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What is the shortcut for orientation?
Blender 2.81
I frequently change the Gizmo orientation in modeling between Global and Normal. There is no shortcut shown.
The Blender documentation says , (comma), but using comma the orientation shown at the top right side is changed, not the one I need (marked red in the picture below). Both have the same tool-tip though.

So there are two questions:
Important: What shortcut shall I use to change the highlighted orientation?
Out of curiosity: What orientation do I change using the comma shortcut and what is the correct name for the orientation I need. Both say "Transformation Orientation".

While both "Transformation Orientation" options have the same tool-tip, they are used at different times.
The left one you marked, is used for gizmos and only when you grab the gizmo and use it, overwrites the "globally" used one to the right.
While the right one is used when you use the G,R and S keys to move, rotate, scale respectively as well as other functions like E for extrude etc.
Only if you use gizmos, will the left one be used, as it also only becomes available when the gizmo is activated. It can be seen as giving the tool it's own specific orientation option.
The documentation is sadly referring to the same link/explanation for both menus.
After looking through the key-mapping, and checking in the console regarding what is reported when changing the selection for either of the two transformation orientation options, i found, that both set the exact same variable:
bpy.context.scene.type = 'LOCAL'
So using , you only get the pie menu to change the right "globally" used "Transformation Orientation", and it seems to me that there is no key for the tool specific options on the left, neither for a pie menu to change them. And adding a shortcut for those tool specific transformation orientations is not possible either.
That sadly means, that there is no solution i can offer you aside the explanation.

If you set the left orientation to Default, the comma shortcut will work for gizmos in object and edit mode. Note: I am using Blender 2.92


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Blender Crashes when Baking High Resolution Textures "Circular Dependency" error
I have a high poly (1,3 Mio faces) photo scanned mesh with 17 generated 8k textures (totalling 500 MB)
All the texture are looking something like this one here:

My goal is to bake those 17 diffuse maps into one single 8k texture. But when I hit "Bake" I first get some errors, which look like this:
Circular Dependency for image "texture_xy" from object "xyz"

and then Blender crashes.

First of all I want to know why those errors occur. But I am also concerned, that Blender doesn't crash because of the errors, but rather because those textures are just to massive in size.
Any suggestions on techniques I can use to bring those 17 textures into 1 single texture?
Would it help to decrease the polygon count of the mesh?

I'm sadly not very proficient with baking yet, but found this under "Circular dependency", maybe it could help shine some light on your problem: cycles bake script error: “Circular dependency ..”

Yeah, I'll check it out, thanks

The issue was just that I did not have sufficient memory. So I had to downscale the high resolution textures to make it work

source: Stack Exchange

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

sort: votes


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How to get the same UV islands to occupy the same place on the texture?
I've created a simple box:

As you can see it has many similar islands that are supposed to use same place on my texture. But when I try to align similar UV islands to same positions (as Shift+S -> Selection to 3D Cursor) Blender removes all regions but one and as result I can see just a gray color on my object at their respective places.
How to fix that behavior? I need all similar UV islands to use the same space on the texture.

I am sure that using the key-combination Shift+S is not the right way, as it pretty much places all vertices of the UV island on the position of the 3D-cursor (the UV islands thus are shrunk to 1 pixel looking as you mentioned).

@Xylvier, I didn't know it, thank you for explanation

As far as i know, there is no vanilla functionality that allows to pack all UV islands on the same place, essentially stacking them on each other.
There is an addon that comes with Blender though that can help a bit.The name is Magic UV, and it comes with it's own Pack UV function:

The needed preparation is not too complicated if you do not have to many of those same islands:

First of all, you will have to make sure they are all averaged out:

(this will ensure that the islands are all having the same size in the UV editor, if they are the same size on the object.)
Now you adjust the snapping option to vertices

Now you have to go through all same islands.(single face or group of faces can be an island, what matters is the island is the same as the one you want to stack on top)
Select an Island and while moving it, hold Ctrl to snap on a vertex that makes the islands stack exactly on top of the other. Repeat until all same islands are stacked up.
Select all UV islands with A
Then finally go in the UV menu and use the above mentioned UV Manipulation->Pack UV function. Adjust the parameters to better suit your needs.

Here a visual demonstration:

Happy Blending

Thank you very much for detailed answer!

@Шах Hello :). If the answer solved your problem, please mark it as accepted (the green checkmark).  Thanks.

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


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How do I rotate the viewport, without leaving the x/y-plane?
I'm looking at an object, sometimes very close, to check visual heights. I'm in orthographic view, straight front.
Now I want to rotate slowly to the left/right side, without leaving the xy-plane (while constructing, not for animation). But every slightest move of the mouse kicks me into space, and I can't check exactly.
I know rotating while pressing alt key. But this is very crude snapping. I need to rotate smoothly or at least in about 5° steps.
I'd like to press Z key, and then keeping movement always stable in xy-plane (like on grap or rotate). It also could help on other axes, or even local coordinates.
How can this be done?

I want to do this with mouse/pen input. Using keyboard with a tiny increment is a pretty expensive work around compared to how nicely r+mousemotion rotates object normally.

Updated based on the comment:
The option you look for is the "Orbit left" using the Numpad 4 and "Orbit Right" using Numpad 6 respectively. At least in my logic that is the only way to rotate the viewport(as in the title of the question) and is not leaving the xy-plane. Not sure how "Roll and Orbit is different here as the result seems to be the same.

The increase or decrease in angle is set default to 15 degree in the preferences here:

Setting the Rotation Angle to 1.0, would result in the "Orbiting" to be a lot smoother.
Here a little visual demonstration:

Happy Blending

That's what im looking for! But not ShiftNum4-6, but plain Num4-6. Almost perfect! (By mouse would have been nicer, but numpad is a cool solution.) Thanks.

Updated the answer, while i still do not know why Rolling and Orbiting seems to result in the same visual result. Also, please consider to accept the answer should it be solving your question.

Rolling and orbiting are not doing the same at (e.g.) FrontView/Num1. Only on Front/Num1 or side View/Num3 xy-plane collapses to 1 line. (Similar movement to camera Suzanne in other answer, whereas your visualisation is in TopView.)

True, only in top view they result in a similar visual result (speaking of Num4/6 and Shift+Num4/6).

One thing you can do to rotate the plane without leaving xy plane is go to front view by pressing Numpad 1 and when you are there press Numpad 5 it will automatically correct your perspective to a XY plane view
If by chance its not aligned in XY view for you to rotate then you just have to press the Numpad 8 or Numpad 2 to align it and then when it comes in XY view.
Now you can rotate it by just pressing Numpad 4 or Numpad 6.
If you having problem adjusting your viewport in single step make sure first that you are in front view. As it will be easier to set in front view rather than orthographic view.


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how to split mesh - by its joining edges
so, usually I'd just grab the desired faces and 'separate>selection', thus making a new separate mesh in the collection list.
but this is going to be a nightmare because of all the faces etc.
BUT I do have a nice clean line to cut along. its easy to select this line of edges, but now how to use that to split the mesh into two discrete meshes?
cos so far i've only managed to separate that specific line..
Dear mods.
Can you show me how to answer the question if there is no 'answer question UI' to use?
I'm trying to give credit where its due, and show subsequent viewers where to find the solution, but instead you just delete my answers.
Presumably its the 'Tick' symbol, which doesn't appear next to Moonboots or Robin's comments. so how do you imagine I can correctly use the site if you don't provide the tools to do so?
I'm trying to give credit where its due, and show subsequent viewers where to find the solution, but instead you just delete my answers. which, DO show the answer.

You can use V to rip, is it what you're looking for?

... followed by right-click to drop in place, and L with the mouse hovering over the contiguous island of faces you want, to select it.


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Do objects need to merged before STL generation
I am an absolute beginner looking to start 3d printing, and I have a real beginner question.
Say I have a very simple model I want to print, maybe two cubes side by side, with faces touching but not overlapping. Ie they have separate meshes.
Does one need to merge those meshes in some way before export to STL, or will the slicer automatically treat them as one component because they are touching?
I know there is a Boolean union operation, but it seems to have problems if edges colocate.
UPDATE:
I put the real model through a slicer (Cura) to see what happened - There are three screenshots at https://drive.google.com/file/d/1rQVpeUMbwKdShReWjvVIWbmQFFGO7vOV/view?usp=sharing. blender,png shows it in blender, cura.png is a preview of the first layer after slicing, cura2.png is the first layer of a test model made using extrusion.
The model is just cubes and cylinders, using boolean operations.Don't know if that is how you are supposed to do these things - I am a beginner (don't even have a printer yet). The end of each bar is cut away with one cylinder, then another cylinder with a hole is placed there. The forward bar is just made of another cube placed adjacent to the sideways bar.
The slicing (cura.png) shows the nozzle going up the bars and round the ends so it appears to treat the ends as part of the bar, but the forward bar is separate from the sideways bar - the nozzle does not go round the whole lot.
I did a quick test with a similar sideways bar, but making the forward bar by extruding the sideways bar so it really was all one mesh - the first slice is in cura2.png. In that case the base layer went right round the outside - it did not treat the forward bar as separate.
So, I am unclear, in the cases of the ends, Cura treated the rounded ends as part of the main bar, but in the case of the forward bar, it did not unless the forward bar was extruded from the sideways bar.

you might get issues as the slicer will create a face there. However with two touching cubes merging is quit easy. Just go to edit mode and merge by distance.

Thanks. So I do need to. The real example was more complex. Had a cube 16x5x1, but wanted a round end on the 5x1 face. So what I first tried was create a cylinder diam 5 depth 1, placing it at the end, then using boolean union. Did not come out right, apparently because boolean doesn't like colocated edges or vertices (?). Maybe this is not the right way to do what I wanted? How should one round an end like this?

could you show a screenshot or include a file pls, also look into this answer maybe it does what you wanted: https://blender.stackexchange.com/questions/7910/what-is-non-manifold-geometry/7914#7914

And you might want to enable the pre installed 3d printing toolbox, that comes with usefull features for 3d printing.

