changes (in a python add on program) to the other objects before the object is really deleted?

Welcome Samer :) Please add details as to what you have tried and what you want to achieve. Might be a good idea to start with the tour: http://blender.stackexchange.com/tour. Enjoy blender.se!

The python api does not provide event handlers for object deletions. All handlers available are listed here).


text:
Sequentially rotate object along two arbitrary axes
I'm trying to rotate an object around one (arbitrary) axis using a child of constraint. Next, I want to 'let go' (i.e. set influence to zero), rotate the object along the global Z axis then 'grab' (i.e. set influence to 1), and rotate the object a second time along the same axis used in the first rotation. I've tried adding empties and also experimented with visual transform, but can't seem to get it sorted out.
What am I missing?
Best regards,
Andrew

I think I may have figured it out...:

frame 1:

use 'child of' constraint to parent object to 1. axis (other object or empty)

frame 60:

rotate axis 1
keyframe object's rot/loc

frame 61:

apply visual transform to object
keyframe constraint factor (1. axis) to 0
keyframe object's rot/loc
add 'child of' constraint to object with 2. axis (other object or empty) as target

frame 120:

rotate axis 2
keyframe object's rot/loc

frame 121:

apply visual transform to object
keyframe constraint factor (2. axis) to 0
keyframe object's rot/loc
add 'child of' constraint to object with 1. axis as target

frame 180:

rotate axis 1
etc.


text:
pivot object over two different axes by pulling on its edges
I'll do my best to explain this... I need to pivot a plane along its X and Y axes by raising and lowering its corners (two at a time).
In the images below, the cylinders should be raised and lowered as indicated by the arrows and cause the plane to tilt accordingly.

In the end, I just want to be animating the cylinders - they should 'drag' the plane along resulting in the tilt motions... Also, moving all cylinders up or down should raise or lower the plane.
Any pointers would be greatly appreciated.
Thanks!

If you're willing to rotate the plane, which in turn makes the cylinders go up and down, you can do it this way. (I'm using blender 2.79)

Select a cylinder, then the Plane.
Go to Edit mode
Select one vertex of the nearest corner to that cylinder, then go to Mesh/Vertices/Make vertex parent, and click on the "confirm" dialogue box that pops up.
Come back into Object mode and repeat 1 - 3 for the other 3 corners.
Give each cylinder a Limit Location Constraint.  Copy each cylinders current X and Y position and paste them into the first two fields of Minimum and Maximum values in the constraint.  That is, limit the location to exactly where they are on the X and Y axes but leave them free to move on the Z axis.
Rotate the plane on the X or Y axis and the cylinders will move (vertically only) accordingly.

Thanks! I finally got around to trying this out. That worked!

You don't have to drive it from the motion of the plane-- you can drive it from the cylinders.  Here's how.  But first....
Let's talk about how your system isn't fully defined.  First, a plane is defined from the position of 3 points on a plane, not 4-- so we can't meet any arbitrary position of the 4 cylinders.  We can make it work by raising one set of pillars, and we can make it work by raising a perpendicular set of pillars, but we cannot adjust the height of both sets and still get a plane out of it-- the four pillars would be non-planar!
There's another issue here too, which is that if you raise the pillars, the distance between them increases.  So if your plane doesn't stretch, it won't be attached to the pillars any longer.
So with that in mind, here's how to drive it from the pillars-- again, remembering that we can raise one set, or the other set, but not both.

Our deforming bones: defPlane, defNW, defSW, defSE, defNE (our four pillars.)  We also have a root, two tracking bones, and two control bones.
We'll start by having our control bones affect our pillars.  NE and SE get a copy location constraint (local to local, with offset) targeting ctrlE, so if we raise E, those go up.  NE and NW get copy location targeting ctrlN.  Since NE is in both groups, it has two constraints, which is why we need the offset.  (Mostly this could be done with parenting, but the one that needs double "parents" means we need at least one constraint, so I just handled all of the relationships in the same way, with copy location constraints.)
TrackX and TrackZ need to get a proper position exactly halfway between their appropriate pillars.  In this case, I did that with an armature constraint (0.5 weight to both pillars).  defPlane needs to get a location in the exact middle of all four pillars, so I started with an armature constraint for it as well, with all four bones in the constraint at weight 0.25.  (There are a lot of other ways you can get this position.  Anything is fine.  This is just what I did.  Note that any bones acquiring position from an armature constraint should be root level-- they're already acquiring the root-bone transform from their constraint targets.)
Now we need to adjust the rotation of the plane.  We'll do this with a pair of locked track constraints.  We'll lock Z and track TrackX in X (duh.)  And we'll lock X and track TrackZ in Z.  For any motion of one control, one of these tracking bones will already be exactly where defPlane is pointing anyways, so one of them is redundant, and order doesn't matter.  And we've already established above that manipulating both controls is right out anyways-- we'll no longer have a plane if we do that.

My best guess is your cylinders need armatures with bone constraints for certain axes (either  rotation or location bone constraints)

yes but what about the plane?

Connect each object to its own bone, and then play around with bone constraints for each. Link all the cylinder bones to the plane bone too.

could you please propose a detailed answer?


text:
Where are my addons?
Where can I get the add-ons for Blender 2.76?

If you are a new blender user, see the link that @cegaton posted to find answers to many common topics for new users.  Anyway, it is better if you can elaborate a bit more your question, to get a proper answer or even some better advice: are you saying that you know where they should be but they aren't there (anymore?), in you local install, or you don't know at all where you can find them?

I figured out why I did not have any add-on files. After I downloaded Blender onto my hard drive I unzipped it in the Download folder because it would not unzip in my C/Program Files for some reason. But I figured out that I can just name a new folder in the C/Program Files and drag the unzipped folder from the Downloads folder, and now it's fine. I hope this answer is helpful to others.

This won't have happened if you'd have already known this tip: http://www.blendernation.com/2015/07/25/restoring-custom-defaults-quick-tip/


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How do I make a 3 dimensional character out of flat picture?
I have a cartoon character (a lion) that is part of my business logo that I want to put into Blender and animate it somehow. Is there any way I can take a flat picture (JPEG) and transform it into a 3D image and then animate it in Blender?

Hi, of course, there is a way, but not "few clicks solution". You need make 3D model manually. Or you can animate them as 2D image. Given the fact how you asked, you are no every experienced about graphics, so you can prepare to few months of learning and gain experiences. Because as I wrote: there is no work for few clicks and explain everythig from modeling, throught materials, animation and rendering to compositing is for a book or series of tutorials.

Thank you so much, I DO have some knowledge of how graphics work but I was wondering if someone here at the Blender forums has found a way to configure vectors for a single dimension image to be transformed into a multi-dimensional image, I do believe it is possible, just haven't figured it out yet. I work with graphics all the time, so, to me, this would be awesome to figure out. I also have a program called Muvizu for animation which is an awesome program but they do not have the option to submit your own images for characters. I will keep on looking for more tips for Blender.

https://guochengqian.github.io/project/magic123/

The question is seven years old, and the two answers are almost as old, so it's time for an update. The answer is now that there is a very easy way to do this. See the new answer I've added below.

You may do it using the Transformers add on. It'll transform every flat textured plane into 3d model.

Activate it in User Preferences. Then go to a Tool Shelf and choose a desired transform option.

