text:
How can I stop the 'bloom' effect shifting direction in eevee?
I have a short space scene that I've included some camera shake on. Everything looks great, but the bloom effect I have on the sun shifts direction with the camera movement!
Have attached a short gif that demonstrates the problem, first at normal speed, then frame by frame.
Any ideas on how I might reduce or get rid of this?
Thank you in advance!

Can anyone help?

Try disabling bloom and using a glare node instead in the compositor, if that still not helps then you can use a gradient map to create bloom effect instead.

If you don't know how then you can just ask by commenting or tell if it works or not.

Thank you for answering! Will give the first a try!

The glare node is ok, but loses a lot of the more interesting aspects of the bloom (Chromatic aberrations, smooth light falloff etc). I'm not sure how I would go about creating a bloom effect with a gradient map, could you point me in the right direction? Thank you for your help so far!

You can add a material to sun and put it in front of planet by only moving it on 1 axis pointing towards the planet, then you can use a radial gradient as a factor to mix an emissions shader with a transparent shader, you can add an color ramp or rgb curves to control fall off and smoothness, now you'll get some basic sun like looking shader for going even further you can use object coordinates and manipulate them using different texture to get your desired results, this is a really flexible method.

Ok will give that a go, hopefully it fixes it!

Thank you for the help, none of the solutions fixed what I needed unfortunately.
However I did manage to fix the problem, and for anyone who is facing a similar issue, here's how I did it.
I figured out that the way bloom was being calculated was in relation to the emitters angle to the camera. With my shake being set on the x axis, small rotations were being amplified by the bloom effect because the angle in relation to the camera was changing and as a result, so was the direction it was 'blooming' the light.
To fix it, I made one very simple change, instead of a shake in the rotation, I applied the effect to the translation in the z axis. The motion feels pretty much exactly the same, but instead of it changing the angle the camera points at, it moves the whole camera up and down a bit. It's worth pointing out there will still be some shift in the bloom effect as the translation still adjusts the angle a bit, but its a lot less noticeable now.
Mission accomplished!


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Why is my smoke only generated for the first frame?
I have a smoke sim that is moving, and has forces affecting it, all seems fine and it moves how I want it to, but the flow object isn't continually generating smoke!
It only does it for the first frame and then that's it.
Can anyone help?

Need to set the type to inflow and not geometry

Thank you so much!

Thank you to Eric Xue, answer was as commented: Type needed to be inflow, and not geometry!

source: Stack Exchange

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

sort: votes


text:
Every time I try to select a single object, it selects everything in the scene. How do I separate them?
I am currently modeling a character and made my head and body separate meshes. Since they were separate meshes, I couldn't join them together.
So my lecturer did some dark magic and made it possible for me to join them together as one mesh (Made it possible to join vertices from the head to the body).
Now, I've run into a problem where even if I simply add a cube to the scene and select it, it selects the head and body as well. Not only that, the cube automatically has modifiers put on it that were on the head and body.
I'm not too sure as to what setting he changed or how to change it back. Help!
P.S I am still relatively new to Blender, so apologies for my noobness.

See Splitting pieces of a mesh into a new object

I think the problem you have is that you added the cube in the edit mode of the character(?). This results in the cube being a part of the character object.
If you really want to have seperate OBJECTS (not only meshes), you have to add the cube in Object Mode. (Mode selection is on the bottom-left corner of the 3d editor).
Another way is to seperate the meshes by selecting the part of the mesh you want to have in a seperate object and pressing P and clicking selection

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


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Running Blender via Python
I'm learning blender and want to create my own module with a custom UI. I'm stuck at the gate just trying to import Blender to run through independent python scripts:
import subprocess

bPath = "C:\Program Files\Blender Foundation\Blender\blender.exe"

subprocess.run([bPath, "--background", "--python", "myScript.py"])

All that's in myScript.py for testing is:
import bpy

bpy.ops.mesh.primitive_cube_add()

All I want to do first is load up a blender render window from Python that makes the cube, ideally one stripped of the interface. I can figure the rest out from there.
My error is
FileNotFoundError: [WinError 2] The system cannot find the file specified

Any help would be much appreciated.

FileNotFoundError: [WinError 2] The system cannot find the file specified

This suggests there is a problem with the path to something in your script. I think you may need to give the absolute filepath to your myScript.py file.
Also, the "\" is an escape character in python, so if you're going to use it in the filepath to something, then you should use one of these methods:
bPath = r"C:\Program Files\Blender Foundation\Blender\blender.exe"

or
bPath = "C:\\Program Files\\Blender Foundation\\Blender\\blender.exe"

Thanks, that was my noob mistake. Is there a way to get blender to create a viewport this way?

