text:
Adding atmospheric perspective to a scene using Cycles and HDRI
I spent a few hours trying to find a solution... I'm looking to get the effect of atmospheric perspective in my scene to help me understand lighting more. I have an HDRI and I'm using cycles and I've tried the following....
Add a volume scatter to the "Volume" tab in World properties. This breaks my HDRI and it just renders black even with a density value of 0.000015
I tried creating a large sphere encompassing my whole scene and adding a Volume Scatter shader to it. Scene renders, but there is no sun lighting from the HDRI, just dark blue ambient lighting it seems. I tried adjusting the density value to around 0.00001 and I can either get the scene to render normally with no atmospherics or as a dark scene described earlier.
Is adding atmospheric perspective in Blender 2.79 possible?

Does this answer your question? Why doesn't an Environment texture appear when the world has a Volume Scatter shader?

I think you want atmospheric lighting if I understand correctly. There is definitely atmospheric support for cycles. However, sun lamps do not work. Use a Point lamp, Spot lamp, or Area lamp. Also, make sure the strength is rather high. You should use Volume Scatter. If you want a mist effect, where objects fade away the further they get, you can try this tutorial. This will allow for less noisy and faster renders.


text:
How do I make dynamic 3D-printable hair?
I am trying to make dynamic hair that can be 3D-printed. It needs to be physics-enabled (so some kind of particle system, maybe?) and, through some kind of transformation, needs to end up as a single "blob" mesh with no gaps or interior faces, so it can be 3D-printed.
I've so far considered / tried:

Manually sculpting the hair - but then it's not dynamic!
Soft bodies - but they don't have the same dynamics as hair!
Metaballs x Hair particle systems - but I haven't found any way to combine the two!

What do you people think? Any help would be much appreciated!

I know this is an old question, but worth linking to this:  https://www.youtube.com/watch?v=OTXPU2P-ElE
Unique method of printing hair

Blender 2.80, add hair at a reduced count, comb it out, go to modifier then convert.
Then place the origin in a center point of the head. In edge, select all, "A". Now "E" for extrude, then "S" for scale, making face. Now in object mode add the modifier for solidify.
Takes some playing around. Maybe shrink a sphere to this. depends.
 Shrink works pretty good for body mesh expressions on Manuel Bastioni models. Nice clean, crisp slice, I always delete behind the eyes and internal mouth.

source: Stack Exchange

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

sort: votes


text:
cycle engine isn't responding
whenever i press f12 in blender 2.8, it doesn't start to render.
In the other hand, it only shows this

if you can help me , please leave your suggestion in the comment.
thank you.

A bunch of possible user errors you can find here: https://blender.stackexchange.com/a/53633/31447

It seems the render is done - it's output is black.

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


text:
Can't install 2.8
I have been using 2.8 Alpha.  Today I tried to install the 2.8 release and it comes up with an error "The specified account already exists"  I've tried everything I know to do and no joy.

As a workaround for when the .msi installer doesn't work: Download the zip archive version (https://www.blender.org/download/Blender2.80/blender-2.80-windows64.zip/ or https://www.blender.org/download/Blender2.80/blender-2.80-windows32.zip/), extract it and add a shortcut to the blender.exe inside the folder. No installation required.

Super.  Thanks a bunch


text:
Apply Transformation Matrix to Existing Mesh
How can I apply a 3x3 or 4x4 transformation matrix to a mesh such that the matrix's transformation is baked into its geometry?
E.g. applying the following matrix...
\begin{bmatrix}
    1 & 0 & 0 & 0\\
    0 & 0.707 & 0.707 & 0\\
    0 & -0.707 & 0.707 & 0\\
    1 & 0 & 0 & 1\\
\end{bmatrix}
...to the cube primitive should yield the result below, only by changing the mesh's vertices.

Thus the object-level transformation depicted in the properties panel will remain unchanged.

Mesh.transform
import bpy
from mathutils import Matrix

ob = bpy.context.object
me = ob.data

M = Matrix(((1, 0, 0, 0),
     (0, 0.707, 0.707, 0),
     (0, -0.707, 0.707, 0),
     (1, 0, 0, 1)))

me.transform(M)
me.update()

..just curious.. how would you kick a 3D view into refreshing, to display the transformed mesh?

Edited answer, added  a call to mesh update.  Personally would do this with bmesh operators, this seemed the simplest answer to this q.

I wonder why blender only applies the rotation component of the matrix and not the translation (last column)

If you create the cube and select it, and then go to the python console, the following should produce what you are asking for.
ob=bpy.context.object

ob.matrix_world=((1,0,0,0),(0,.707,.707,0),(0,-.707,.707,0),(1,0,0,1))

I don't know that there is a way to manipulate that directly in the UI.

Thanks much, this does indeed help! Yet, this method plainly sets the mesh's object-level transformation. I can then, of course, simply bake the object-level transformation to a mesh, but it's a bit tedious for a mesh with a non-identity object-level transformation. I'd have to note down the object-level transformation, zero it out, use the console to input a matrix (for the object-level transformation), apply the current object-level transformation, then re-input the previously noted object-level transformation. Perhaps there is yet a faster way to bake in a matrix transformation?

I'm not sure what you mean by 'bake'.  Are you wanting to keyframe, perhaps?  Or are you wanting to bake in terms of materials?  Do you have something you are trying to accomplish by 'baking'?  That might help clarify for me how to do what you want. :)

By "bake", I'm referring to the function of the "Apply Object Transform" operation, which takes the object-level transformation and applies it to the vertices of a mesh. In other words, changing the level at which the transformation exists (from object as a whole -> to vertices), so that the object-level transformation resets to zero and the appearance of the geometry is kept unchanged. Moving every individual vertex (by the matrix) instead of moving the object's position as a whole. It's kind of like taring a scale.

Run bpy.ops.object.transform_apply(rotation=True) after setting the matrix world.


text:
How to: material for custard ( preferably pap )
The mesh is ready but all material combination I'm trying don't even come close to resemblance.
PS: is the content of the plate I'm trying to recreate.
Any help?

Have you got the Mesh shape for the custard in the bowl and have you set up the lighting? If those are done then you just need to play with the Cycles nodes. How realistic do you want it? For instance, I can see some subtle colour changes in the custard. Try Mix node with a Glossy and BSDF Diffuse nodes.

Could you share the .blend file?

Yea, the mesh is ready. I'm still a newbie so my try out didn't work out so well.


text:
How do I hide these lines from automatic weight bones?

So I'm making a Sonic model and I rigged the fingers with automatic weight bones, and these weird lines appeared. I'm trying to render it in OpenGL, but these lines won't disappear. Is there a way to hide them?

N->Display->(uncheck)Relationship Lines


text:
Better way to remesh from a solidworks file?
I was wondering if someone had some advice for me. I'd say im intermediate with blender after being on and off with it for 6 years. I am not currently using 2.8 but thats a different story. I work at a watch company as a Videographer and I thought about putting some 3d animations into the mix. I saw a tutorial on youtube that showed a way to import an STL file into blender but the mesh is really gross. I get the STL's directly from our watch designiners who use solidworks. I have been joining verticies and removing doubles while also using "tris to quads" and it cleans it up pretty good but theres still work to be done.
My plan is to simplify the meshes so that mapping looks correct for shaders and then I want to be able to import into element 3d in after effects for quick simple animations of say just a watch spinning in circles and yes I do know how to animate the hands on the watch.
I am just trying to see if theres a much faster easier way to keep the mesh the way it is but making the topology less... Dynamic? Making the mesh just quads
So heres what I have figured out so far.
-joining verticies and removing doubles
-tris to quads
-shrinkwrap modifier
-mirror modifier (most of the watch parts are symmetrical)
The shrink wrap seems to work a little bit but on some more complex curves, it tends to get lost. For instance trying to shrink wrap from the watches strap lug holder...um... thingy to the actual case itself.
are there some other quicker better methods to remesh/ retopologize an existing object other than what I mentioned or is it basically what im already doing.
just to be clear I will be using subsurf mod once I have a better mesh
heres the youtube video I watched for solidworks to blender.
https://www.youtube.com/watch?v=r1nlNYSxvMs&t=318s

your question is a bit too broad, maybe share just one  part of your mesh to see how we could simplify it

There is a paid add-on Open VDB remesher https://gumroad.com/l/jqLNZ
Have not used it, but looks interesting


text:
Wheels of the car sinking on ground plane
I'm trying to make a drivable car.  I made the  floor a rigid body passive. The wheels are either convex hull or cylinder and the scale is applied (ctrl+A).
When I press play in the blender game, the wheels sink into the plane.
I made one cube and 4 wheels and I get the same result.
I parented wheels ,child, to the car. Car its rigid body, no sleeping convex hull. Wheels are not collision, plane its static.
What am I missing?

Have you tried to enable the physics visualization to see what's going on? Maybe the wheels aren't in the correct collision shape or radius.

ty for you ansver  not help mi . ,I do not know how to put the  blender file here ..so mi email its crypes@live.com if its ok for you

Upload blend files on this site: https://blend-exchange.giantcowfilms.com/ , edit your question and post the generated link on it. Delete your email from your comment, as it could bring spam to you.

i can t upload they tell mi error uploading ,i try more time...no way working

ok I've done this with python script from this tutorial,,,How to add vehicle suspension in the blender game engine (HD)...https://www.youtube.com/watch?v=sB23rVp6IQ4...............in python you need to increase radius


text:
How can we fake landscape erosion?
Blender's landscape fractals are pretty basic but erosion, as from decades of rain, can increase appearances drastically.
Have you 'successfully' - a relative term here - eroded your geometry using/mixing textures or shaders?

Not super realistically. I have an approach at this, which involves taking the slope and cavity to create an erosion-like displacement effect, but this is not really how erosion works. As far as I know, the only truly realistic way to attack this project is with actual coding. Heres an addon you could check out: https://www.blendermarket.com/products/erosion-add-on


text:
Worley noise generator in 2.79?
2.8 has something I'm not investigating yet, but did anyone make an Add-on compatible with 2.79 that generated the Worley texture specifically for Materials?