I have added an update above, and a link to a ZIP file with three screenshots (blender and two from cura). Confusing results after slicing. I have the 3D printing addon installed - haven't worked out what it does yet!

The slicer is handelig seperate meshes as seperate meshes, and single meshes as single meshes. Here is a clean exaple: https://gofile.io/d/TkqXbc. I suggest also looking up some tutorials if you are planning on using blender for future projects.

Thanks for your help.


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Tool or addon for showing textures on PC
I'm fairly new to Blender, but have done some small things and a lot of tutorials in Blender.
Due to this I now have a lot of different textures on my pc, but am lacking the tool or addon for Blender that can easily show what I already have.
I can of course just use the explorer and do searches, but is there or are there tools, that can show me my textures, like the preview under texture?
Thanks in advance

Did you tried IrfanView or some other Image-Database Tool - organizing your stuff is highly recommend !

I have organized by stuff :-) but are needing the tool in Blender that presents the texture (including bump, displacement, color...) in a preview form (like you can do on the texture tab. This an help me when I have 10 different wood floors for a plane and need to find the one that "looks the best".
with a "simple" image tool, I just get the different images one by one
it might not exist, but a kind of texture assets addon

Unfortunately Blender doesn't have an automatic material preview functionality. As of yet, there are only add-ons (also paid ones) who deal with asset- and material management.

Metaphor - Which add-ons exist for this - have tried to look, but can not find some that matches my requerments.
(I will also of course pay for others work if they are worth it)


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Strange UV Unwrapping behaviour with Seams
I get strange UV unwrapping behavior when Unwrapping any object that has Seams.
In the example below, I show the results of Unwrapping a simple beveled cube with and without Seams.

I understand that strange results can be shown in a UV Editor window if the scale of the object is not uniform. However, the scale of my object has not been changed and is at 1 in the example. If anyone knows what causes such a dramatic effect and has a solution then please let me know, because this problem is effectively making it impossible for me to texture my models properly.

in the Operator box, try Method > Angle Based instead of Conformal

I'm going to assume that this beveled cube was made from a Cube mesh.
When you add a Cube mesh to your scene, it automatically creates a UV map for you. Beveling the cube without unwrapping it after does not change this map by much (although it does result in some weird mapping).
However, when you made a seam and unwrapped the mesh, the old UV map was trashed. Blender now tries to figure out how to unwrap the whole mesh to a 2D space with the seams provided. However, Blender cannot do this because the provided seams are not sufficient.
Now, imagine your mesh was made of paper. You want to cut the paper at the appropriate edges so you can "unwrap" the paper to make it completely flat without tearing it. If you only cut the edges you marked as a seam, you cannot do this.
This is what Blender is doing. Because it cannot completely flatten the mesh, it gets confused and makes a whole mess of overlapping faces.
When marking seams, use the strategy above to try and place seams at the correct spots.

wouldn't a "smart uv project" with "island margin" > 0 work ? (i'm bad at this kind of stuff, but i'm curious.)

@ker2x Maybe, but in most cases, it's better to manually unwrap the mesh yourself. This will help you gain more control over how the UV map flows.

okay, thank you


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can't rotate, scale, grab only cube in object mode
as I write in the title, I can't rotate, grabe and scale the cube in object mode in blender 2.9. When I try to grab the cube, the origin (the little sphere) moves but not the cube; I try to unselect "only locations" in trasform pivot point menù, but it's not select and it doesn't work. when I try to grab, rotate and scale camera or lamp it works.

Comments are not for extended discussion; this conversation has been moved to chat.


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UVOutline Problem when texture
https://gyazo.com/5cf6c595588ae0348db013e1f8bec38f
So that's what happened, the UV outlines show when the mesh is  rendered from a distance or an angle, the texture image is jpg, I've tied raising the bleed value, but it still didn't work, any help?

Hello :). I'd recommend adding some images directly into the post. Not everyone is going to click the link.

sure, thanks :D


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I'm trying to flip an animation, but maybe its the rig, my animation just don't flip the way I want it to
So don't worry about the animation, basically I just wanna test out how to make flipped animations, but it seems like my rig has something wrong with it, and the animations just don't be flipping the right way I want it to. Please, anyone help?
The Animation(Don't worry about it, just a random pose, I just wanna test the flip out):

I added a flipped one some frames after it:

It seems like the animation has got it, the keyframes are somewhat flipping right, it's just some of the axis are acting weird, I'm really new to this animating and rigging thingy, can anyone please help me out? Any suggestions or tips will help too :D

It may be because some bones have not flipped the pose because they are not named correctly, or because their orientation is bad and in that case you need to roll them in Edit mode (Ctrl R)

maybe tell what bone doesn't work properly and share your file: https://blend-exchange.com/


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Mesh shading looks wierd

Here's the mesh—it doesn't have any doubles or split parts. However, it exhibits this weird reflection regardless of whether it's set to smooth shading or not. This issue has occurred sporadically in version 2.8. I have managed to work around it by deleting and remaking the meshes. Nevertheless, considering that it could become significantly bothersome in the future, I have decided to create a post. Is there any way to fix this?

did you check the orientation of normals and cleared geometry data (if available)?

as MikoCG says, go into Object Data >Geometry and Clear Custom Split Normals Data

I did, Recalculated Normals, and there are no nodes for this mesh.

in that case please try to share your file with https://blend-exchange.com/ and paste it to your question so that we can check it

uploaded the file

Your problem is here:

Click on Object Data Properties (green reversed triangle) and click on 'Clear custom split normals data'
EDIT: Oh and your normals are probably reversed, use Alt+N to 'recalculate Outside'
Your object now looks as it is supposed to look like:

(Note: I am using a few addons so you might have less options in that selection)

It's just a matter of recalculating normals : in edit mode, shift+N. You can also toggle smooth shading after the fact : in object mode, right click -> shade smooth.


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How modify sphere mesh in an animation with shape keys
I would like to start from a sphere/ellipse, move its vertices in order to obtain an irregular body.
The problem is that I want to create an animation of the vertices movement.
The starting model and final one are shown in the following figure

You may try a controlled Fluid Simulation to create your mesh.  The simulation will be taking over vertex placement.  This may or may not suit you.  Of course you may also try texture displacement.

You can do it easily with shape keys if you don't change the number of the verts. Why do you want to change it?

How can I do it with shape keys?

FFeller can you write the procedure with shape keys?

You could simply use a Displace Modifier and apply it as a shapekey.

First add a Subdivision Surface Modifier followed by the Displace Modifier and then a second Subdivision Surface Modifier.
Your modifier stack should look like the image below:

The texture can be anything grayscale, but for this example I used the below:

Once you are happy with the result of the texture you choose, apply the first Subdivision Surface Modifier, and apply the Displace Modifier as a shape key.

The remaining Subdivision Surface Modifier will not be able to be applied, and shouldn't be anyway.


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Animation nodes - animate object attribute/transform with Object ID Key and Sound Evaluation
I have followed several tutorials using the ID Key function in Animation Nodes to change the size of the objects. I'm trying to set up the nodes so I can use the spectrum from a sound clip to animate objects based on their ID Keys. But I'm completely stuck and need some help to see what I need to change.
I had read that the Spectrum Falloff type in the Sound Falloff node is based on the indices of the objects. So I thought by replacing the Evaluation Sound node with the Sound Falloff would solve my issue. But it doesn't seem to make any difference.
Any suggestion how to solve this? Thanks.

[Update] After adding the Get List Element node, I've changed the sorting for the ID Keys by either random or by names. The playback did not change. The images are all at frame 30. I'm including my blend file as well.
Sort by random 1

Sort by random 2

Sort by names

Blender file.
SoundSpectrumCubeTesting

Your example index list is $(10,14,3,\dots)$, which means you want the 10th object to scale based on the first frequency band, the 14th object to scale based on the second frequency band, the 3rd object to scale based on the third frequency band and so on. So, if we left the sound data untouched and reordered the object list such that the first element becomes the 10th object, the second element becomes the 14th object and so on, we will get the desired effect. The same reordering should be done to the object's locations. This reordering is easily achieved by getting the objects and their locations at the ID indices:

Thank you. What you described is exactly what I want to achieve. I uploaded some more screenshots and my blender file. I added the Get List Element node, but I don't see the change. Could you take a look and let me know what other settings might be wrong? Much appreciated.

@fuzzcats My bad, I forgot to say that the object's locations has to be reordered as well. I updated the answer. See the new example.

YAY! Thank you very much @Omar-ahmad! It worked!


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Projecting a 2D road onto a 3D elevation mesh
I'm trying to create a track for Assetto Corsa (a racing game) based on a real mountain road that's close to where I live. It's an ambitious endeavour, but I hope to learn a lot in the process - even if I won't eventaully finish the whole road.
What I've already done is: I imported an SRTM elevation file with this excellent plugin which turns it into a georeferenced mesh. I had to delete big parts of this mesh because it was huge, but now I have the mountain ready.
Next I imported an OSM file containing the road in question with a plugin written by the same author. Now I have two gereferenced objects which superimpose perfectly from what I can tell.

Perspective view with the road floating above the mesh
The problem is that, while the mesh is 3D and ready to use, the road is a 2D path. What I want is to have a 3D path of the road (with elevation) which I can then use as the basis of the road for the game as explained in this tutorial.

Top down view
I think I can obtain this path by:

Intersecting an extrusion of the 2D road path with the 3D mesh, but how do I do this? I went as far as creating the extrusion, but I don't know how to do the intersection.
Using Knife Project to cut the mesh with the road's projection. Again, I tried, but Blender crashes, so I'm not sure if I'm doing it right.

Any help appreciated.

you can do that with the shrink wrap modifier as follows :
original mesh

Add the shrink wrap modifier :

and you will get this

if the road is not curved enough " didnt follow the mountain exactly " try to subdivide it before applying the modifier

don't use the subsurf modifier use the subdivide tool "w in edit mode" so you don't lose the details of the road

The Subsurf is the best way to go, you just need to change the method from Catmull-Clark to simple, in-order to retain details.

