text:
How to batch convert between file formats?
I have about thousands of files I need to convert into from one format to another. Both formats are handled by existing add-ons..
I assume the script process would go something like this:

Select every source file in a directory and it's sub-directories
Store the path and filename of the source format.
Delete everything in scene and import the file
Export the file to the destination format with the same path and the same filename as the original file, with a different extension.
move on to the next item

The problem is that I have very little experience with Blender, and Python is not my area. The manual solution of importing and exporting works perfectly fine, as there is no need for anything to be modified.

what are using to import .meshdata ?

Was wondering if you could point me in the direction regarding batch exporting
since you found good success in the endeavor. I am looking to importing a
whole bunch of FBX file then save them individually into blender format. I have looked over the stuff posted here but did not really understand how it
all fit together. Is there a add-on plugin that you wrote yourself or packages
you could share so that I can edit them to the fix the files I needed to convert
Thanks for your time.

https://gist.github.com/HsiaTsing/31361ea018637aa1781c#file-ply2obj-py (This code uses the Blender Python API to batch convert 3D model file with ''ply'' format to ''obj'' format. It is only tested on Blender 2.64.) Also works on Blender 3.1.0. Easy to change I/O formates.

Set the path variable and change the import line to whatever importer you are using :
import bpy
import os

path = 'C:/path/to/files/'  # set this path

for root, dirs, files in os.walk(path):
    for f in files:
        if f.endswith('.meshdata') :
            mesh_file = os.path.join(path, f)
            obj_file = os.path.splitext(mesh_file)[0] + ".obj"

            bpy.ops.object.select_all(action='SELECT')
            bpy.ops.object.delete()

            bpy.ops.import_scene.obj(filepath=mesh_file) # change this line

            bpy.ops.object.select_all(action='SELECT')

            bpy.ops.export_scene.obj(filepath=obj_file)

Although I have one issue. I can't seem to find the correct importer function. Here's the init.py: http://pastebin.com/G980EA2h
and here's the meshdata_import.py: http://pastebin.com/bKkWiVMD
Here's a meshdata file: http://dump.no/files/78e43d0cb895/MeshP_NAM_Bridge_01_part01_Mesh_lod0_data.meshdata
the error occurs on this line: bpy.ops.object.mode_set(mode='OBJECT')
With the error: RuntimeError: Operator bpy.ops.object.mode_set.poll() failed, context is incorrect.
Disabling everything bellow the import line causes no errors, but also no imported files. Could you have a look?

Okay, it now successfully imports all the objects, but it's still getting the "RuntimeError: Operator bpy.ops.object.mode_set.poll() failed, context is incorrect" error. caused by "bpy.ops.object.mode_set(mode='OBJECT')"

@MatsBakken ( sorry I was away ) can you just comment this line and try again (it's not that crucial )

Wow, I didn't actually think of that. It works now! Thank you! Although it only does the specified directory and not it's sub directories. I guess I should read up on python.

@Mats see if this helps

That looks exactly like the code I just wrote. Thank you for all your help! It's greatly appreciated! The script works perfectly now!

this works, but when you import a lot of meshes, blender will crash after a while because it runs out of memory. This mainly happens because textures, materials and the like are not dereferenced when you delete the object.
To fix this issue I used the answer by Amir found here: https://blender.stackexchange.com/questions/48836/purge-unused-data-e-g-particle-system-or-groups-by-script
Basically you need to call bpy.data.materials.remove(block), bpy.data.textures.remove(block) and so on, in every iteration of the for-loop
EDIT: old thread, but answer is still valid. I'm on Blender 3.6.2

This script is an example of how you can loop over all files and convert from one format to another.
This example converts all .obj files to .x3d, but changing the formats is trivial.
CONVERT_DIR = "/my/test/directory"

import os

def file_iter(path, ext):
    for dirpath, dirnames, filenames in os.walk(path):
        for filename in filenames:
            ext = os.path.splitext(filename)[1]
            if ext.lower().endswith(ext):
                yield os.path.join(dirpath, filename)

import bpy

def reset_blend():
    bpy.ops.wm.read_factory_settings(use_empty=True)

def convert_recursive(base_path):
    for filepath_src in file_iter(base_path, ".obj"):
        filepath_dst = os.path.splitext(filepath_src)[0] + ".x3d"

        print("Converting %r -> %r" % (filepath_src, filepath_dst))

        reset_blend()

        bpy.ops.import_scene.obj(filepath=filepath_src)
        bpy.ops.export_scene.x3d(filepath=filepath_dst)

if __name__ == "__main__":
    convert_recursive(CONVERT_DIR)

I'm getting this error when I use this script:
TypeError: Converting py args to operator properties: : keyword "use_empty" unrecognized


text:
How to retrieve the thumbnail from a .blend file?
I would like to retrieve .blend file thumbnails without using Blender at all, just plain old python3.
Also if it would be possible to explain how the .blend file works and how the process of retrieving the thumbnail works?

Yes, this is possible and infact has been done already,the script to do this comes bundled with Blender: see blender-thumbnailer.py.
This Python script runs without Blender, eg extracting a PNG image from my.blend:
blender-thumbnailer.py /input/my.blend /output/thumb.png

Details
To extract the thumbnail from a .blend file you have to use a basic .blend file parser, however - this is written in such a way that its quite simple to extract the data without having to understand the entire blend file format, instead - you only need to read one of the serialized BHead blocks. (See link above).
Using blender-thumbnailer.py as a reference: writing this in another programming language, or saving as a different image format should not be a very big task.

source: Stack Exchange

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

sort: votes


text:
How to achieve dramatic composition with low poly models?
I started learning Blender a short time ago, and i want to achieve something like this:

But the only thing I can achieve is this:

I really don't like my result. How could I improve my skill, and get the desired result? Do you have any recommandations/tips or good places where to start learning(especially low poly)?

it seems nice! just not identical... and the upper image is also better lighted, and probably post processed...

For starting with Blender I recommend this http://gryllus.net/Blender/3D.html website, as for low poly modeling i suggest learning sculpting, topology and re-topology, basically you sculpt a model using as many polygons as you need, and then using it as a reference, model it again piece by piece to get a good-looking high-quality and low poly model

Not a full answer, but a few tips and notes you might find useful. Try using triangles instead of quads, when you can. The decimate modifier is a very useful tool you should look into using. Model the face in greater detail, since that is one of the places that the eyes get drawn.

Related - https://blender.stackexchange.com/questions/733/how-do-i-make-a-model-resemble-one-with-low-poly-count. Also some useful tips - https://blender.stackexchange.com/questions/6628/which-is-the-best-way-to-model-a-low-poly-coat?rq=1

Thank you a lot for your answers! @Gwenn, I just tried using triangles instead of quads, and it actually gives me the effect I like. Thanks for your tip. Here's a fresh sketch that i just did: click

would you mind posting the results after changing to triangles?? I'm really interested

The following is help from a design perspective, more than a tutorial on how to achieve this all within blender, so an edit to do these things is more than welcome.
You've made some good headway and his chest and legs are looking great/similar to the reference. The feedback I'm going to provide is more thorough than it is a reflection of the quality of your work, so hang in there :)
Most important difference is the color scheme. Colors are VERY important. You can create a cool color scheme for free using Adobe's online color scheme app. (just google 'adobe kuler') the closer it resembles life, the less abrasive it will feel to the viewer.
There's a 3 point lighting set up on the original artwork. The back light (rim light) helps to subtly highlight the edge in the silhouette. The colour scheme for the original has a golden hour feel to it. Golden hour is a film term for the time of the day with the most beautiful warm colors appear to saturate the day. If you type in Golden hour into the 'explore' portion of kuler you'll find hundreds of variations.
On the other hand, your lighting setup looks a little too much like a desk lit table top in comparison, and the effect is a little mundane of a situation... I feel like you can do a lot better than that!
The next problem you'll need to tackle to get close to the quality of the original is the silhouette previously mentioned. Take the original into a image editor and trace a line around the form of the character and his accessories. See how even the silhouette ALONE says everything about the character, and in an interesting way?
Silhouette is paramount to a good character design, because a good character must be easily recognized and our easiest way to identify an object is through the silhouette.

See how easily you can identify an character with silhouette alone? It matters big time. So take a careful look at your character and see how you can push him so that he has a more interesting/unique silhouette, and somehow it'll appear cooler :). The rule of thumb for pushing, is choose the most interesting aspects of the character and make them read more.
Another point about silhouettes is that they can make or break a character depending on the intent. For instance, your character looks quite round and therefore cuddly, if you are going for a mean badass viking, you might want to try something a little more angular and foreboding.
The last big thing to address is that you seem to have a few too many continuous strips/groups of flat planes of geometry in your character. At the moment he looks a little lifeless. Adding extra dimension here and there will breath some character and life into your creation, like there is in the original. To do this, find pictures of strong men on google from different angles and pay close attention to the angles of their faces and muscles. Try not to go overboard, because too much detail = straying from that simplistic style. Just think of each triangle as though it's a brush stroke in a minimalist painting.
And on a minor note, the original artist has applied a film grain and vignette. The grain breaks up the subject a tad to make it seem less perfect, the vignette softens the corners and draws attention into the subject.
But you've made a fantastic start my friend, the quality is above average.

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


text:
How to access the bundled Python executable for subprocess in Blender scripts?
There is now a python executable in the blender install folder, It's clearly said that it was included for subprocesses purposes (here : https://developer.blender.org/T43486)
But how can we access it through scripts ?

The path to access this is bpy.app.binary_path_python
The exact details on how you should run the process are up to you, and not Blender spesific.
Best try the subprocess module, but os.system will work too.
Heres a very simple example calling a Python sub-process.
import bpy
import subprocess
import time

command = (
    bpy.app.binary_path_python,
    "-c", "import time; time.sleep(2)",
    )
proc = subprocess.Popen(command)

while proc.poll() is None:
    print("Waiting...")
    time.sleep(0.1)

print("Finished with exit code %d" % proc.returncode)

For an example of how to run Python as a subprocess without locking up Blender, see this Q & A.


text:
How to render an image with edits based on custom input, from the command-line?
I would like to write a webservice, which renders images using blender using the passed pose of the camera.
This means I need to start blender within python, pass the scene, place the camera and render an image to a file.
Does anyone have a hint where to start looking first?