Is there a difference between Worley noise and a  Voronoi texture, which is provided? (Excuse my ignorance, I've been trying to check, but it isn't clear to me, yet)

I can't get mathematical about what the difference is, but yes. :) The Worley is a variation or iteration of Voronoi - a lot of diagrams label Worley as f2 but that's not helping me Node it into existence. Voronoi breaks down to spheres around points, Worley generates linear gradients so a displacement might cast something like little funky pyramids instead of styrofoam-like shapes.


text:
Can we preset Graph Editor Interpolations for Elastic?
Pressing [T] in the Graph Editor with an Active Keyframe lets you Set Keyframe Interpolation - Dynamic Effects: Elastic, is a choice. With that choice come basic presets, .8 Amplitude, 4.100 Period
I want to do this 59 times and seem to have to do this by hand (!!!) but wouldn't complain IF I could adjust the preset so each new occurrence is right for my project. This is easy to understand in practice but tough to explain but can I adjust the presets? Copy/Paste includes the Interpolation but ALSO the keyframe value.
I'd settle for the ability to copy/paste just the adjusted Interpolation settings, can we?

59 times I needed .8 to become .04 - lots of clicks unless you know something I don't.

The first tip is that pressing T will apply the interpolation to every selected keyframe.
First, to simplify the graph editor, hide curves you aren't working on.

It would appear that you want to do this to every third keyframe, so select all won't help. We have the common selection options in the graph editor.

B to box select keyframes
C to circle select keyframes
⎈ Ctrl RMB to draw a lasso around keyframes to select

I'm thinking if you zoom out enough to see all or most of your keyframes, you can use circle select to quickly select the keys at each "corner" of your stepped fcurve.
That is about where blenders UI stops being helpful. Then we can often turn to python to help automate repetitive tasks like this. We can use the text editor to type and run longer scripts. For smaller tasks, the python console can be used to type out commands. Pressing ↑ Up arrow can bring back the previous command so we can change a single value (like the index number of the keyframe point) before repeating.
If you have selected the keys that you want and used T to set the interpolation to elestic, we can set the amplitude and period of these keys -
import bpy

obj = bpy.context.object
fc = obj.animation_data.action.fcurves

for c in fc:
    for k in c.keyframe_points:
        if k.interpolation == 'ELASTIC':
            k.amplitude = 0.8
            k.period = 4.1

In your example you appear to be setting every third keyframe, you may need to add some extra keys to maintain the repetitiveness as at least one appears missing. We can use a repetitive sequence like this to automate the entire process.
import bpy

obj = bpy.context.object
fc = obj.animation_data.action.fcurves

# adjust this to 1 or 2 to get the right keys
startidx = 0
for c in fc:
    if c.hide: continue # skip curves we have hidden
    for i in range(startidx, len(c.keyframe_points), 3):
        c.keyframe_points[i].interpolation = 'ELASTIC'
        c.keyframe_points[i].amplitude = 0.8
        c.keyframe_points[i].period = 4.1

You may also run the script and then select the first and last keys to undo the elastic setting if you didn't want it over the entire curve.


text:
Converting geometry into Bones
Bones to mesh ISN'T what I'm hoping for. I thought this would be easy but I have Objects that follow simple rigid body physics and the lame fish shape. Can't I deform the fish using those box shapes as Bones?

The goal, perhaps you see, is ragdoll-like meshes, not just ragdoll boxes.

it's not clear to me, do you mean that you don't want any bone, you want these boxes to act like bones?

Yes. I was hoping for envelope weights or some such Parenting.


text:
Animation Nodes Using Time/Frames to affect Objects Materials
My desire is to illustrate dates of sales for townhouses by changing the visible material (changing colors, or changing Shaders, etc). The order of what houses sold when are out of sequence; it's real-world dates I'm using and the time scale is one frame to one day.
I have 98 houses and 98 dates spread wildly over three years. I see tons of tutorials for changing colors, etc. based on the location of an empty, but I know too little about AN to make the leap from that to what I need which would tie a list of "dates" (frames) to Objects to trigger a material change or Mix.

Can you post some example text of what the dates look like? Do you have a method to correlate each date to each house? (eg, is each house a separate named object, and you have a name for each date?) Ways to attach the dates to the objects, is the first problem. The rest may be quite an open-ended question with many solutions/steps. A first suggestion would be using basic scripting (copy/paste operator calls) in a for-loop to set each object's pass index to the numerical value of the date. Or add keyframes directly via script. Not sure AN makes that part any easier.

ex. December 20, 1972 address 7865 sold (all data entered by hand). Correlation method is what killed me when I originally asked. Suddenly remembered Key:Value in Python (Lists, Dictionaries and ... something). AN can do this? Searched AN Docs finding Loops and also wondered if the answer begins with that - Setting an object's pass index seems important but scripting keyframes seems more accurate. Those are useful tips!

The 'object pass id'  was just an example of a property you could set per object which you can then read as a numerical value in the node tree (i.e. via an Object Attribute node). I could write up an answer showing how to script-convert those dates to keyframe numbers and set a keyframe on an object based on that, if that would help? The main problem seems to be how to set the data somewhere in-scene. After you have the frame number readable in-scene you can use AN to do anything you like with it, right? (Also, to be clear, are you on Blender 2.79b for this?)

Here's one possible way to go about converting your date data into something you can utilize in Animation Nodes or elsewhere.

Paste the below script into a new text block in Blender's text editor.
Paste your date / address list into the triple-quoted text block of the 'houseData' variable. I've followed your example format. The below is assuming you have an object named eg '7865' for every house, already added to your scene. (inserting / creating those 98 objects in a script loop is outside the scope of your question as written, so apologies for not covering that here).

Note: The script is splitting the date from the address using the word 'address' just as you wrote it, but feel free to change the format with any short separator as needed, and just edit the entry.split("address") part accordingly if you do.

Run the script (alt-p in the text editor or press the Run Script button).

import bpy
from datetime import datetime

housedata = """
December 20, 1972 address 7865
January 31, 1973 address 1234
March 6, 1971 address 9999

"""

# The chosen start date will correspond to timeline frame 0...
startDate = datetime(1970, 3, 1)    # (yyyy, mm, dd) -> 1st March 1970

dateformat = "%B %d, %Y"
# Format codes are explained in the table here:
# https://docs.python.org/3.7/library/datetime.html#strftime-strptime-behavior

# separate the text lines, discard blanks:
entries = [e for e in housedata.splitlines() if e]

# Now, we set pass_index on all objects named as whatever came after
# 'address' in the text list above.
for entry in entries:
    dateTxt, addressTxt = [t.strip() for t in entry.split("address")]
    date = datetime.strptime(dateTxt, dateformat)
    datediff = date - startDate
    dayNum = datediff.days

    houseObject = bpy.data.objects[addressTxt]
    houseObject.pass_index = dayNum

# Note: pass_index is 0 by default.

Now in Animation Nodes, you can read each Object's pass index using an Object Attribute Input node with the value pass_index in its entry field.
Using a Time Info node will give you the current frame, and a Compare will let you see if those match.

The rest is a matter of setting up a list/loop node to run over all the objects in question, instead of selecting one specific object as I've done in this example screenshot. That part should be well covered by the Animation Nodes documentation.


text:
Which Nvidia RTX attributes are the important ones?
This RTX family of Video Cards includes different generations of GDDR ram and amounts and multiple price points as well as so many clock speeds and OC options.
Rather than just throw money at a high-end card, which of these attributes best contributes to the Cycles render for the smartest purchase?

Too much possibility to the question. It is not that simple to render a scene by only some aspect in a GPU. Thing depends on how you use it, how you render it, what is the context and other hardware performance, even which OS platform you use can make a difference. Also, the ray tracing process may being include in future of Cycles rendering pipeline, that should be important as well.

General speaking, just go to see a performance website for rendering performance. You should find enough information there.

Possibilities is all the question is about - I'm trying to parse this https://blogs.nvidia.com/blog/2019/11/21/creative-apps-rtx/ vague claim by Nvidia and Blender's architect, Lommel (who might have been quoted out of context). Knowing where that performance website IS would answer the question to my satisfaction (or someone's experiments). Blender's RTX article in July 2019 linked to by Nvidia isn't enough info.

https://code.blender.org/2019/07/accelerating-cycles-using-nvidia-rtx/

You could roughly multiply GPU cores and boost-clock for performance BTW. Only same core generation work.

“With NVIDIA RTX, core ray-tracing operations are now hardware accelerated by the GPU, making this the fastest version of Cycles yet.” - Brecht Van Lommel said.
Cycles core computing method is ray trace. And if this thing is supported by GPU hardware directly, then it will be fast to compute ray trace part. So, RT core number will benefit Cycles most in general.

But the whole Blender Cycles use OSL/GLSL for rendering. Not every thing in those complex shader node bottle-neck is to compute ray trace result. See this chart in official Blender Optix support post:

You can see that not every scene got the same boost from using Optix. Since not every thing is boost by new architecture.
Also, there are some special unit to do other calculation in RTX family as well(texture, Render Output):

Those unit (including RT unit) performance are almost directly proportional to GPU Cores in RTX family. So I think don't bother on what core are best for Cycles. Cycles benefit all performance from them.


text:
How to drive camera's Y location with same camera's Focal Length
This isn't for an animation, so I'm not inserting keyframes - as I view the model through the virtual camera, I want to experiment with different focal length values in Eevee and Cycles; but to not lose the model, I want to move along the Y-axis specifically to keep the model roughly the same size in the frame.

Can't you just select the camera then press G + Y to move the camera on the Y axis? While keeping the camera focused on one object by setting the camera to do so in the camera settings?

Sure, but that would not be driving the camera's movement with the Focal Length.

The local -Z axis is the "business end" of a camera.  Related https://blender.stackexchange.com/questions/107365/align-camera-to-view-precisely-and-automatically-without-manual-fiddling    https://blender.stackexchange.com/questions/128185/check-if-the-whole-plane-is-being-on-a-orthographic-camera-render-or-get-a-prop   https://blender.stackexchange.com/questions/130404/script-to-render-one-object-from-different-angles

Last night when I should have been sleeping, I wondered if I'm looking for a scripted expression. Camera's Z; d'oh! Yes, thank you. :) I think my first time making some python code will be ugly enough to offend a lot of people; I'll use another object to control both parts of the camera, Location and FL. I'll find out what the code call part is for Focal Length. I'll drive it with a shapely empty's Rotation, maybe parented to the camera (in view).