Opening blender with the "--background" flag means you're opening blender without a UI. From what you've said, it sounds like what you want to do is make an Addon. I recommend downloading someone else's well-made addon and having a look at their code and reading this tutorial.

Thanks, I was able to get a blender window to show up with the cube added. I will sort the rest out from here.

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


text:
bpy.data.object 'NurbsPath' name is "NurbsPath.001" and cannot be "NurbsPath" while bpy.data.curves name can be either "NurbsPath" or "NurbsPath.001"
In python console if I
def selected_curves():
    print("active objects:")
    crvs = []
    for obj in bpy.data.objects:
        if obj.select:
            print( obj.name)
            print( obj.type)
            if obj.type == 'CURVE':
                print('is a curve' )

then call
selected_curves()

I get:

active objects:
  NurbsPath.000
  CURVE is a curve
  NurbsPath.001
  CURVE is a curve
  NurbsPath.003
  CURVE is a curve

Then say try an lookup above in bpy.data.curves say:
bpy.data.curves['NurbsPath.000']

Traceback (most recent call last):
  File "", line 1, in
KeyError: 'bpy_prop_collection[key]: key "NurbsPath.000" not found'
While:
bpy.data.curves['NurbsPath']

yeilds
bpy.data.curves['NurbsPath']

but
bpy.data.curves['NurbsPath.001']

yeilds
bpy.data.curves['NurbsPath.001']

as does
bpy.data.curves['NurbsPath.003']

yeidling
bpy.data.curves['NurbsPath.003']

Why is object name NurbsPath, but curve name NurbsPath.001.  Is there some logic to this?

bpy.data.objects['NurbsPath.001']
bpy.data.objects['NurbsPath.001']

bpy.data.objects['NurbsPath']
Traceback (most recent call last):
File "<blender_console>", line 1, in
KeyError: 'bpy_prop_collection[key]: key "NurbsPath" not found'

bpy.data.curves['NurbsPath']
bpy.data.curves['NurbsPath']

bpy.data.curves['NurbsPath.001']
bpy.data.curves['NurbsPath.001']

Some blender basics.
bpy.data.objects is a collection of objects of type bpy.types.Object, as is context.selected_objects and context.scene.objects.  The properties and methods of bpy.types.Object are available to all objects of any type.
Each object has a data part. When an object is created its type is set according to its data.  This cannot be changed, eg trying to give a 'CURVE' type object a 'MESH type data will result in an error.
Each object has only one data member.
>>> for ob in C.selected_objects:
...     ob.name, ob.type, ob.data, type(ob.data)
...
('Empty', 'EMPTY', None, <class 'NoneType'>)
('BezierCurve', 'CURVE', bpy.data.curves['BezierCurve'], <class 'bpy.types.Curve'>)
('Cube', 'MESH', bpy.data.meshes['Cube'], <class 'bpy_types.Mesh'>)

for example the curve type object above has one data member of type bpy.types.Curve.  All curve type objects in the file will be in the bpy.data.curves collection.  The curve object is not equivalent to the curve data object.
>>> D.objects['BezierCurve'] is D.curves['BezierCurve']
False

but rather the data part of the object.
>>> D.objects['BezierCurve'].data is D.curves['BezierCurve']
True

Can set the data to any other data of the same type.
>>> C.object.data
bpy.data.curves['BezierCurve']

>>> C.object.data = D.curves['BezierCurve.001']
>>> C.object.data
bpy.data.curves['BezierCurve.001']

Each data type, can be used by none or many objects.  There is no direct reference from a data object to its object. To find all the objects that use the "BezierCurve" data in a scene would  use something like
>>> [o for o in C.scene.objects if o.data is D.curves['BezierCurve']]
[bpy.data.objects['BezierCurve']]

I guess the real question here is how do I go from bpy.data.curves to bpy.data.objects and vise-a-versa.  Say given a curve how to find it's obj?  ... and given a obj it is obj.data correct?

@bitminer (apologies missed this comment) Yes: Finding the data given the obj is simple it's obj.data.  The last line above shows how to find obj(s) in scene given data.