Exactly what I was looking for! Thanks for your answer. But now I hit another bump in the road. Pun intended. :-)

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


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Weird flickering in my model when I rotate the camera and even if it's fixed
I was working on this model and everything was going fine. After I finished making the hands I took a look at the full model and noticed this weird flickering. Naturally I tried merging by distance and recalculating the normals, but nothing changed, the flickering continued when I switched render engines.
I tried re-opening Blender and restarting my computer but the problem continued.
Here's video: Weird flickering in Blender 2.83
What troubles me the most is that it wasn't happening earlier today, I clearly made a mistake or pushed a wrong button in the process of modeling, but I have no idea what exactly.
EDIT: Google-Drive Blend File

Hello and welcome. for me it worked out to make a new file and then appending the object from your .blend file into it. No flickering anymore. Reason, sadly not sure, but it looked like z-fighting.

The issue comes from floating point rounding error due to the clip start / end of your camera view. Basically you have somehow set the camera view to have a culling range that is too wide (from 0.0001 m to 1000 m) so the viewport rendering is flickering when you zoom out.
To fix it, set the clip start to a higher value (0.01 m should be good). Go to the right side panel with N and inside the "View" panel.

This is likely because your mirror modifier is copying and mirroring each side independently without culling one side. Check you mirror modifier options and check bisect then check or un-check flip to choose which side to delete and which side to mirror.

Probably what you did was apply the mirror modifier at some point.

That's not it, I even deleted the mirror modifier without applying it but the problem continued. I edited the question with a link to the blend file.


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Add materials to copied object
I'm very new to Blender and I'm watching Grant Abbitt's tutorial and it's so good but I got 1 bug. When I need to add a material to an object, this material goes to every object which i copied from the original!
I already tried to click on the object and set a custom material but still the same, i can't get two objects (copied) with a different material. Anyone can help?
This is the video i followed Complete Beginners Guide to Blender 2.8 | Free Course | Part 4 | Materials, but it does not work for me.

Possibly, you've copied the object using altD (duplicate linked), you should use shiftD (duplicate object) instead so that the new object will have its own data.
"duplicate linked"

is called a deep link. This will create a new object with all of its
data linked to the original object.

See the documentation here.

This is work Thank you so much.

Just for completeness, Blender lets you associate a material with the Object, rather than its Mesh, even on a per-face basis, by selecting 'Object' in the dropdown in the lower right of the area illustrated below:

All these cubes are AltD instances of one another:

You can make your object a single user with its own material
Go the 3d view header and use
Blender Object - Relations - Make single user

Object > Make Single User > Object & Data & Materials + Tex.


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Changing an object size/rotation doesn't update information in Transform window
I have downloaded an object file from the internet. The object imports fine except for when I try to change the scale/rotation of the object. I do not see the Transform window information update when I make a change.
Below rotation not being updated in in the Transformation Panel.

The outline should be yellow in order to transform the active (context) object. Not sure how something like this can happen. Is there a second object in selection?

You are right, there is a second object which is selected, otherwise the dot would be yellow, not orange

This situation can occur if you select 2 objects, and then hide the last selected one.
With the last selected object hidden the rotation will center around the only available one now and it looks exactly like this.
Here the procedure to get to the same situation:

Solution: Make sure the object you work on is the active selected one, yellow outline.


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Problems in sculpting mode

I am new to blender and have been following Blender Guru's donut tutorial. When I go in sculpting mode for the icing I always end up getting getting holes for the icing. But When I select the donut I have no problems. I have applied the solidify modifier and the subdivision. I have played with the settings. Nothing is working. The donut looks fine when I am on layout and edit mode. I can sculpt but on it but the wholes wont go away.

I've had a similar problem before. The solution for me was to use Alt + M  to clear any masks that might have been applied to the model by applying the modifier.
Not sure why it happens, but I think it has something to do with the Subsurf modifier.

Thanks for your help but I tried it and it didnt work for me.


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Blender Video Editor Preview doesn't show any image
I've been using Blender for over a year now, and this is the first time I have had this problem. I am editing a small 2000 frame video, but ever since I saved it the preview will not show images or play audio clips. Rendering it still upholds the transparent (checkered) image.
But, there is one thing. A singular picture shows around the 1500 mark and a singular video clip shows directly after. After this video clip the preview goes back to transparent. This shows that there is not a problem with preview, but with the settings.
What could have caused this? It's a genuine emergency that I have to resolve ASAP.

Please sahre your rendering settings

@MFarooqi what settings would you like to see?

render properties and output properties..

@MFarooqi I added the picture into the initial post.

would you mind to attach a timeline preview along with proxy and cache + media properties.. or if possible please share your blender file.

Also please share the preview window.. where you can't see anything

Try to use the Sequence Render Animation in the VSE view menu.


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Rotation vector does not update transform node

Rotation vector does not update transform node.
Without the rotate vector node the object rotates.
Don't know what I am doing wrong.

The purpose of the Rotate Vector node is to take a vector pointing in a certain direction and reorient it into another direction. Taking the vertex normal and rotating it by 90degrees on the X axis. The vector you're rotating is (0,0,0), so it essentially does nothing.

Thank you very much. The reorientation will be useful in the future.


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Boolean using a two part pimitive is not cutting through like the other 3 instances
The fourth boolean is not cutting all the way through like the same object does on the other three holes. The boolean cutter is a cone and cylinder. It performs correct on three but not the 4th one. I dont know if its the 1st one or the last one.

How do I attach a blend file to this post? Here it is:

You can add a .blend file to your post by editing it and uploading the file to: https://blend-exchange.com/

Thanks. Hopefully this issue will get some attention.

Had I had normals displayed I would have caught this.
I used the scale of -1 to flip the object to what vertical transform I needed. That action had flipped the normals to point inward. This is what caused the Mesh Boolean to fail. The necessary correction was to add the Flip faces node to enable the normals to point outward.

Hi, thanks for the post. This site is not a regular forum, answers should be substantial, stand on their own, and thoroughly explain the solution and required steps. One liners and short tips rarely make for a good answer. If you can, [edit] your post and provide some more details about the procedure and how it works, perhaps add a few images illustrating some steps and final result. See How to write a good answer?, otherwise it may be converted to a comment.


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Why do duplicate 'Curve to mesh' node streams not have identical output lengths?

The two were setup to produce a curve to mesh segment using the same arc.
There is nothing I can do to get the two to equal. My suspicions are floating point error or some values hidden in node with no user access.
I have no clue as to what to do. I can not at this time identify which one is the correct arc length.

The input values of the two Transform nodes don't match. I don't understand what you are trying to achieve with "get the two to equal". More informations would be great.

The arc length is whats in question here. Same arc input to both nodes yet the curve length of the curve to mesh output are not the same.
Without putting another pic up, both arcs start at the same X position behind the icons on the right side.
As can be seen the arc are different lengths on the left.

It's impossible to tell with one picture. Feels like bottom thread is farther away. Consider uploading your file to https://blend-exchange.com/.

They have identical output lengths, that is exactly your problem here. With two arcs based on the same circle radius and the same sweep angle, you get exactly the same length on both.
But you move them slightly apart from each other and also rotate them a bit differently on Z (probably to align the starting points better?), and since they are no straight lines, from some viewpoint this will result in different angles between their respective start and end points, thus making them seemingly sized differently.
This is a sketch how it looks like in your setup:

You can already see the effect which you are experiencing that the outer arc looks a bit shorter, although they are exactly the same and start at almost the same location at the bottom right.
Now let me exaggerate the effect by moving the red arc a lot more, just to the right. Viewed from some viewpoint/camera (black dot) they start in the same location, but the viewing angle width (black arrows) of the red arc is smaller than for the blue arc, making the red one appear smaller to the viewer, although the red and blue endpoints are exactly the same offset apart (shown in green) as the starting points (and the arcs still the same size).

Now what you need to do in order to make them appear the same size for the viewer, is create two different arcs, the one that's further apart needs to have a larger radius. This is the very basic principle of perspectivity, objects further away from the viewer appear smaller. If you do not want to have different sized arcs, you have to live with the fact that perspective distance shrinks objects. Or you have to use an orthographic camera.

By the way, of course this has nothing to do with the fact that these are circle segments and therefore curved. Perspective works on all objects, even right angles, straight lines etc. As soon as there is an offset between them which is not perpendicular to the viewing direction, objects of the same size can appear differently sized.


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How to start playing the video from the green cursor rather than from the beginning of the time-line?
In Video Editor mode hitting Alt+A starts playback from the beginning of the timeline.
How to start playing the video from the green cursor?
(I found this question asked on reddit by nightmareFluffy, but it is too late to answer it there.
It's one of the most basic things for video editing and I could not find an answer to it anywhere so I'm posting this question here for others to find.)
My version is 2.79

With the current default installation from 2.80 on (left-click-select), the Playback shortcut is Spacebar. Alt+A is reserved for Deselecting.

I have 2.79 should've specified that - spacebar opens some dialogue to pick an action. Thanks for the tip, I'll upgrade I guess : )

From the Timeline editor's bottom menu select Playback and tick Follow.
Then Alt+A will play from the cursor.

Related: What are the hotkeys to navigate the timeline?

This answer is outdated and no longer valid: There is no tickmark in the Playback menu called Follow, but only "Follow Current Frame" and alt - a does no longer play video (I think they changed it in one 3.x release)

Even with those controls, I couldn't get Blender to play from the beginning of my clip. Why? The video timestamp that I was trying to play from was outside the "frame range" in the sequencer. As a result, it bumped the playback start time to the beginning of the current frame range, which was the beginning of the video.
To fix: In the sequencer, clicking View -> Range -> Set Frame Range to Strips extended the frame range to the full strip. Once I did this, I was able to play from any point in the strip.