OKAY I'M KIDDING :), NOW SERIOUSLY:
There's no such way to do it fast. If you manage to invent a tool that may do such thing automatically you'll be probably a millionaire :). While there's a very simple way to transform 3d model into 2D image (using e.g. shapekeys), reverse process is impossible (at least right now :)).
As @Shubol3D said there are no shortcuts. You'll have to master a lot of skills to create your lion model. It's very time consuming process, so if you like to save it I suggest you to go to Blenderartists.org forum and make a paid job offer there. There are a lot of super talented people, who may do it for you.
But if you still want to do it by yourself...
Here are some ultra basic 3d model production steps:
First of all get familiar with this topic: Resources for Blender It's super useful for the blender beginners.
MODELING
You should start from setting up the reference images for modelling:

How do I set a background image while I am editing?
How do I scale my reference images correctly within Blender and is there an easier way?
Modeling with reference image

First add a cube. Use Toggle Quad View option (Ctrl+Alt+Q) to split the screen into quarters and set separate background images for each one. Adjust their positions, so they fit the cube position in Top, Front and Right 3D views.

To make the modeling workflow faster use a Mirror Modifier:

Is their a way to create half of a model and duplicate other side

How can I make the mirror modifier work right?

Divide the cube into two identical parts with Ctrl+R and delete one half of it (X). Add a Mirror Modifier to it. Now you may model just one half of the mesh and the other one'll behave symmetrical.
Enter Edit Mode and start modeling basing on the background images you set:

What techniques are used to begin creating new models?

There are few buttons which are very helpful in modeling: G- for grabing/translating vertices, edges and faces, S- for scaling them, R- for rotating, E for extruding and F for filling the holes. You may also subdivde the desired faces using Ctrl+R shortcut.
Start with extruding the cube to create a basic shape that fits the background drawings. Then subdivide it successfuly to add more and more geometry and details.

Thanks to quad view you may control the shape of the mesh in every view at once. Fit it to the background drawings as accurately as you can.

Finally you may add a Subsurf Modifier to make your model smooth. Go to the Modifiers header, activate it, set the desired subdivision levels and smooth it even more with Smooth shading option in Edit panel of the Tool Shelf.

I think that in your case this tutorial may be a good start: https://www.youtube.com/watch?v=6mlGT6T9bfQ
It shows how to create a 3D animal model based on the 2D images.
UNWRAPPING AND TEXTURING
To unwrap your model properly you may need to make seams for it:

How to properly unwrap my mesh?

How to Place the Right Seams for UV Unwrapping

Select the edges you want to put the seams on and press Ctrl+E-->Mark Seam. Now select the whole mesh (A) and press U-->Unwrap.

Now you want to put the texture on your model. Though there are many methods to do it, I prefer the texture painting with Stencil method:

How to make textures in Blender without any flat work with a painting program? (3D painting)

Select your model, set up the shading type to Texture and go to Texture Paint mode. Add a new Paint Slot-->Diffuse Color in a Tools bookmark of a Tool Shelf (T). Add a new texture in the Texture panel on the left, then go to the Texture header on the right, select Brush and open a texture, which will be used as a stencil for painting. Paint the texture and save it.

Now add a material to the object and assign a newly created image texture/textures to it:

Add an image to an object (Blender Internal Render)
How are texture maps imported into Blender? (Cycles Render)

Go to the Material header and add a new material (click New button).

IN BLENDER INTERNAL: Go to Texture header to assign a texture to it. Add a new texture, set its type to Image or Movie. In Influence panel check the Color checkbox. Set the viewport shading to Texture to display it on model.

IN CYCLES RENDER:  Go to Node Editor, check the Use Nodes checkbox and set up nodes as pictured below.

Basic tutorial showing how to UV unwrap an animal model and apply a texture to it: https://www.youtube.com/watch?v=p4ngVoGIj1Q
RIGGING AND ANIMATION
Now you have to construct the rig (skeleton) and parent it with your model:

how to rig the body
How can I automatically generate vertex groups for an armature?

Add a single bone (Shift+A-->Armature-->Single Bone) and extrude it (E) in Edit Mode creating a skeleton. Limbs can be mirrored from one side to other using Ctrl+M command.

When your skeleton is ready you may you may parent your mesh with it. In Object Mode select your model, then your armature and press Ctrl+P-->With Automatic Weights. It'll automatically create specific vertex groups for the specific bones.

Finally you can animate your bones:

How to make an animation / armature remember poses?

Select a bone in Pose Mode, translate it using R,G or S and press I to keyframe it. Go to the next frame on the Timeline, translate it again and keyframe again. Press Alt+A to play the animation. Adjust your keyframes spacing in Dope Sheet Editor. Control every aspect of your animation using curves in Graph Editor.

Very, very basic tutorial showing how to make the skeleton for your animal and how to animate it: https://www.youtube.com/watch?v=Kr6-_NT_olo

that first gif is awesome.

Pack your things boys, this site can now officially be closed. Possibly one of the best answers of BSE ever. This basically answers every question about Blender ever made in the past, or that may still rise in the foreseeable future.

dat gif tho. could you please explain how you did it? is it even yours? lol so amazing.

@cegaton I've heard the rumors, that it'll have this kind of functionallity until the Blender 3.0 release ;).

@Duarte Farrajota Ramos LOL.

@ARadish I've just scaled (S-->0) Suzanne, then did some tweaks to create a rectangular plane, keyframed the shape key and textured it (Project from View). Then animated the transition between textured diffuse and color diffuse shaders.

@PGmath It's quite hard task to explain everything, as every production aspect requires a tutorial, not a simple answer. I'll try though :).

So, there could be a transformer's plug in! Just add some topographic-map-like relief data (contour lines) embedded in a rectangular plane mesh, then reverse Paul's manual technique, but programmatically scaling (S -->x), where x is the contour data (e.g. "height") at a vertex, then loop through all the vertices. ... or am I hallucinating after staring at that GIF too long?

@PaulGonet  Way more detail than I had in mind :P thx!

@PGmath Thanks! This is the most hard-earned upvote I've ever got :D.

The transformer's plugin is actually technically possible, but there will be some problems such as hidden objects and objects filled in the wrong spot, such as the tail being placed between the 2 pairs of legs and the tail itself (which would look really wrong...)

@Bradman175 - indeed ... could be useful if the objs are simple ... add the hidden details later. @ Paul Gonet ... thanks for the effort. Answers such as yours are why I'm here!  (And meta.blender has several discussions about the pros and cons of "tutorials" ... SE in general frowns on them, wanting simple, black-and-white answers. Clearly that's impossible for many things Blender, requiring "workflow" answers and details like yours... at some unclear boundary, workflow becomes tutorial. But I sure don't care about that ... so here's to more sophisticated workflow !

@PaulGonet Why are your answers so good?! You're crushing me inside :D P.S. I totally second Duarte's comment.

@Shady Puck Thnx! I wish I had the blender knowledge you have when I was your age :).

This is as good of an answer as anyone is going to give you without having it done for you, mark it as an answer to give the user credit, for not only time and effort for the job, but also because he did so in a way that it is a virtual walkthrough.

Awesome answer! great gif, too.

@Paul Gonet Hey, I loved the cat and the monkey. So cool!

@PaulGonet: I love how you created the fake "Transformers Add-on" window! You thought of everything!!

Use Photoscan,and if it didn't turn out like you wanted then you can use the shapes to make it,but I reccomend using MakeHuman or the Manuel Bastioni Laboratory. I'm making a FNaF fan game with human characters,and when I finally found out about this,I used the sliders to make the character exactly like I wanted to. This is your answer. But if it's a lion you're talking about,I highly recommend that you use reference images to sculpt the anatomy of the lion without mane first,then you model it using the sculpture as a base,then use the Subdivision.
The Subdivision Surface modifier will increase the polygon number,I also recommend you to use image textures from the internet to trace the shape and for symmetry,use a mirror modifier for one side,then when you apply it,swap the weights with their opposites. Then you can detach a limb,one by one and parent it to the armature set with Automatic Weights. Then add mane using hair particles and go to the Blender Guru's site to learn how to make realistic fur.