Objects are an invisible shoebox that fits around your curve. It's the pivot point between the global space and your curve. It's not the curve. Inside most objects, there's data. That means, a data block is linked with the object, in this case curve datablocks.
That means curve datablocks can be used by several objects and they'll look identical.
In your first code you iterate through objects, in the second you try to access curves with the names that you've found in the objects. That can only work accidentally because the names don't have to be the same. But they could be.
That's the confusing part, I guess. The object 'BezierCircle' and the curve datablock 'BezierCircle' can have the same name while not necessarily having any connection except their spelling.
import bpy

curve_list = [] # list to collect curveblock names
print("\nYour object data:")
for ob in bpy.data.objects: # iterate through all objects
    if ob.type == "CURVE": # if it's an object holding a curve
        print("Obname: {:17}, Obtype: {}, Linked datablock: {}".format(ob.name, ob.type, ob.data.name))
        curve_list.append(ob.data.name) # include the name in the list

print("\nyour curve datablocks:")
for cu in curve_list: # go through the list of curve names
    print(bpy.data.curves[cu])


text:
Preview and Final Render Materials are Different
In my node editor I have the following Materials set for the water which is made with a fluid simulation.

In the preview window it looks like this (Which is how I want it.)

Then when I render out the image it looks like this (Not how I want it.)

Below are my render settings

I tried detaching the glass node and I still got the see through look. I tried closing and reopening the project file. I tried changing the camera too incase I messed something up with the lens. I can't seem to figure out what's happening and how to fix it.

Try setting your Render Samples equal to your Preview Samples.

Just tried. Still the same outcome.... lol

So I had to make sure that the resolution of the simulation between it's preview and final render were the same


text:
Hair Particle system and Fluid Simulation interaction
Making a scene with grass made with a hair particle system in a fluid simulation. I was wondering if there is any way for the hair particles to be able to sway based on the fluid simulation. If so how would I go about it? What physics should I be playing with?

tl,dr
You can't, the fluid simulation system is not meant to interact with non-fluid object/forces/particles.
Keep in mind, that software such as Houdini is free for the apprentice version and allows to export geometry to Blender (as an obj sequence e.g.).

This answer assumes you are a proficient Blender user, given the complex context of the question. Adress unclear things in the comments and I'll extend the answer.
The Manual Way
Manually scatter force field in your scene. Such as Wind. Rotate them manually and keyframe their strength to mimic the flow of the water. Force fields influence hair particles.
This will probably be the fastest way in Blender internally.
The Hack

Keeping the Fluid Domain setting "Generate Speed Vector" box checked opens up a Hack.
The wrong movements in the demo gif arent limitations, but I didn't want to pursue the matter further. (My obstacle needed different geometry.)
Create the Vector Pass for the render layer. Then place an orthogonal camera directly above your scene. We will output the speed of the surface into an image sequence with the following compositing nodes. Don't forget to choose (e.g.) OpenEXR as to not loose negative or higher values.

Choose a small output Dimension (10x15 in my case) and render it.

LTR: image sequence of speed vectors; orthographic camera directly from above, left-lower corner matches (0, 0); render settings
With this method we only get the speed vectors for the surface, so it still won't come close to mimic a realistic result.
Now, we will grab the direction values of each pixel, and place a wind force field at the corresponding 3d position.
First, create some Wind Force fields, since my image is 15x10 pixels, I need 150 forcefields.
import bpy

w, h = 15, 10

for x in range(0, w):
    for y in range(0, h):
        bpy.ops.object.effector_add(type='WIND')
        pass

fields = []
for ob in bpy.data.objects:
    if ob.name[:5] == "Field":
        fields.append(ob)

i = 0
for x in range(0, w):
    for y in range(0, h):
        fields[i].name = str(x).zfill(4) + "_" + str(y).zfill(4)
        fields[i].location = (x, y, 0)
        i += 1

I saved my motion images to "//motion####.exr". Sadly, image sequences don't update on frame change from python, so we will have to load each image separately. Create a new image "motion_image", then execute the code. The comments should make the functionality clear.
import bpy
import mathutils

# method for reading a pixels values
# an image (as in bpy.data.images) has the attribute pixels, a list of values
# in pixels, rgba values come after each other (they are not grouped)
# rows aren't grouped either, they come after each other
# [0x0_r, 0x0_g, 0x0_b, 0x0_a, 0x1_r, 0x1_b ... 15x10_a]
# more info here: http://blenderscripting.blogspot.de/2012/08/adjusting-image-pixels-internally-in.html
def getPixel(pixels, x, y, width):
    idx = (x + y * width) * 4
    return pixels[idx], pixels[idx + 1], pixels[idx + 2], pixels[idx + 3]

scn = bpy.data.scenes['Scene']