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View Port Guide/Grid Broke? Front, Back and Side Cameras
A weird bug has appeared when I view through the default Front Back and Side camera views in Blender.  The square grid has an odd triangular effect (see image below).  This happened a couple of days ago and seems to have happened over night.  It doesn't effect modelling or renders (as far as I've noticed) but it's quite annoying to see - especially when I don't what's caused it.
This only seems to happen when viewing through cameras on the axis (numpad 1,3 and 7) and occasionally in the orthographic view (numpad 5). Normal perspective cameras don't have this issue.
I've looked around and can't find an answer to the issue though, if I'm honest, I don't know what to be searching for. I've also uninstalled the software, re-installed, reset preferences to factory setting etc. but still get the same result.
Has anyone had this issue before and resolved it?  I have accidentally changed a setting and not realised?
Thanks in advance

Hello :). This looks like a GPU issue (although a cool one). Update your GPU drivers or perhaps try a different Blender version.

Use Alt + B to clear the clipping region, or use the menu View > View Region > Clipping Region.

Have had the same issue for a while - not a GPU problem.
I am using mac _ not sure if this is relevant but I have just fixed it by going to the "view" settings of the N panel. I am guessing you have a pretty huge number for end clip plane. I reduced that number and the grid got fixed.
I think blender viewport gets confused when it tries to calculate a very very long clipping plane.
Hope this works for you too!


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Blender 2.8 render wireframe select specific edges
I would like to render a plank with a notch, as shown below, in wire-frame mode.
It should only show the outer edges, means I would like to not show the edges highlighted with the white arrows.
Is there such an option?
Also, related, why are some edges thicker than others?

To hide the edges between faces that lay on the same plane, use a Decimate modifier above your Wireframe modifier.
Set it to Planar mode, and adjust the angle limit if needed.

The inconsistent line thickness is caused by the original mesh having been scaled up in the three dimensions with different scale factors. The mesh "remembers" these factors and applies them to the modifier results, making the wireframe stretched weirdly. To fix the problem, you must make the mesh "forget" that it has been stretched, and make the new scale permanent ("Apply" the transformation). To do so:

select the object
do Ctrl+A > Scale.

How did you make the notch? I used 3 loop cuts and one grab of the center edge to move it inwards. However, I then have 144 faces and the "decimate" modifier does not work as it should (I need to crank the angle to 90 and then some faces appear again).

A cube with 3 loop cuts (which is what also I did) is 18 faces, not 144! 144 is what the wireframe gets you, but note that the decimate modifier should go ABOVE the wireframe modifier! (See when I click the little up arrow in the gif)

Got it, that was the trick!

if the question is about Wireframe view, rather than Wireframe modifiers, this (older) answer may be relevant

There is an option to hide wireframe edges between faces that are at a small angle.
It's in the "Overlays options" menu of the 3D viewport, under Geometry > Wireframe:

I'm surprised as I would expect all the edges you've identified to disappear for values less than 1.0, yet two are remaining. I'm checking whether this should be considered a bug.


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Having a problem with Substance Painter or UV. Only some fragments of unwraped UVs are working ok

Hello! I'm having a problem with UVs in Blender.
I made this little handgun model, unwrapped it a lot of times to make it work, but unsuccessful. When i exported the model as .fbx file and loaded it inside Substance Painter, all the UV maps turned out grey as you can see on second screenshot. Of course I can only draw on some correctly working UV islands on the right and nowhere else.
I have no idea what i could do wrong, because it's literally my first model in Blender.
I have tried connecting parts of the mesh with boolean modifier, making different seams before unwrapping, changing position of UVs islands in the UV editor of Blender, as well as giving every part of the mesh its own material.

In Edit mode, please make sure there is no Hidden face (Alt+H). Then check your UV again. My guess is one or more faces are taking the whole UV space.

@thibsert, i've tryed this again and couldn't find any hidden faces.
Maybe something happened because i dissolved some edges? I had like two strange lines (edges) going through my bottom and top part of the gun for no reason.

Hi :) I'm not a Substance Painter user (yet) but ........... Check out this short tutorial  https://www.youtube.com/watch?v=RydSV0lKfHI&feature=emb_rel_end  At 5:00 looks like your problem. In the second video is explained one method to overcome this. ( at 4:05 )   https://www.youtube.com/watch?v=BhKQiuzQipg


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Drawing in 2D using a reference image, strokes keep appearing behind the reference image
I'm using Blender 2.82, I'm drawing using a reference image but the strokes keep appearing behind the image, how do I solve that?

The option to solve your problem can be found in the Object Data Properties of the reference image object like in the picture below:

to get there you need to switch in object mode and select the image reference object
There is also an option to set the reference image to be in the front, BUT using transparency.

Happy Blending


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Blender 2.83, compatibility with files from older versions
This might be a silly question, but when opening a file from Blender 2.79 in Blender 2.81, the layout of the screen is different and some materials get messed up.
Does this or something like this occur when opening files from 2.81 in 2.83? I'm contemplating downloading the latest version and I'm in between projects and don't want it to mess up my workflow.
Thank you for your help!

No there wont any big issues like that when opening files from 2.81 in 2.83 but do note that any of your fluid simulations will not work properly as there was a new engine called mantaflow that was introduced in 2.82 and replaced the old engine.

Thank you very much!

Blender has advanced a lot. It used to be that it would run on very humble hardware. Not any more. Newer releases use newer hardware as well and maybe they won't run well at all on older machines. Keep in mind that when you save files in newer versions, they might not open again in older versions.

Yes, you can do it (you can always have more versions of blender installed on the same computer). You only need some care about the liquid/smoke/fire simulations that have been updated recently.

My computer has the capability of an old microwave, every download is a big decision and a stressful one lol


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rendering with a graphics card
Actually i want to change my render engine .
When using Cycles i want to render on my graphics card (Radeon), but it is shown in OpenCL and not in CUDA as shown in the picture above.
Is it ok to change the settings in the properties panel render tab to GPU compute?
It is taking lot of time, how to reduce the rendering time by my graphics card?
If any mistakes in the question, sorry i'm a beginner, i don't know how to explain my question, thank you.

CUDA is only for Nvidia graphics cards. Since your GPU is from AMD, it's in the OpenCL tab. Was that what you were wondering about?

in rnder tab do i need to change to gpu computing or the cpu for better render

If you want to use the GPU, then you'll have to set the Device to GPU Compute. It won't make a difference to the quality of the image (unless you're using volumetrics).

While you can use "GPU Compute", since you have a GPU, it will use all devices selected under CUDA or OpenCL, means you could select the CPU as well and maybe speed up the rendering. While you only asked for GPU, i believe some users (including me) use not only the GPU. But that is something you can test if it's reasonable for you.

If you want to use only GPU for rendering you have to increase the tile size to improve the performance. https://docs.blender.org/manual/en/latest/render/cycles/render_settings/performance.html#tiles


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Why is my Image Texture set as 'Map # number' format?

Like the tittle above, why does my Image Texture show as numbers although I already re-linked it from a specific folder with a specific filename? Is there anyway to convert it back again to its original filename?


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Change the material displayed in the Node Editor from Python
Would like to be able to change the material node displayed in the Node Editor from Python after running an operator to create a new material node in Python.  In the Node Editor, I can click "New" and have a new node created and displayed (see the image below).  I can also select which material to display.  Is there a way to do this from Python?

Use Case
I am linking the material from another .blend file and would like to display the new material in the editor so the user can immediately start working on it.  The new material node is not linked to any object by default, that is left up to the user.  The code looks like this:
with bpy.data.libraries.load(blend) as (data_from, data_to):
    data_to.materials = ['fancy material']
# Change the Node editor display to show the new node?

While trying to figure out how to change the displayed material node, I found this code that displays the template_ID but do not know how to change it display my new material nodes. (Edited for brevity)
class NODE_HT_header(Header):
    bl_space_type = 'NODE_EDITOR'

    def draw(self, context):
        snode = context.space_data
        # Custom node tree is edited as independent ID block
        layout.template_ID(snode, "node_tree", new="node.new_node_tree")

Realizing this isn't the best "blender" behavior, is it possible?

You'd like to assign an imported material to a object in your scene, right?

The node editor automatically shows the material from the selected object in the scene, so I think there is no need to write any node editor code. If there is a reason, please provide a use case and let me know what else you need - removed my answer.

@poor, added more details and a use case.  Basically, I want to change which material node is displayed in the editor from Python code.  Just the same as if I had clicked New or selected the material node.  Thanks!

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


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Strange object.ray_cast() behavior
object.ray_cast() is not behaving as I would expect in Blender 2.77. I understand that it expects object local coordinates, but this problem happens when the object is not translated, rotated, or scaled.
If I edit the shape of the cube mesh without moving the cube, the results of ray_cast() seem plain wrong.
Steps to reproduce

Create a cube at 0,0,0
Move a vertex of the cube from 1,1,1 to 5,5,5
Create an empty called "src" at 2,2,2
Create an empty called "dst" at 2,2,6

Run this python
cb = bpy.data.objects['Cube']
src = bpy.data.objects['src']
dst = bpy.data.objects['dst']
hit, loc, norm, face = cb.ray_cast(src.location, dst.location)
bpy.ops.object.empty_add(location = loc)

This is the result on my system. The new Empty created at the interesection point is selected:

The source and the destination are both at x = 2 and y = 2. The cube has a surface at x = 2 and y = 2. So why on earth is the intersection point at x = 2.22222, y = 2.22222?

Raycast argument Vectors need to be in object's local space.
Ray cast is behaving as expected.  The first parameter is the origin of the ray  src.location and the second is a direction vector, which from a target would be  direction = dst.location - src.location (most commonly normalized)
The vectors also need to be in the local coordinates of the target object being ray-cast onto. Simplest way to calculate another object into target objects local space is multiply the global coord by the target objects matrix world inverted
origin = cb.matrix_world.inverted() @ src.matrix_world.translation # use @ for * in 2.8

Test script, using object references as in question.
mw = cb.matrix_world
mwi = mw.inverted()

# src and dst in local space of cb

origin = mwi @ src.matrix_world.translation
dest = mwi @ dst.matrix_world.translation
direction = (dest - origin).normalized()

hit, loc, norm, face = cb.ray_cast(origin, direction)

if hit:
    print("Hit at ", loc, " (local)")
    bpy.ops.object.empty_add(location = mw @ loc)
else:
    print("No HIT")

Ah, I see. So the "origin" is relative to the object location, but the "direction" is relative to the coordinates given for "origin." The docs and forums keep saying everything is in object local coordinates -- this in't really true for the "direction" and the docs should probably be updated to make that clear. I was thrown off by all the stuff about everything being object local.

authors: никита худолей


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Weird artifacts in my UV mapped texture
Any ideas what's causing those chunks of geometric artifacts?  Argh.