This solution uses only 1 driver, to drive the y value of the camera's transform depending on its focal length.
I used a linear regression calculator online (Search "Linear regression calculator" on your favorite search engine) and I mapped a few values of the focal length and the resulting y value necessary to keep more or less the same objects in frame. I arrived at a value of y (transform) = 0.28 * focal length +1. I assume the exact values will be different from scene to scene but it can be found quite easily using said regression calculator. I used this simple setup :

In order to drive the y transform value, right click in the focal length field and choose "Copy as new driver". Right click in the y transform field of the camera and choose "Paste driver". Right click again in the field, and choose "Edit driver". Then change the evaluation type to "scripted expression" and enter the above formula (in my case 0.28 * lens + 1) :

The result :

Edit :
If you want to use this technique to be always true for its local z-axis, that is to say the forward/backward axis of the camera, follow this :

Select the camera, Press SHIFT + S then choose "Cursor to Selected"
Press  SHIFT + A then choose "Empty" (whichever type)
Add a "track to" constraint to the empty, set it to one of the objects of focus in your scene. If you don't have a particular object, just add a new empty and set it somewhere in the middle of your scene. The constraint should look like this :

Select the camera object, then the empty, and press CTRL + P, choose "Set parent and keep transform"
Now when you move the empty around your scene, the camera should follow it exactly and always turn toward the focus object you chose earlier.
Do not move the camera directly . If you followed previous steps this should already be working. You will most certainly have to tweak the values a little bit though.

Result :

Wow. The linear regression tip is really handy. Local -Z might be more general than Global Y? Maybe not, you'd have to define a target...

Of course ! I updated my answer for the local Z axis

I am delighted. At first I didn't think this was really answerable - then I stumbled and fumbled my way onto another object affecting the Camera Global Y (thru Transform constraint) and that Y location Driving the "lens" mm. There's no Copy/Paste involved, it updates IRT like your update; however, yours answers the initial question! So I'm picking it. Mine answers the later thought, so I could be compelled to post it unless BSE frowns on such things. "Linear Regression." Never heard of it until now. Sincere thanks!

@HelloHiHola Alright, I am interested, do post it if you find the time ! A Linear regression is just a way to "reverse engineer" an affine equation of type y = a * x + b when you just have several x values and their corresponding y values. It only works for linear equations though. (no y = a * x ^2 + b * x + c for instance, this one is a little bit more complicated since it can have multiple or non-real solutions) anyways, MATHS are fun ! :)


text:
New to Blender Unable to create an A Frame Building
I am new to Blender and to this whole 3D world.
I want to build something simple first. And I saw an A-frame cabin video named "How to model a low-poly a-frame cabin in Blender | Blender 2.7 Beginner's Tutorial".
I have a mountain scene on my layout with many Pine trees already there.   And a nice 1:87 scale A-Frame cabin would look perfect there that I can 3D print.
So when watching the video I saw how to add a plane: Shift+A for Add Plane
I made a ground, 100 on X-axis and 100 on Y-axis which I have no problem with.
I then Shift+A for Add Cube, N for properties: X: 6.5 m, Y: 6.5 m, Z 6.5 m.
But then I get lost. How did you make the A-Frame?
I played back the video about 50 times and do not hear how and when to use Hot Keys. They are hard to see without seeing the keyboard.
So what Hot Keys do you use to create the A-Frame?

Hello and welcome, Tom! I got lost, too. It's hard to answer your question when you talk about a video that only you have seen ;-) Post the link to video or add a screenshot.

Blender is not great for the kind of CAD design you want to do.  I'd suggest one of the free CAD programs instead.  I suspect you meant this video but it's for an old version of Blender so you will get lost.

Thanks guys for your  response    I have made some progress but stuck on step 8 of the video that Marty posted.  On her video I see the XYZ Axis arrows on my cube I do not see them I do at the first 4 steps as soon as I hit TAB to go into Edit mode they disappear.  How do I get them on my view?

Hello! Feel free to edit your question and add details. The A-frame is created by scaling the top face of the cube along the X-axis. In Edit mode press 1,2, and 3 for the Vertex, Edge, and Face selection modes. Press T to see the toolbar. There you can activate the gizmo. (the XYZ Axis arrow thingy). Widen the icons to see their labels. Shortcuts: E=extrude (1:44 in the video), Ctrl+R = add edge loops (2:44), I = inset selected faces (6:43).

Hello  Yes I am making progress I have the A-Frame made now.  But I am having issue moving the object so I can select both sides and the top of the roof.   When I place my mouse pointer near the object and click on "G" it just moves the entire object  I currently see the face of the A-Frame   I hover over the object select "L"  then I select "G" but the entire object moves around I need the object to show the top and right side then move the object to show the other side of the roof.   How do I do that?   Thanks

Sorry for the late response. Are you in Edit mode? Blender is very context-sensitive. It matters which object you have selected, which the active object is, in which editor mode you are, and even where your mouse pointer is. Grant Abbitt has updated his tutorial for complete beginners. Maybe you want to check it out here: https://www.youtube.com/watch?v=jnj2BL4chaQ&list=PLn3ukorJv4vuU3ILv3g3xnUyEGOQR-D8J

Creating an A-frame house is not hard when you are familiar with the Extrude, Inset, and Add Edge Loop operations.
Start with the default cube. Then switch to Edit mode with Tab (or Ctrl+Tab to get a pie menu).
In Edit mode, make the toolbar visible (T) if it's not here. You can drag the toolbar larger to see the labels. Tooltips show you the keyboard shortcuts.
Press 3 for Face Selection mode, then select the top face of the cube. Select the Scale tool and scale down the face along the X-axis and you will have the A shape. Alternately, you can press S for scale and then X to restrict it to the X-axis. Move the mouse to scale. If it overlaps you need to move the mouse away first to have a wider range. Enter or left mouse button (LMB) to confirm, RGB or Esc to cancel.

Then you can select the Extrude tool, and select the left, top, and right faces (Shift+left click) of the cube. Extrude them up to create the roof. Select the front faces of the roof and extrude them along the Y-axis to have the roof overhang a bit.
After the extrusion of the roof, you can adjust the thickness when you move first the left and then the right faces of the roof along the Normal direction. For this, you can switch the Transformation orientation to Normal. Don't forget to switch it back to Global when you're done.
In the Adjust Last Operation popup (F9) at the bottom left, you can adjust the settings of the last operation. This is useful to give both sides of the roof the same thickness. Just copy & paste the value for Z.
Tip: when you cancel the extrusion you can get sometimes duplicated vertices. This can cause problems later. To get rid of them you can Merge them By Distance with M.

To follow the next steps of the tutorial select the Vertex Selection mode 1. Then you can select vertices and add edge loops with the tool or R. To change the number of loops use the mouse wheel or Numbpad + and Numbpad -. In the popup Adjust Last Operation you can also change it afterwards.
Shift+Z toggles X-ray and wireframe shading (Z) at the same time in Blender 2.8.
For the face insets select Face Selection mode 3 again.

I now have the Aframe made and  exported it to an STL file and sent it to my friend with a 3D printer.   It came out great except for one thing it was a solid piece.   This is for my Model railroad and I would like to add lighting to the inside of the building.    How can I remove the inside of the cabin   If I place the object in Edit Mode and do a CTRL 7 to turn the object upside down so I see the bottom  AND THEN extrude OUT  THE INSIDE  but not sure about how to accomplish this  any ideas?   Thanks

Congratulations! :-) Yes, if you want to make the inner part of the cabin hollow just do it the way you described. Go to the bottom view and select the bottom face, then inset the face (key I) and create the thickness for the walls. Now select the newly created center face and extrude it (key E) in the direction of the roof along the Z-axis.  This creates the inner room. It's cubic, but just scale it down along the X-axis as you did with the top face in the very first step. And it created the inner A shape. Done :-)


text:
EEVEE viewport and procedural materials
Is it possible to use procedural textured materials in the blender 2.80 EEVEE viewport?
Are the procedural maps that come with Blender 2.80 enough to compose any material?
Are there procedural map plugins that I can get?

Please ask only one question at a time. Give us some info on what you struggle with, and what you have tried so far to get the result you want. As the question stands, the answer would be "yes, no and kind of", which doesn't provide a ton of value to anyone.

I was wondering if the procedural textures that work in Blender render work in EEVEE too?
Yes or no ?

yes, they do, but things like displacement and vector displacement nodes don't work in Eevee.


text:
texture procedural in AO
How can I add a texture procedural to the AO of a material?
both on itself and on the objects the AO casts a shadow on? preferably with different textures for each channel ?
I want to make dirt that exists between two objects that are side by side on the EEVEE or bake in Ccycles to use it in EEVEE I want to use the AO result with a procedural texture to draw dirt

AO doesn't affect shadows; AO doesn't affect any object but the object it's on.  Meanwhile, AO doesn't mean anything anywhere except Eevee, where you have an AO input for Specular BSDF (where how to make procedural AO is trivial-- probably not what you're asking.)  What is your goal from AO?  Where are you rendering?  What is it you hope to achieve?

Don't tell me in comments.  Comments are temporary and people won't read them to answer your question.  Put it in your question.


text:
How to remove icon sphere from toolbar
I added by accident the sphere icon to my toolbar. How can I remove it from the toolbar? Thank you,
Have a great day,
Sandra

If you keep pressing on the button you'll have access to a dropdown menu that will let you choose the primitive you want. You can't remove the button from the tool bar though:


text:
I cannot emulate 3rd mouse button on MacBook
Attempting to use a trackpad without a 3-button mouse. From this forum and others I see going to Edit | Preferences | Input | Check emulate 3 button mouse
And choosing Emulate 3 Button Mo.. selecting either Alt or OS Key
Then, expected if I press G, then held the Command (Alt) or Globe/Fn key, I would see the graphic showing ability to snap to an axis. The graphic does not appear and holding the key has no effect.

You say "Then, expected if I press G, then held the Command (Alt) or Globe/Fn key". I don't know anything about Macs, but I thought that the Command key on a Mac was the equivalent of the Ctrl key, not the Alt key on a Windows machine?

I use a Wacom pen on my Mac and use the ALT-key, no need for the Fn-key. I would use that for the numpad to change views.


text:
Efficient way of extruding moulding shapes out of walls
I have a model of an apartment, which is all of it a single connected mesh (the vertex for the floors connect with the ones on the wall, etc) and I wanted to extrude small mouldings at the bottom of each wall (0.1m high, 0.025m thick), where it connects the floor, such that the floor would also be pushed by the extruded mouldings. I've been looking around for methods that would introduce the least amount of vertices, and that altered the mesh as little as possible (keep the floor vertices connected to the walls, and the walls to each other). However, I only found solutions using booleans, or curves with bevels. I'm new to Blender, so I was hoping to learn ways of doing this within the Edit Mode of my object.
Here's my current process:

Knife tool to cut the top of the moulding

Adjust the height of one of the cut vertices to 0.1m, then scale-z x0 the rest of the cut vertices relative to the first one, to align them vertically

Extrude all of the cut faces that have the same normal

Knife tool to cut an edge along the adjacent wall, and merge the cut with the extruded mesh, to connect both

Delete the floor vertices left behind the extruded area, which will result in unseen faces, and connect the other wall to the extruded area.