So your webservice will have blender on the server, correct? Then an external party will connect to the web service, and pass the scene and camera, and then your web service will render the image and return it? I'm assuming you don't just want the client to pass a blend file?

Actually, the client (javascript, not actually human user) passes the camera position and orientation (quaternion). Then the webservice is expected to deliver the image of the scene from that pose (ori+pos).

So you have a presetup blend file on the server, and the only external input is the camera info?

How does the client generate the camera info? In a local blend file with the same scene, or is it arbitrary?

... it doesnt matter, or does it? What I want to do is something like this in pseudocode:
scene=Bleder.new
scene.loadFile(myFileName)
scene.setCameraPose(position, quaternion)
scene.render(outputfile_path)

I suppose it doesn't matter, I was just wondering how you were generating the camera data on the client end.

Ok, so I'll attempt to answer this one. Some of it will be pseudocode, and some will be actual code.
The basic pipeline would be:

Javascript submission of camera data in the form of text variables to your web service. The syntax of this data will be up to you since you're building the web service api yourself.
Once the request has been made and received by the web service, your back end code will need to generate a Shell script command to call an instance of your blender application on the server.

Syntax would something like:
blender -b scene.blend -P pythonscript.py -o //outputpath -F PNG -x 1 -a -- camVar1 camVar2 camVar3

where

scene.blend is your scene file on the server
pythonscript.py is your launch script that will process your input
variables
everything following the "--" are raw input variables and the camVar values are written into the command from the backend code

Your pythonscript.py file will start like this:
import sys

# these variables are read backwards from the end of the shell command
camVar1 = sys.argv[-3]
camVar2 = sys.argv[-2]
camVar3 = sys.argv[-1]

See also: How to pass command line arguments to a Blender Python script?
Then in the same python script you can set the camera properties from the input variables, and render out the image to the output folder.
The web service backend would have to be monitoring the output path for the rendered image to be written, and then serve it back to the initial web request. It may not be fast enough for an immediate web response, so you may have to serve the image via a image link notification.

Let me know if this is enough detail to get you going.

Note that it may be simpler to pass in json data (as an argument, or the path to a json file for eg).


text:
Adding a driver to a Cycles node via Python
I'm trying to add a driver to a Cycles Value node using Python. So far my code is:
node = material.node_tree.nodes.new("ShaderNodeValue")
node.driver_add("default_value")

However, this just gives me a 'property "default_value" not found' error. I've also tried:
node.driver_add("value")
node.driver_add("outputs", 0)
node.driver_add("outputs[0].default_value")
node.driver_add("nodes['Value'].outputs[0].default_value")

None of these work either. So my question is: how do I exactly add a driver to a Cycles Value node? It can be done via the UI right-click menu, but I can't find a data path that driver_add() will accept.

You need to add the driver on the output, not the node directly:
fcurve = node.outputs[0].driver_new("default_value")

or
fcurve = node.outputs['Value'].driver_new("default_value")

The driver expression is accessed like:
fcurve.driver.expression

Thanks! Still finding my around Blender's API so I appreciate the guidance.

I would suggest doing it with the GUI first and then examine the data structure.
I.e. added a driver to the Composite Node

The path is relative to node_tree.
So try to add the driver to node_tree with the given data path
import bpy

#right click on the socket value of the node -> Copy Data Path
path = 'nodes["Composite"].inputs[1].default_value'

scene = bpy.context.scene
scene.use_nodes = True
driver = scene.node_tree.driver_add(path)


text:
How can I make a camera walk animation?
I want to get my camera to have a walk animation. How can I do it?
It doesn't have to be complicated; I just want to make it like it's walking.

Make it go from point A to B with some keyframes:

In the Graph Editor, select the Z location track only (press ShiftH to display this track only), and in the N panel, open the Modifier panel, add a Noise modifier, play with the Scale and Strength values (you can enable Restrict Frame Range option if you want the modifier to begin and/or stop at a certain frame):

Result:

If you want someting more regular, keyframe a movement on Z location and make it cyclic with a Cycles modifier instead (or press ShiftE to automatically create the modifier):

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


text:
Can Blender be used to send to a factory to create silicone products (mass production)?
I got started on a project early January.  The job was to model silicon baby products using reference images he sent and make them look like they were professionally taken in a studio.
I completed the job successfully, but now he wants to use the models I made and have them manufactured and turned into real silicon products and have them mass produced.  He asked if I thought my models would meet the technical specifications to use them produced at a factory.
He wasn't sure if Blender was something like CAD software and I'm not sure either, but I have read that you can create the products in Blender to have them 3D printed, but I'm not too sure this is the same thing.
How is this done? Is Blender enough, do I need some plug-in that will help meet all the specifications, or is this something more suited for CAD software?  He's talking about mass production, so I don't want to mess this up! If more specialized CAD software is needed, is it easy to pick up for a Blender user, and is there an easy one to start of with?

Do you know the specifications that your model has to meet? If not, this can't be answered! Obviously CAD software is designed for this purpose, but as long as you can make a valid model using any software, the factory doesn't care what software you used to create it.

Well, I use Blender to manufacture parts as described in this thread here: https://blender.stackexchange.com/questions/212949/boolean-operations-in-sverchok/212983?noredirect=1#comment359972_212983. These are exported as stl files and printed through a process called laser sintering in a PA12 material. So this works just fine for me.

Wow, everyone had a lot of good answers here!  I will have to think of which one is the best answer.  I can't thank you guys enough!  @joojaa  I feel, may have brought up a good point.  From what I gather this will need to be mass production ready. But these products are very simple.  I will refer this information back to my client to discuss our future plans.

The one important thing to check that nobody has mentioned so far is the absolute dimensions - a visual model is great if all of the dimensions in the view are correctly proportioned but if your dummy is 5 units long by 3 wide it is important to know is that 5 cm, 5 inches, 5 m, 5 km, 5 mm, etc. This is the one area where CAD tool tend to score over blender. You can also use companies like Shapeways, (who will accept blender files) to make single test items at a reasonable cost. they will even 3D print in wax so that you could use lost wax moulding.

AFAIK, CAD software and blender are not that different, especially for 3D printing. The main difference would be operation, and maybe some tools to make sure the object could be made with a mold. Just do some checks:

Make sure the geometry is watertight, commonly referred to as being manifold. You don’t want any holes!
Double check that all the normals are pointing the right way.
Make sure the mesh is high poly enough that the resulting product won’t look polygonal like a low-res video game object.

If you have already printed a few things with this model and they are totally fine, I’d say you’re good to go. :-)

Just a side note for the third point, it may be helpful to use flat shading instead of smooth shading to ensure you’re viewing the object as it will appear when produced (since, of course, you can’t use fake normals on a real object).

Your first sentence is not really correct. There is a huge difference between how geometry is represented for graphics and manufacturing. In Blender a model is a collection of vertices/edges/faces. In CAD a model is a parametric body, i.e. a series of features (extrude, cut, revolve, sweep, etc.). While you can ensure a model in Blender is manifold and thus can be used to represent a solid, it is still a collection of flat faces so truly curved surfaces are not possible. All manufacturers I have worked with (including for 3D printing) want STEP or parasolid files which are of the latter type.

OK well, my bad. But Blender does export to STL, right?

Blender does export to STL.  But STL is a mesh format, not a parametric solid.  This hugely depends on how OP intends to manufacture the parts and what volumes are meant by "mass production", but I don't know of any manufacturers which would take a mesh as reference.

I guess I don’t really either, but 3-D systems used to accept STL files before they went down. And no, they didn’t go down because of what format they accepted. Really, honest.

Zargul is correct about what is needed for the model. There is more to it than just making sure a model is manifold. A molded product must meet certain restrictions of not having deep recesses that may keep the product from releasing from the mold. Save out an STL file and send it to the mold manufacturer. They will be able to tell you if your model meets specs and will probably have suggestions for fixes or even someone on staff who can fix it up for you. There will likely be a good bit of going back and forth with the manufacturer to get the design in shape for manufacturing, so make sure you charge for multiple iterations or make it clear to your customer that iterations will cost more.

There are two kinds of 3D file formats in common usage:
Mesh formats: The model consists of flat triangles or polygons. This is the native format of Blender, and can be exported as .STL which is widely supported.
Surface formats: The model consists of curved NURBS surfaces. This is the format preferred by CAD applications, as it gives better precision and surface quality. Blender has some modeling tools for NURBS surfaces described here. It does not support direct export to .STEP or .IGES, which are the preferred formats in CAD world. It can export surfaces to .OBJ, which should be possible to convert to .STEP without loss of accuracy, perhaps with FreeCAD.
In mass production they take your 3D model and design a mold based on it. Whoever does this would definitely prefer to receive a surface-based model. But almost all CAD packages have a way to convert mesh formats to surface formats with a small loss of accuracy. Most critically, the accuracy of all round holes is lost: a 20.00 mm hole might become a 19.99 mm hole. The accuracy of conversion depends on the size of the triangles in the mesh.
If your object is more of artistic quality than having precise 0.01 mm dimensions, you should be fine providing .STL export from Blender. You may want to specify that it is ok if the conversions result in some dimensional inaccuracy, as long as the general shape is preserved and smooth. Ask also to verify the model after conversion, and make sure that there are no remaining triangles or they are small enough - otherwise it could show up in final product.

In addition you can activate the "3d-print toolbox" in the plugin section to get some information about your model.
As it is not clear what type of model and what specification for production would be needed its difficult to give proper feedback.
Blender is not CAD software which uses primarely nurbs, as those have perfect surface information and thus is well suited for production.
But as described in the other answers, enough density and clean, manifold geometry will certainly work.