# grab our prepared image and its dimensions
img = bpy.data.images['motion_image']
width, height = img.size[0], img.size[1]

for frame in range(scn.frame_start, scn.frame_end):
    # this may take a while, so here the update in the console
    print(frame)

    # load the image from disk into our Blender image
    img.filepath = "//motion/" + str(frame).zfill(4) + ".exr"
    bpy.context.scene.frame_set(frame)
    bpy.context.scene.update()
    img.reload()
    img.update()

    # see CoDEmanX's comment: https://blenderartists.org/forum/archive/index.php/t-268545.html
    pixels = list(img.pixels[:])

    # loop through all pixels
    for x in range(0, width):
        for y in range(0, height):
            r, g, b, a = getPixel(img.pixels, x, y, width)

            # access the wind force fields through our naming system
            ob = bpy.data.objects[str(x).zfill(4) + "_" + str(y).zfill(4)]

            v = mathutils.Vector((r, g, b))

            # convert the direction to a quaternion_rotation and calculate the strength
            ob.rotation_quaternion = v.normalized().to_track_quat('Z', 'X')
            ob.field.strength = v.magnitude * 200
            ob.keyframe_insert('rotation_quaternion')
            ob.field.keyframe_insert('strength')

Don't forget to set all forcefield object to quaternion rotations. ⎇ Alt LMB on a property to change it for all selected objects.
I also offseted my forcefield (0.5, 0.5) to center them in the pixels.

Now we have lots of crazy forcefields which we can use for further experimentation.


text:
Artifacts when baking with point lights
I get artifacts on my textures, it seems to be caused by point lights being close to the mesh when baking,
is the only solution putting the point light further away?

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


text:
Lock displayed frame interval to time
As you can see in image below, I'm using Blender for Video Editing, displaying vse, timeline, dopesheet and graph editor. I have locked time in  all of the windows. You can see the green line set in the same frame at each one of them... Excepting of the timeline, which is set to a different frames interval. If I press play, the line will "come out" of my dopesheet and graph editor, and I will have to scroll to it's new location, in order to modifying what I see. I wonder if there's any way to lock window's displayed frames interval to time, so they kinda move allthogether with the green time cursor.
Thanks!

I asked for this some years ago and it could not be implemented. You can try hovering in the window you want to zoom and press the period key ( . ). This will snap the view to the play head (green line)

Thanks @3pointedit
Pressing period key worked well on vse and graph editor. It worked neither on the timeline nor on the dopesheet. It makes workflow a bit smoother, thougt!


text:
Missing 3d text on animation render
I've been making a video with some clips, a couple of photos, and 3D text hovering over them. On VSE, I set, in this order fron lower to higher, an audio track, a video track with a blank sheet on it, used as background, another video track with some clips and images, an effect track to manipulate those clips and images, and, over all of them, an "scene tracK" for the text, made in 3d viewer. I created several text objects, set black and green opaque materials for them, and keyframed their location parameters to animate them so they apperaed and dissapeared over the white background or over the clips and photos. The white background was set as Cross blend, and the rest of the clips were set as Alpha Over blend. I used Blender Render, and my office pc works with windows 10, has 16gb ram, and some mid range CPU and video processor.
I worked on it the whole day. Everything was going well until, prior to render it, I realized that my green text had suddenly gone black on vse viewer. On 3D rendered view, it was still green. Then, going to the beggining of the video, I found some of my text was just missing on my vse viewer. I changed to 3d view, and I could see that it was there, animated as I had planned before. By that time, I had to leave my job, so I sent myself the project and the files to finish it home. Now, I open it at home, and see that the text has gone transparent on the VSE viewer, and it's on screen when It should be out of it. What a mess, ain't it? I guess I made something wrong during my day work and it's getting me mad not knowing what (specially as I had to make this video for today :P)
Thanks for reading! Surely someone here will make me see what was my mistake
I clip an image showing my vse tracks and the text which shouldn't be there (it's keyframed to be totally transparent at that time).