I'm sure there's a better, easier method to achieve this, right? Deleting the original floor vertices in the last step also deletes the floor faces, which forces me to re-create them later. I could instead merge these extra floor vertices to the extruded ones, but the whole process feels very brittle and prone to create bad geometry, so I was hoping if anyone would have any tips on how to achieve this result in a better way. Doing this on multiple faces at the same time would be ideal.
Let me know if there's any more info I can provide, many thanks!

I'd argue that the efficient way of doing this is not as a single mesh, but as a separate object. Possibly using curves or whatever other technique is suitable for you. https://blender.stackexchange.com/a/178627/19307 https://blender.stackexchange.com/a/58567/19307

Thanks! I committed to extruding from within Edit Mode for this, but I'll take a look at those for reference

For the top of your moulding you can choose the front view, activate the knife and cut orthogonally and through the whole mesh (KAC):

For the floor edges, choose the top view and cut the different edges.Then select all the faces on the floor, press AltE > Extrude Manifold and snap on the vertices (it won't leave any interior faces):

Or do a simple extrude up and snap, then go into Select > Select All by Trait > Interior Faces, remove these faces:

Thanks! Extrude manifold from the floor directly saves a lot of steps.

Loop cut and extrude the bottom portion you want.  Select all of the new top corner edges and give a Bevel Weight to the edges (bevel weight appears as a blue edge in the viewport).

Then use a Bevel modifier with some extra segments to your liking, Limit Method -> Weight, and a Custom Profile.

Changing the profile will model your molding accordingly.

Problems with this method and Shade Smooth, since you wanted all one object.  Probably fixable with a very particular bevel profile that preserves Normals for one segment down the wall.  Also don't know how fiddly this would be with complex shapes, but as long as you can keep everything straight and only give bevel weight to that one edge loop I think it should be ok.

My mouldings are intended to be as low-poly as possible, so I ended up just extruding without bevels, but this is neat!


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Is FBX converted to blender doomed to have messy mesh?
The origin file is either 3dsMax or Maya. The mesh was clear and quadrangles back then. However, when it is opened in blender, it becomes triangular messy mesh as showed below. I have tried several FBX files. They are all like that. Am I doing something wrong? Thank you.

The mesh should not be triangulated on import. My guess is that the mesh was exported with triangulate.
You can try to run Tris to Quads operator in the Face menu (Alt-J) but usually it will not give the desired result.

Thanks for the advice. I finally found out while exporting FBX from 3ds max the option of "Preserve edge orientation" should be unchecked to avoid triangulation.


text:
Unable to select items on outliner
I'm new to blender and I'm struggling with a few things that are probably tiny but I just can't quite get them. The biggest issue is selecting different parts of the mesh in the outliner. Specifically, selecting to make the name white on the outliner and allow me to edit that part. I click on the grey symbol with three white dots in a triangle. 1 out of 100 times it works.

The second issue is every once in awhile the texture of what I'm working on disappears. I feel like a button accidentally gets pushed and I'm unsure how to turn it back.
Before:

After:

Hi. Please only ask one question at a time. If you need to ask multiple questions, make separate posts.

In the Outliner, when you click on the object mesh icon, it allows you to enter in Edit mode and to edit the object mesh, it doesn't allow you to precisely select one part of the mesh if that's what you're trying. If you don't see anything when you click on this icon, maybe it's because your object is not visible on your 3D View, it can be on another layer for example. Also, when you try to edit an object, why don't you select it and press tab to enter in Edit mode? This is the classic method.
About your display problem: You must accidentally press Z, it makes you switch between Rendered (or Material) mode and Wireframe view. See what happens on the bottom horizontal bar of your 3D View.

The Outlined is a bit of a different animal from the 3D view, and the click behavior in one isn't the same as the click behavior in the other, and the Outliner can indicate different object selected than the 3D view. Selecting the white triangle will take you to that object and put you into Edit mode.
Select the white triangle to the right of the name to enter Edit Mode for an object. Select the yellow triangle to the left of the name to select that object in the Object mode. The yellow triangles to the right of any name are the child objects, and you can select those by clicking them but it's harder to remember the exact order so usually people expand the object to see the children. It gets confusing when you click the empty space to either side of an item in the outliner, because that only highlights the name but doesn't select it in any way. To select a highlighted object(s), right-click and choose Select. The highlighting option is available because it makes it easier to select multiple objects at the same time (using B to make a box, or shift-clicking). The highlighting ability is redundant and it would be better for Blender to immediately select in Object mode when you highlight (which is similar how Windows and most other software works), but that's the way Blender 2.79 does it.


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Screw modifier with mutiple curves (how to get good result)
The screw modifier is good for creating a solid mesh from a single curve profile, but it does not seem to provide any options for handling multiple curve profiles.
This is the result of using a screw modifier on two (asymmetrical) curves. The generated mesh does not line up at the seam, since the two profiles generate independent submeshes.

Can the screw modifier interpolate between the two curve profiles as it rotates around and creates each vertical slice of the mesh? The dimension of interpolation should be the radius of any point on the curve, measured from the central screw axis.
Diagram:

A result with clean topology would be a bonus, if possible.

Here's a more exact solution using python. Make sure your shape is on the XZ plane and the number of vertices are exactly the same on the left and on the right of the Z axis. Select the top most vertex and run the script. This will generate a new object that interpolates each ring of vertices from the left curve profile to the right curve profile.
Simple Profile with segments=16:

Complex Profile with segments=32:

Now you have a cleaner interpolated profile:

Here's the script:
import bpy
import bmesh
import math
from bpy import context as C
from bpy import data as D

def deselect_all_objects():
    for obj in C.scene.objects:
        obj.select_set(False)

def traverse_vertices(bm, pairs, forward):
    start_vertex = bm.select_history.active
    iterations = int(len(bm.verts) / 2)
    i = 0
    visited = set()
    stack = [start_vertex]
    end = -1

    while stack and i < iterations:
        vertex = stack.pop()
        if vertex.index in visited:
            continue

        visited.add(vertex.index)

        if i > 0:
            pairs[i-1][0 if forward else 1] = vertex.index

        neighbors = [edge.other_vert(vertex) for edge in vertex.link_edges]
        stack.extend(neighbors if forward else reversed(neighbors))
        end = neighbors[1]
        i += 1

    return (end.co.x, end.co.y, end.co.z)

def init(bm, obj):
    if not obj:
        raise RuntimeError("You need to select a mesh!")

    bpy.ops.object.mode_set(mode="OBJECT")
    bm.from_mesh(obj.data)
    total_verts = len(bm.verts)
    selected_verts = len([v for v in bm.verts if v.select])

    if total_verts % 2 > 0:
        bm.free()
        raise RuntimeError("You need an even amount of total vertices")
    elif selected_verts != 1:
        bm.free()
        raise RuntimeError("You must select exactly 1 vertex")
    obj.hide_set(True)
    return [[0, 0] for _ in range(int(total_verts / 2)-1)]

def cubic_bezier_z(z1, z2, t):
    mt = 1 - t
    mt2 = mt * mt
    t2 = t * t
    z = z1 * mt2 * mt + 3 * z1 * mt2 * t + 3 * z2 * mt * t2 + z2 * t2 * t
    return z

def create_mesh_ring(bm, v1, v2, segments):

    x1, x2 = v1.co.x, v2.co.x
    r1, r2 = (abs(x1), abs(x2)) if x1 > x2 else (abs(x2), abs(x1))
    z1, z2 = (v1.co.z, v2.co.z) if x1 > x2 else (v2.co.z, v1.co.z)

    h = segments // 2
    verts = []

    for i in range(segments + 1):
        f = i < h
        j = (i + (0 if f else 1)) % (h + (0 if f else 1))
        p = j / h if f else (h - j) / h
        angle = math.pi * 0.5 * p

        r = r1 if f else r2
        x = r * math.cos(angle - (0 if f else math.pi))
        y = min(r1, r2) * math.sin(angle)
        z = cubic_bezier_z(z1, z2, i / segments)
        verts.append(bm.verts.new((x, y, z)))

    return verts

def create_mesh(bm_orig, ref_v, end_v, pairs, segments):
    mesh = D.meshes.new(C.active_object.name + "_result")
    obj = D.objects.new(mesh.name, mesh)
    C.scene.collection.objects.link(obj)
    C.view_layer.objects.active = obj
    obj.select_set(True)

    bm = bmesh.new()
    bm_orig.verts.ensure_lookup_table()

    prev_verts = None
    v = bm.verts.new(ref_v)
    v_end = bm.verts.new(end_v)

    for p in pairs:
        v1, v2 = [bm_orig.verts[i] for i in p]
        verts = create_mesh_ring(bm, v1, v2, segments)

        if prev_verts:
            for j in range(1, len(verts)):
                v1, v2, v3, v4 = prev_verts[j], verts[j], prev_verts[j-1], verts[j-1]
                bm.faces.new([v2, v1, v3, v4])
                if p == pairs[1]:
                    bm.faces.new([v, v3, v1])
                if p == pairs[len(pairs)-1]:
                    bm.faces.new([v_end, v2, v4])

        prev_verts = verts

    bm.to_mesh(obj.data)
    bm.free()
    return obj

def get_reference_vert(bm):
    x, y, z = bm.select_history.active.co
    return (x, y, z)

def add_mirror_y_modifier(obj):
    mirror_modifier = obj.modifiers.new(name="Mirror", type='MIRROR')
    mirror_modifier.use_axis[0] = False
    mirror_modifier.use_axis[1] = True

def add_subdiv_modifier(obj):
    subdiv_mod = obj.modifiers.new(name="Subdivision", type='SUBSURF')
    subdiv_mod.levels = 1
    subdiv_mod.render_levels = 2

def main():
    obj = C.active_object
    segments = 16
    bm = bmesh.new()
    pairs = init(bm, obj)
    v = get_reference_vert(bm)
    traverse_vertices(bm, pairs, True)
    end = traverse_vertices(bm, pairs, False)
    deselect_all_objects()
    obj = create_mesh(bm, v, end, pairs, segments)
    add_mirror_y_modifier(obj)
    add_subdiv_modifier(obj)
    bm.free()

main()

I think the closest you can get is using Bridge Edge Loops. For it to work you need to select and rotate half of the vertices by a very small amount like $0.0001m$ with RZ0.0001, and then select the other side, excluding the center top and bottom vertices. Then go to menu Edge > Bridge Edge Loops and increase the number of cuts by any desired amount to fix your topology needs. Make sure you use Interpolation method Blend Path. And then add Mirror Modifier.