These may be overlapping faces of the model and so something like Z-fighting; or overlapping faces of the UV map. Try to W > Remove Doubles on the mesh and UVs > Pack Islands on UV map.

Would help if we could look at the .blend

Thank you. The blend file is here: http://www.aworkofmarc.com/1/New_Barrel.blend

Related - http://blender.stackexchange.com/questions/5441/cause-of-black-artifacts-in-render

Remove doubles in the mesh
What happens in your mesh now is  Z-fighting. Notice the clipping while rotating view around the barrel:

While in Edit mode select all and press W > Remove Doubles. It will delete ~800 double vertices.
After that you can split normals either by adding Edge Split modifier or activating Auto Smooth in Object Data tab.
Also see:

Overlapping faces:
Cause of black artifacts in render?
Overlapping faces in mirror modifier causing z-fighting

Edge Split modifier vs. Auto Smooth:
How to smooth shade an object while retaining hard edges?


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Through-walkable object with collision!
I wanted to make a nice game, but I am having a problem with water. I am trying to make a simple underwater shader and motion, but I have to make my water so the character can also walk through it. It also must have collision, so I can activate the properties. How can I make its physics work like that?

Could you specify why you need collisions?

I need collision to activate property which makes the plane(which makes underwater shader) visible. Also I need collision to play sounds when walking under water... And... To make player loose health when being too long inside of water...

You can have the water detect collisions and not actually register any collisions by setting it to ghost.

Once that box is checked, anything that hits it detects the collision, but it physically treats it like a no-collision mesh. So, you can simply have a logic setup similar to this one on your character.

Yes... it really worked:)


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Define " as a shortcut
Is it possible to attribute a shortcut has a symbol as the inverted comma or square bracket ?
I edit to give a little more information.
I created an operator who write me directly in the text éditor ""
and which places me the cursor directly between both.
I'd like to attribute the " as shortcut to this operator.

It's a bit complicated because of different keyboard layouts and how Blender processes input events. " on an US keyboard is apparently Shift+' (single quote, which is Ä on my German keyboard). The value Blender uses for this key (event.type) is QUOTE (and event.shift = True). Double quote on a German keyboard however is Shift+2, so a different key, The event.type for the 2 key is simply 2.

That you for your answer. I remembered an answer that you had given with a script here: http://blender.stackexchange.com/questions/8796/custom-modal-operator-event-timing. By using it, it shall seem that I just need to put 'THREE' for the even type. I use en french keybord ;)

The problem is that a model operator needs to be running in the background to capture Unicode = " input. You can't create a key binding in this way.


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Poll function for a BoolProperty
I'd like to add a poll function to my BoolProperty, but I don't understand how it works.
Is it similar to the poll function of an operator? What represents the "object" argument of this function?
EDIT after Teck-freak answer:

There is no poll function for Properties. You can hide the property in the layout or (even better) block the layout (layout.enable=False) so it can be seen but not used. You can also fake the behaviour within the update-funktion, but you'll need a second prop

With respect to your image, that was likely an old version of the API...you should post the link that you used. If you look at the current version (link in my answer), there is no such function.

The image come from the 2.79 API documentation
https://docs.blender.org/api/2.79/bpy.props.html?highlight=boolproperty#bpy.props.BoolProperty

There is no poll function for Properties.
HOWEVER:
You can skip the property in the layout or (even better) block the layout (layout.enable=False) so it can be seen but not used.
You can also fake the behaviour within the update-funktion, but you'll need a second property.
Finally you can define getter, and setter functions for your property.
BLOCK THE LAYOUT:
row = layout.row()
row.enable = False
row.prop(self, 'MyBool') #this will appear grayed out

GETTER & SETTER:
def get_MyBool(self, context):
    return self.MyBool_internal
def set_MyBool(self, context, value):
    if not self.dont_touch_MyBool:
        self.MyBool_internal = value
MyBool_internal = bpy.props.BoolProperty() # This is where its actually stored
MyBool = bpy.props.BoolProperty( # This is for your user-interface
         name='MyBool', get=get_MyBool, set=set_MyBool)

ABUSING THE UPDATE-FUNCTION: (Documentary only. Avoid if possible.)
def update_MyBool(self, context):
    if self.dont_touch_MyBool: # condition to check if changing mybool is allowed
        self.MyBool = self.MyBool_Backup
    else:
        self.MyBool_Backup = self.MyBool
MyBool = bpy.props.BoolProperty(name='MyBool', update=update_MyBool)

You can read more about bpy.props here
BLOCKING CERTAIN INPUT:
Let's say you'd like to define an integer that may NOT accept multiples of 2 or 3.
# this will only be called if a valid entry is made
def upd_MyInt(self, context):
    print('Entry accepted')
# This is where its actually stored
MyInt_Internal = bpy.props.IntProperty()

# This is for your user-interface
def get_MyInt(self, context):
    return self.MyInt_internal
def set_MyInt(self, context, value):
    if value%2 and value%3:
        self.MyInt_internal = value
MyInt = bpy.props.IntProperty(get=get_MyInt, set=set_MyInt)

Sorry, I misspoke.
Speaking of the poll function, I wanted to talk about the function that the poll parameter of the property expects.
I edited my post to add an image

I have litterally NO IDEA where you got that part. Properties have no poll function . However you can achieve what you want by defining your property with getters, setters, and a second property in the background. If you state more about your goal, I might be able to help you.

It's weird because it's from the Blender API.
But it doesn't matter, I sould have to get what I want by "blocking" the layout.
Thanks for your help :)

@pistiwique Ah I see. 2.79 is fairly new and we tend to program with the second or third-newest version instead, to avoid bugs and crashes. It seems the poll-function would take the object the property binds to as first, and your value as second input.

Just as a side note, the Accepted answer above (Teck freak) gives this error in Blender 2.79:
TypeError: set keyword: expected a function taking 2 arguments, not 3

see here

@N.Wells Hey. Thanks for the input. Could you tell me what you did? It might be that you have to skip context, but that would be weird. please give me a minimal failure example so I may test it. thanks in advance

From: https://blender.stackexchange.com/a/19431/28015

[P]oll, checked before running the operator, which will never run when poll fails, used to check if an operator can run, menu items will be greyed out and if key bindings should be ignored.

A poll operator method would not make sense for a property. You may be looking for the update method.

update (function) – Function to be called when this value is modified, This function must take 2 values (self, context) and return None. Warning there are no safety checks to avoid infinite recursion.

Using the poll for pointer properties.


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Streched Texture
I'm new to this community and in the process of learning Blender.
I have a problem that I hope some of you can solve.
I have tried to apply textures to several of my walls but the texture is good in some parts but other parts are streched. In the examples below you can see the result.
Process I followed:
1ste Cube Top
Add Mesh > Cube
Altered dimentions X 0.25m / Y 5m / Z 2.5m
Object > Apply > Scale (to set the scale back to 1)
UV Editing > Unwrap (tried: Smart Unwrap, Manunal marking seams and unwraping, and cube projection)
Shading > new material > Add > Texture > Image Texture (tried with both a jpg and a png)
2nd Cube Bottom
Add Mesh > Cube
Altered dimentions X 0.25m / Y 5m / Z 2.5m
Object > Apply > Scale (to set the scale back to 1)
UV Editing > Unwrap (tried: Smart Unwrap, Manunal marking seams and unwraping, and cube projection)
Shading > new material
As you can see the texture of the bottom wall is stretched if you compare it to that of the top wall.
I added a Texture coordinates and mapping nodes but that din't help.
The only solution I found is to play with the scale on the mapping node (see pict 5 and 6). I extrapoleted that the Y axis of the bottom wall is 2x larger than that of my top. So I changed the Y scale of the mapping note to 2 (2x larger that the Y scale of the top wall).
If you got only 2 wall that easy, but if you want to create a maze or a building interior it becomes to much work.
Is there another way to use the texture as a pattern, or did I do something wrong?

you can go into your UV editor, and scale down the part that you don't want to be stretched on the x axis.   If you're not sure how to do this, I would recommend watching this video: https://www.youtube.com/watch?v=Y7M-B6xnaEM

You messed up the scale on the mapping node. Why isn't it 1:1:1?

The UV unwrapping is maybe messed up. Try unwrapping that very wall only in the uv editor. If that doesn't help then use the mapping node's scale bar to adjust it. Hope it helps

we already figured it out, they had their mapping wrong


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Boolean operation between a form and a spiral
I'm designing a real object: a cylinder box dispender.
It will be 3D printed: two mirror versions of the same object (named Half.shell) will be printed and then screwed or glued together.
Just before gluing/assembling these two parts, I want to insert a thin band of metal between them, and give it a spiral form, so a spiral groove must be made available in the Half.shell object.
Context is Blender 2.9.1 with extra curve add on.
The problem I have is when I want to make the spiral groove into Half.shell object.
I've built a spiral of cubes, starting with a cube, add modifier array of 780 objects, then add modifier curve following an archemedian spiral curve created with the extra curve addon.
I've tried boolean modifier as well as BTool addon to make the difference/groove, with no success: the resulting shape is a real mess with triangles going everywhere and nothing becomes editable from this point.

Edit1:
-the Spiral.of.cubes object sometimes grows by itself, as if I've scaled it on the X & Y axis, and reopening blender can help, but not always. This problem occurs when I'm changing selection in object mode and edit mode.
-so may be the way I'm doing the spiral.of.cube is not the good way.
-Spiral.of.cube is in fact a spiral of parallelepiped 1.5x1.5x2mm

Hello, so what are all these cylinder for? I guess your problem is just between the spiral and the shell? Just to make sure...