I found the answer by myself. The issue was caused by linked data on copy-pasted text. I didn't know that copying an object linked the original and it's copy propierties. When I animated the copies that I then modified as new text, I was animating the originals too. By deleting copies keyframes, I was deleting the ones which animated the originals. And by changing copies colour, I was changing original's colour.
I also learnt that duplicating (shif+d or alt+d) is better than copy-pasting


text:
"Latex" Surface Modifier interaction
I'm looking to have interaction between object 1 (Suzanne) and object 2 (mesh / plane)
I've made try mixing "cast modifier" "clothes" "collision"
How is it possible to see the Suzanne in the mesh when Suzanne is closed to it ?
The picture is the cast modifiers
Best
Zoltan

any suggestions will be really appreciate


text:
Complex 2D animation rigging
I want to animate a few custom characters. They need to be 2D. I have all body parts individually (PNG files) parented to the 3D meta rig at the corresponding angles. I have front, quarter-turn, and side view. I wuld have no problem if I was allowed to use separate bone structures for the same character. I have been key framing the alpha fade parameters to hide unused assets when rendering. The biggest issues I have are the toggling between eyes and mouths on each character.
I have a separate rig for the mouths using UV mapping technique and sliding a bound obj over a map of the mouths. When I have 2 or more mouth rigs in a scene, the rig glitches and doesn't render. I just copy the rig when
For the eye rig, I have one asset for the different eye colors and a separate one for all the eye lids for each direction the character faces. I do not know how to set this up.
All tutorials I have access to say I must redraw all assets in Grease Pencil then manipulate them. That would work, but I already have the assets made by an artist.
I have both blender 2.79b and 2.8 beta.

THats what I have

i hope, i understood problem (not sure), For toggling eyes / face etc.

you can create a simple property to control, which elements (meshes) you wanted to show / toggle.
i.e > add a property on a control bone. assuming default name is 'prop'
now, for example, you want face side (v1) when prop is 1 and face front (v2) when prop is 0.
in blender 2.8 setting up drivers is pretty fast / easy.

right click on property and copy as new driver
select face side , in object viewport display setting, right click paste as driver
select face front, do same as above step 2.
try changing property value, both objects will hide or unhide (don't panic)
select one of them, edit driver, change 'average or sum' to 'scripted' and replace expression '0 if prop==1 else 1'

select ground plane and change prop value in side bar (to test). i hope this helps.
SAMPLE FILE:

Clarification Please: Which property value am I using to hide obj in no. 4? In the current build, under the materials properties tab, I have key framed the Z transparency Blend value at 0 and 5. Also I could not open the sample file.

@Katherine, just update answer. goodluck


text:
Treat node group as 'final image' with vector input
After you have created a node setup ( eg. creating a shape from operations on co-ord constituents ) is there a way to alter the resulting output with a new vector input ?
I could create an image instead, and use the vector input to map the location, rotation, scale etc. However I want to use a custom generated UV co-ordinates on a custom shape without making it an image texture. The reason for this is to retain the procedural elements.
Ideally the solution would be either a custom node script, or a technique whereby a nodegroup can be treated as a texture, with it's own vector input affecting the result , not the input.

How would this be different from a node group with a vector input?

A vector input says nothing about how that vector is used inside of the node group. My question is specific to how new mapping coordinates can be used on a node group. (similar to if you exported a nodegroups result as an image, brought it back in as an image, and then applied new mapping vector )
Substance Designer has the transform node which can be used in this way, as well as the pixel processor node.


text:
Unity model is distorting when animation is running
I'm developing a game with animated models, like 'Ethan'. I'm getting new 3D Modes and replace with ethan in Blender. But when I start animation in Unity, model is distorting.
Model in Blender:

Distorting Example:

Weight painting defines how much a mesh follows each bone. With a weight of 1.0 the mesh follows the bone exactly, with a value of 0.5 the mesh will move half as much as the bone.
To me it looks like the hand has a weight of 1.0 but the sleeve has a weight of maybe 0.8 so it doesn't move with the bone the same amount as the hand.
With the shoulders this is a similar problem, due to having a disconnected mesh this tears the pieces apart. The edges of the two meshes that meet at the shoulder need to have matching weights so that they move the same amount. But then you shouldn't need to have a disconnected mesh in the middle of an asset that should be considered one object.
In blender, you can view the weights for selected vertices in the properties region (press N) while the models list of vertex groups is available in the mesh data properties.


text:
Removing Unnecessary Vertices on Mesh Like Terrain
Actually the tittle not correct at all but I can't find any words to describe my problem. I'm using blender and ripper for reach to my favorite game's map.
I don't have any problem importing etc. This my imported model;

As you see, there is too much grass, rocks and trees on the terrain of mesh. This is my problem. Is there any way to remove other-terrain objects in blender (or any other modelling software)? The terrain is continious but other objects start vertices have an angle bigger than normal angle which used by terrain continue vertice. Look that image:

Otherwise, if you see the second image, the terrain have tilled (e.g. 2x2, 4x4 I don't know the magnitude) squares basically. Maybe this can give a way for solve my problem. Is there any way?
Thank You..