Why is everybody down-voting me?

We're finally here! I wrote in multiple places that the AI tools are extremely limited and can be replaced by a very basic modelling skill. This changes with...
 www.meshy.ai

Click on the green "Get Started" button
Register new (free) account
Click on "Image to 3D"

Drag an image in this field:

Click the green "✨ Generate" button

Here's my test: I started with a PNG file.

I actually used 10 times (in each dimension) bigger image, but new BSE limitations didn't allow me to upload it. I don't know if having a high resolution image was beneficial... It's a logo of an armadillo. It's flat - monochromatic: blue/transparent. The background and features of the armadillo share a color (transparent). It's abstract - it isn't an actual real photo traced into an illustration, it doesn't have proper shape of an armadillo nor proper perspective. So it's a very tricky input. Here's the result from Meshy:

It successfully differentiated the features from the background (as opposed to making holes in the face), as well as figured the shape just about right. Well, "about" is the keyword here, let's look at the topology:

It looks like playdough shaped by a 6 year old kid. If you thought it is created by a human, you wouldn't be impressed. But because it's created by AI you are impressed... It kind of looks like low poly, but is high poly.
Meshy also allows you to download the file, with one of the formats being .blend!

In the right panel, you have an option to decimate and to convert to quads as well!

Low poly hides the imperfections, however it still looks like a very shoddy job because it's asymmetric:

As a comparison, here's what I modeled manually (before even knowing about Meshy, so it didn't affect my work in any way) in a few hours:

The topo of ears is weird, because at some point I applied subdivision and sculpted, so before taking the screenshot I added a "decimate: unsubdivide" modifier. So the topology could definitely be further improved if a better workflow was used. The coloring was done by casting a shadow from the original image in Cycles, and then baking it into a texture.
It begs the question, however, what if I took the render of my work as an input for Meshy?

The ears are asymmetric by design (they are asymmetric in my model):

It seems the AI Doomsday is still not going to happen tomorrow, but perhaps Meshy is a good tool to use to quickly prepare a base shape + texture for further sculpting. You will end up, however, with a topology that doesn't have some logical connection with your shape and isn't symmetric.

The question is seven years old, and the two answers are almost as old, so it's time for an update. The answer is now:
Yes, there is a way. A very easy way.
I don't know if this is the only way, but I found a very easy way in a YouTube video by Nik Kottmann:

Go to the free online tool, Monster Mash.
Import the picture.
Draw lines around the segments of the object, such as the body, legs, and ears of an animal.
Click "Inflate" to magically turn the picture into a 3D object.
Click "Animate" (not to animate the object, but just to turn on the option for the next step).
Export the object as a glTF (.glb) file.
Import the glTF file into Blender.
To see the surface textures from the original picture, change Viewport Shading to "Material Preview".
Switch to Edit Mode to reveal the vertices of the object and modify the object as desired.

The video runs through all the steps for doing the above. Nik takes a picture of a rhinoceros and turns it into a 3D object in Blender in a few minutes. I ran through his steps with a picture I generated in Leonardo and got the same result.
Pretty amazingly easy!

Thank you for writing the up-to-date answer! It will probably get very old very soon, as better algorithms exist already: https://guochengqian.github.io/project/magic123/ and in the case of Monster Mash, where no fancy stuff is being done to the texture (just a projection from view), anyone with moderate experience in modelling will be able to produce better results within a short span of time (as Paul Gonet's answer shows). Still, this technique could save some minimum amount of time for a basis shape for modelling (paired with quad remesher for good topology)...

@MarkusvonBroady - Re Magic123: That does look way better, but it appears to be only available for linux. Do you know anything about when it might be available for Windows or online?

@MarkusvonBroady - Re "anyone with moderate experience in modelling": I'm new to Blender and to animation, but experienced in computers, so not afraid of learning new tools. I was impressed by the extraordinary detail of Paul Gonet's answer, but it seemed it would take a long time to learn what he was teaching. When you say "better results within a short span of time," would you think that I should be able to follow his instructions and get up to speed in the techniques if I give it a solid focus for a day or two, or should I expect a longer learning curve than that?

I've been using Blender for 5 years and there's still a lot new things I could learn, so I'm not going to lie a single intensive learning session is all you need; however the blenderguru's donut tutorial teaches a lot and can be finished in a day or two. Then just start working on your project and google a problem whenever you have one - also once you get some familiarity with the basics, go through this video to find out about which features you missed: https://www.youtube.com/watch?v=1jHUY3qoBu8 ; as for Magic123, I didn't try it, but you can use WSL on Windows.

authors: Назар Панасюк


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Joining two windows doesn't work
I click join area and then the Area Options dialog disappears and nothing happens.

Close the timeline first

If you look at the system console, you will see an error printed: areas don't share edge. You can only join areas if the fully share an edge, but in your case the right-hand area shares an edge with two other areas.


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Blender assign material to object -> Unity
I haven't found a tutorial about it and I'm completely lost. I've applied materials for assets I've made, never touched the Texture properties however, but the materials wont ever follow. I've read things on the internet where people say that it's just about drag and drop the textures. But I haven't found any that I used in Blender...
It's really annoying when you've spent hours on making something, and then not seeing it as it's done in the game is annoying.
Am I just stupid, or can you find a solution to it? Because I would be more than thankful for it!
Thanks in advance!

Do you use image textures? If so you simply drag the image files into unity. You can't import procedural textures or materials created using cycles nodes.

I use the "Add a new material slot", add the color I want and then I apply that to whatever. I don't use image textures since I'm doing a low poly art project.

check out the quick tutorial video on youtube "FBX Importing to Unity 2017/2018+ | Where did my textures go?" it wraps up the issue how to assign your textures to your material.


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Texture-less/colourless .obj file when opened
I have an MMD model which i exported from PMD/PMX editor in .obj format, but when I import it into blender (ver. 2.75a), it's missing it's textures, same thing happens when I open it in Keyshot, anyway to fix this/re-colour textures?

related: http://blender.stackexchange.com/questions/24020/importing-obj-with-mtl-and-image-not-working-properly/24024#24024

Obj files do not store color/texture information. However, it can contain a reference to an *.mtl file.

You can check the obj file content and look if it contains a reference to an mtl file - which itself stores the colors of points/textures
Or maybe you can use another format when exporting (ply does store color information for each point for example).


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How do I get blender to work on OSX El Capitan?
Ok, so recently I updated to El Capitan, and I have had so much trouble figuring out how to move the camera around and just do basic trackpad movements like I used to be able to do. I have followed this tutorial since I started using blender: https://www.youtube.com/watch?v=nCgt4ODsWYQ
and it has worked until now. Does anyone know how to fix this?