For 3D printing meshes are fine. But 3d printing is not exactly mass production ready.**
However, if you need your object made with a CNC machine like say you need aluminum or steel injection molds made then the CAM operator is not going to be happy with a mesh. Why because its really problematic for the path planning to have a angular surface*. So be prepared to pay for your own work again in the engineering department and time to market as they will be calling you on the phone a lot.
While the CAD can sometimes approximate surfaces out of a mesh this isn't entirely ideal for the mass production team for several reasons. When I have had to do this we have been charging the same as if we would have designed the piece to begin with. But it depends on the company.
The thing is you don't want to have to redo a 50,000 tooling cost because of a auto conversion error. Though you can probably live with a lot less than that for vacuum/rotary casting of silicone.
* the fact that it looks right in rendering is irrelevant its all well to approximate a surface for rendering with something that has no bearing on physical truth. But for the CNC it is physical truth or no dice.
** Well, you can make a casting master in a resin printer then spend time post processing it to become a master and mold it in platinum silicone which can then be used as molds for processing. But this all depends on do you need a 100, a thousand, ten thousand or hundred thousand units.

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


text:
How can I dig a hold between two object?
I have two models. Is there a way to make an Edge in one model by using another model's shape?

if you "just" want to make an edge you could use the knife tool. If you want to cut the geometry you can use boolean modifier

You can join the two objects (Ctrl + J), go in Edit mode, select one of the two meshes and go into the header menu → Face → Intersect (Knife):

It will create an edge along the intersection of the two meshes. Result:


text:
Understanding the bump node
I see a lot of tutorials that explain how to use a bump node by demonstrating its use and giving a hand-waving explanation regarding what it actually does. Things like it "perturbs the normal".
OK, but how? I'd like to know, so I can understand how to control it more precisely.
The current problem I'm facing is that I'm trying to make a tile floor, and need to normal to follow the curve around the edge of the tile. The center face of the tile is a straight-up Z normal, but then edges have a curve to them before the tile disappears into the mortar.
But if I use the "Factor" output from the "Brick Texture" as the "Height" input to the bump node, I would expect that the normal is straight up Z where the tile/brick face is, and is simple scaled to zero where the mortar is.  Instead, if I view the output of the bump node, I see that the edges of the tile have X and Y components to them.  How is the direction of the vector being changed?
And what does the "distance" input do?
Yes, I've read the documentation.  The explanations are similarly imprecise and hand-wavy.  That's fine for a surface level understanding, but I'm hoping to gain more precise control so I'd like a deeper understanding.

blender manual

@Emir:  I stated in my post that I've already read that.  It still doesn't make sense to me.

the bump node is a converter that takes b/w data, like procedural texture outputs, and converts them into a normal map

see also: https://blender.stackexchange.com/questions/21035/how-can-a-normal-map-affect-the-look-of-a-model

That link offers a very basic and practical explanation of how normal maps work (and fail to work) with low poly meshes, which the OP above almost certainly already knows. I too would like a deeper explanation of how normals work, such as how they alter light calculations, or why normal maps have so many funny colors in them, instead of just black and white like so many other kinds of maps. One question I have is: how exactly do vertex normals relate to face normals? Is a face normal orientation somehow the mathematical combination of each of its vertex normal orientations?

@R-800 .. actually,  at least as far as I understand, vertex-normals are calculated from the surrounding face-normals, (perhaps weighted) and then, in a sort of feedback, used to interpolate smoothed normals over the triangles they define.. I think this would make a good question in its own right.

Okay.  Let's say we're rendering a bump map fed by an image texture in Eevee.  I'll give a general run-down, but I may simplify some details.  You'd be best off just reading a bump map implementation in some shader code (OGL or HLSL).  That will tell you exactly what's happening, and it's a lot more accessible than you might think.
The bump node samples the image texture three times.  First, at the UV of the sample being evaluated; then, a slight offset in the U axis; then, a slight offset in the V axis.  The size of this offset depends on your zoom, texture resolution, and FoV; as you get closer, the offset gets smaller.  (I think it actually samples at a screenspace offset of +1 pixel, and then calculates based off of that, but understanding it in terms of UV is probably more intuitive and amounts to the same thing.)
Each time we sample the image, we get a number.  For each of our numbers, we subtract the bump node's midlevel, multiply by the bump's scale, and then multiply by our object's scale.
Then we calculate how big those UV offsets were in terms of world space-- we calculate the change in world space, divided by the change in UV.  In Eevee, that's pretty easy, because our video cards are designed to work on four samples simultaneously, because calculating these deltas is really important for texture filtering, which is really really important.
Now we know, in two orthogonal axes, how much our height changes over a given world space distance, which lets us calculate a slope.  For example, if our height changes 0.5 units in the direction of increasing U over 0.5 world space units, then we have a slope of 45 degrees.  If it changes 0.25 units over the same world space, we have a slope of 30 degrees.  (This is some basic trigonometry.)  We take our base normal and rotate it, in the axis of changing V, by the slope we get by looking at the change in height in U, and we rotate it, in the axis of changing U, by the slope we get by looking at the change in height in V.  Now we have a normal that's different than the one originally calculated from our mesh.
If you're okay with calculus, the tl;dr of all this is, we calculate the derivative of our height map and use that as our normal.
How we use this normal depends on the shader.  Each shader does something different with a normal; a normal is a fundamental part of almost every shader, and their differences have a lot to do with what they do with their normals.  So I won't go through all of them.  But we can consider a diffuse BSDF with a 0.0 roughness, which is called a Lambertian diffuse.  If we shine a light on this surface, what color do we get?  It depends on the angle of the light, relative to the angle of the normal.  The color we get is equal to the dot product of the surface normal and the reversed light vector (in whatever space, just so long as they're in the same space) times the color of the light, times the color of the surface, times the falloff fraction.  The output color (before color management) is the sum of the contributions from each light.

This is exactly what I was looking for,  thank you!

This answer is a very late supplement-to-a-good-supplement-to-a-good-answer, but I'll chuck it in anyway, just in case it gives a different angle.
The Bump node approximates tangent-space normals from a given height map. In other words, given a set of heights (yellow,below) it approximates the normal vectors to the slopes (blue). In tangent space, Z is the normal of the underlying geometry, (perhaps interpolated by smoothing)  and X and Y are the U and V of the map. The XYZ of the approximated normals are encoded as RGB.

I don't know Blender's implementation ( Can someone help here? Is it buried in library functions?) But  X and Y components of the approximation can be derived by convolving the height-image with X and Y Sobel filters. In convoulution, a matrix of values is passed over the image, and each central sample's value becomes the sum of the contributions from itself, and the matrix-shaped grid of surrounding samples, as weighted by the values in the matrix.

I would expect that the normal is straight up Z where the tile/brick face is, and is simple scaled to zero where the mortar is.

The length of the normal vector to the slope is always set to 1. The output of Bump node does not represent heights, or scalar values. It represents directions. All blue would represent the original normals in Tangent space, in which the underlying normal-direction is defined as (0,0,1). The colors are the new, modified, directions of the slope-normals, in that space.
The 'Strength' setting of the Bump node, by inspection, is a mix between the approximated normals and (0,0,1). So, as it's reduced, it makes all slopes shallower; they deviate less from the original normal of the surface. The 'Distance' setting scales the height provided by the height-map. As a consequence, it will also make the slopes shallower or steeper.. the distinction is subtle.. but the 'Strength' setting, as far as I can see, chucks some information away.
You can get curved tile profiles from a black-and-white setting of the Brick texture, using a parallel one to put in the colors:

With this sort of result:

.. but I found the color-ramp settings quite hard to find, and a bump-map is an approximation.. there are likely to be artefacts. Better to bake normals from a real model? Or make a procedural tree with the express purpose of making tiles with rounded profiles?

To complement @Nathan's very nice answer with practical examples:

The Brick Texture FAC output includes mortar smoothness (as a gradient).
As you probably know, Bump node interprets gradients as a slope.

The Bump Distance value controls the height of the Bump, so you can match real geometry.
It's in meters, so you may need to scale it down to get a useful result.
[Top view] Metallic cones 0,5 meters high matched by a Bump map set to 0,5 meters

Thank you.  Understanding and controlling the distance input was the solution to my practical problem - @Nathan's answer was key to understanding the rest.  Thank you both!


text:
Grid floor disappears and cannot see outline of selected objects
What did I do? I somehow changed my view setting and I can no longer select anything with RMB. Please see screenshot:

You have ticked an option that displays only objects that will be rendered. Open the Properties panel with N and untick Only Render under Display. You can actually select objects (the 3d manipulator widget is still being shown) and move them as normal, you just cannot see the visible outline.

Did I hit a key command for that? Don't want to repeat.

@kjfagan No, there is no shortcut, you were probably poking around.

HUGE. Thank you so much. Yeah, probably hit it on accident.

@kjfagan feel free to accept the answer if it solve your problem. This will help future users.

@iKlsR, actually I think there is a shorcut (can't remember if I bind it myself, or if it's default): ALT + SHIFT + Z

@Polosson It's not in the keymaps and that doesn't work on my end. You probably binded it.

The original question was asked in 2014, 7 years ago. Now we are on blender 2.91. The down arrow next to Overlays icon in upper right corner of 3d viewport   produces this window . If grid is checked and floor is unchecked, what you see depends on the frontal vs top views and the orthographic vs perspective views.
Front ortho view grid
Front perpective no grid
Top perspctive no grid
Top ortho         grid
If grid is unchecked and floor is unchecked
Front ortho no grid
Front perspective no grid
Top persective no grid
Top ortho no grid
If grid is unchecked and floor is checked
Front ortho no grid
Front perspective no grid
Top perspective grid
Top ortho no grid
If grid is checked and floor is checked
Front ortho  grid
Front perspective no grid
Top perspective grid
Top ortho no grid
I hope that is clear and I hope it helps future blender users

In my case I was viewing the 'Layout' view instead of the 'Modeling'

Came here because my grid floor plane had disappeared as well.  Realized it was because the 3D viewport shading was set to "Render".  Changing it back to Solid fixed it.  Shift+Z

In my instance, on Blender 2.80, I had to select "Grid" within the viewport overlays dropdown

And "Viewport Overlays" can be found from 3rd dropdown menu in top right corner of the viewport (icon looks like outline of circle overlapped with filled circle). As far as I can see, it cannot be accessed via normal menus nor context menus anywhere.