Just for clarification, all geometry is in a single object and you want extract the terrain mesh (or remove objects that are not terrain)?

Yes, we can say that :D

But I can't select every part, because too much vertices there. Is it automated system? I can't understand.

You can select a single vertex of the terrain and then use Select Linked (Ctrl + L). Once the terrain is selected press P to separate the selection into a separate object.

Hello again, I tried your way but it not selected every terrain, only selected one square of terrain like this; https://imgur.com/a/SzULKas

Your terrain mesh isn't connected then.  Perhaps selecting by material is quicker, if you have a smaller number of materials for the terrain and they aren't shared with non terrain objects.

Hmm, then there is no way other?


text:
How can I edge slide to an accurate value on one axis?
I want to slide this edge to 38.4cm on the Z axis. The only way I know how to slide edges is double tapping G and sliding it with the mouse, which is not accurate enough for my needs.

Is there a way for me to type in a specific global value without messing up the right side of the mesh?

I deleted my answer. Not easy, but maybe related https://blender.stackexchange.com/questions/38955/how-to-use-absolute-value-in-loopcut-and-edge-slide

I got this to work, but it's prone to interpolation errors.

Add a loop cut in the center

Calculate the distance you need to move.
For me only the Z axis was relevant, so I tooke the end point o=400 and the starting point (lower edge of the mesh) a=96 and got the length by calculating the difference (l=o-a=304). I wanted the cut to be z-16 from the top, so I needed to move by 288 from the bottom. 288/304 gives me a factor, but because I halved the distance by cutting in the middle I need to double the difference this ratio has to 1.

Press GG enter the ratio and pray to interp

Sorry, previously added a completely wrong answer...
After some struggling I agree that is a shame that you can't set a precise sliding end position (at least on global axes) or at least snap to some other vertex or edge... this should be fixed, imho (although it is not currently considered a bug... https://developer.blender.org/T41346).
I have another workaround, not very much elegant but at least you could try this, too, at least this is what I tried:
First I duplicated this edge:

then, I selected those edges, whose Z value was 0.00, and grabbed (not slided) them to a precise value (0.2 in my example)

of course ending with this wrong result, though you can see the duplicated edge I created before, as a "reference" that keeps the correct slope angle...

then, tried to correct the wrong vertex position (only one in this case), after activating snap to edges

I then grabbed (locking on X axis) until the vertex snapped to the "reference" edge)

Finally, I had to delete the "reference" slope edge

here you see the "real" edge selected after removing the "reference" one

That's it, I hope at least this gives you an alternative...

Because if there isn't some fancy option I don't know about yet it messes with the mesh like this

I've just modified and then restored my previous answer, not sure if it will answer you, it's more a workaround, but still...

This is still a lot of struggle, but it's a whole lot more practical than what I did creating a plane and intersecting it. Thanks a lot! I think this is the closest to a decent solution we will get.

Just press GG Z .384 Enter. Sometimes you need to type - (negative) to invert the direction of the movement.

I tried this before and it doesn't work. Maybe my settings are off, but this moves the edge somewhere completely off. Here is what happens for me:

Maybe you'll have to apply the scale of your object first (ctrl A). If the object hasn't a scale of 1.1.1 all measures get deformed.

Just tried applying the scale - same effect.

You'll need to know the height before and devide it with distance you want to move.
In example lets say height is 2.9m. So type "gg=0.384/2.9"

I solved the problem by creating a plane, moving it to the desired Z-coordinate and intersecting the meshes, but I am still very much interested in alternative solutions, as this is obviously not always a feasible solution.


text:
How to Create Connecting & Disconnecting Fluid / Bubbles?
I'd like to create this simulation in Blender, with different connecting and disconnecting bubbles splashing with fluid sims. Is it even possible? Do you please know what option in Blender creates this effect, that different bubbles gravitate towards each other when they're close?
https://www.shutterstock.com/cs/video/clip-23042995-3d-rendering-wave-swirl-ink-background-black

Thanks!

I'd recommend using Meta-Balls and a particle system in this case.

Step 1: We need a few Objects in the Scene to get started.

a Plane (our Emitter)
a Metaball (our Particle Object, this will be duplicated)
a Force Field (to get some turbulences going)

Step 2: We then add a particle system to our Plane, and set it to render an object, there we put in our meta-ball.

Step 3: We adjust some settings to our liking, i also turned off the gravity influence, then the particles will start rising. Mainly i'd change:

random particle scale
random velocity

We then get particles that emit at different speeds and sizes, once they are close to each other, they will merge, as metaballs do.
I've added my file for you, in order to get it looking nice i had to change the scale of the metaball object and particle, otherwise the divisions of them won't seem to work well and i got just some weird triangles floating around.