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How can I apply decimate modifier to multple files and save them as a different file automatically?
I am developing a game where game consist lots of buildings. I finished modelling of buildings. But in optimization of game I understood that I need to use some thing like a LOD system. For that I want to export my buildings with decimated versions of them. Each buildings in different file.
Can I write a script that performs that operation automatically?
For example script can take a root file as input and iterates all the folder under root. Then exports all blend files with decimated versions.
I know python but I've never write script for blender.

yes, off course. you can!...   please check some references like https://blenderartists.org/forum/showthread.php?249833-Open-a-file-from-Blender-using-python  or others... ... the main is the blender appi documentation.  http://www.blender.org/api/blender_python_api_current/

Ok, I wrote a script for my purpose. Maybe it will be helpful for somebody.
Here is the python script that decimates model and save as a new file.
You can change iteration and decimateRatio
import bpy
import os

##Cleans all decimate modifiers
def cleanAllDecimateModifiers(obj):
    for m in obj.modifiers:
        if(m.type=="DECIMATE"):
#           print("Removing modifier ")
            obj.modifiers.remove(modifier=m)

numberOfIteration=2
decimateRatio=0.3
modifierName='DecimateMod'

for i in range(0,numberOfIteration):
    objectList=bpy.data.objects
    for obj in objectList:
        if(obj.type=="MESH"):

            cleanAllDecimateModifiers(obj)

            modifier=obj.modifiers.new(modifierName,'DECIMATE')
            modifier.ratio=1-decimateRatio*(i+1)
            modifier.use_collapse_triangulate=True

    fileName=bpy.data.filepath
    fileName=os.path.splitext(fileName)[0]

    #Trim decimate version of file name
    indexOf_=fileName.rfind('_')
    if(indexOf_!=-1 and fileName[indexOf_]+fileName[indexOf_+1]=="_d"):
        fileName=fileName.split("_d")[0]

    fileName='{}{}{}{}'.format(fileName, "_d",str(i+2),".blend")

    bpy.ops.wm.save_as_mainfile(filepath=fileName)

Also you can run this script with a bash command for all child files having .blend extension.
find . -name '*.blend' -exec blender {} --background --python myScript.py \;

Thanks to Attie for bash command

What does the use_collapse_triangulate attribute do? I see that it is described as "Keep triangulated faces resulting from decimation (collapse only)," but what does that mean? When I check or uncheck the corresponding option ("Triangulate") in Blender's GUI, I see no change in the number of faces or triangles in the resulting mesh. So, what does it do?

Is there a wayto apply the newly added modifiers before saving the file?


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VSE how to transition from one video strip to another with effect like turning (flipping) page?
I would like to setup a video transition that looks like if you were turning a book page (with the current strip image) so that the new video strip appears after page is turned.
Is there a way to do this transition in BLENDER VSE?

Not only in the VSE, but you could do something and in the 3D viewport and compositor i.e. you could make a green page, and a blue page, and use a color key node to key out each color in the compositor.  Then render this and throw it into the VSE. Repeat for each time you need to transition.  For example, throughout my recent video (see 2:10 for example), I made a custom transition with a tardis. I animated green between the doors at the beginning, and then keyed out the green and replaced it with the end of an animation in the compositor.

Just adding to @Shady Puck's  comment, you might find it easier to model the turning page (plane sudivded and rolled back with bones?)  firstly, outputting the video as PNG files using the OpenGL renderer, that are Alpha Layered so all behind it is invisible.  Use that in the VSE to lay on top of the page underneath.  Alpha layer doesn't require Chroma-key compositing - it just happens!

@bruno: I guess you looked for a prebuilt transition like that. If you just looked for this, the answer is no, blender's vse doesn't have such fancy prebuilt effects.

The VSE is not built not make 3D effects. But neither were the edit systems of last century and they could do it. So lets try.

First thing to do is grab 2 source images to transition between.
Then decide how long the transition will be. This is important as the effect is made up of wipes which are variable length and animated transform effects, which you'll need to modify by moving keyframes.

Notice that the wipe goes from the background image to the Metastrip stack. It is labelled Wipe Background.
The next part is key!
There is a wipe from the Wipe Background metastrip to the incoming shot, it is called Wipe Incoming. They are both oriented at 45 degrees.
Inside the Metastrip is the rotated and translated image, there is also a drop shadow and highlight effect.

At the bottom is a duplicate of the source image strip and an adjustment layer. I use an adjustment layer in case I want to swap out the source image for some other shot.
Then the adjustment layer gets a transform effect strip that is rotates the image 90 degrees, anti-clockwise and moved to the top right corner. This is animated to the lower left corner. When you add a wipe of the same duration it looks like a page peel.
First I add a Gaussian blur to the Transform strip, then I duplicate the Transform layer above the blur strip. The first transform effect gets a Curves modifier to make it all black, this will be the drop shadow.

Above the Transform effect strip I add a a color effect and make it all white. Then I add the same wipe between the white and the Transform strip. When you soften the wipe it makes a fake Highlight.

The metastrip can quickly be altered to work with any source strip, but the wipes will have to be applied to the strips. Although you could add an Adjustment effect strip to the incoming strip, making it a completely stand alone effect.

In VSE I don't know how. However you can model a book, and on the pages you can build a double sided material: you need a geometry node with "backfacing" connected to the fac of a mix shader node. Connected to the mix shader's shader slots, will be the 2 movies/image sequences you want for the transition. Next, you just need to rotate the page as you want/need. There are tutorials on model a book or animate the pages, like this one: https://vimeo.com/11232299 node setup would be something like this https://blenderartists.org/forum/attachment.php?attachmentid=154566&d=1316065621&thumb=1
I talked to a friend and he recommended a external free software called VSDC video editor, as it is easier to acomplish this (http://www.videosoftdev.com/free-video-editor/download)


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export to .3ds with smoothing groups?
Does anybody know if you can export to .3ds with smoothing groups in your model? I am trying to export to .3ds because of the fact that Battlefield 1942 has a tool called 3ds convertor (yes, it's name is spelled like that) that converts .3ds to .sm which stands for standard mesh, and is the native 3D format for Battlefield 1942. Also, Battlefield 1942 standard mesh models uses the material ID feature in 3ds Max for this to define different materials for what kind of surface the model should have.

Blender doesn't have a concept of Smoothing groups like 3ds max, here you define sharp edges, but they should be kept intact when exported to 3ds. Material IDs are called material slots, and should also be exported faithfully by default

I see. Well, can you tell me how you define the slots in numbers, so that I can define a surface for my collision mesh?

See http://blender.stackexchange.com/questions/16397/how-to-fill-a-mesh-with-solid-color/16398#16398. You can't specifically define slot numbers, just slot order

Alright, I will see if that can solve the issue. Otherwise I'll have to go through Gmax to get it done. Thanks for your answer anyway!

I posted in the bug section of Blender, and it seems that the smoothing group export feature probably won't be added.

Bug reports are not for feature requests

Yes, I found that out. I won't make that mistake again though.


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How do I model across a mirror modifier?
I am modeling on a set of windows right now, and they are not symmetrical along the X axis, where I need the mirror modifier to mirror the other half of the superstructure. This is what it looks like. The problem basically arises when I need to make the windows non-symmetrical across the mirror.
One possible way would probably be to apply the mirror, make the adjustments, then separate the windows from the main superstructure and finally joining them with the superstructure afterwards?

add another mirror modifier

If I would, should it be above, or below the original one?

play with the order up and down how it fit to the model

Simply by using the copy command on the modifier, I suppose I don't need to separate the windows geometry from the original mesh.

Solution: Separate the geometry that will be non-symmetrical, and rename it.

Select the object (by right-clicking on it), then press Tab on the keyboard to enter Edit mode.
Then, select the geometry that you want to separate, and press P (hotkey for separating) and you are done!

Now you can press Tab again to go back into Object mode and see the separated geometry.
You can also rename a mesh by selecting it in the Outliner edtior (the object list in the far up-right in the default window layout), double-click the object's name and type in the new name instead of the one with a ".001" at the end given to the object by default.


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What is GPU tile size contingent upon?
I've read a lot about this but most of what I've found is anecdotal or personal experience.  My question is more about architecture.
The optimal tile size for GPU's is universally stated to be 256x256.  But all GPU's are different.  They have different interfaces, # of cores, memory, etc.  Why is 256x256 the universal constant?  If it's the memory interface, there are cards with 128-bit and 384-bit interfaces.  Would their optimal size be 128x128 and 384x384?
I've found that for my GTX-970 (256-bit), if I keep the multiplied tile size as close to 65536 (256x256) as possible, I always get the fastest render times.  But that number doesn't correspond to the number of cores (1664) or the amount of memory (4GB) on my card.
Ultimately, how is the optimal tile size determined for a specific GPU, architecturally speaking?