It's not automatic or exact, but this is a really good approximation. The bridge edge loops operator gets a little confused at the poles, especially on complex shapes. But, on the simpler shapes, like the one from my OP, this method is close enough that manual tweaking can finish the job. Getting a good topology seems to lie in having an exact & uniform vertex distribution (by segment length between vertices) for every profile curve when converting them to meshes. Will need to find an addon that can do this.

@TiberiumFusion Here's an exact python solution https://blender.stackexchange.com/a/301109/142292


text:
Copy shape key to a different object with similar geometry
Is it possible to copy a shape key between objects with similar geometry? Specifically, I am looking to transfer shape keys from a higher poly mesh to a lower poly mesh that are very similar in shape, but have different topology.
Contrived example:
Here I have two meshes with similar geometry.

The mesh on the left has a shape key.

If I align the mesh on the right with the mesh on the left, such that the verts are generally next to their counterparts... (this will have varying degrees of error for more complex shapes with different topology and scale)

...can the per-vertex transition data for the first mesh's shape key be interpolated and copied to the second mesh? Can I adjust the interpolation strategy? (similar to how vertex weighting can be copied between dissimilar meshes with varying interpolation methods)

Even if you have equal geometry, but different vertices order, transfer will fail. Shapekeys are very strict to this. Try shrinkwrap or mesh/surface deform to mimic shapekey from source object.

Also depending on your requirements you can create a Lattice animated with Shape Keys that can be used for multiple objects.


text:
Creating a spiral along a bezier path
How can I create a spiral that follows an arbitrary bezier path?
Here's an example of this in Fusion 360:
So, in other words, this is a bezier curve that winds itself around another bezier curve to produce a spiral. The spiral profile, climb angle, and distance from the central bezier curve should all be customizable.

Enable the "Add Curve: Extra Objects" addon to create spirals easily in the add object menu and add a curve modifier to it.

I gave a detailed answer about a phone cable here. If you want to keep a curve instead of a mesh you can do it the way below. At the end you can convert your curve to mesh if you want. I'm not sure you can use 2 curves and array a mesh along the spiral though. So:

Create a spiral.

Create another curve, a straight one this time. Give your spiral a Curve modifier with the second curve as Object.

Select your spiral. In the Properties panel > Object Data > Shape > Choose Fill > Full, and in Geometry play with the Bevel Depth and Resolution values.

Move the straight curve, the spiral will bend.


text:
Rendering Animation Only showing world background?
When I am in my file and choose to look at the work space in the render mode instead of object mode everything appears to look correct. The 2 planets and tie fighters I have moving are in place, lighting is hitting both objects and everything appears to work okay. However something is happening when I go to render my file, It appears that the world background I created, black with stars occasionally is the only thing that is appearing? Is it covering the cameras view? Are the other objects in the scene invisible? What am I missing? Thanks.

Possible duplicate of Render result is completely blank?

https://blender.stackexchange.com/questions/67490/why-does-my-object-not-show-up

Can you post screenshots or include Render Layer information? I'd like to see it happening; I think it's something elementary but difficult to nail down with only text. Did you tinker with Cycles display/render settings to make things 'invisible' to the camera?


text:
Choose active tool in Python
Is it possible to choose active tool in Python?

You can use the wm.tool_set_by_id() operator.

Example for a button:
layout.operator("wm.tool_set_by_id").name = "builtin.select_box"

Example operator:
import bpy

def main(context):
    bpy.ops.wm.tool_set_by_id(name = "builtin.move")
    for ob in context.scene.objects:
        print(ob)

class SimpleOperator(bpy.types.Operator):
    """Tooltip"""
    bl_idname = "object.simple_operator"
    bl_label = "Simple Object Operator"

    @classmethod
    def poll(cls, context):
        return context.active_object is not None

    def execute(self, context):
        main(context)
        return {'FINISHED'}

def register():
    bpy.utils.register_class(SimpleOperator)

def unregister():
    bpy.utils.unregister_class(SimpleOperator)

if __name__ == "__main__":
    register()

you can call the operator inside another operator or as in my first example you can add button to a menu/panel.

Thank you very much!

You can set it active tool via bpy.ops.wm.tool_set_by_id() operator. However it is important to execute the operator in the right context. So running this operator from the wrong context won't work. Here is a simple method that sets the tool with the right context override:
def set_active_tool(tool_name):
    for area in bpy.context.screen.areas:
        if area.type == "VIEW_3D":
            override = bpy.context.copy()
            override["space_data"] = area.spaces[0]
            override["area"] = area
            bpy.ops.wm.tool_set_by_id(override, name=tool_name)

If you want to know how the active tool_name is called, just go into the console and type in bpy.context.workspace.tools and then press Ctrl+Space. This will show you the current and last active tool id name which you can use as parameter for your set_active_tool() method. Just select your desired tool and see how it is called.

But, would it be possible to have no active tool (like set_active_tool to 'None')?

In the Scripting workspace or in console you can run this:
import bpy
bpy.ops.wm.tool_set_by_id(name = <idname>, space_type="VIEW_3D")

Where <idname> is bl_idname of a WorkspaceTool you want to choose. (idname is an instance variable, while bl_idname is a class variable of a given tool)
This works for tools in 3D Viewport.
The active tool is then available through:
bpy.context.workspace.tools.from_space_view3d_mode('OBJECT').idname

Where 'OBJECT' is a mode the tool is selected in.
To switch between modes, there's this api:
bpy.ops.object.mode_set(mode='EDIT')
bpy.ops.object.mode_set(mode='OBJECT')


text:
How do I add weapon bones to Autorig Pro?
I am using Autorig Pro.
How can I create a weapon bone on a bone made in Autorig Pro and parent the bone to the hand?

I guess you can either create a new bone in the existing armature (for example duplicate the hand bone) or simply parent the object to an existing bone of your armature (like the hand), the object itself can be part of the character but it also can be a separate object


text:
Symmetry issue 2023
been working on learning blender and making a model. Unfortunately after merging objects and remeshing them it changes the symmetry/origin and I tried using some methods I saw to fix it but it does not work. The origin to geometry doesnt work, origin to 3d pointer doesnt work, tried shift + c method. Nothing works unless I go abck to the point of before merging objects but I want them to be merged. When I try the mirror modifier it makes the model look like this

how do I fix this ??

Hi Please use a title that reflects the content of the question. It should be descriptive but succinct, unique and identifying, summarizing the issue so that users can at a glance understand what your post is about. Use the [edit] link below your post and avoid anything not strictly essential to the post. Remember, your title is the first thing potential visitors will see, and makes your question findable for future users. See "What is the problem with posting an image or link and asking “How do I do this?""

if you enable the X symmetry but the object is not symmetrical, the sculpt won't act the same on the 2 parts, you need your object to be symmetrical first

the thing is I used symmatrey to sculpt both objects seperately before merging so I am not sure how to check that

This problem may be because you forgot to turn on Symmetry during engraving or your coordinates are not correct, if the latter is the case please use Ctrl +  A to adjust or solve your problem.

that fixed the issue, to which I did apply to all transformations and it worked !

@moxartz Hello and welcome. Please don't reply "Thanks" as an answer or comment, instead upvote the post that helped you. If you feel it completely solved your issue consider marking it as accepted.

@Kiara Hello and welcome. Rather than take photos of your monitor post actual screenshots instead, see How to take a screenshot. Photos are harder to read because we have to look past external interferences (like reflections, smudges or Moiré patterns) and guess if we are looking at hardware issues such as a malfunctioning display or connections, a software level issue like driver malfunction or glitch, or actual artifacts or issues with the model itself.


text:
Assistance with starting blender
I'm using 2.79B Blender for Windows due to an addon that works with it, and have tried both portable and installer varieties, when I launch the program a terminal or Windows console host window opens, remains open and nothing further happens. (pictured is a host window)
Using the 3.5 blender, it launches correctly, but every other variety of blender that I have installed experiences issues similar to or the same as the ones I have described for 2.79b, or are not compatible with the addon I'm using.
What steps can I take to solve this issue? What can I do to get a diagnosis?
Thanks for your time!

Hi Please use a title that reflects the content of the question. It should be descriptive but succinct, unique and identifying, summarizing the issue so that users can at a glance understand what your post is about. Use the [edit] link below your post and avoid anything not strictly essential to the post. Remember, your title is the first thing potential visitors will see, and makes your question findable for future users. See "What is the problem with posting an image or link and asking “How do I do this?""

Try running it from your files and not from an internet shortcut.


text:
Is it possible to go back into sculpt mode after posing a model?
I made a simple "T" pose model out of cubes which I joined using the boolean modifier. I then added a simple armature to it and was able to pose the model. However, it now looks like "sculpt mode" on the top left has disappeared from the drop-down menu (same menu that has object mode, edit mode, etc). Is it possible to go back into sculpt mode after posing an object?
My thought behind this is that I would like to sculpt a model, then pose it, and finally refine it based on the pose. For instance, if I bend an arm, the bicep should flex; or, if I turn a model's head, tendons in the neck on one side will be more prominent. So, I'd like to add these details after it has been posed. Is that a bad way to do things? If so, is there a better way?

if you cannot see "Sculpt mode" then you probably still have selected the Armature object. You need to select the mesh object in the outliner.

@Blunder that was it- thanks! Feel free to submit as an answer if you want credit :)


text:
The texture is correct in render and uv but not in texture paint. How can I edit the correct texture paint?

The texture paint is the only one that is wrong. Render and shading are correct but I can't correct it in paint plus every time I do try to paint it will paint on the wrong material.
I have two collections, one for the face and the other for the hair and the materials for them both. The face material is on the hair mesh while not being assigned to it.

Make sure that you've selected Mode > Material in the N panel > Tool > Texture Slots, if you've selected Single Image you are painting on the selected image which may not be the good one:

Bingo, this was the answer


text:
Viewport doesn't update when modifying geometry nodes with scripting
Learning how to use blender python scripting and am editing some existing geometry nodes on an object. When I do so however, the viewport doesn't reflect the changes i've made. Any help would be greatly appreciated thanks. Screen-recording of issue

can fix this by toggling into edit mode and back but surely theres a better way

I solved this issue by calling modifier.node_group.interface_update(context)
context = bpy.context
modifier = context.active_object.modifiers['GeometryNodes']
modifier['Input_2'] = 5.0
modifier.node_group.interface_update(context)

Also note that modifier['Input_2'] in this case is a floating point number, and you should use 5.0 instead of 5.
(https://docs.blender.org/api/3.3/bpy.types.NodeTree.html#bpy.types.NodeTree.interface_update)

Have you tried setting 5 instead of 5.0 and got any weird behavior/error? Every time I test, integers work just fine and are converted to floats behind the scenes.