I had the same issue just now. Make sure your clipping distance is set up to 0.001m-10000m.
I know this is a little late, but hopefully it'll help anyone else looking around.

Clipping distance of 0.001m-10000m will probably cause viewport rendering artifacts / z-fighting (if changed in viewport) due to too high range of values set for showing the geometry with that precision which isn't necessarily supported by some GPUs. Also viewport grid usually doesn't require too precise clipping values since it's just optional displaying tool for convenience

With the Z Euler axes, you need to have the viewport render to options. This enables locks on the rotation and location, making the grids visible. If that doesn't work, make sure the Archimesh is set, and not the other way around. The face orientation won't matter unless your motion tracking is off. The X & Y axes have a certain way of moving, different from that of the Z, so facing the front will give it a slightly altered look. If still your grid is not visible, set the origins of each mesh (not light or other object) to center. This will most likely transform your grid, and then you can parent it to some object in your viewport. Display is also important. Go to the render zone when the rest of the steps are done, delete all keyframes. This done, your textures won't take up as much of the GPU, making space for your grid. The grid is actually the last thing your system will try and keep with everything else to take into account, and therefore it tends to disappear. Under options, selected should be location, because the grid is your location. If all else fails, close blender, restart your laptop, download the latest version of your PC

Also, in my case I was in the wrong Workspace tab, Shading. Switching back to Layout got the grid back.


text:
Parts of mesh appear dark in 3d view and in render
I have an issue with a part of my model. It looks weird in object mode as well as in a render. Please look at the attached screencaps.

I checked and all the geometry in and around this problem have all 4 verticies and 4 edges, making one face. this entire section was rebuilt after I forgot to extrude something. The odd thing is that just these two faces look weird but not the surrounding ones that I stitched together in the same manner.
I looked in ortho views and they are all aligned so it isn't that some verts may be offset.

In edit mode select your mesh and do Ctrl N

thanks that fixed it. Why?

Killerpixler: the normals for the dark faces were flipped. CTRL+N in Edit mode recalculates the normals so they're all going the same way. You can read more about them at the bottom of this page: http://wiki.blender.org/index.php/Doc:2.6/Manual/Modeling/Meshes/Editing/Faces


text:
How to use the golden spiral composition rule
We've all heard of this magical thing called the golden spiral, which derives from the golden ratio; However, I feel like there's a general confusion around how to use it in the composition of an image.

This image includes both the golden spiral and the golden triangles.
The golden spiral is a logarithmic spiral where the growth factor is φ (phi); Where is the positive root of:

Which is, by defenition:

This pattern is present all throughout nature, since the ratio of two consecutive numbers in the Fibonacci sequence tends towards φ.
So, how does one apply this rule to the composition of an image?

http://digital-photography-school.com/divine-composition-with-fibonaccis-ratio-the-rule-of-thirds-on-steroids/ Has some nice illustrations.

This question appears to be off-topic because it is not about blender.

Andrew price actually just came out with a new composition video that discusses the golden spiral along with many other composition topics.

@PGmath I know, but he does a bad job at explaining it.

From what I gather, you want to put the main focal element at the limit of the spiral, and some guiding lines along the spiral itself and along BD and CE.

@PGmath the focal element at the *center* of the spiral.

Yes, the center being the intersection of BD and CE.  To explain it mathematically would require too much math for a comment, sorry!  You sound like you know quite a bit about the math anyhow (a little calc I) correct?

I've written a meta post to discuss whether these should be on or off topic.


text:
How to refresh loaded textures
I am working on a scene, and using CrazyBump to export Displacement and Normal maps; I want to tweak the textures, but currently I need to restart Blender before they update.
Is it possible to refresh them, without restarting Blender?

With the texture displayed in the UV/image editor, press AltR or Header > Image > Reload image:

There is also a refresh button on the source selector for any image datablock. In the node editor, the full datablock settings are in the Properties region. To reveal this region, place your mouse over the node editor view and press N:


text:
Beginner question: Increasing poly density for a single side of a cube
I am new to 3d-modeling, so please bear that in mind and if you find some fundamental flaw in my explanation below, do not hesitate to tell me.
The mesh I want is a cuboid with a lot more faces on one of its sides compared to the others. I inserted a cube, scaled it and applied  transformations, subdivided it once and added a few edge loops to help subdivision. The resulting mesh then looked like this:

(Up until this point everything worked as I expected)
In order to get more polys on one of the sides I selected its four inner faces and subdivided them, the result was that adjacent faces "degenerated" into n-gons, which I want to avoid (because the target application does not like them). This is the resulting mesh, where I selected the resulting ngons using select->facesBySide:

This of course makes sense, because these adjascent faces now have more than 4 vertices, but I am not really sure how to proceed from here. I currently see only two solutions to this problem:
1) Either subdivide the whole mesh evenly (which is actually not a solution at all, because the resulting mesh will have the same poly-density on all sides)
2) Connect all the new vertices of the adjascent faces (the ngons) to a "corner vertex" by creating new edges for each, which results in a set of many ugly stretched out triangles.
Both solutions seem undesirable to me. So how would a more experienced poly-modeler approach this?
Thanks in advance!
ps. I realize that this is a beginner's questions which probably has been answered a million times. Unfortunately I did not find anything, but if you know a post or a tutorial explaining these things, it would be great if you could post the link.

We still need to know why you want to do that to find a solution.

is it necessary that it stays one object?

@Bithur I want to do that because I wanted to make a virtual "canvas" for use in zBrush: The idea was to paint on one side of it using zBrush's brush engine. Since I pretty much need one poly per pixel for painting in zbrush I didnt want to waste too many polys on the backside of the "canvas" and subdividing the mesh evenly would cut my available "pixel count" to half (more or less)

@gladis: no, technically it is not necessary that it stays one object, but it would be nice if it would :)
I think other zBrush users just paint on a subdivded plane, but I kind of liked the 3dimensional "feel" of a canvas with thickness. (Also I try to force myself to make some basic meshes in Blender every now and then to learn some proper 3d modeling :) )

However, isn't it pretty common that people want to use higher detail on one side of the mesh and lower detail on the backside? How do people generally do that? I think I missed a very basic lesson in 3d-modeling here :)

When you subdivide a face of a mesh, you also subdivide all of the faces which share edges with the face you subdivided. But while a mesh is part of one and only one object, an object may contain more than one mesh. This is the key to the solution to your problem.
One way to do this is to take your original cube, in edit mode, and delete only the face (X > "Only faces") in which you want to increase the vertex density. Then select two opposite edges which helped define the face you deleted, and duplicate them using the duplicate tool (SHFT - D). Use the F key to create a face between the duplicated edges. You now have an object with two mesh sub-objects, a plane, and the other five faces of the cube. For convenience, you can assign these two sets of vertices to different vertex groups, so that the sub meshes can be more easily selected individually, but even so they are part of the same object. Now when you subdivide the new face, you will have no impact on the five faces of the other sub object, and as long as you don't move the four pairs of vertices defining the overall edges of the new face, or that outlined the old face, individually, the two meshes will maintain their relative position.
Another way to accomplish the same thing is to select the face in the original cube that you wanted to subdivide (in edit mode), and instead of deleting it, press the P key selecting the option "selection". You have now made the face you want to subdivide a separate object. Selecting this new separate object, and then the cube (in either order), and pressing the key combination CTRL - J combines the new face with the other five faces of the original cube as a single object, but leaves them as independent sub-object meshes.
In both cases, you can subdivide the individual face as many times as you want, without affecting the other sub-object, but all six faces in the two mesh sub objects are part of the same object, and when the object is manipulated, the six faces are manipulated in the same manner.

Thank you very much for your reply. This was very helpful! Weirdly, I would never have thought of separating the object into different meshes, I need more practice I guess. This totally makes sense of course, so thanks very much for the tip :) Is this common pratice when working with complex meshes? I guess one might get problems if it is necessary to animate the object, but for static meshes this seems to be a very nice clean solution.

This works very well for me, I just have to be careful when I subdivide the separated object in zBrush in order to avoid holes at the transition between the two meshes; masking out the backside of the canvas and only subdividing the front plane works well though and it looks  lot "cleaner" than my previous approach using triangle fans
Thanks very much again, this was very helpful!

@n-i-c-l-a-s, complex items are often constructed of multiple objects. Consider a child's tricycle, and assume it is to be animated to the wheels turn, and the handle bar and front wheel turns, as well.. Starting from the back, the rear wheels will be one object, the frame and seat a second, the handle bars and front wheel assembly a third, and the front wheel and pedals a fourth. Now, in the case of the frame, the seat and the frame may be part off the same object, but for convenience, they may constructed of separate mesh sub-objects.

Keeping the sub-meshes in proper orientation to one anther is made simpler by using the parenting facilities built into Blender.

I am glad you asked that question. I see many meshes from beginners with triangles or Ngons (polygons with more than 4 vertices) when it's not necessary. In most cases it's easy to change mesh density using only quads--once you know how.  The image below shows some examples to get you started.  Good luck.

You can't subdivide a plane without turning the adjacent faces into ngons or triangle fans. If you want the mesh fully connected you must create a transition between the two resolutions.
Within the one object you can have several disjoint meshes with highly varying amounts of geometry (granularity of tessellation). You can detach the plane from the surrounding geometry by selecting and and pressing Y and then subdivide it (that way the surrounding geometry isn't modified because it isn't attached in a topological sense)

I've scaled down the subdivided plane in the last example to show that it is detached from the surrounding geometry. It depends heavily on your use-case which of these options is most suitable.