There is a addon bundled by default called Auto Tile Size that calculates this automatically. Never used it myself, not sure how it works, but assuming it was well built, and the math is correct, then perhaps investigating it's code will shed some light on the matter.

A good idea... I looked at it briefly and it looks like it's taking an optimal "power of 2" as the standard (attempting to keep CPU or GPU at 100%) and then dividing the tiles based on the resolution of the rendered frame in order to keep the tile size as close to the optimal power of 2 as possible (i.e. no "stragglers").  It still doesn't explain the architecture of GPU, though.

The infamous answer to this question is:
It depends
The 256 x 256 recommendation that is given many times is a very good starting point. In general it will lead to decent render times and sufficcient image update cycles while you're waiting for the render to complete. But as with any renderer, tuning this setting can indeed lead to speed-ups, depending on

the final render pixel size
the complexity of the scene
the tracing engine used
the GPU you're running the render on
how many pixels are irrelevant (because they don't sample anything, as there are no objects hit by the rays)
likely many more factors

The most important one is the final render pixel size. If you render super high res, having a smaller number of tiles to be computed in total can speed up the rendering. At a resolution of 1280 x 720, you won't see much of a difference. At 8.000 x 6.000 you very likely will. When rendering on our TitanX rigs, we tend to go to 512 x 512, sometimes 1.024 x 1.024 tiles with such resolutions to cut render time. Less complex scenes also tend to support bigger tiles better, but again, no general rule here.
The GPU merely matters in terms of what generation it is (Fermi, Maxwell, Pascal, etc), the number of cores, and the amount of memory present. Maxwell GPUs can to my knowledge benefit from bigger tiles, with the others I have no personal experience.
The tracing engine I only mention because of a "feature" in Windows: TDR Delay. If you Google that, you'll find heated discussions plus a Microsoft support page on how to set it. Basically, when you render, a work package is sent to your GPU (the tile), and the system waits for the results to come back from the GPU (the resulting sampled image at a certain number of samples). If Windows does not hear back from the GPU after 2 seconds (the TDR delay), it restarts the graphics driver - and kills the rendering while at it. Especially when using Branched Path Tracing, the answer time for the GPU increases by A LOT. That causes renders to fail. Reducing the tile size is one fix to this, setting a higher TDR delay value another.
Auto Tile size
An Add-on called "Auto Tile Size" is bundled with Blender, which makes setting the tile size more convenient. When enabling it, you'll however notice that it actually doesn't set the render tile size to 256 x 256. Istead, it tries to choose values which are close to this, but round them up or down, so that the image is split up into tiles of all equal size. See this example:

The Render Dimensions are set to 1280 x 720 pixels, the tile size is set to 256 x 240. Why? Because that gives the GPU 5 x 3 = 15 tiles of equal size to process. If you keep the tile size at 256 x 256, the last row of tiles will have a height of 208 pixels, as 720 cannot be divided evenly by 256. This is potentially, but not necessarily, inefficient.

Nice answer. I have encountered that TDR Delay problem while using Branched Path Tracing myself, had look up how to increase it, otherwise I was unable render. Also worth mentioning that the larger the tile size the longer the response time, so if you plan on using the computer for something else while rendering, larger tile sizes will make it "slower".

Nice answer and very informative, thank you.  However, none of it addresses my question (though you began hinting at generational differences).  Why is it that my video card (or other cards) performs better rendering 65536 pixel tiles than any other value?  What about the physical card and hardware determines that?  In other words why is that number more efficient than any other?  Is it the memory interface?

@DuarteFarrajotaRamos True, if you are rendering on the main GPU (which also displays the viewport), you'll experience lags. If you have dedicated GPUs for rendering and don't use the main card at all, the interface remains butter smooth  :)  And I guess many imagers have run through the TDR hell with us, that's one 'feature' I loathe about Windows...

@bertmoog I'm not sure if the question can be answered that precisely. If I'm not mistaken, even the core Blender devs have found out about 256 as the best starting point simply by trial and error.

Yep, my bling guess is that GPU architecture+graphics driver code+Operating System+All other software and external factors from a  complex and intricate enough combination to make it non trivial to point out exactly what makes one combination better than other.

@aliasguru +1 That's really interesting.  Maybe it has more to do with the Cycles engine than with the hardware.  FWIW, I bought a 128-bit 1050TI and the magic 256 still holds true for it as well.


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How to model a light source using a spectral distribution curve for the color
My previous attempt was unclear so I'm rephrasing the question:
I'm making a promo video for a certain type of lighting and at one point, I'd like to show the difference in the spectral power distribution (see graph below) of the light output for each type of bulb.  In other words, I want to use the SPD to color the light emitted by the bulb into the room based on wavelength and output power.
I have the SPD, I just need to use it somehow to color the emission source.  This is all I can think of but it's not exactly mathematical and I'm not sure it really captures a realistic representation and I don't know if it just basically averages the colors together:

It produces this light:

But I would rather have the emitted light follow a curve similar to this if at all possible:

Thanks for your help.

You may want to consider using an engine such as LuxRender or Maxwell which will directly support SPDs via a text file or the like.

That's very interesting, I've never used anything but Cycles, I'll look into it.

Have you looked at the wavelength and blackbody nodes?

I have used the Blackbody node but I didn't even know about the wavelength node... checking it out...

Hmmm... would be neat to have an input to the wavelength node to determine the Q of the color selection but I'm not sure how to do it.

To accomplish this you would require a wavelength to XYZ conversion, and then from XYZ to sRGB / REC.709 primaries conversion.
Make sure that you obtain linearized RGB values from your wavelengths. If you are using normalized wavelengths, display linear (0.0 to 1.0) would suffice.

1.) When you say XYZ to sRGB conversion, do you just mean to ensure the display color space is in sRGB (i.e. there's no sRGB conversion node unless you mean combine RGB)?
2.) How will using the XYZ channels help to plot a curve over the spectrum with certain high Q peaks?

Also, according to this: https://blender.stackexchange.com/questions/31375/is-separate-rgb-identical-to-separate-xyz  .... the RGB and XYZ nodes are identical except for nomenclature.

Uh... Not spatial XYZ. CIE 1931 XYZ. You won't be able to use Blender to achieve this.

Ah, I see.  Blender can't do this even for a simulation?

If you were careful and know the precise values to set up in nodes as well as the intended meaning and how to use the results, I suppose a very driven person could do it. It would be hell however. :)

Ok, I appreciate the info


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First Person/Fly mode camera is moving by itself
I tried searching but didn't find this problem.
I've been having problems with the Shift+F mode as of a few hours ago. Never had the problem before and I haven't installed anything new, so I'm convinced it's a key I pressed that might have messed something up.
When I enter first person/fly mode, sometimes, it doesn't respond to my mouse inputs and I have to right click out of it. Most other times, whenever I move the mouse to look around, the camera will continue to move to the right after I have stopped moving my mouse. I know there isn't any mouse input going on because when I exit out of fly mode, the mouse cursor stays perfectly still.
I exited out of all of my softwares that deal with mouse inputs (logitech software and stuff), I restarted blender, etc.
The weird part is, when I open a new file, I still have the problem, but it's harder to duplicate the issue.
Also, there's nothing showing up at the little console thingy at the top.
I have no idea what I might have done to cause this.