Ok, that was not the case when I tried it (Blender 3.3 and 3.5)
The input option disappears and when using interface_update it was set to 1.0 (default_value).

I just checked to be sure and you're right, in the case of setting geonode modifier values, must use the dot, thanks!

Is there a better way to set a geonode modifier value?
That would call the setter and convert the int into a float.
Because right now we access directly to the stored/internal value.


text:
How would you go about retopologizing hard surface models that have a lot of detail?
So, I made this robotic hand that has a lot of bevels and some booleans. I'm not really sure how i should go about retopologizing all of the details, since I'm only really familiar with retopologizing smoother surfaces like humanoid bodiens. So I was wonder, weather I should make shapes, that simply don't have the bevels, or something completely different? For refference, here's my mode
I mean, it doesn't look that high poly, but when I go into edit mode:

It has nearly 140k tris, and from what I see, it looks like most of it is being caused by slices as such:

as well as some of the bevels, as seen in the last image. So, do I just simply have to retopologize it without the bevels and slices, or is there a different way, or well, at least a more correct one.
Any help would be appreciated. Thanks!

Whats your goal with retopologizing?  Do you want to make it more suitable for bending or non-rigid animation? Reduce poly count? Something else?

@gandalf3 I wanted to reduce the tri count, so it's not too much and I can export it to a game engine afterwards. From what I've heard, it seems like a lot of tris for a model that'll be imported into a game. These hand objects in particular won't be deformed, since I'll be parenting them to bones, so it'll only move along the bones, so I'm not sure weather the tri count matters that much in this case.

140k indeed sounds fairly hefty for a single hand. Since its not deforming, you don't need to care about having triangles or uneven geometry too much so, here are some tools which may be suitable:

Decimate modifer (and Decimate Geometry in edit mode)
Dissolve edit mode tools

How much you decimate is of course tradeoff of detail for speed, which is typically made based on your performance needs, your engine's optimization features, your artstyle, and how much it'll be seen (i.e. is this a player character's hand which will be on screen all the time vs an npc or something). There's not really any hard and fast rule, but for example, the small surface greebles and details may be better off removed entirely and instead baked to a normal or displacement map. Here is the documentation for texture baking in cycles; the setup can be a bit fiddly if you aren't used to it, this question might help.

Thank you very much! So I got rid of the small details, as highlighted in the last photo of the post, so I made a low poly, that doesn't have such details and kept the high poly, and then baked it as any other humanoid model.


text:
Function not working when being called by operator
I'm doing a scritp with several functions. All of them have been tested and work fine if you execute them from a py file. The problem is when I put them on an operator and call them when pressing the button they stop working. It seems as if blender is not able to get the current active object to do whatever I'm telling it to do.
Because is work related I can't really share the code but one of the parts where it crashes looks like:
ob=bpy.context.active_object
for i in range(0,len(bpy.context.object.data.polygons)):
        ob.data.polygons[1].select=True
        bpy.ops.object.mode_set(mode='EDIT')

The loop is longer, but the error comes up in that line. Menawhile, executing the same function from a py file works fine.
The error is

AttribueError: 'NoneType' object has no attribute 'data

Any idea?

What are you trying to achieve?

In this part I'm separating some faces. But that's not the problem. As I said, the code works. When I put it on a operator in the properties panel suddenly the script cannot access the selected object even though you can see in the viewport that it has in fact been selected.

Hello. I'm a bit surprised, active_object should be available in the properties panel. But please note bpy.context.object and bpy.context.active_object can point to different entities, if you use the "Pin" feature in the properties panel, bpy.context.object  will point to the pinned entity if you run your operator from the properties panel. bpy.context.active_object however should always pont to the one selected in the 3D viewport, and active_object is context-wide and I think file-wide so there shouldn't need to be a context override here

import bpy

bpy.ops.object.mode_set(mode='EDIT')

for i in range(0, len(bpy.context.object.data.polygons)):
    bpy.context.object.data.polygons[i].select = True

Try switching to Object mode prior to selecting.

Not what I'm trying to do. Also, you need to switch to Edit mode after doing the selection so that the mesh updates, not before. As I said, my problem is that when I put my code (that works fine) on an operator in a panel, it's no longer able to see the selected object. And this does happen in several functions.

@AntGarGal I think their point was that you don't need to toggle edit mode at every step of the loop for the selection to update, you'll see a severe performance hit if your mesh is very dense. It should be after the for loop, not inside it. So either you have included too much information with this line since the error seems to fire just before or you didn't include enough information. cheers

I found a workaround though I'm not sure is the best solution. Apparently when executing the operator from the porperties panel it's not able to run operators from the 3D viewport. Digging around I found that adding this loop before the lines does work, though it's a bit confusing to which ones they have to be added to as not all 3D viweport operators fail on my code.
for window in bpy.context.window_manager.windows:
   with bpy.context.temp_override(window=window):
       'Do whatever'


text:
Super low fps when I import my own exported obj or fbx file
I have made my own head with hair in blender. But when I export it to fbx or obj the file is super slow and I cannot do anything... The fps is below 1 when I want to play the timeline. Is there something I can do about this?

This might be due to high poly counts.

Is there something I can do about that?


text:
How can I transfer weight paint between different vertex groups of the same object?
I'm very new to Blender, and I'm mainly learning how to model environments for historical recreations. I'm using BiomeReader to scatter vegetation in a project, and it requires a new vertex group to set the density of every different type of plant or scattered object with weight paint.
This means that I have a single mesh with several vertex groups. The problem is that I need all these vertex groups to have the exact same weight paint and I can't figure out how to do it other than manually painting every single group (and I will go insane if I have to do it like that), since all the other questions on a similar topic are about transfering vertex weight between different objects. I can provide screenshots if needed.
Thank you!

Is the weight constant, in these separate vertex groups?

You may copy vertex weights using this menu:

it will create an exact copy of weights in a new vertex group
More advanced way is using Weight Mix modifier, that allows different methods to blend vertices and mix mask.
Set Vertex Set to "All" (tell Blender that you want to affect all vertices) and in "replace" mix mode weights will be transferred from B to A.

When you are ok with results, apply modifier.

Thank you! The Weight Mix modifier worked perfectly :)


text:
Can motion sensors be used to make a character move in Blender?
I just wanted to ask if motion sensors can move a model made in Blender. For example: if let say a I have a motion sensor on my elbow and hand if I begin to move my hand in an up and down motion is there a way for it to be translated over to Blender and if there is can you guys tell me the what is used.  Thanks.

Yes, it is possible to even move a human skeleton in real time in Blender but you need a few things to implement it.
A few external software, an XBox One Kinect and an adapter for it, in order to be able to plug it into a computer USB. The computer has to have a USB3 connection and for this a USB controller by Intel or Renesas, otherwise it will not work.
I would not recommend the XBox 360 Kinect because that has a lot less resolution and less features.
Instead of writing a mass of info here I rather give you a YouTube link where all this is explained in detail, including how to make all this work in Blender in real time. You will find all the links to the hardware and software that you need in the description of the video.
https://www.youtube.com/watch?v=1UPZtS5LVvw
What you learn there you can apply it to whatever you want to achieve.

I am glad I could help.


text:
preserve/save context in modal
how can i avoid losing the context with this modal operator?
import bpy

def get_next_area(area, reverse):
    #context = bpy.context

    areas = [
        "VIEW_3D",
        "VIEW",
        "UV",
    ]

    if reverse is False:
        for index, c in enumerate(areas):
            if c == area.ui_type:
                if index == len(areas) - 1:
                    return areas[0]
                else:
                    return areas[index + 1]
    else:
        for index, c in enumerate(areas):
            if c == area.ui_type:
                if index == 0:
                    return areas[len(areas) - 1]
                else:
                    return areas[index - 1]

class SM_change_area_type_modal(bpy.types.Operator):

    bl_idname = 'sop.sm_change_area_type_modal'
    bl_label = "S.Menu Change Area Type Modal"
    bl_description = 'Calls Change Area Type Modal'
    bl_options = {'REGISTER', 'UNDO', 'GRAB_CURSOR', 'BLOCKING'}

    def modal(self, context, event):

        area = bpy.context.area
        print (area)

        if event.type == 'WHEELUPMOUSE':
            area.ui_type = get_next_area(area, False)

        if event.type == 'WHEELDOWNMOUSE':
            area.ui_type = get_next_area(area, True)

        # -------------------------------------------------------------#
        #+ Finish/Cancel Modal
        elif event.type == 'LEFTMOUSE':
            return {'FINISHED'}

        elif event.type in {'RIGHTMOUSE', 'ESC'}:
            return {'CANCELLED'}

        return {'RUNNING_MODAL'}

    def invoke(self, context, event):
        #self.first_mouse_x = event.mouse_x
        #self.first_mouse_y = event.mouse_y

        # self.initial_backdrop_offset = bpy.context.space_data.backdrop_offset

        #self.mouse_path = []
        context.window_manager.modal_handler_add(self)
        return {'RUNNING_MODAL'}

def register():
    bpy.utils.register_class(SM_change_area_type_modal)

def unregister():
    bpy.utils.unregister_class(SM_change_area_type_modal)

if __name__ == "__main__":
    register()

Get the area from its index in the screen.
Without any "proper" explanation I had an inkling that if the area was indexed from the screen it will remove the context issue seen in code above.
>>> for i, a in enumerate(C.screen.areas):
...     i, a.ui_type
...
(0, 'PROPERTIES')
(1, 'CONSOLE')
(2, 'OUTLINER')
(3, 'TEXT_EDITOR')

The properties area above will always be the zeroth item of the screen areas no matter what its type is changed to.  (Unless areas are joined during operation)
When invoking get the index of the current area in the screen, use this to get the area.
self.screen_area_index = context.screen.areas[:].index(context.area)