I'd recommend to take a look at the wiki regarding metaballs too (mainly resolution and threshold): https://docs.blender.org/manual/en/latest/modeling/metas/index.html?highlight=metaball

You sir, are awesome! This is all I need to get going :-) Thank you so much!

no problem! :) i'd be happy to see your results someday!


text:
Fragments when rendering Volumetric Lighting in Eevee
Ive tried rendering several shots using Volumetric option in Eevee but only in one case I encountered this error, where my volumtetrics get all choppy and fragmented.
I tried all sorts of settings, increasing sampling of render and volumetrics, turning off Density for the Principled Volume shader, just leaving Emission on, etc. I always get this choppy result.
Can anyone point me in a direction of a possible solution please? :-)
UPDATE: Weird thing is, this also happens when I turn off volumetrics completely... No idea what this is. Anyone experienced anything similar?

Do you mind sharing the file?

Ouch sorry, Ill do better next time ;-)

I solved the riddle, fortunately :-) From some reason, in the compositing section, a Glare option with Ghosts settings got activated. It probably got set up automatically when I was  fiddling with Eevee rendering settings? Anyway, I manually unconnected the node and that solved the problem :-)


text:
How to texture a racing helmet (with all its logos)
I'm trying (and failing to) shade a racing helmet. My initial approach was to have multiple UVs for different parts of the design, but I'm finding it impossible to match perspectives properly.
Looking at models for sale on Turbosquid and CGTrader to see what the pros are doing isn't helping a lot either. For example:

How did this person texture this? You can see in the render that the white lines are pretty straight on the 3D model, but all over the place in the texture. Did the artist use a different UV (say project from the left view) and then baked those lines onto a new UV?
How would you tackle this? It's driving me nuts, and I can't find the answer.
Thanks!

My guess is they used a vector style path tool to make the lines. Notice how they start and end in alignment with the topology of the helmet; with an exported image of the UV layout as a reference, those would be pretty easy to do in inkscape. Something like shrinkwrap + baking is another possibility, especially for the logos.

We don't know how this specific artist created the unwrapped/distorted image texture.

Did the artist use a different UV (say project from the left view) and
  then baked those lines onto a new UV?

This is a common technique called Projection Painting which is widely used during texturing. Since I found no clear overviews in any answer, I will demonstrate the basic steps.

Create a UV map, I named mine uvmapUnwrapped and unwrap it, maximizing used space and minizing distorsion. As you noticed, one cannot add any images onto the current 2d uv layout with them being distorted.

Create a second UV map (the plus-icon) which places a logo (or other desired image) neatly onto the object. I loaded the Blender logo in the UV editor and found that unwrapping the subdivded cube from orthographic front view with Cylinder Projection worked best for this szenario. But there are plenty of other unwrapping methods. U

At this point, both images should be showing correctly on the object when their respective uv maps are active.

Select the object and enter Texture Paint Mode. Go to the Slots tab, choose Image as mode, select the uv layout image as canvas layout, which we're going to paint on an choose its matching UV map layout.
We could now paint on the object by drawing strokes on it in the 3D view.

Go to the Tools tab, select the clone brush. Check the box at clone from image/uv map. Select the logo image and its matching uvmap. You can now "draw" the logo onto the texture.

Thanks for the answer. This was really helpful, and it made me find the amazing stencil mode in texture painting. Which was exactly what I was looking for.


text:
Fluid Obstacle while animated by modifier
I'm new to 3D animation, and was trying out Blender. I've come across an issue that I'm not sure how to fix.
I wanted to try throwing fluid onto a subdivided plane, whose vertex's are being moved by the modifier 'displace'. The strength of displacement is being modulated by an audio file I put in through "bake sound to audio file".
The problem I'm facing is getting the fluid to interact with the displaced plane. I can't apply the displacement because that unhooks the f-curve and it stops being animated. Does anyone know a method (even if I have to start from scratch) that would allow me to make this interaction possible?