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Blender keeps crashing when I open a file
Never had a problem.... until now, it opens fine, but it instantly crashes when I open a file, any file. It works while I work in the New/Start Up file, but it also crashes when I save that and try to Open it...
It started crashing after I (a few minutes ago) deleted all files from the C:\Users\MyName\AppData\Local\Temp folder... where it stores some of the .blend files... (I guess for a backup)... not sure if it stores any system/app files there also....
Any idea how may I solve this and or check what is causing the problem....
Thanks guys

I did reinstall Blender, btw.... into the same folder... will try to install somewhere else.... Oh and when I hit Recover Last session it says it can not find quit.blend file from that Temp folder....

Hell yeah. Removed Blender and installed it into a new folder. Works fine. Phewwwww.

Although this post is a few years old, this .blend file crash issue is still quite common. Here are some solutions that usually work:
Simple but effective approach:

Delete user preferences (File > Defaults > Load Factory Settings)
Restart Blender
Try to open your file with Load UI disabled in the open options

If your file still crashes when opening directly:

Create a new Blender scene
Go to File > Append
Navigate to your problematic file and import the objects/collections you need

If the above methods don't work, have a look at this article with more advanced solutions, including how to recover corrupted files: 3 Ways to Prevent a Blender File from Crashing on Opening


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Does Blender downgrade textures?
Kinda focusing on what is not working here, but hey, I noticed that Blender kind of downgrades my textures/paint-work ... it gets a bit pixelly after I switch to Object mode and then back to texture paint mode..
Maybe its just my impression, but it does seem to me as if the textures get kind of bland and pixelly after a while....
I am using 2048x2048 px res right now, too small?
Am I alone in this? May I prevent this somehow?
Would be really nice if my textures stayed nice and smooth the way I paint them....

Check your UV map to make sure there isn't a small area of pixels being mapped to a large surface area of the mesh. This could cause the sort of pixelation you describe, as the pixels would be stretched out and enlarged.

Blender doesn't change the textures in any way by itself and this applies to all possible actions.
The texture size does not necessarily define its quality, it depends on the source (image texture, procedural material, tiling, up/donwscaling...) but normally I'd say that everything from 1k upwards is fine.
You might want to check Blender's System Settings. Hit Ctrl+Alt+U, go to "System" and play around with the settings for "Mipmap" and "Anisotropic Filtering". Deactivating them seems to help in many cases.


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Can you save UV images automatically? (Along with when you save a file)?
So a lot of times I lost all my texture paint work, sometimes I forgot to save it, sometimes it mysteriously turns to a previous 'save'. Either way, it would be much easier if the textures would save automatically along with a 'overall' file saving... its kinda hard to keep track when you have multiple materials...
Maybe there's an addon?

There is a script - http://blender.stackexchange.com/questions/13407/auto-save-images-along-with-blend. See also http://blender.stackexchange.com/questions/14050/uv-map-model-turned-black-on-saving-how-to-recover

Ah thanks man. So you just copy the text, save the file as .py and just Install as an addon?

Yes as it's already covered everything there. See http://blender.stackexchange.com/questions/1688/installing-an-addon. Also basics of creating addon - https://www.blender.org/api/blender_python_api_2_71_release/info_tutorial_addon.html.

authors: Максим Муранский


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How to avoid having pixelly textures?
So the process of creation of this mesh was as follows:

Quads (Edit Mode) > (applied) Subsurf mod
Sculpt mode > Dyntopo for details
Decimate mod

Not sure if this was supposed to look this way, it is not as bad, when rendered though.
Even though the mesh does not look as bad, I am aware that my workflow is not as 'correct' as it  should be I guess...
Wait, it IS pretty bad when rendered ... the bumb map really emphasized the pixeliness here...
Maybe for the future... how may I avoid such results (in having such pixelated textures), should I follow a different process/workflow? Or is it somehow System/Settings related? I tried tuning a bit with the Mipmaps and Anisotropic settings, not much changed...
This is probably a more broader question, but hey, I would appreciate any pointers or tips...
Thank you for your time

enter image description here

It is hard to understand what you are asking. What is the bottom left image? Add the image descriptions where it suggests to. Where is this "pixelinnes"? Do you mean at the dark brown patch on the right of the top image?

Yeah, sorry about the descriptions, the editing in here is a bit confusing. On the top image, I painted the surface a bit (on the right side) (with yellow and brown colors). You can clearly see pixeliness... The Bottom left image is my mesh that I am trying to paint on.... I added a blue texture (bottom right) so you can see the 'pixeliness'....


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Node editor - I do not have Diffuse BSDF node available. Why?
Being really new to rendering things, I have little knowledge no how things work in Blender (texturing/rendering wise).
Watching Firechild's tutorial on how to create a golden ring.... he does have Diffuse BSDF and Image Texture nodes available.... which I do not... (there is only 'Image' node)
Downloaded some model from Blendswap and these nodes are there....
My question is what exactly affects the selection of nodes available to a particular scene? Does it has anything to do with the materials/settings used?
Thanks for your reply!
Cheers

If you're using Cycles, I can't see any reason that these nodes shouldn't be available. If you press Shift+A, what options are you given?

Maybe you are in the wrong node tree type: http://blender.stackexchange.com/questions/53336/particular-nodes-are-missing-from-node-editor/53338#53338. Can you add a screenshot of your node editor and scene?


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UV mapping for exporting blender textures to unity
I am using UV mapping for exporting textures to unity. Firstly i map the object with smart uv mapping and then bake it. After that I save the image as png;  add it into material as texture of object in unity.
With that process should I save and export blender file again after mapping objects or can i just use texture files directly? How unity understand UV maps if I just add textures as png files? I am assuming composite nodes are not exported with that method. Are there any method for exporting composite nodes?
And are there any easier method?

The image texture files (.png etc.) don't contain any mapping information on their own. I suppose it might be possible to bake the mapping to an image if both programs make some assumptions about the space such a mapping is represented in, but I've never heard of things being done that way. Depending on exactly how you are importing/exporting, you might be better off adding the texture to the object in blender, then exporting object, texture, and UV map from blender all at once.

You have to export your model again once you UV mapped it, because unity will not be able to get the UV data as your model don't have them.


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Is there a way to get perfectly smooth normals on a cylinder that is tapered like a cone?
I have a cylinder with 24 faces that I tapered so it is shaped like a cone, but the normals get sharp looking, as you can see here:

The normals appear to be facing in the propper direction:

I've tried "Shade smooth", I've tried adjusting the "auto smooth" and I've tried with and without end-cap faces, and I've tried with and without adding extra edge loops towards the top and bottom, and I've tried with and without extra subdivisions along the length of it.
The faces are planar quads, so I'm unsure why they appear this way. Is there a way to fix this? It even shows up like this in Unity too.

I can make it appear smooth by having lots of vertical subdivision to the point that the faces are more square than rectangular, but that's just "solving" the problem by creating another problem of having way too much geo.

Are you willing to consider shader-based solutions?

@Nathan, well, the thing is I am using this geo in Unity and specifically when I'm making my own shader for it it causes issues. My shader looks perfectly smooth until I do anything involving the normals.

That makes it sound like something else is your issue.  I'd want to know what you're doing with normals.  Specular?  Or something different?  In any case, you can make a perfect normal map for a cone using shader nodes-- but yeah, the geo leaves something to be desired, and although you can minimize the issue, I know of no way to get base normals on a cone perfect.  Note that the simplest way to solve, good normals without too much geo, is to just bake high-to-low normals.

I'm simply adding a fresnel effect (dot product of normal direction and view direction). Even simply visualizing the normals (plugging normals straight into Albedo or Emission) reveals the terrible normals. What do you mean by "bake high-to-low normals?"