Edited code:
Added class properties for current area index, the index of the area in the screen, and the ui type when invoked.
When operation is cancelled go back to original ui type.
Changed the behaviour to pass through when no event is captured.  Not required, personal taste, found it a very handy little tool to flip between types, while still being able to use other tools. Would need to reconsider what finishes the operator in this case.
import bpy

class SM_change_area_type_modal(bpy.types.Operator):
    ''' Tooltip '''
    bl_idname = 'sop.sm_change_area_type_modal'
    bl_label = "S.Menu Change Area Type Modal"
    bl_description = 'Calls Change Area Type Modal'
    #bl_options = {'GRAB_CURSOR', 'BLOCKING'}
    index = 0
    screen_area_index = 0
    save_area_ui_type = ''

    def get_next_area(self, area, delta):

        areas = [
            "VIEW_3D",
            "VIEW",
            "UV",
        ]

        self.index = (self.index + len(areas) + delta) % len(areas)
        area.ui_type = areas[self.index]

    def modal(self, context, event):
        area = context.screen.areas[self.screen_area_index]

        if event.type == 'WHEELUPMOUSE':
            self.get_next_area(area, 1)
            return {'RUNNING_MODAL'}
        elif event.type == 'WHEELDOWNMOUSE':
            self.get_next_area(area, -1)
            return {'RUNNING_MODAL'}
        elif event.type == 'LEFTMOUSE':
            return {'FINISHED'}
        elif event.type in {'RIGHTMOUSE', 'ESC'}:
            area.ui_type = self.save_area_ui_type
            return {'CANCELLED'}

        return {'PASS_THROUGH'}

    def invoke(self, context, event):
        self.screen_area_index = context.screen.areas[:].index(context.area)
        self.save_area_ui_type = context.area.ui_type
        context.window_manager.modal_handler_add(self)
        return {'RUNNING_MODAL'}

def register():
    bpy.utils.register_class(SM_change_area_type_modal)

def unregister():
    bpy.utils.unregister_class(SM_change_area_type_modal)

if __name__ == "__main__":
    register()

Please try and adhere to the operator class naming convention
class SM_OT_whatever_else(Operator):
    bl_idname = sm.whatever_else


text:
How do I make something light sensitive?
Say I I’m shining a flashlight (spotlight parented with camera) at something, how do I make that something react a certain way. (Ie. what sensor do I need to use for an object to be able to detect light?)
Any simple tips would help, just a beginner here.

For the light itself you can't, but you can fake it using a physics object with the light shape and detecting this object through collision. The file below is a working example, and contains the instructions below on the Text Editor for convenience.
Use the Outliner to click the described object and check the given properties.
Project Structure

Scene '_lib_props':

'player' objects in the first layer, all added to the group 'player'.
'box' objects in the second layer, all added to the group 'box'.

Scene 'scenery':

'ground' and 'walls' are mesh objects.
The 'player' is a group instance of the group 'player' from the lib scene.
The 'boxes' are group instances of the group 'box' from the lib scene.

Player Structure
Check the Outliner for a better overview of the structure of the player.

Object 'flashlight_lamp_collision' is a mesh object parented to 'flashlight_lamp', and it contains the following properties:

Property 'flashlight' to be detected by the boxes.
Physics type Static, Ghost enabled, Invisible enabled, Collision Bounds set to Triangle Mesh.

With these options, this object can be detected by the 'box_sensor' objects.
Box Structure
Check the Outliner for a better overview of the structure of the box.

Object 'box_visual' is a mesh object parented to 'box_sensor', and it contains the following properties:

Physics type Static, Collision Bounds set to Triangle Mesh.
Object 'box_sensor' is a mesh object, and it contains the following properties:
Physics type Sensor, Invisible enabled, Collision Bounds set to Triangle Mesh.

With these options, this object can detect the player's 'flashlight_lamp_collision' using a collision sensor.


text:
Does Ivy-Gen Work on Animated Meshes
Does the Ivy-Gen tool work on a deforming or animated mesh, or can it be applied only to static objects?  I have found no examples of it being used on an animated character, for instance.
Thank you in advance!

Can you be more specific of desired result? Some reference ...

Hi!  Yes, as the question implies, I'd like to have some vines growing along the limbs of an animated character.   Having been unable to find a single example of anyone doing that [not saying they haven't - I just haven't found any], I began to wonder if the tool were limited to operating only on static meshes.
In another forum, someone mentioned using Deformers or Geometry Nodes.  I will be looking into any and all options, but I've only had Blender for a few days, and have a lot to learn about it still.

Please include important parts into your Q not into the comment. Yes, Mesh Deform modifier or GeoNodes sounds the way, for beginner sounds to me a big bite. I asked for details, because just let move Ivy with mesh can be done with modifier, but it is another story for growing (you mentioned now) or if you expect some parts of branches (or leaves) should wave as reaction on a mesh movement ... growing along limbs - how the beginning should looks like? Or is it out of camera view? To give you something see answer ...

Geo Nodes
One of the option based on Shortest Path node ... this could work, just as name whisper ... it can be a glitchy since transforming vertices by armature could change state of what os shortest path for GN :)

Original post
To make it work select a vertex of grow beginning (on your limb object) and Assign it to Vertex Group  called "StartPoint" (or call it as you want , just choose the same name listed under GN Atribute node.
Edit:
To avoid re-shortening path (mentioned above) you can split the node tree into two separate stages ...
First Step
use beginning of the node tree. It builds vines structure ... Apply modifier.

Second Step
Assign to this structure the second part of the node tree ... plus add Armature modifier to this as well with enable Bind to > Bone Envelops

Probably beginner friendly "old school" way ...
Ivy Generator
Enable build in addon Ivy Generator. Add New Ivy (with setup fits your needs).
Cage
To by able animate it with the limb you can use Mesh Deform modifier, but for that you need a "cage object that covers all Ivy vines ...

Duplicate your limb model add Solidify modifier and try to cover all Ivy vines (if there are still some out of the cage you can fix that manually later)
add Remesh modifier with some lower resolution just to simplify cage
Apply modifiers (and manually or by sculpting adjust shape of cage to cover all vines)
Select cage object and than Armature object and parent them (Ctrl+P) Armature Deform With Automatic Weight ... so now your cage follow the same animation of your limb.

Now select Ivy object and add Mesh Deform modifier > Object set your cage object and press Bind
Grow Animation
Simple one can be achieved under Curve Properties > Geometry > Start&End ... just set value O for beginning frame (keyframe) and value 1 (keyframe) for last frame of grow.


text:
How do I close the left menu?

How do I close this menu? That is to the left of the "main screen" or "grid"

To make things less confusing, let's make sure we use the same words for the same things.
For this, I highly recommend everyone to read User Interface — Blender Manual. It contains all the official naming of Blender's UI elements, it makes things way easier to communicate when we use the same words for the same concepts ;)  And it also explains how to use the interface.

I guess what you are talking about is an Area:

The Blender window is divided up into a number of rectangles called Areas. Areas reserve screen space for Editors, such as the 3D Viewport, or the Outliner.

Conversely, here's an example of what we could actually call a Menu:

Most headers exhibit a set of menus, located at the start of the header.

Areas in Blender can be split in two areas, or you can merge one area into another.
To merge an area, you can either  RMB the line between the two areas and select Merge, or  LMB drag the corner of an area into the neighbor area you want to merge into:

Dragging from an area corner outward will join two areas. The area that will be closed gets a dark overlaid arrow. You can select which area will be closed by moving the mouse over areas. Release the  LMB to complete the join. If you press Esc or  RMB before releasing the mouse, the operation will be aborted.

Hover your mouse over the right hand edge of the menu and you should get, I don't know the word, the left-right movement arrow icon showing up. Then left click and drag to the left, it'll collapse the menu and hide it.
This is true of any menu in Blender.


text:
Blender evee rendered image plane blurry
I imported an image using add images as planes. Rendering in evee. Rendered result is blurry. How to get it sharp? Sharp should be the standard without having to change options…

I provide the solution myself. Change image interpolation in the material from linear to closest.


text:
Weird Protruding Vertices while in Sculpt Mode
I'm doing an axe but when I get into sculpting, the vertex from the edge get crazy. I don't know if it's because of the original mesh or because I did something on sculp mode. No matters how many times I smoot that part and they go to their place that they pop again to where they where after a few seconds. Any help would be great.

Did you try to do a merge by distance bevor the sculpting, and applied mirror modifier?

yes, i did that and by doing that i created tris and i think my model collapsed because of that. I'm redoing it now without tris and it seems to be working well

Perfect, could you add this as an answer so others know to avoid tris in this situation?


text:
ZeroDivisionError when trying to import molecule with double bonds from pdb file
I'm getting an error specifically when I'm trying to import CO2 with double bonds. I tried several other molecules like benzene and there this issue doesn't seem to appear at all.
I first used Avogadro and also Molview to create the molecule and saved it as .mol.
With OpenBabel I tried to convert it to .pdb with the "generate 3D coordinates" enabled as I did for the other molecules. When importing the .pdb into blender, I had the stick option enabled. This worked for the other molecules as well.
However, the same error (see below) keeps on appearing for CO2.
Python: Traceback (most recent call last):
  File "C:\Program Files\Blender Foundation\Blender 3.5\3.5\scripts\addons\io_mesh_atomic\pdb_gui.py", line 198, in execute
    import_pdb(self.ball,
  File "C:\Program Files\Blender Foundation\Blender 3.5\3.5\scripts\addons\io_mesh_atomic\pdb_import.py", line 1377, in import_pdb
    all_sticks = read_pdb_file_sticks(filepath_pdb,
  File "C:\Program Files\Blender Foundation\Blender 3.5\3.5\scripts\addons\io_mesh_atomic\pdb_import.py", line 427, in read_pdb_file_sticks
    dist_n = dist_n / dist_n.length
ZeroDivisionError: Vector division: divide by zero error

This is the output from OpenBabel I'm getting
COMPND    UNNAMED
AUTHOR    GENERATED BY OPEN BABEL 3.1.1
HETATM    1  O   UNL     1       1.004   0.006   0.071  1.00  0.00           O
HETATM    2  O   UNL     1       3.398   0.006   0.071  1.00  0.00           O
HETATM    3  C   UNL     1       2.201   0.006   0.071  1.00  0.00           C
CONECT    1    3    3
CONECT    2    3    3
CONECT    3    1    1    2    2
MASTER        0    0    0    0    0    0    0    0    3    0    3    0
END

I changed the "Stick/bonds" type from dupliverts to normal and skin but nothing worked so far

That appears to be an error in a third-party addon or program so is off-topic here. - This is a Q&A site run by volunteers to help with problems running Blender and its built-in addons only. Suggest you ask elsewhere.