Yes, you can hide or delete them. They will be real world objects (jars or something like that), so I've drawn them to check they fit into the inside of the spiral.

there are several problems like for your spiral inner faces and overlapping vertices, that's easily fixable before applying the modifiers if you delete 2 faces of the cube and click on the array merge option, but your shell has also bad topology like inner faces, overlapping faces, flipped normals, you need to fix that and the boolean will work much better

also you should probably simplify the topology of the flat surface of the shell (where the boolean will happen), it will probably help

Thank you. When saying boolean modifier you mean regular/default blender boolean modifier or BTool add on ?

I wil search on the forum how to do all these operations to obtain a better topology for my shell.

Regular Boolean modifier, I'm going to make an answer except I can't go fully in detail for your shell object as there are several problems that you need to fix and that are hard to explain in few words

What you need to do :

Select your spiral cube object, delete 2 faces so that it won't generate inner faces, apply both the Array and Curve modifier, press Alt > Merge By Distance:

Fill each tip with F :

The topology of you shell is messy, go in Edit mode and press Alt > Merge By Distance, in the Operator box choose a Merge Distance of 0,001 :

But you also need to delete inner faces, overlapping faces, and you need to recalculate the normals (AltN), especially if you plan to print in 3D.

Once everything done, you can merge all the faces of your shell surface, where the boolean is supposed to happen:

The Boolean will work fine:

Your help is really appreciated. Thanks a lot.

Some additionnal questions: To Compute normals: Edit Mode->Select all->Alt N->Recalculate outside ?

Yes, also, check the normals: open the Viewport Overlays panel and enable Face Orientation

Thanks a lot, you saved me days. Hard for me to check this toggle since all menus are transparent (graphic card is an old ATI from 2012, seems to be no more supported in new versions of blender...) and this region is full of static information underneath,

So maybe use a previous version of Blender, Boolean has been improved in 2.91 but it should work with 2.79

When "Face orientation" is checked, faces become blue or pink instead of grey, is that a normal behavior or is it my outdated graphic card ?

it should be either blue (normal orientation) or red (invert of the normal), but it may be altered by a setting (?)

Blender 2.79b was not able to reopen my blender 2.9.1 .blend file (crash).
So I've exported to .obj in 2.9.1 and opened the .obj with 2.79b without any problem :I've just loose the collection hierarchy but it's a minor problem.
The rendering with this ATI fire pro is way much better with 2.79b than with 2.9.1

If you can't work with 2.8 or 2.9, and can't open the file in 2.79, you can append all the obects: File > Append > double-click on the file, go in the Object folder and select all

That's a great tip. Thanks.


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How Can I Fix This Gap In My Fluid Domain?

Just to start off and explain things, I've been having this problem whenever I try and create a fluid domain so I created the simplest example possible. The bounding box seen is not the domain but an exact copy to show the boundaries. I used to have great fluid simulations, now this happens and for some reason any objects set to obstacle are ignored by the fluid, any help would be appreciated
Also, if you're having trouble seeing the problem, download the blend file and if it's not my computer causing it locally, you should see that the fluid doesn't collide with the domain properly, there's gaps between all the sides.

Can you add the .blend file so we can take a look? Just the screenshot isn't much to go off

@m.ardito there's a gap between the fluid and the domain, the collisions aren't working properly

Increase the resolution to reduce the gap.
The "glitch" you are experiencing is indeed an artifact of the low-resolution simulation.
The fluid simulation is computed on a grid of N × N × N small cubes, N being your "Final" resolution setting. Every detail of the 3D world, like the boundary location or an obstacle, that is smaller than the diameter of these cubes may be ignored by the simulation. Therefore, you should always expect gaps that are as large as one N-th of the edge of the simulation box.
In your example, you are simulating at N = 65 and visualizing the "Preview" mode at N = 45. Since your gap is around 1/45-th of the box size, it shouldn't be considered a glitch.
Increase your "Final" simulation resolution to ~150 and switch the "Viewport display" to "Final" to see the difference it makes.

Your file simualted at Final = 300 and Viewport display = Final

I, like you, also remember perfect domain to simulation walls parity, but I think I just never noticed the small gap before.
I checked Blender 2.78, 2.79, 2.8, and 2.5, all exhibit the same behaviour.
So I'd say this is as it has always been.

I had it working perfectly and then in the same version this started happening (I was on like 2.3 or something) and then I updated and it stayed consistent, hopefully we can find an answer to if this changed in an update, I've also been having problems with fluids ignoring things designated as obstacles, any troubleshooting I can do that would work or should I be more specific?

best thing right now would be to ge 5+ people to notify if theyre getting the same bahaviour, I don't think anything external can break this, if I understand correctly this depends solely on cpu. I tried looking at a few other videos online and while it is difficult to tell I'd say that the gap is there.
kinda offtopic but why do you care about the gap? it's not something that I can see being a huge problem.


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Where can I find a proper API reference?
I can't believe I have to ask this, but where do I find an actual API reference for Blender scripting? I just can't seem to find one. I see tutorials but no proper reference documentation.
For instance, this page feels like it should be giving me a list of all the members of bpy.data but I don't see any way to get that information. The "next" button just takes me to the next section, and "modules" takes me somewhere else entirely.
What am I missing?
EDIT: The linked dupe DOES NOT answer the question. Clearly you did not read my question. I can't find the ACTUAL API REFERENCE. I don't understand why this is so complex to answer.
How do I know what each "class" (or whatever the python equivalent is) member variable and function is?

Have you looked at https://docs.blender.org/api/current/index.html ?

Or this one if you need "newest" https://docs.blender.org/api/blender2.8/

And also writing a documentation is a huge job and not that necessary. Blender as an opensource project including all those function, it is hard to keep documentation good as other software like Unity or Javascript, they both make effort on their documentation.

@stphnl329 That's the same page I linked, only for 2.8. How do you actually find an API reference from there? As in.... I don't even know how to describe. Those pages are not API reference. Like.... for instance, with Unity I can see the Transform class. https://docs.unity3d.com/ScriptReference/Transform.html From there I can see every member variable and function available. How do I find that same sort of thing for Blender?

@Hikariztw See above ^ Also you have to be kidding about documentation not being that necessary. Documentation is exceedingly necessary. It's literally not possible to use an API without documentation.

@Clonex I haven't gone through and done scripting yet with Blender, but I'm under the impression that they've explained some basic functions/commands that they've built in, then the rest of the API are variable names that are meant to be self-explanatory as they directly correspond to various properties/buttons in Blender

@stphnl329 I'm sure the API names are self-explanatory, but WHAT ARE THEY? How do I know the member variables and functions? There MUST be documentation for this somewhere or no one could ever write any scripts!

In the "for instance" 2.77 documentation link posted  above  you overlooked =====>    Type: bpy.types.BlendData <=====

Have you looked through this page? https://docs.blender.org/api/current/info_api_reference.html# If you right-click on a property in Blender and select online manual, it'll redirect you to the website, and if you change the dashes to dots at the end of the redirect URL, that's the property name (ex. URL:  docs.blender.org/manual/en/2.81/scene_layout/object/properties/transforms.html#bpy-types-object-location  means the location property is bpy.types.object.location

Not every API is well explained in Blender Doc. By my experience, some function and structure is really missing. Which required coder to guess how to use them. Also, the python code have some tips in Blender Interactive console

@batFINGER Thank you! It seems like you were the only one to actually understand! It seems an odd way of laying out the docs, but hey, at least they're there. Thanks!

@batFINGER The question is open again. If you want to make your comment an answer I'll accept it :D

@Clonkex In case you didn't notice, you can click on the type field to see what's inside the classes, e.g. by clicking on bpy.types.BlendData on this page you see what attributes it stores. This applies to the entirety of the API docs and allows you to traverse the class hierarchies.

@RobertGützkow Thanks, yeah that's what batFINGER pointed out and what I had missed. Makes a lot more sense now but I still think it's an odd way of laying out the docs.

Look for class members, (properties, methods et al), in the classes doc page.
bpy.data is  a reference to an instance of the bpy.types.BlendData class. All the members of that class will be found in the documentation page for the  class (or type),
Most python documentation, I am familiar with, is organized this way, and has often, as is the case here generated from the source.
There may be many references , in this example scrolling down to reference section see that context.blend_data is also  an instance of bpy.types.BlendData.  Note Even though context.blend_data and bpy.data are both of the same type and for this case mostly the same object, but it is not necessarily so. Might start using me = context.blend_data.meshes.new(...) for methods where context is passed.
A type with numerous references is the  blender object. bpy.types.Object for instance the context object of any blender object type. The target of a driver, modifier, constraint on an object. A member of a collection: blend data objects; collection objects or scene objects  etc etc etc etc.
Blender uses the convention: names of properties and methods are in lower case, classes in title case. eg bpy.types.WindowManager is a class (being in bpy.types is a bit of a give away too), bpy.context.window_manager an instance of it.
Turn on developer extras to get an API link by right clicking on a property.

Note; for some functions, right clicking and copying data path / looking up the API reference doesn't always give you the right path.


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How can I disable symmetry in sculpting mode?
I know this has probably been asked before, but I'm watching a tutorial where the guy's sculpting and telling you to disable Symmetry X under the sculpt menu.
The video:
Mine:

I'm surprised by the other answer. No need to go to the N-panel, scroll etc. it's right here on top all the time. Just check or uncheck the axis to toggle symmetrize.


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Subdivision Surface Problem
I have a soldier model:

When I add the Subdivision Surface modifier, this happens to the model:

Does anyone know how to remove this?
I just wanted to add smoothness to the models, but not that.

The model appears to be split into individual faces. Go into edit mode, select everything with [A], press [ALT] + [M], then By Distance to remove doubled vertices. If that model wasn't made to handle subdivision surface though, you will likely not get an ideal result.

How to upload an image to a post

If your using 2.79 (like me and my boomer friends(lol)) then the short cut for remove doubles is [w].

The split faces subdivided look a lot like what a quad would if subdivided. Thus as @Rekov already mentioned, you should be fine after doing the following:

Deactivate the Subdivision Surface Modifier (faster depending on the model)
Go in Edit Mode
Select all elements of the object with A, either mode, vertices, edges or faces will work
Press Alt+M and select "Merge by Distance"
Go in Object Mode and if you did not do yet, RMB Shade Smooth
Activate the Subdivision Surface Modifier again
Smile

Happy blending.