"What do you mean by "bake high-to-low normals?" Google "blender how to bake normal map for unity".

Ah, I know what you are talking about now. That doesn't solve the problem, as the vertex normals are the issue. I shouldn't have to use a normal map.

You can use that to get high poly normals onto the low poly, so that you have the benefits of high poly cone (good normals) and the benefits of low poly cone (few vertices.)  Vertex normals are not the issue-- they are identical between high and low poly.  Interpolation along the faces is what is bad.  Vertex normals will not solve the problem on a low poly.

The issue is due to "long inner" triangles.
To lower this effect, add some loop cuts:

His comment under the question sounds as if this is not what he wants. But I would do it like that as well because that's basically the only way.

@GordonBrinkmann, Ben talk about a lot of vertical subdiv... I don't think four loop cuts is "a lot"... but we'll see!

No, it isn't... but your cone is wider at the bottom. The narrower it is, the worse the shading gets ;)


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Is there a way to rotate and pan view while in knife tool and other tools that lock the view ports?
It seems there are many tools, such as the knife tool, that cause the viewports to lock up when you are "in" the tool. By "lock up" I mean that while in the tool I cannot rotate, pan, or zoom the view. This would be super handy and seems like a no-brainer. Thanks for your help!
-Ben

What is the problem to rotate / grab the view while in the Knife tool by pressing MMB / Shift + MMB ? You can also zoom as usual, by scrolling the wheel.

That's what I mean. I expect I SHOULD be able to do that, but I can't. I say the view locks up and the normal mouse navigation you are describing does not work as long as the tool is active.

I'm not sure where the problem is, as it works for me pretty well (versions 2.74 and 2.75 )

Wait, silly me... I've been using not a regular mouse but a 3D mouse (3Dconnexion) and got so used to it that I forgot I was doing it. I just tested with regular mouse and it IS working as I would expect. So I guess the issue is that this 3D mouse stops manipulating the view while the tool is active. I guess there's not likely a solution for that as it is a third-party issue.

I figured out my problem. I am using a 3Dconnexion 3D mouse and it does not manipulate my view while a tool is active. The normal mouse/keyboard ways of rotating etc do still work as expected while a tool is active.

I would submit that as a bug, you shouldn't have to switch to a normal mouse. 3dmouse support is programmed into blender so I expect the issue is there.

Actually I am facing the same problem. However in my case it's related to the modelling settings I am using (industrial standard, with alt + left mouse button for tumbling). It's not possible to tumble while using the knife tool. I sincerly hope  this issue will be fixed in Blender 3.0 ;-)

This does not really answer the question. If you have a different question, you can ask it by clicking Ask Question. To get notified when this question gets new answers, you can follow this question. Once you have enough reputation, you can also add a bounty to draw more attention to this question. - From Review


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Can a shape key be negative?
It seems shape keys can't manually be set to a negative number or a number larger than 1. I've even tried using a driver to drive the value of the shape key beyond either of these extremes with no luck.
What I am trying to accomplish is a single shape key of an object bending forward, with the hopes that a -1 value of the shape key will bend it backwards as well, so that I can drive it with a sin function so that the bend oscillates back and forth without having to animate and synchronize two separate shape keys.
Is there a way to push a shape key into the negative? (And as a secondary question, can it be pushed past 1?

You can set the Min and Max Values in the Range fields:

Wow, that was right in front of me, huh? Thanks!

Glade to help you ;)


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Why does "sin(frame)" where frame is "1" set a shape key to 0.841 and not 0.017?
I am trying to animate a shape key oscillating between -1 and 1 by driving it with the expression "sin(frame)".
I would expect that to result in the shape key value being "0" at frame 0 and 180, a value of "1" at frame 90, and a value of "-1" at frame 270.
Instead, I am getting a very rapid oscillation which never becomes negative, and has bizarre values that I wouldn't expect. The sin of 1° is 0.017, so I would think the sin of 1 frame is 0.017, but instead it is resulting in 0.841.
Here's a screenshot of this simple setup at frame 0:

And at frame 1:

Thank you for your help!
-Ben

Use this expression: sin(radians(frame))
The sin function expects angles in radians apparently

that seems to be it, however it seems shape keys can't be negative. Do you want to post that as the answer so I can accept it?

Just did, cheers. You're right about shapekey min and max values.

The sin function expects angles in radians, rather than in degrees,
which is why the correct driver expression will be:
sin(radians(frame))

Here's an example of this expression driving the Z value of a cube (you can see that it does indeed get negative values as well, and oscillates between -1 to 1):

Though as you pointed out, shapekeys have a min value of 0 and a max value of 1.


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Change material of object between multiple scenes
I have a car model I am rendering. I have several render layers I am compositing. It is simple enough to render and output the animation, but I also need to render the same animation from two different cameras. Furthermore, I need to also render from the same two cameras but with the car being a different color.
It was easy enough to create a new scene that is linked to the other so I can have a scene for CameraA and a scene for CameraB, both with the car being the same color: Blue...
I am going to use a Python script to render all of the scenes instead of me having to hit render for each one, but I cannot figure out a good way to create the scenes for the other color of the car. If I link the scene, changing the color changes it for all scenes. If I make a full copy of the scene, I could have the color be independent, but then I have multiple copies of cameras and everything.
I wonder if there is a way to make a material color change depending on which scene is active or being rendered. Any ideas?
(I am using Cycles, if that matters.)
EDIT:
Here's a basic setup to see what I am wanting to do. If there was some sort of switch or script that would select the Blue node if rendering Scene1, the Red node in Scene2, and the Grey node for Scene3.


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How to use the Freehand Curve drawing add-on?
Enabled/Installed the add-on, can not get it to work though...
There's the Options tab in the T-Tools panel, but there is no Draw Curve button in the Create tab.... Shift+LMB does not work as well...
Any idea why this might be?
Thanks
Peter

Took me some tries to figure it out myself:

Add a Bezier curve to your scene
Tab into Edit Mode (with said curve selected)
Shift+LMB draw your freehand curve
Delete the Bezier curve from step 1

Oh, its RMB for me. Cheers :D

Though, for some reason, I also do not have the tolerance feature/setting, and the ability to switch btween Cursor and Surface and also pressure radius........ :((


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Why does Mirror modifier sometimes go to the wrong side?
This might be a very trivial issue, but even with origin being at the right spot, the mirror mirrors at 'random' angle.. like here:

What does contribute to this behaviour? Is there an easy fix for this?
Thank you all

The object probably has a rotation, so its x axis is not aligned to the world x.

ok is there a way to reset this?

Alt + R in object mode.

oh cool, thank you very much! it worked.


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How do I weight paint belts and straps?
I have been attempting to weight paint the straps on this particular model for quite some time but have been unsuccessful in getting it to move naturally with the armature. I have approached the problem with the following techniques but have not found one that works well yet.

Automatic weighting
Transfer weight (Transfer mesh data)
Weight Gradient
Painting by hand

The straps tend to clip through the model when the hips are rotated and do not stay with the buckle.
Below is a few pictures of the model.

Any advice on how to go about painting this or link to a tutorial would be appreciated.

Are the belts and the cute lil kitty one object? If not, you can always select the cute cat, shift select the belts, and ctrl j to join. Then weight paint it as normal.

What is this rig and character used for? I assume its not for a game because of the polycount? If you render the animation in Blender you  could include a shrinkwrap modifier below armature in the belt that would correct the clipping. Or try to simulate the belt with physics but perhaps that would be little backwards.

The cat is for a game, I'm trying to make it for the unreal engine but am having difficulty finding things out such as acceptable polygon count, what modifiers work ect.