Thanks very much for your reply! This helped a lot! In particular the part "You can't subdivide a plane without turning the adjacent faces into ngons or triangle fans. If you want the mesh fully connected you must create a transition between the two resolutions" cleared up a lot of confusion for me. As I wrote above, I couldn't think of a solution other than using ngons or triangle fans and it is very helpful to know that there is none :) (except for separating the object into mutiple meshes)

I think in my case, the triangle fans wouldnt be too much of a problem, but I thought this was bad practice, because people seem to be very fond of "all-quad"-geometry.When I tried this first the triangle fans kind of screwed me, because I didnt think about it sufficiently and stupidly had all the triangle fans on the front of my "canvas" (instead of the sides) which led to some very ugly artifacts later on(after sculpting and painting),  which were not visible in zBrush, but became very apparent when I rendered the lowpoly mesh with a normal map in other applications. Thanks very much again!


text:
Chained Transformation Matrices not producing predicted result
I have a problem for a few days and I can't solve it =[[
I have a composite object of 4 parts and I'm trying to do the translation and rotation operations on it.
Each part of the object has a rotation and translation matrix (so I have 4 different rotations and translations).
The steps are:

Calculates the transpose of the rotation matrix;
Place all the objects in the origin (0,0,0);
Define "Origin to Geometry" for all objects;
Conversion of the transposed rotation matrix to Euler Angles;
Modify the position and rotation of objects with their translations and rotations;

Here is a part of my code:
for i in range (1, 5):
    print ("done " + str(i))
    bpy.context.scene.objects.active = bpy.data.objects["obj"+str(i)]
    obj = bpy.context.scene.objects.active

    with open('info/info_' + a + '_00' + str(i-1) + '.txt', newline='') as inputfile:

        results = list(csv.reader(inputfile))

        r1 = results[4]
        r2 = results[5]
        r3 = results[6]
        t = results[8]

        r1 = [num.strip().split(" ") for num in r1]
        r2 = [num.strip().split(" ") for num in r2]
        r3 = [num.strip().split(" ") for num in r3]
        t = [num.strip().split(" ") for num in t]

        #with transposed matrix
        a11 = float(r1[0][0])
        a12 = float(r2[0][0])
        a13 = float(r3[0][0])
        a21 = float(r1[0][1])
        a22 = float(r2[0][2])
        a23 = float(r3[0][3])
        a31 = float(r1[0][4])
        a32 = float(r2[0][5])
        a33 = float(r3[0][6])
        t1 = float(t[0][0]) # value of x
        t2 = float(t[0][7]) # value of y
        t3 = float(t[0][8]) # value of z

        #http://nghiaho.com/?page_id=846
        rot_x = atan2(a32,a33) # result in rad
        rot_y = atan2(-a31,sqrt(pow(a32,2)+pow(a33,2)))
        rot_z = atan2(a21,a11) # to degrees -> degrees(rot_z)

        bpy.data.objects["obj" + str(i)].location = [0, 0, 0]
        bpy.data.objects["obj" + str(i)].rotation_euler = [0, 0, 0]
        bpy.data.objects["obj" + str(i)].rotation_euler = [-rot_x, rot_z, -rot_y]
        bpy.data.objects["obj" + str(i)].location = [t1, -t3, t2]

PS: I change the sequence of rotation angles because blenders coordinate system is different
The result is is below. The strange is that the object are disconnected, which can not happen. Does anyone have any suggestions?

I also have attached the camera image that I have and that I wish

I know that the difference is small but it can not continue my work with this.
information about the matrix
Blender file
Original file
Thanks a lot!

Does anyone know another method to perform the rotation / translation of an object in blender?

are object center, scale as the originals, are you sure the calculation is precise and should output the desired result

Yes I'm sure. I've already performed the operation with another software and the result is equal to the "expected"

here is a page about using matrix for transformation but i think you will get the same result, they seems to be shifted ti the right a little that's why i think the origin is off the center

you just find the transform matrix and assign it to obj.matrix_world , BTW are there any parenting relations between this objects (their transformation will be relative to the parent )

I do not know if I understand your question correctly, but there is a relation between the objects. With the given matrices they should be connected.

in blender one object can be child of the other (it moves in the space of the parent not the world space) and how did it go with the matrix ?

I got the matrix by another method, then I realize the calculation to find the Euler angles.
I have no idea if they are children of each other. I got the objects exploding an entire object and by setting the Origin to Geometry, that's it.

so did you try the matrix way ? (sorry i couldn't understand )

Sorry, I hadn't seen your answer. I will try to use Matrix.Rotation and Matrix.Translation when I get home and then I'll analyze the results.

after trying if the problem still persist ,please upload a working example file

Let us continue this discussion in chat.


text:
How can I subdivide this object so my particles emit more evenly from faces?
I'm trying to emit particles from this face, with the particles spread evenly/randomly across it... however, because the faces are spread across it horizontally, the particles are not covering it how I would like.  They're mostly clumping up where there are higher concentrations of vertices.
I'm guessing the solution would be to subdivide it in a way that there are more vertical cuts, resulting in more square faces, or more vertices spread evenly throughout the surface.
But when I try and simply subdivide I only end up with more horizontal faces.  And the knife tool is way too tedious to achieve the level of detail I need.
How can I pull this off?
Project file

I don't imagine you need to edit your mesh for this. Just ticking the Even Distribution option of your Particle System under the Emission > Source panel should do. The old particle system is pretty finicky so you might need to enable and disable it a few times, undo/redo, or reset the timeline to see it, but it does work:

At the end there, I'm selecting everything, then X (Delete menu) > Limited Dissolve to get rid of most edges without affecting the outline. That can also be a help in situations like these if you don't want to bother with remeshing.

Oh man I'm glad you mentioned forcing the particle system to update because I was banging my head against the wall wondering why Even Distribution wasn't working.  Per your answer I just cycled the number of particles and viola! everything magically jumped into place.  Thank you!

To start, I disabled the particles from preview so you can see the mesh better. Use a Decimate Modifier set to Planar to remove all the "junky" topology. Apply the modifier:

Then select the whole mesh and extrude (E) it "upwards" on the Z-Axis. This is necessary for the next step to work:

Add a Remesh Modifier set to "Sharp" with octree depth of 8 or so.

Select one face on the "top" of the mesh then pick Select > Select Similar > Normal from the menu at top:

Then pick Select > Invert from the top to select all the faces not on the "top" of the mesh.

Delete those faces:

Move the mesh back "down" on the Z-Axis (if necessary):

Unhide the particles:

I just noticed, however, that the particles go a bit wonky after this.  You will probably need to re-do your particle system (delete and re-add the modifier ) , and possibly apply rotation and scale to your object as well.

Hey man thank you for this. @Kuboa's solution actually solved my problem without needing to do this, but I'm super glad I asked and grateful for this explanation. This is literally a technique I knew nothing about, and it will come in handy a lot in the future (and in the past had I only known!).  Cheers

@GlenCandle Yeah - I thought you wanted  the mesh subdivided in addition to the particles "just working" - at least you can use the example if/when you need to clean up dirty topology in the future (I'm guessing that mesh came from an SVG - they always need cleaning).

Ha, yeah, SVG.  I had to clean up the control points, but I never knew a good way to clean up all the faces after converting to mesh.  And I always wondered what the Remesh Modifier was good for. Now I know! Thanks again.


text:
How can I make a Voronoi fracture in Blender?
How can I make something like in the picture in Blender?
I would also like to apply different textures on each cell.

The Voronoi texture node can be set to output 'Position', (The position of the feature-point of the cell, in the space the texture is given,) and 'Color', (a random color per cell). These numbers let you make switches, in a similar way to this answer.
First, the Kintsugi cracks, as described by @Chris:

The 'Scale' input gives a general size of the fragments
The 'Thickness' input gives the thickness of the cracks
The fiddling about with division-by-thickness, etc. gives a 0-1 range of distacnce inside the crack-mask, so it can be put through a color-ramp to give the profile of the gold-bump.
The straight Black/White mask is sent off to be the factor between the gold, and background material.

The Texture Coordinate and Scale are branched off to keep a second, parallel Voronoi node in sync. with the above, distance-to-edge one...

The second Voronoi node generates the same pattern, but with different information. (Distance from feature-point, Position of feature-point, and random Color per cell.)
Here, we've tapped out the Red channel of the random color, which gives us a random number between 0 and 1 per cell. The 'Multiply Add' makes a crude sort of seed, to change the random options; keep the Multiply much larger than the number of choices. The result is a randomish number between 0 and 10 per cell.
The number can be used as a switch by cascading Mixes, between shaders, or colors, or anything else...

Above are a couple of entries. If the random number is less than 3, the output is the result of the mix so far. Otherwise, the new color. Then the mix is handed on down the chain. In this example, the switch is between image textures. The overall result is a random-image-per-cell.
The whole tree looks like this:

This is the sort of result:

A simplified version, mixing 5 colors..

This is Amazing! Thank you very much for posting this! Is there any way to add a different displacements on each cell also?

See...I told ya...he is the procedural master of all classes!!!

Hi, @NivSad! Thank you!. I'm going to edit to include a .blend to share. So, while I'm at it, do you want a random amount of displacement, or random pattern of displacement?

@Chris I'm no master.. here are just some examples out of many... check out Erindale and Simon Thommes out there.. and on this site, Rich Sedman. Also important not to get carried away, and remember what you want, in the end, is a picture. Not a bunch of nodes :D. So, Ian Hubert.

Hi @Robin Betts, core idea was to have like a leather on one cell, one to be rock, one plastic... So I am just curious to know, is there any way to make different displacements for each cell individually?
Thank you for taking time to solve it, I really appreciate!

@Niv You can mix anything using your random-number-per-cell, so, you could use Mix Shader nodes in place of Mix RGB nodes, in exactly the same way, to mix entirely different shaders, instead of images. However, this will make for a large and unwieldy shader-tree. Unless you have to automate this, because, say, you have to make dozens of balls, I'm not sure your own  geometric Fracture method wouldn't be more manageable?