@JohnEason io_mesh_atomic is indeed a builtin addon. see https://github.com/blender/blender-addons/tree/main/io_mesh_atomic But bugs should be reported to the official bug tracker. Go to Help > Report a bug in the header of the interface in Blender

@Gorgious Ah ok. I didn't realise that. I was confused by all the talk about external programs in the question. There's also a bug report button in the Preferences > Addons entry for that addon.


text:
Is there any principle about using "edge loop" when building a model?
I'm trying to build a laptop this time, and edge loops disturbed me somehow.

Edge loops will create "useless" verticies and edges at the position where I don't need them. Should I remove them with "dissolve verticies/edges"？
Sometimes when I want to keep the edge sharp with edge loop tools, the curve corner that should be maintained is also affected, turning into a slightly sharp curve that I'm not expecting.
An extra question. How can I build up the keyboard? By generating edge loops according to the key position and the gap between keys? (Some efforts in the 1st pic)

I'm still learning to build something and I'm not sure when I should use edge loops and when not, or how edge loops should be applied. I'm hearing!

Are we talking about game graphics, low poly?

@Jackdaw I was an amateur contributor converting cars from other racing games into GTA San Andreas about 6 years ago, and I quitted. Yeah, I'm a bit influenced with that low poly concepts and that influence has come to me these days. But I have to learn about 3D again as a serious work, as I'm going to seek jobs in advertising (what I major in now) and 3D is what it requires. So I think I have to give up some concepts that I used to learn, and study for what 3D personnel considers.

There are so many ways to solve this depending on your end need. I think it's important to be pragmatic about how you spend your time modelling. If it looks good then it is good. Simpler topology can make it easier and faster to model and also quicker to render. Model much, do many misstakes and learn from them.


text:
How to create a notch on a surface w/o messing up with the edges?
I was making the lid of the Starbucks cup and this problem occurs to me. I don't have a clear idea how to make the notch on the lid for drinking. Knowing about the knife tool I gave myself a try, with the tool cutting edges on the surface. And here comes my result:

But I don't think that's a perfect solution because when SubSurf is applied to it, the normals of the vertical part around the notch don't seem as perfect as the other vertical parts, with some uneven feeling:

Meanwhile, if I want to give it Solidify, some black parts appeared:

I'm a beginner in Blender for a week or two and I'm still praticing modeling after some basic learning from BlenderGuru. Any suggestion is appreciated!

You could do it with this topology, at the beginning use i to inset. Then you can add some edge loops if you want to be more precise...


text:
Subdivide Button in Blender 2.8
In Blender 2.8 i have been unable to find the location of the subdivide button in any menu in edit mode and have only been able to get it using the search key. The lack of any keybind is also making it quite difficult. I am using beta 2.80.41

You can now right click in Edit Mode to open up the Specials Menu if that's your question.

Didn't think to check the right click menu for the subdivide function. Yep it's there thanks for the help.

The Subdivide operator can be found:

In the Context menu aka Specials menu (RMBor W in case of using 2.7 keymap)

As part of the Edge menu in Edit Mode

Or via Spacebar by searching for Subdivide

The default keymap for Blender 2.80 is Left Click Select, so the "W" shortcut won't work (and will actually do a different thing: changing the selection mode) for a new user using defaults

@NicolaSap You are right, I am using 2.7 keymap... I have updated the answer.

Just a note for newcomers: Spacebar is not default for Search – it's F3.

The following info are based on 2.8 and onward. 2.79 and previous versions have it differently.
By default, the fastest way to subdivide between edges selection is Right-Click, followed by pressing S. Right-Click is now a fully integrated context menu (its content is based on the active menu and the type of selection)
You can see the Subdivide in the Context Menu when in Edit Mode with Edge active.
If you don't Right-Click after selecting the edges and then press S you'll activate the selection scaling mode. If that happen, just right-click to cancel and turn-off the selection scaling mode.

EDIT
If you have the Right-Click set to Select (which was the standard in 2.79 or previous), then you won't be able to bring up the menu with that key. In that case, you can press W to call the Vertex Context Menu (Subdivide is the first item in this menu)

You can only subdivide once now. To get more than one subdivision you need to use the Loop Cut tool (Ctrl + R ), unless you want to subdivide something like a cone.

Go to Edit Mode, right click on the object, then select Subdivide, after that change Smoothness from 0 to 1 and its ready, you have the same function that the older version had.


text:
Why does render resolution affect output quality?
The two images below are sections of the same image rendered at different resolutions.

The blurry one to the left is rendered at 600x350 and then cropped to the section shown here. So there is no scaling or other processing of this image except cropping for the sake of clarity.
The sharp one to the right is rendered at exactly the same settings except for the higher resolution of 1200x700 then down-scaled and cropped to the same size as the first one.

I'm fairly new to blender and 3D-rendering in general so do not understand why the first one is so blurry when the scaled one sharp. Can this be fixed and in that case how? I thought that the imgages would be rendered as sharp as possible for the given resolution. But in this case that is obviously not the case.
Is there some switch or slider or property that should be adjusted to get it right? Or is this behaviour to be expected?
I'm running blender 2.80.42.

What did you use to downscale your image? For example Photoshop by default uses bicubic algorithm that applies sharp (as Martin mentioned)

I used [https://imagemagick.org/] for the cropping an scaling as: convert src.png -resize 600x out.png

There are 2 reasons:

the down-scaling can have a sharpening effect on its own - depends on the algorithm used
the higher resolution image contains more traced samples per the same area = less noise. The less noise the less blurry image. Let's say single pixel in original size received 100 samples, the same area in double the resolution would receive 400 samples.

So the apples-to-apples comparison should be rendering the original resolution with 4x the sample count and down-scaling the higher resolution with a method that does not add any sharpening.

This behaviour is what I would have expected. If you render in higher resolution, you naturally get more information into the image. Scaling it down then makes it look sharper. Google "bicubic sharper".
The edges in both renders are not 100% sharp, they are always a gradient.
Lets say the edge between the black part and the background is a gradient in the size of 4 pixels in both renders. When you scale the bigger one down to 50%, the gradient is also scaled down - now it has only a size of 2 pixels, which makes it look sharper compared to the smaller render. the interpolation adds some sharpnes too.
Edit: just found another thread on the same issue:
Why does increasing resolution and then downsampling to desired size increase render quality?

I'm not sure I understand or accept your answer. With this reasoning the image would appear sharper the smaller you make it, and that is not the case. If you scale it down infinitly to 0x0 or 1x1 it will not be infinitly sharp I think. The act of scaling down an image is actually removing information from it and by doing that it seems counter intuitive to get a sharper result. Please explain this a bit more...

This is hard to explain... Sharpness means local contrast. In the example I gave, the scaled down gradient has only a size of 2 pixels - one being black, the other being white. This is the maximum sharpnes you can get.

But maybe the effect you described comes more from the fact that your bigger render has just more information (total samples). Scaling down a bigger render with a higher total number of samples has the same effect as rendering a small image with a higher sample count.
Example: picture size 200x200 pixel, 10 samples per pixel:
200x200x10=400000 samples in total ----
picture size 400x400 pixel, 10 spp:
400x400x10=1600000 samples in total.

So if you render your smaller image with the same number of samples (40 spp), you should get more or less the same result (without the sharpening effect of the scaling)
The math would be:
200x200x40=1600000 samples in total

The naive answer, ignoring clever downsampling algorithms and assuming simple averaging, is that your second image is not 'sharper'. But its colors are more accurate, so the contrasts over the boundaries between regions of color are higher.
The more point-samples that are taken from the original domain, (let's assume that has infinite resolution,) the more accurately each pixel will represent the average color in the area of the original domain that it covers.
To reduce the case to the absurd, suppose only one sample could be taken for the entire area represented by your cropped section. Then it would all be one color, no matter what the resolution of your final image. As 'blurry' as you can get. Now imagine 2,4,8.. and so on...


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Can I make a mesh object transparent to sun light in Blender yet stay opaque in the viewport, using Cycles render engine?
I'm building a landscape with a visible moon. The moon should shine its light over the landscape. The moon is a  round transparent plane containing a moon image + a light emitting object behind it to make this image visible. I still need a powerful light source to illuminate the whole landscape and draw dramatic shadows.The light should come from the direction of the moon. To me it seems that point, spot and area lights are no choice. They would be visible bright spots. Now I've tried sun light. The problem is that When that light is set up to come from the direction of the moon, the moon is throwing a shadow on the camera and on the light path of the atmospheric fog (the dark 'halo' around the moon in the image). So ideally, the moon should be completely transparent to the sun light, still being visible when rendering. Is there a way?

First of all: why do you put a light emitting object behind the moon to make the image visible? Just use an Emission shader for the moon and plug the image texture into the Color. And if you don't want it to cast a shadow on the environment or like in this example on a ground plane, go to the Object Properties > Visibility > Ray Visibility and disable Shadow:

Thank you Gordon, your advice did the trick.

@jacerman You're welcome. If this solved your problem please consider accepting this answer, read more about it here: What should I do when someone answers my question?


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Boolean modifier leaves a hole in the object
I am working on patterning a wheel with a cylinder shape. See the image below:

I am using a very simple Booleam Modifier:

It worked in like 99% of the cases, but for some reason, at a specific angle it leaves a hole in the object:

I don't know why at this position, nothing chaged, the object is the same as in the last x positions, the modifier is the same. Moving the objects to another location does not help. Making the cylinder a bit larger or smaller does not help either. Any suggestions on how to resolve this?

did you try changing to solver-fast?

yes, but with the fast option selected, it does not do anything, as if I did not apply the modifier at all.

ok, pls provide blend file, thx


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How To Make A Swirled Chameleon Tail
I'm very new to blender and I'm trying to make a chameleon tail. How do you create the swirl shape? I also want to rig it after. What's the best way to go about it?

https://blender.stackexchange.com/questions/56396/logarithmic-curve-with-spiralling-cross-section/ https://blender.stackexchange.com/questions/230571/what-is-the-easiest-way-to-create-a-pigs-tail/ https://blender.stackexchange.com/questions/252268/trying-to-curl-a-snake-tail-stl-file-in-blenderhttps://blender.stackexchange.com/questions/252268/trying-to-curl-a-snake-tail-stl-file-in-blender https://blender.stackexchange.com/questions/159890/how-to-taper-a-coil/ https://blender.stackexchange.com/questions/7088/create-flat-coil

https://blender.stackexchange.com/questions/49639/how-to-smooth-an-arrayed-object-so-the-breaks-between-objects-are-less-obvious/ https://blender.stackexchange.com/questions/230372/snake-defensive-display-animation/