I had similar problem for shoulders straps. Three points here in my experience :

Weight the buckle the same weights (uniformally)
Weight the extremities of the straps the same as the buckle
Space the next straps vertices at the first point of the cat shape they need to be "linked" to

Something like that https://gyazo.com/87bf0a45e2723b477d715645ae540be6
The idea is to keep the buckle linked to somekind of tangent point of the cat belly. And for the strap, to allow them to stretch between the buckle and the next "on skin" vertices.
Another way to obtain the result (maybe) is to shape all straps starting from the cat curves (using the knife tool probably : copy the cat and cut) so that you both keep the appropriate weights (from the cat) and also give all the good bending edges inside of the model. That can probably be easily done for the straps... but more difficult for the buckle.


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Why can I see through a face when another is close?
When I have two faces that are close together I can see through face in front depending on the several factors.
The camera's zoom impacts this a lot. The farther zoomed out I am the worse this is.
Perspective/Orthographic impacts this. Orthographic reducing the problem but not fixing it.
The angle I view this from impacts it. Head on being the worst and 90 degrees being the best.
How can I minimize this issue?
Example:
Zoomed out

Zoomed in

EDIT: This appears in both edit mode and object mode but is much more prevalent in edit mode.

Is this not also related to a subsurf modifier introducing surface intersections?


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How would you go about this guy's fur?
I'm sculpting this dragon and, so far am pretty happy with how it's turning out. However, I am not sure how I should go about modeling his fur. The target platform is the unreal engine 4 but for now I am just trying to get a nice model before retopology.

I think your best bet would be to create a group of mesh hair objects, and then use a particle system in Blender to place and arrange them as needed.
Then before importing into Unreal Engine, you'll have to apply the particle modifier and convert the hairs into mesh objects.

Particle system looks promising. How would I go about UV mapping and texturing the hair's once they have been converted to a mesh? Since Unreal does not play that well with blender, I need to make the materials after it's exported where I wouldn't have particle data.

Well, you should be able to UV unwrap the source hair mesh object. If you wanted to texture across a group of particle hairs, you'd probably have to apply the modifier and then group them into a single mesh object, which isn't ideal.

Alright so I ended up doing the following:

Create a particle system for the hair.
Using particle edit, cut and comb the hair.
Convert the particle to a mesh using the convert button in the modifiers menu.
Convert that mesh to a curve.
Bevel the curve with a simple shape (I used a triangle)
Convert that curve back to a mesh.
Unwrap the hairs using smart UV project. This lays all the hairs out side by side.
Create texture for hairs.

I don't know if this is going to work with retopology but for now it looks OK though i'm a little sad I don't have that much control over the color.

If you have a UV map on the hair, you can make the hair texture desaturated and make it any color you want by using a color overlay, or you can use the UV with a gradient texture to control procedural colors. I'm not sure but I believe that you can convert a gradient on a UV to weight and use a weight map to color your hairs as well. You have many options when it comes to color control over your object.


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Problem importing the blender model into unity
I followed a tutorial in youtube into creating the rig and animations of a humanoid model. I successfully finished the tutorial but when I import it in unity, and make the rig humanoid I get this error.
Causing the whole rig to malfunction. I don't understand because the bones are complete. Tried renaming the foot bones but it does not fix the problem.
Here's the blend file: model

In Blender you need to rename the bone AND any weight groups you have already assigned when parenting to the armature. The armature bone name needs to match the weight group created for the mesh, otherwise the foot won't be moving with the bone in Blender or in Unity.
Additionally in Unity you can go to Rig-tab and click the button configure the avatar where you can manually assign the left foot to the bone that your model has. But I assume if you fix the weight group naming first (which is mandatory for the rig to work) Unity should be able to correctly automatically detect the foot afterwards.
Finally after you have configured the avatar you can proceed to importing the animations.


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Slow Motion Water Physics Settings
so does anyone know some settings to get slow motion fluid in Blender?
Starting from a basic scene and tweaking settings to get slow motion fluid. Any answers are helpful and thank you for your time!

Render it out as a 60fps animation and slow it to 30fps in post

Select your domain object, go to the physics->Fluid tab, and change the speed value to something lower than 1, for example to 0.5 if you want the simulation to have half the normal speed.


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Fluid interacting with objects
What is the correct setting for fluid interacting with objects in the scene. What needs change in the obstacle panel in the fluid simulator. My settings right now are the object has the obstacle fluid settings applied to it and in the panel I have the VOLUME INITIALIZATION set to BOTH with a PARTIAL SLIP and NO IMPACT FACTOR. Is this correct?

More information and some pictures would be nice...

You can have a quick "basic" fluid simulation in this way:

open a default file (cube),
select the cube
press SPACE, type "quick",
the list will show some "quick" setups
choose "quick fluid".

You'll get a ready-to-go basic fluid simulation with a "fluid cube" ready to splash into a bigger cubic domain (select wireframe mode to see inside the domain)

now, add another simple object below the "fluid cube", like a sphere. Be sure that all the sphere lies inside the cubic domain, though.

add "fluid" to the sphere through its physics property tab, and set the "type" to "obstacle".

now select the domain, and bake the simulation

once finished backing, playback the animation, the "fluid cube" will splash onto the sphere, interacting with it and then will go to the bottom of the domain

(moved the camera to see the fluid covering the sphere, from bottom view)

Then you can change this example to fit your needs.


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Scaling an object up and down in an animation?
i'm trying to make a very easy animation rotating an object (pretty much a plane) while making it grow and shrink. i know there must be an easy way to do it as i've done something similar before but my brain's done a fart and can't seem to get it right.
at the moment when i try to scale the object down in a keyframe it scales to that size permanently, affecting the size in all other keyframes. does anyone have any helpful tips and tricks? thanks in advance!

If you have moved and rotated your object and only created Location and Rotation keyframes, without creating any Scale keyframe, the animation will take into account the first Scale keyframe it meets and the scale of the object won't change until it meets the next Scale keyframe. If you want to make sure that the scale is taken into account at frame X you should keyframe with LocRotScale (or LocScale or RotScale).

Thanks so much!!!


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Transforming Blender Render Textures to Cycles Textures
I am having some really tough trouble translating my blender materials to my cycles rig. Normally I manage to work it out by looking at YouTube videos, but I am moderately new to Blender. I want to transform my project to Cycles because I was getting to much noise in the render, is there a good way to eliminate noise in a Blender Render?
In the Blender Render project I assigned a texture to the material now when I do this in Cycles, the rig texture comes out really fuzzy. I have disabled mipmaps in user preferences and the texture has a FELINE filter, but it still comes out blurry.
Please help if you can.
Thanks.

To correct the blender internal material, is one thing, convert that material to cycles, is another. Try not to mix different questions. If you can share your render result, and/or your file (best using http://blend-exchange.giantcowfilms.com/, as it's permanent), someone will take a look and suggest corrective actions, or suggestions to convert it to cycles material.

I'm not sure what you mean by eliminating noise in Blender Render if you are moving to cycles, but if you are looking to remove noise in cycles, there is already several answers in Blender StackExchange FAQ: Frequently Asked Questions on Blender Stack Exchange
BlenderGuru made also a great article about the topic: https://www.blenderguru.com/articles/7-ways-get-rid-fireflies/
For the second question, by looking at your texture I assume you want pixelated look. Answer is very simple, you can turn back your mips and get rid of the filter. All you need to do is set Sampling, the second field under the image name field currently have set as Linear to Closest.

Thank you for your help, like I said I can't really word it properly because i'm pretty much a beginner. I will try and resolve the problems.

I had this same problem when I tried to do the same thing: my textures came out fuzzy.  To fix this, simply change the interpolation of your texture from "linear" to "closest" in the material settings .