I am so happy! Thanks you!

May i ask you to accept the answer as solved if it did solve your question.


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No Supported GPU found (windows 8.1 using bootcamp on mac pro 5.1)
I trust you are all safe and well in these trying times.
I've spent hours going through posts on here and other places to try and get to the bottom of the issue I am having and this is my last resort.
I am running Windows 8.1 through bootcamp on a mac pro 5,1. I have just purchased an interim GPU to replace my stock card so I can do some cycles rendering and help with the general running of the software, I intend to upgrade this down the line. It's a EVGA GTX 680, I know this is on the lower end of things in regards to running Blender but as far as I'm aware it should show in the preferences.
With the Nvidia drivers installed in OSX it works, albeit not as well as it likely would in windows. I've installed the latest CUDA drivers and the Nvidia drivers and it's not showing up. I've tried uninstalling Blender and reinstalling it as someone suggested in one of the many posts I have read. I've tried earlier builds of Blender and none of them seem to work either.
If someone could shed some light on this i'd really appreciate it. I've been a Mac user for 25 years so Windows is pretty new to me, it's driving me mad, seems like to do the simplest of things is a huge pain in the back end.
Many thanks
Neil

In worst case, any linux distribution should do it...

Thanks for that, After a few more hours messing about I managed to have some sucess using an older version of CUDA toolkit. I may try the Linux option to see how that works.

Cool! Recommend elementary OS which feels like OSX or classic ubuntu/debian to get start with.


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Blender 2.8 Armature for Secondlife and Avastar
I'm just starting to learn about making animations with Blender 2.8, primarily for Second Life, and have completed some tutorials for Blender 2.8 that were really very good! Well, as a start at least :)
As I understand it currently the armature for blender to use for Second Life is only provided by the Avastar add-on. That's fine I don't mind signing up for that however it seems that there is currently no release available for Avastar that works with Blender 2.8 One was due last year but the Machinimatrix site has a post from Gaia Clary from Nov 8th 2019 saying it was almost ready but had hit delays due to compatibility issues between Avastar and Blender 2.8. That was of course almost 6 months ago now and I can't find anything else :(
I do realize in these current times all plans are liable to be messed up by things way outside of anyone's control. So what I'm looking for is some advice on my options which I see as follows:

Continue to wait for the Avastar version compatible with Blender 2.8 - I'm reluctant to do this as I have no idea in the current climate how long this would be.
Regress my Blender 2.82 to Blender 2.79 to use the working Avastar - I'm looking at this as one of the two favorite options at the moment.
Switch to another animation authoring tool that doesn't require Avastar - This being the other favorite but having spent days on the Blender tutorials would kinda suck but does have the advantage of avoiding this 'middle man' type relationship between Blender and Avastar.
Attempt to use a non Avastar armature for Second Life such as the riggify human meta-rig - Scares the hell out of me as I have no idea how this will work in my target environment!

It's an obstacle I didn't expect and I'm really finding it hard to get much information. So is anyone able to offer me some advice or maybe point out anything I have wrong or missed?  Thanks in advance.
Leni

Welcome to SE!  SE is a place to ask specific technical questions, and I'm having some difficulty ascertaining the question (about Blender) here.  The gist of the question seems to lie elsewhere (in Avastar's domain).  You might have more luck contacting Avastar directly or checking out BlenderArtist.

Hi to re-phrase it, I'm hoping to animate in Blender and am looking to find a way of obtaining an armature to use in Second Life. Currently it seems that Blender defers this to Avastar, which isn't working at the moment. So my question is what are my options for getting my Blender animations to work with the Secondlife skeleton. To me that's technical but maybe not so much to this forum, idk this is my first post here :)

We can help you with the mechanical operation of exporting, but as for meeting Second Life's animation needs and what is going on with Avastar, we cannot help you.


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Programmatically crop render region to geometry
I have a complex geometry nodes setup and a script to render out multiple viewlayers as separate images. For context, I'm generating the fixed imagery necessary for previewing a framed canvas product on our website. The script changes some parameters on the geometry nodes for each canvas size, ultimately resulting in 234 images.
According to this answer, I can set the render region like so:
bpy.data.scenes['Scene'].render.border_min_x
bpy.data.scenes['Scene'].render.border_max_x
bpy.data.scenes['Scene'].render.border_min_y
bpy.data.scenes['Scene'].render.border_max_y

I'm not super familiar with scripting in Blender (or even Python itself - more of a C# guy). I guess I need to somehow find all geometry in the scene and project it to the camera near plane, then find the bounding box of all vertices.
The question: How can I programmatically set the render region to crop the final render image to only encompass the geometry in the scene?

I discovered there's a utility function called world_to_camera_view. Once I found that, it only took a little more googling to get a result that I was happy with:
import bpy
import bpy_extras

# Setup
scene = bpy.data.scenes['Scene']
cam = bpy.data.objects['Camera']
objs = bpy.data.objects

def update_render_region():
    min_x = 1
    min_y = 1
    max_x = 0
    max_y = 0

    # For whatever reason, update_tag is what you call to update an object's actual display data
    # This is necessary if you've just programmatically updated a geometry nodes modifier property
    for obj in objs:
        obj.update_tag()

    # Now get the evaluated depsgraph. This has to happen after the objects have had update_tag called
    depsgraph = bpy.context.evaluated_depsgraph_get()

    # For every mesh object, find its vertices' positions on the screen
    for obj in objs:
        if obj.type != 'MESH':
            continue

        # I'm working with geometry nodes and it needs to be evaluated to
        # actually have any vertices to iterate
        obj = obj.evaluated_get(depsgraph)
        for vert in obj.data.vertices:
            positions = [(obj.matrix_world @ v.co) for v in obj.data.vertices]
            for pos in positions:

                # The magic sauce!
                coord = bpy_extras.object_utils.world_to_camera_view(scene, cam, pos)
                min_x = min(min_x, coord[0])
                min_y = min(min_y, coord[1])
                max_x = max(max_x, coord[0])
                max_y = max(max_y, coord[1])

    # Set the render region and enable it
    scene.render.use_border = True
    scene.render.border_min_x = min_x
    scene.render.border_min_y = min_y
    scene.render.border_max_x = max_x
    scene.render.border_max_y = max_y
    scene.render.use_crop_to_border = True

# Do the rendering (fill in your own code here)
for size in sizes:
    frameObj.modifiers['GeometryNodes']['Input_2'] = float(size[0])
    frameObj.modifiers['GeometryNodes']['Input_3'] = float(size[1])
    update_render_region()
    render(size[0], size[1])

# Be a good citizen and reset the render region
# (A better citizen would remember the old render region )
scene.render.use_border = False
scene.render.border_min_x = 0
scene.render.border_min_y = 0
scene.render.border_max_x = 1
scene.render.border_max_y = 1
scene.render.use_crop_to_border = False

I'm mostly a C# programmer so this is probably horrible Python. Use at your own risk

EDIT: This answer tackles this question using extra math steps. OP has found a built-in function bpy_extras.object_utils.world_to_camera_view(scene, obj, coord) to use instead.
I used the concept of "change of basis" from linear algebra. First, I projected the vertices of each object to the plane of the camera frustum. Then, using basis vectors that define the plane of the frustum along with the lower left corner of camera frustum, we can define the projected corner point in terms of these basis vectors and the lower left corner. The stretching scalars of these basis vectors thus tell us what the border min and max values need to be set as.
import bpy
from mathutils import Vector, Matrix
from mathutils.geometry import normal
from numpy import cross, dot

# these need to be true to set border
bpy.context.scene.render.use_border = True
bpy.context.scene.render.use_crop_to_border = True

# get corners of camera frustum
scene = bpy.context.scene
cam = bpy.data.objects['Camera']
bpy.context.view_layer.objects.active = cam
camType = bpy.context.object.data.type
# normalize to ignore camera scale
matrix = cam.matrix_world.normalized()
frame = [matrix @ v for v in cam.data.view_frame(scene=scene)]
origin = matrix.to_translation()
frame.append(origin)

# frame 0 thru 3 are corners of camera frustum
p1, p2, p3, p4 = frame[0:4]

# camera location
l = cam.location

# horizontal basis vector of camera frustum
v1 = p2 - p3
# vertical basis vector of camera frustum
v2 = p4 - p3
# get normal vector of plane
normal = cross(v1, v2)

# objects stored in collection
col = bpy.data.collections['Collection 2']
objs = col.objects

# list of horizontal scalars
s1s = []
# list of vertical scalars
s2s = []

# get each objects coordinates in terms of new basis vectors and p3
for obj in objs:
    verts = [obj.matrix_world @ v.co for v in obj.data.vertices]
    for v in verts:
        # direction of line to be parameterized, if orthogonal, direction should be normal
        if camType == 'ORTHO':
            direction = normal
        else:
            direction = l - v
        # parametric value for projection to camera
        t = -(dot(normal, v) - dot(p1, normal))/dot(normal, direction)
        # vert projected to camera frustum
        vP = v + Vector(t * direction)
        # matrix with v1 and v2 as basis vectors (has to be square in order to invert)
        mtxB = Matrix((v1, v2)).to_3x3()
        # find scalars to stretch basis vectors to projected point on frustum
        scalars = (vP - p3) @ mtxB.inverted()
        # horizontal scalar append to all horizontal scalars:
        s1s.append(scalars[0])
        # vertical scalar append to all vertical scalars:
        s2s.append(scalars[1])

# mins and maxs
x_min, y_min, x_max, y_max = min(s1s), min(s2s), max(s1s), max(s2s)

bpy.data.scenes['Scene'].render.border_min_x = x_min
bpy.data.scenes['Scene'].render.border_min_y = y_min
bpy.data.scenes['Scene'].render.border_max_x = x_max
bpy.data.scenes['Scene'].render.border_max_y = y_max

I actually ended up finding a solution on my own (turns out there's a utility function called world_to_camera_view. I've posted it as an answer. Your answer almost answers the question, but not quite, because it doesn't take into account that I'm working with geometry nodes. Also, while bounding boxes would have worked in my specific case because I'm only working with cubes, it wouldn't necessarily work for non-cube geometry (unless the bboxes are aligned to the camera?).