@Robin Betts I think I understand you now.
Anyway, It would be really nice if blender would make just a checkbox while doing a cell fracture to keep the margin. It would be much shorter way then yours and mine. Hope it will come some day :D
Thank you for your help!

check this out:

of course you could also use bump to have a bit more "3d" look like in your pic

Thank you for sending it but I would like then to apply different textures on each cell (eg: one to be metal, one to be letter...) i am not sure if this can be done over nodes. I guess I should use something like cell fracture but then I don’t have this border around... Do you maybe have some other way?

damn...i should read better :( ...but Robin Betts can help...and do this with shader nodes, i am sure :D

No worries, I done a cell fracture and then separate outlines and added a solidify modifier to outlines. It’s similar effect and a bit longer method so If someone find a better solution to this, I would really appreciate :)


text:
How can I transform an object into a sphere?
On YouTube I only found some solutions using geometry nodes. Therefore I would have to build the object I want to transform with geometry nodes as well.
But the object I want to transform is a highpoly model of a brick which I purchased on Blender Market. Is there maybe a modifier or some other way to round the corners, make it inflate or some other effect to turn the brick into a perfect sphere?

There are probably several ways to do it but you can try the Cast modifier:

You can also select all in Edit mode and press AltShiftS (To Sphere). You can save the shapes as Shapekeys:


text:
Easily navigate around a rotated object
I find it kind of cumbersome to edit an object that has been rotated. I know I can set the navigation to „local“ to make things easier, but then I still cannot use numpad 1, 3, 7, etc. to easily jump between the views. Is there a way to use these shortcuts on a rotated object or is there an alternative?

In the default keymap it’s Shift + Numpad.
To align a view to an object’s local axis without Shift, tick the 'Align Active' option in Preferences → Keymap → 3D View → View Axis

huh. had no idea this existed, thanks :)

oops.. I just saw it´s included in the default keymap (2.9.5) with Shift + Numpad. Answer edited.

Shift + numpad doesn't seem to work in Edit mode though, from what I undertand he's asking for Edit mode

Here it also works in edit mode (Windows 10, 2.93.5). The alignment is done to the active geomtry.

@relaxed, oh you're right it works if you select a face in Face Select mode


text:
How can I increase the gap between loopcuts?
Using the "loopcut" function first, is there a way to widen the gap between the lines?
I think it's going to happen with "Scale". It's only increasing in volume. :.-(

You can indeed do what you want with Scale, you just need to lock the transformation to the X axis to prevent any transformation on the Y and Z axes. Press S followed immediately by X to lock the transformation to the X axis, and only the spacing between the edges will be modified.

@PeterMortensen Please don’t make edits changing “X axis” to “x-axis,” because the former is what is used consistently throughout the Blender documentation and related material. Also, though the first sentence may technically be a comma splice, this sort of joining of conditionally related clauses is benign and common.

enable symmetry in one axis. For example "X" axis

alt + select clicking on the loop to select the loop

Press the G + X to lock to X and only move in the X axis.

You can now resize the loops in the way you want.


text:
How do I delete a face?
By hollow, I mean that I want only the sides and the base of the frustum to be visible. I already have a 3D Cone Frustum so now I only want to subtract the inner regions from the cone. So, my question is of course, how to do that ? I thought of using boolean but it only shows the option of a cone, so is it possible to use another one as a boolean modifier ? if yes, then how. I am a total noob and hence forgive me if its a bad question.Thanks in advance.

In Edit Mode enable Face select right click on the top face you want to remove.

Then press X or Delete. This shows the Delete popup menu, where you can select Faces.

Though this can remove the face but this removes both faces. I only want the top face to die and want the bottom face to stay

doing that leaves me with this which is exactly not what I want... http://tinypic.com/r/30ivm2g/8

SO, @stacker what is it that I'm doing wrong ???

@user3219 You probably had the other face select as well, press 'A' to select/deselect all before clicking the face you want to remove.

I tried deselecting all faces then clicking the face I want to delete, but it refuses to get selected, how do you select a face exactly, i tried everything you said, @stacker

@user3219 Are you sure that you're in edit and not in object mode? Right click selects the face.

Note that this will result in a non-manifold mesh (the "walls" have no thickness). You can add thickness with a Solidify modifier.


text:
Blender interface appears gray?
I'm not sure what's going on, but today in the morning when I opened blender it had turned gray from black.
I don't think it's affecting any type of performance, but it is not feeling right while working, is there anything I can do to revert this change?
I'm using Blender 2.50

Blender 5? Do you mean 2.65, 2.55 or 2.50?

2.5, @GiantCowFilms

I'm Guessing that what every you did to make it black was reverted.

I don't know what to do to make it black, though made a check in the settings, but that wasn't of any use

Blender is gray by default. Is it possible you were using the bundled Back to Black theme? Try enabling it in File menu > User preferences > Themes > Presets > Back to black.

Ok, that did the job, @gandalf3

Blender is gray by default:

So it sounds like the theme you were using was somehow reverted.
There is a black theme bundled with blender called Back to Black. If you select it in File menu > User preferences (or CtrlAltU) > Themes > Presets, then blender looks like this:

To set this as your default theme, click Saver user settings at the bottom of the user preferences:


text:
Import object without bpy.ops.wm.link_append
Is it possible to import an object from a library file through Python without using bpy.ops.wm.link_append? I want an object to appear in bpy.data.objects without updating current scene.

Since Blender 2.72, there are two separate operators:

bpy.ops.wm.link()
bpy.ops.wm.append()

Apart from operators, there's also a lower-level API to import datablocks (selectively) from .blends: bpy.data.libraries.load()
The docs include a few examples how you can use this function.

+1. It seems that bpy.ops.wm.link() doesn't support wildcard (http://blender.stackexchange.com/questions/69985/link-all-objects-meshes-and-materials-from-another-file-with-wildcard)? As a workaround, I used the code by @der_die_das_jojo, but that actually appends everything over, although the name is scn.objects.link()... Any better ideas?

Here is an example how to use bpy.data.libraries.load() and link it to current scene
import bpy
scn = bpy.context.scene
filepath = "D:\\File.blend"

#append object from .blend file
with bpy.data.libraries.load(filepath) as (data_from, data_to):
    data_to.objects = data_from.objects

#link object to current scene
for obj in data_to.objects:
    if obj is not None:
        scn.collection.objects.link(obj)

I often get EXCEPTION_ACCESS_VIOLATION on line: scn.objects.link(obj). It occurs randomly but almost on every other attempt.


text:
Cutting a shape out of an object with another object
I'm trying to recreate these F holes in the body without cutting into the bodies mesh
The F holes and body are two separate meshes.

I am completely lost as to how to cut out a hole in my main body mesh without messing it up.
Is there any way to use the F hole mesh to make a hole in the body mesh?
http://imgur.com/a/rDoVR

You can use the Knife Project tool as described in the answer here.

You could also use a boolean modifier.


text:
How send HSV value to color picker?
How send HSV value to color picker in Blender from Python console?
By default we can send only RGB :(

How about using a script with a function that converts HSV to RGB? You would have to execute the script instead of entering the command in the console.

You can use the mathutils.Color type to convert HSV to RGB:
from mathutils import Color

c = Color()
c.hsv = 0.0833, 0.4, 0.5

print(c)
# roughly Color((0.5, 0.4, 0.3))

If you want to assign the color to a RGBA property (4 floats), you need to either do:
bpy.context.object.color = c.r, c.g, c.b, 1.0 # 1.0 is alpha

or a bit ugly looking tuple concatenation:
bpy.context.object.color = c[:] + (1.0,)

Alternatively, import the Python standard library module colorsys and use its conversion functions:
import colorsys

colorsys.hsv_to_rgb(0.0833, 0.4, 0.5)
# (0.5, 0.39996, 0.3)

Thank you very much CoDEmanX! I have one more question:
How refresh color picker element, after I set new value?

If it doesn't update automatically, flag it to let Blender refresh it by calling Region.tag_redarw() on the editor region where the property is shown in.


text:
Selecting specific control points on a mesh when using box selection
Is it possible to select vertices/edges/faces that the selection only touched
not all of the them?

Do you want to unselect some of the elements that have been selected using box select`?

Are you looking for deselect all? That would be the A key by default.

no.When i click b on edges i need to select 2 vertices to select an edge. is it possible to select the edge just by moving over him?

Probably you should press C instead of B?

To select an edge you should switch to edge select mode and right click on the edge or by using CtrlTab. To select more edges hold Shift while pressing RMB.

See Documentation on Selecting


text:
ImportError: No module named 'Blender'
I'm new to Blender scripting (and to python too), I started to try to use it but I already get some error...

Traceback (most recent call last):
  File "", line 1, in
  ImportError: No module named 'Blender'

This is my script...
import Blender

I know this sounds ridiculous, but I cannot find the solution...

It looks like you are following a tutorial/code written for Blender 2.49 or lower. However, if you are running that code in a current version of Blender 2.50 and upwards there is no module named Blender. That's why you get that Import Error.
A good place to get information about the current API and Blender script writing in general is the current documentation. It contains :

Blender/Python Quickstart: new to blender/scripting and want to get your feet wet?
Blender/Python API Overview: a more complete explanation of python integration
Blender/Python Addon Tutorial: a step by step guide on how to write an addon from scratch
Blender/Python API Reference Usage: examples of how to use the API reference docs
Best Practice: Conventions to follow for writing good scripts
Tips and Tricks: Hints to help you while writing scripts for blender
Gotcha’s: some of the problems you may come up against when writing scripts

...and a whole lot more :)

Thanks! I'm running on Blender 2.76, so I'm sure it will be useful. Let's dig into that!


text:
Extend Frames On Bezier Circle Path Animation
When putting an object to follow a path on a beizer circle. The frames it takes for a full 360 motion around the circle is 100 frames (from 1 frame to 101).
I was wondering if I could extend the frames to 201 for a full rotation. And how to go about doing this task.
Please and Thanks!

Yes, it's quite possible, and (luckily) easy, too!
Select the Bezier Circle. Go to the Properties panel > Object data tab > Path Animation dropdown and change the Frames: value to 200.

Although timing wasn't mentioned in the OP, doesn't doubling the number of frames like that also make it take twice as long to complete the full 360 motion?

@HowardPautz Timing was the whole question. Read it again. Plus, they accepted it, so it must be right :)

oh, DUH, I fully misread it the other way round %-/ LOL  (-1 for my brain)

@HowardPautz Haha, it's cool. We all have those moments (at least I do!).


text:
Voronoi map in the compositor
I just saw this on codegolf and thought it would be an increadibly cool application of the Blender compositor for NPR.
Perhaps coupled with a blur shader this could make a nice painterly effect.
Is there any way of creating a Voronoi map effect in the compositor?
This is the effect (from the codegolf topic above):

What does Bl.SE mean in your question above?  Blender has Voronoi texture.

Are you looking for this effect, or does it specfically have to be in the compositor where everything takes place. I wrote a script that generates a VertexColor map given an input photo and a polygon-mesh (could be voronoi based) to put the colours into http://blenderpython.tumblr.com/post/117154100009

@zeffii No, I'm looking for this specific effect. The codegolf I linked to has examples so I could do this as post processing outside of blender but that would not be ideal.

@atomicbezierslinger Yes Bl.SE is blender.stackexchange, Blender has a Voronoi texture but that is not what I'm looking for, see the codegolf link.

I tried a few things with Cycles material nodes and I just can't seem to manipulate the vector the right way. Sorry, looks like you can't do this within Blender without coding some kind of script yourself.

Bingo.

There's a Voronoi Texture that has been scaled to match the aspect ratio of the output image
The coloring of the Voronoi texture is set to Position
The color information from the image is recombined with the color information from the voronoi texture using a UV map. UV interprets colors as coordinates where red=x green=y blue=z
Two more ramp textures calm the randomness of the voronoi texture's positioning down. Unfortunately, the "position" coloring of the Voronoi texture isn't based on true position, but rather is totally random. If it were based on true position, then we wouldn't need the baseline ramp textures at all. (time to make a feature request!)

This is about as close as one could get, I think. The scale of the voronoi texture could maybe be controlled by the image if you ran some filtering to find edges. (which just requires placing the source image ontop of itself with "difference" mixing, and shifting the upper image by a pixel or two on both X and Y)

+1 That is what I was looking for. Also probably the most awesome/beautiful abuse/creative use of how blender handles UVs. Would you mind sharing the exact RGB start/stop values for the color ramps?

The ramps are pure blue to pure magenta, and pure blue to pure cyan. positions 0 to 1, linearly. Think of them like a "red ramp" and a "green ramp" except you need blue to be 1.0 at all points because it controls "Z" which becomes the alpha.

There are multiple things happening in the algorithms presented in the link you shared, but the most important thing that's happening is not possible in Blender's compositor.

Converting an image into a fixed of points
transfering that set of points as a parameter into a hypothetical "voronoi" node. There is no such data type
using a vornoi algorithm to fill in polygons with sampled colors from a set of points

Now, in theory you could reduce that set of instructions into just one step

a python compositor node

but to do that is no small chore
There are plenty of clues in the codegolf post on how to process the image, how to find edges, how to make that bitmap into a set of points, how to process the points into polygons, and how to fill them.
I'd like to offer up the code for a python compositor node that just does all that for you, but it would just take a terrible amount of time. An onerous amount of time. Enough time that the short answer to your question is "no."

On the other hand! If you're also interested in exploring the general effect and breaking out of the compositor-node-constraint, there are other things you could explore. (in your comments, it seems you're only interested in voronoi specifically, but i'll try anyway)
Here's an image that was made with a "lens" made from a box, one side heavily subdivided, displaced with a cloud texture, and then decimated. The lens is using a glass texture with 0.02 roughness to generalize the colors coming through each face. If the displace filter was made to transpose over time, the facets would change and shimmer.
While it's not exactly what you asked for, in my opinion, it falls into the non-photo-realistic category. I think you could go quite far with it -- especially with render layers feeding into the compositor.

this is a nice idea

about the compositor python nodes do you have any ( even simplest ) working example that respond to composting ? I would be highly interested

I would also be interested in python nodes that work in the compositor, perhaps i (or someone else) should ask a question...

I spent a few hours trying to figure it out so I could feel like I knew what I was talking about while writing this answer. There are templates for python nodes that comes with Blender. Text Editor -> Templates > Python > Custom Nodes. That's as close as I got.


text:
Braid not colliding with clothing (Curve Problem?)
UPDATE: I noticed during the animation the curve the armature is following stretches out and although is still attached to its origin point keeps falling. Is there a way to keep the curve from stretching so much?
I am currently working on a model that uses a softbody on a curve that controls bones on an armature (like in a tail.) I got everything to work except when I run the animation the braid does not collide with the clothing on the mesh (no clothing modifier is applied, the dress is controlled by the armature). In fact, the settings for the soft body act differently once they were parented to the rig. (on previous tests I did get this to function.)
You can see in the attached picture that the braid is disappearing into the clothing. I tried putting various collision objects in front of it but nothing responded, which leads me to believe it is a problem with the braid

You can download the .blend file here. https://drive.google.com/file/d/0B8yH3EeGiUo4bkxmV2kzMkZvazg/view?usp=sharing
I would really appreciate any advice, I have been working on this for days!

I had a look at your blend file, nice work. A couple of suggestions, your soft body physics are applied to the curve controlling your armature, and not the braid mesh as I would have expected. If you start blender from the command line the look at the output after loading your blend file there is a dependency loop reported " Dependency cycle detected:
braidCurve depends on MandanWoman30 through Bone Parent
MandanWoman30 depends on braidCurve through Spline IK.".

It is my understanding that the soft body is on the curve because it is controlling the swing of the armature. I did try several tests where I added various physics to the braid but so far I have not gotten anything to work. Can you expand more on what a 'dependency cycle' is?


text:
How do I install this add-on?
I'm trying to install this addon but can't:
https://sods-blender-plugins.googlecode.com/files/io_import_z64_v4.rar
I just installed Blender 2.7.5, I was using 2.7.2 previously.
I have placed it into the addons folder and tried to install using file several times.
it says there's an unexpected EOF when parsing, ast.parse can't read it,  and addon missing 'bl_info' gives bad info.
Blender's console:

I've done everything I can to try to figure out how to get the addon to work and have been unsuccessful.

Did you activate it under the "add-ons"-tab in your user preferences?

I was unable to activate it since it didn't show up in that tab. I also tried pressing install using file, as noted in my post.

Going to the home page, and clicking on the issues tab for the addon, I see that a similar issue was reported more than a year ago, but that no further information has been posted to the google site.

the file: http://www.pasteall.org/59458/python

Looks like you have two installs that may be conflicting. In the screenshot you have 2.75/scripts/addons/io_import_z64.py as well as 2.75/scripts/addons_contrib/io_import_z64.py

you will have to edit the file yourself. You can delete the empty line between "category" and "anim stuff", it seems to trip up the bl_info parsing:
bl_info = {
   "name": "Zelda64 Importer",
   "author": "SoulofDeity",
   "blender": (2, 6, 0),
   "location": "File > Import-Export",
   "description": "Import Zelda64",
   "warning": "",
   "wiki_url": "https://code.google.com/p/sods-blender-plugins/",
   "tracker_url": "https://code.google.com/p/sods-blender-plugins/",
   "support": 'COMMUNITY',
   "category": "Import-Export",
   "Anim stuff": "RodLima http://www.facebook.com/rod.lima.96?ref=tn_tnmn"
}

its not actually the Anim stuff line that does it. There is a bad Binary character in the whitespace between the end of the line before, and the start of "anim stuff" delete the blank line fixes it.

yeah, there's all kinds of indentation issues with that file.


text:
Blender settings and Windows drivers for OpenCL rendering
I recently got a Radeon RX Vega 64, first time AMD GPU user, so I'm not quite sure how to set Blender up for it and/or the drivers I'll have to have installed in order for it to work correctly.
So far the performance has been quite erratic while on GPU rendering (on CPU it works fine). A lot of crashing.
1 - Apart from selecting my Video Card as a Cycles Compute Device I wanted to know if there is anything else I should make sure to set up within Blender.
2 - Also, and maybe more important, what kind of Windows drivers do I have to install for it to perform properly? I'm not familiarized with AMD drivers.
All information I find specifically for Blender, addresses problems pre-2.79.
Thank you.

I've done this. I'm used to working with Nvidia GPUs, so I know the basic settings. I'd like to know specifics for AMD. I know nothing about drivers for those for example.

Just go to http://support.amd.com and download the latest driver. You cant do much wrong. Other then that, there's no special setup needed.
Also: As you can see here, the OpenCL/AMD support in Blender got a huge leap with 2.79.


text:
How can I exactly use normals? Are they even useful in the first place?
I tried to bake some pants, but they look like that... is that normal?
Also, is there a explain like I'm five guide on how to use Blender textures like normals and ambient occlusions, like what I'm I supposed to do with them and how I should use them the final and epic day where I will make one that actually works?

It seems it worked, thanks.

it looks like there are small details that don't show up on your normal map, maybe share your file so that we can test a bake? As for your second question, it is much too broad, please be more specific

@moonboots https://pasteall.org/blend/9e7c4ad24bff40f5a216849568d659ed

You are trying to bake from multires, I've also failed to make it work, I don't know why, so  maybe apply it and use Selected to Active?

If one of the answers solved your problem then upvoting and marking it as accepted is enough, there's no need to edit the question with "solved, thanks".

I think there might be some issues with your workflow, I have baked the normals from multires and this is my result:

To achieve this I redid some of the UV-maps to reduce stretching:

and then bake from multires, on the 'low poly' mesh with the multires modifier set to 0:

One good thing of using the multires modifier is that you can bake directly on the same object without the need to use cages.  For baking with high res, low res and cages you need all 3 objects to be on the same place, and the high, low poly to intersect each other.
Please note that the normal map image texture is 2k with no alpha channel (not needed) and 32-bit floating point for maximum precision.

i tried using the ''bake from multiresulotuion'' before and it just baked everything white, will try again by adding those nodes

those nodes (shader nodes?) are for rendering, not for baking, for baking you only need to add the Image Texture -> new, uncheck alpha (not used for normals) and check 32 bit floats, ensure that the image texture is selected before baking.
For baking you only have to check the bake from multiresolution, and lower the resolution of the multires modifier (i left it as it was) of the mesh.

Judging from the screenshots in the question you are both using very different blender versions, maybe this is why you don't have the same result ?