Ain't nothin like getting humbled by a built-in function when you do something the long way! Also, yes, you are right about needing to project each objects vertices instead of each objects bounding box corners, so I used some monkeys instead of cubes. I corrected my post, but still kept it without the built-in function.


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Armature origin
I am making a shooting game . I wanted my hand and head to face the direction of the camera so it can look/shoot up or down.But when i face downwards or upwards , it result is not what i wanted . Have a look at this.

This is obviously the origin problem . Have a look at the origin location.

I tried shift+ctrl+alt+c to set it to geometry but it doesnt work in armature.
Any solutions? Please help . Thanks and Over

the head and hands are separate objects ? how they are following the bones "parent, constraint "? what are you using to move the bones " animation, constraint "? if you can upload a sample file it would make things easier :)

I am sorry , I know this is very rude to someone who is willing to help but i don't really want to share my file for some reasons . I know where the problem is , just need to know how can i set an origin for my another half armature. Yes , they are both seperated using ctrl+alt+P. So that when i move my mouse , the hand and head will move instead of the whole body. As you know , they rotate around the origin . So if only i can set an origin for each of the upper half armature , the problem will be fix , but how ? Hope you can help me . Thanks alot.

I managed to fix it . Just remembered the solution. Enter edit mode and move the bone to your desire position for the origin.


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Blender Game Logic Actuator
I managed to be able to control my player hand with mouse using mouse actuator.However, the hand move at the opposite direction i want. For example ,  when i move mouse down , the hand go up .And when i move my mouse around , the hand kind of turn around .

What is wrong with my actuator settings?
Here is the sample file:   http://www.mediafire.com/download/1sz9taf3bd8j28u/samp.blend

to reverse the hand direction set the sensitivity to -1.0 :

also pay attention to the local/global axis you are using ,the camera was turning in the right direction because you used the local axis while the hand local axis are not in the right orientation

I am really grateful that you help me . But i have a few questions. How do i set the hand into the the right orientation ? And the gun doesn't point towards the middle of the camera, how to make it point towards the middle? I tried adjusting the Min and Max . It works but not really accurate. Is there any other way?

@XavierChoo for now i think you should keep the hand as it is since it's working (although you can "apply Rotation" to change the local orientation but this may mess up the animation you have ) , and for aiming you can take a look at this  and if you need more help just ask :)

Amazing ! Just what i need ! But i don't really understand the explaination of the py from David . His testing demo file was removed . Can you show me an example of it? That would really help me out.

I changed my rig into something that can move much more realistic . But the hand weight paint doesn't work as well like the previous one. So i am stuck at making it point towards the center. This is a personal request but can you help me check out my new rig and make the hand and head point towards the mouse? If only i finished this , my game will almost be complete since i know how to make good AI . Please help if you can . Sry for the trouble and thanks alot.Here is the file  http://www.mediafire.com/download/rpvgidxbadd517s/Sample.blend

@XavierChoo Hi there, this may be late but I'll try to work on that and since I have no prior experience I may take some time

I am out of words to express my gratefulness.Thank you so much!

so how is the progress going?

@XavierChoo sorry i got dragged away with other things, here is the file, any feedback is welcome


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BGE Character dynamic
I am making a simple game. Setting the Box to dynamic and my armature and character to static , with ghost option activated  so that it won't collide with the dynamic motion box. However , I got myself into a weird situation which had never happen before.When i  play the game , the character was standing on the floor as i wanted . But the character change its shape when i tried to move it . Walking right and left doesn't seem to be a problem but when i press w to walk infront , it flew off to the mid sky and when i press s to move backwards , it went out of shape like the picture below show. Need a solution as fast as possible.

I tried to save the file so i could upload it here to be more specific. But after i save it and open it in another blender window . This is what i get.

After checking my settings , i finally found a solution.
It appears that after animating my character , i didn't turn off the auto-keyframe button which is in the animating layout. Thus , when i move around my character , it automatically set location to the character meshs. Which corrupt with my armature and dynamic.So i deleted my character meshs action editor and it fixed it .
Hope this will help people who will come across this problem like me .
Remember to turn off your auto-keyframe button after you done animation.
Cheers and have a nice day.


text:
Cubic character armature deform
I am making characters similar to minecraft . This is the product that i make myself.

However... look at that arm. I am having trouble trying to find out what's the problem with it . This is the final product that i wish to have.

I want my character arm to be excatly like the second picture .
Anyone can help?

There are too many vertices in your arm. If you leave only 1 loop in the elbow with 50% weighting on both bones you'll get the correct result with armature modifier set to Preserve Volume. If you need more vertex resolution you will have to make corrective shapekeys or corrective bones to get this shape.

Sorry , i tried doing what you said but am still in a state of confusion.And one more thing . How can i add the rig movement limit. I have added the file that i wish my final product will be like . ( look up there ) If you try to move the arm ik up . It stop when the arm is at its limit . how do i do that? And please continue helping me in the deform part .


text:
My weight painting only works at 100% no matter the shade
I am trying to weight paint using blender 2.73a, but no matter what weight I assign to a vertex or what shade the weight painting is it always gets influenced 100% by the armature/bone.
Has anyone else had this problem?
I add this picture of a cylinder and one bone. As can seen the weight paint is not uniform, but the entire cylinder follows the bone.

Or am I totally not understanding weight paint.
I also add a link to the blend file below:
blend file of cylinder with bone

If you isolate part of the model and load the .blend to PasteAll.org and paste the link here, someone may be able to find what is wrong.

This is how weights work.
The weight doesn't define an influence of a particular bone; It describes the Mix factor of influence between multiple bones.
So a vertex with 1% weight on one bone and 0% on all other bones will be 100% influenced by the 1% bone.
A vertex with 1% weight on one bone and 50% weight on another bone will be almost entirely controlled by the 50% bone.
In other words, a vertex is always influenced 100%. Weight only controls which bones do the influencing.

To get a result similar to what I think you are expecting, add a second bone weighted to all the vertices by 100%. Now the first bone's weights will cause non-uniform influences, as you might expect.

Thank you for the feedback. I must say I'm slightly disappointed that a lower weight value would not simply soften the effect of the bone. I'll play around with it.

@pietvdwest You can achieve this "softening" effect by mixing in another (static) bone. I tried to describe this in the second half of my answer, but I don't think I did it very clearly..

The explanation given above (by Gandalf3) is accurate, but a little hard to understand for those new to Blender. It may help to clarify how this problem comes about and how to fix it:
When creating bones, Blender will automatically generate a vertex group with the same name; which links the vector weights to the relevant bones. However, an associated vertex group may not be generated if you import an armature, and sometimes when you duplicate / copy-paste / rename bones (or delete vertex groups).
So, if you've got a 'head' bone that's connected to a 'neck' bone, but only have a vertex group with the name 'head', any weight painting done over the neck area will result in a 100% weight. This happens as Gandalf3 explained... if there are no weights (from other bones) controlling those vertices, Blender calculates all weight values applied to the area as 'the only thing that needs to be considered' = 100% influence.
To fix the issue, you either need to add bones, or determine which bones don't have vertex groups and create them (with the same name as the bones - and assign vertices to them).


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Snake hook in sculpt mode is creating glitch like shapes instead of smoth tentacles
I don't have too much expirience in sculpting, but I have seen on videos i'ts seemingly easy to make smoth tentacles. But in my case what I get are ugly ditortions on ends. I tryed adding more verticies and using Multires modifier but it hardly helps. Is it just how snake hook works ?

Dytopo efects

The answer provided by @Gorgious is correct. Have a look at the documentation for dynotopo, particularly detail size. The object should should be at least somewhat subdivided before using snake hook, smaller detail scale will also help.

Dyntopo and Multires are absolutely different workflows which shouldn't be used at the same time. Note after using dyntopo mesh is triangulated and can have bad shading. If using Dyntopo, there are Relative detail and Constant detail. Relative depends on the zoom level in viewport, Constant depends only on the number entered in its settings. However none of your screenshots show settings for dyntopo.

I subdivided the hell out of it @Timaroberts

You need to enable Dyntopo in the left panel, otherwise the tool will only displace geometry, until it gets horribly mangled and creates artifacts.
Dyntopo will generate new geometry on the fly, provided you don't move your mouse too fast it should create a smooth hook.
Don't forget to tweak the detail size if you think the generated geometry doesn't fit.

Also consider using the latest version if you can, there has been gigantic improvements since 2.79 in the sculpting area.
Link to the official download page

if that was this easy I would't ask here.  I already tryed to use dytopo and i have seen the effects on tutorials, but for me the dytopo somehow makes things worse. Instead of generating new geometry it somehow dicreases it, and it takes ages to enable it. The snake works the same in both 2.79 and 2.8, thats the biggest problem. See on the main question

Dear Rex, no need to get defensive, we are all learners here. Please read again the 3rd sentence of my answer. In short, click the arrow on the left of dyntopo and lower the detail size.


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My rig does not move my character correctly
I created a character, I inserted the bones and the rig, when I use the pose mode and move the rig my character deforms and I cannot animate it. I searched a lot online but found nothing about it. I hope someone can help me because I don't know what's wrong.

Hello, hard to tell, please share your file here: https://blend-exchange.giantcowfilms.com/

Hello, I just uploaded my file, i need help please. Thanks

Yes but you need to copy paste the link it gives you  ;)

Sorry, i don't know if it's right, it's the first time for me ...

The problem is that the normals of your mesh are flipped so it gives bad parening:

To fix it, select your mesh, select all in Edit mode and AltN > Recalculate Outside. Then reparent to the armature With Automatic Weight. It should work much better. If you need to make some corrections, display the good layer, i.e. the one with the bones that are supposed to deform your mesh:

Then select the armature, shift select the mesh, switch to Weight Paint mode, check each bone and give some corrections:

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