No, I don't think so.  The baking process is the same https://docs.blender.org/manual/en/2.79/render/blender_render/bake.html
However, he is using a very old, 2.79 version, i'm using the lastest stable (3.0).  You can download it from Steam and it will keep it updated.  Totally recommended that you upgrade to latest or LTS (long term support). 2.7 is very, very old.


text:
Can I apply an old texture paint file to a new object?
When I already finish making the icing of my donut, I want to texture painting my donut. For speeding up the process, I open my old texture paint file and apply it to my donut, but the end result looks like this:

The one below donut picture (first donut picture) is my old texture paint file, and the end result I want is this:

When I first make the old texture file, I paint it in texture paint mode, not in the UV/image editor. I can't apply a texture paint file to my object, because I paint it in texture paint mode, not in the UV/image editor. How can I apply it to be like the second picture? How can I do it?

No, it does not matter how you created the image. What matters is how it’s mapped to the 3D object, I.E. the object’s UV map. The maps of the two doughnuts are not the same,  so the texture is getting mapped onto the new doughnut in the wrong way. If you make the UV map of the new doughnut synonymous with the old doughnut’s UV map, that would fix it. However, the map looks kind of auto-generated and arbitrary for the new doughnut, and I’m guessing the same goes for the old, so intentionally reproducing it may be difficult. If the old doughnut’s UV map is too arbitrary to reproduce, I recommend you just start from scratch and unwrap the new doughnut manually before repainting it.
If you are desperate to preserve the old texture, though, you might be able to bake it from one UV map to another, but that is beyond the scope of my knowledge at this point.

oh ok, thank you, at least now i know that i can't just texture painting my object using my old texture paint file

You can transfer the UV map from the first object to the next object, or at least try: https://docs.blender.org/manual/en/latest/scene_layout/object/editing/link_transfer/copy_uvmaps.html

@josephhansen I doubt that topology will match, but if it does, that would work.

I guess.

In your texture, it looks the same as the donut in the first picture. You don't have any texture information which looks like the second picture, so you lost some data, i.e., roughness, normal and so on.
So the solution is find your old profile, look into BSDF, and copy those data to your new BSDF. If it works, the way to fix your problem is to bake a series of textures.

I have copied the bsdf same as the old one but the result is just like you see in the 1st picture, i wonder if i want to transfer my uv map from one object to another, but the object not having same shape and texture.Is that possible?

Must the shape of them be exactly the same?

BSDF what? BSDF settings? BSDF parameters? Something else?

This is incorrect- without duplicate UV mapping, this solution will not work

@josephhansen BSDF node, i have copied it exact same way as the old one, but the end result is just like in the first picture

@josephhansen i learned that by using data transfer modifier, i can transfer my old object's uv map to the new object, but when i tried to transfer using it, the uv map didn't transferred at all, my new object's uv map still blank

The Data Transfer Modifier is not how you copy UV maps, the Blender documentation has some advice and there's some tutorials out there. Google "blender copy uv maps between objects"


text:
Why is material colour's assignment not working properly?
I am following the making cup tutorial and I have already finished making the cup, and I am kind of curious what if I assign a different colour for my cup's inside instead of my cup's outside colour.
But, as I assign the colour to it, the colour has a strange pattern of the cup's outside colour like this:

I check the wireframe of my mesh, but I don't see any of the cup's inside mesh intersect with the outside one. What is the problem? What's wrong with this? Why is the assigned material's colour not
working properly?
Here is the blend file https://pasteall.org/blend/a237b6c6ef234f83ae86cd96951309d7

There are 2 problems:
You have overlapping faces, some are orange, so select all and press M > Merge by Distance to remove these faces:

You still have orange faces, it's because on the bottom you have a ring of faces with the orange material. As you have a Subdivision Surface modifier it tends to stretch the faces. Switch to transparency and select this faces ring:

Assign it the blue material and you are good:

how do you edit the object while having colour? Are you edit it in rendered view mode?

In order to switch to Edit mode, select the object and press Tab, or Ctrl Tab to switch from a interaction mode to another. You can edit an object in whatever display mode you want: Solid, Material, Rendered preview modes...

Thanks moonboots


text:
How can I create an extruded curved wall?
I am (completely) new to Blender, but I have a lot of experience with engineering 3D model software. I made the following in Inventor, but exactly what would be the standard way to achieve this in Blender?

I am struggling with whether it should be one object, where the block has had the curved section extruded from its surface. Or whether it should be two objects.
I also am struggling with how to create the two concentric arcs.

so do you want it to be one or 2 objects?

@moonboots I am not experienced enough with Blender to know what difference it will make, I'm afraid, and why I should care if it is 1 or 2 objects. Thanks.

Welcome to Blender Stack Exchange! A couple of good concepts to understand in general are: 1. An object is like a container that holds your geometry. While in Edit Mode it's like you're poking around inside the container and changing the contents. When you move your object, its contents go with it. 2. Most objects contain mesh data (polygons). Some contain curve data (vector paths). There are other types of objects too. If you make a Linked Duplicate you'll end up with a second object shat shares the same inside data. A regular Duplicate has unique data.

If you have no particular reason to do it with one mesh, do it with 2 separate meshes (or 2 separate objects), as it will be much simpler. For the curvy wall, create a cube, keep only an angle, select the angle edge:

Press CtrlB to bevel, use the mouse wheel to add segments, or type the parameters in the Operator box (at the bottom left of the 3D view):

Select all, press AltE (Extrude) and choose Extrude Faces Along Normals:

For the floor, create a plane, scale it, extrude on Z.
If you want to easily change the wall thickness, don't extrude, use a Solidify modifier and tweak the Thickness value:

Only apply the modifier when you're sure about the thickness (you need to be in Object mode to apply):

Thanks. Just out of interest - if I wanted to come back later and change the thickness of the wall, how would I do it? If I select the outer faces and then try to extrude along normals back the other way (in an attempt to reduce the wall thickness), then it cuts inside the wall, leaving theend caps in tact.

In that case maybe don't extrude and use a Solidify modifier instead, see my edit

Great, this is useful to know! Thanks for the edit.

I would add a plane, go to edit mode, press E and move your mouse like this:

Then select these:

Press G X and move your mouse:

In object mode, press Shift + A: Curve → Arc
Change the angle to 90 like this:

Now press R Z -90

And with G, Shift + Z move your arc:

Select the last vertex:

Press E X and move the mouse:

In object mode, add another curve → rectangle.

And in your arc object, choose bevel-object: rectangle.

Now choose your rectangle again and size it to your needs:

Select "fill caps":

And with object → convert → to mesh, you can turn it into a mesh and select "autosmooth":

Result:

Thanks very much, either answer would solve my problem - the one above just seemed to be quicker, with fewer steps. Thank you.

It took me a while to figure out, but it seems like you need to enable an "Add On" to get the "arc" option that you used, right?

That’s right ‼‼‼

Thanks. In your answer, you have a step which says "and in your arc object choose bevel-object: rectangle". Is this an option that should be found somewhere after selecting the arc and going into Edit Mode? Thanks so much for your patience :)

If you click on the curve symbol of the arc (curved line with 2 rectangles in green) you can see a bevel section (maybe you have to oben it by clicking) , then click on „object“ and then you can choose anno object

Yep, got it. That option was a little hidden! Great, it works now, thanks!

You are welcome


text:
Objects being moved with each other inside an area
I have accidentally enabled a mode which creates a kind of smooth brush whenever I move an object. And when I drag it across the axis everything inside the circle gets moved as well. How do I stop this and what is the keyboard shortcut?
 - This is the difference in the tool bar, in other .blends without the problem there is no (Smooth).
 - This is the circle in which everything in it also gets moved, this can be re sized but not removed. And even if I re size it until it is almost gone, it still creates problems.
If someone could help me figure out this problem it would be much appreciated.

This is called proportional editing and is enabled by pressing O.

Available Shortcuts for Proportional Edit tool:

O to enable/disable Regular mode;
AltO to enable/disable Connected mode;
ShiftO to switch among the Falloff types.


text:
Use a texture as an influence map without showing any diffuse color
I'm trying to use material for color and texture for the appearance (smooth,rough...)
But it assigns me the color of the texture too.
I'm trying to make the gem in here: http://www.blendswap.com/blends/view/70566
Thank you!

You need to disable the Diffuse Color check box under Influence in the texture panel (or set it to 0). This prevents the texture from showing any color when rendered.

Both objects below use the same texture and have the same material colour, the second one also has Normal checked as an example of using the texture as a bump map.


text:
Placing spheres in a perfect circle on a ring
I am trying to place multiple spheres on a circle ring but am finding it really hard to get them into position. Is there an quick method to accomplish this or is there a tutorial that teaches such stuff.
Below is a quick illustration of what i want to achieve

Add a single sphere, and a curve to the scene (a Bezier Circle should do). Reduce the size of the sphere down to about 0.1 depending on the scale of the scene you're in.
Next, add an array modifier to the sphere and bump up the counts to about 10 or so you can see something. Finally add a curve modifier to the array of spheres. The spheres should follow the curve and you can now increase the array count depending on the scale of the sphere until both ends meet.
End result:

NB: If after doing this, the spheres don't connect at both ends evenly, just select the sphere in object mode and scale it slightly until they meet. You can also hold Shift while scaling for more precision.
An alternative (but more cumbersome) way is to use dupliframes, see How can I duplicate a mesh along a curve?

all the sphere are not similar shape . The front sphere are little bit elongated

@atek Right, not counting the example image which is due to perspective the size difference is negligible. See the new blend I attached. For an alternative, see the marked duplicate.

i think i was wrong i take my words back. Due to image i have seen so i said it. I was searching for my answer i have posted http://blender.stackexchange.com/questions/66272/how-to-rotate-object-along-path-path   can u plz help me to solve it

@atek see the link in my answer.

i have tried about the dupliframes but i was not successful. can u plz take my file and show me a demo plz

@ iKlsR as u have show me dupliframes i done with the path method but the problem is i cant delete the path and get the object to 1 single object i have posted my question plz go through http://blender.stackexchange.com/questions/66328/how-to-convert-path-to-an-single-object