From experience, animated obstacles (whether the mesh is actually animated as in your case or even just moving/rotating within the fluid domain) do not work correctly - the fluid can result in being repelled through or away from the obstacle and effectively ‘disappears’ from the domain - it is not a physically accurate simulation. I believe there are fluid sim developments in the pipeline (mantaflow?) or possibly you could try flipfluids (paid for addon?).


text:
How can I increase the performance in Edit Mode (ver 2.79/2.8beta) for my map project?
I am quite new to Blender and even newer at taking part in forums but there‘s always a first:
I am trying to create quite a detailed map for a videogame. It is supposed to become something like 1.700 km x 900 km big.
My problem:
As I have subdivided my single mesh of a land mass into more vertices (aiming for faces equivalent of less or 1 squaremeter), I encountered the problem that having more than ~99k vertices makes my edit mode laggy and I would still have a long way to go to reach a level of detail that makes it not able to perform or even move around in the viewport without a tremendous amount of coffeebreaks.
My question:
Is there a possibility to increase the performance of my edit mode? In older versions there was supposed to be a checkbox called „VBO“ in the system preferences, but I think I read it was removed for reasons I don‘t know.
Maybe my goal is a little too ambitioned, when I am using my ver
Macbook Pro
2,6GHz intel core i7
16GB Ram
Intel HD Graphics 4000 1536 MB
On OSX El Capitan
If you have some advice for me, I would be glad!

How about splitting your map into separate pieces, which don't have that many polygons. Object mode and sculpt mode are also more performant in manipulating geometry.


text:
Why is my imported obj not showing up on the grid where I need it to be
I'm having trouble with my imported object. Its nowhere near the center of the grid where I need it to be.. I press the . key on my numpad and it takes me to it, but I am using a minecraft rig and need my object near the rig. This is probably basic to most of you but something I really need help with if you could! Thank you!!
The rig I am using shows up perfect in the center of my starting view where it needs to be

This method has always worked for me:
Firstly, is the origin of the Obj object at the center of the scene (0,0,0)?
If so, skip step 1 and go straight to step 2.

Select the imported obj object whilst in object mode; press Shift+Ctrl+Alt+C. A menu will pop up with a few options - choose Origin to Geometry. (An orange dot should appear near the center of the object).
Press Shift+C to reset the 3D cursor to 0,0,0 (this will change the view but as long as you  don't deselect the imported object this won't be a problem).
Press Shift+S and select the option Selection to Cursor - which will move the selected object to the center of the scene.

You will probably want to apply the location of the object after this. You may also need to get the origins to match, but that's for a different question and probably has already been answered somewhere.

For me blender always imports geometry to place where it was exported from.
Eg. if I exported mesh that was in 10,0,0 then it would be imported to 10,0,0, not 0,0,0.
What I would do, is first, check if origin/pivot/TheThingGeometryRotatesAround* of your mesh in c4d is centered on your object, not somewhere way off. Then I would double-check if its in 0,0,0 prior to exporting.
After that I would export and import in blender, should work :)
*) Different software have different naming convention for something blender calls origin and 3ds max calls pivot, and probably different in other software.


text:
How to append a scene from an existing .blend file to the current .blend file?
I just want to append a scene (named "fred" which is the ONLY scene in the file) to the existing open blend file. Seems like this should be easy, but I can't find out how to do this. So, after the append there should be two scenes: the orignal one and a new one named "fred".
I know the name and location of the file and the scene I want appended.
Thanks for any help.

Sorry, but I already looked at that message and it is not the answer. Please reopen.

@Batfinger The link you refer to deals with collections and objects. I'm trying to figure out how to import SCENES. Can you help?

I have no issue doing this with File > Append > (select .blend with "fred" scene) > Scene Folder > "fred" scene > Append, then the scene is available in the top of the window in the Scene section.

The link to docs in dupe answer  first example append scene.  Surely it is unnecessary to have a separate question on how to link / append  each data block type.. How to append a mesh, how to append an object, how to append a lattice, how to append a camera, how to append an armature...

@batFINGER Thanks for the link to the docs.


text:
Gravitational Orbit
I want to make a gravitational orbit simulation using the python interface on blender. I want it to be realistic (kepler orbits). The path should be ellipitcal with the sun at one of the foci and the orbiting planet should speed up when its closer to the sun so as to obey the second law. I am not sure what the best way is to approach this simulation if people have suggestions.
Thanks

Couple of mine that are somewhat related https://blender.stackexchange.com/a/91511/15543  https://blender.stackexchange.com/questions/132925/planetary-system-simulation-with-real-orbital-datas


text:
How to proper model Toilet as in example
I'm quite new to Blender, but already got some experience modelling.
I'm trying to model a Toilet as the one shown in the photo attached, but i'm having issues to achieve the same shapes below the main vase, I've circled the area on the image to let you better understand what i'm talking about.
Are you able to describe the step by step model instructions that will help me to achieve the final results?
Thank you so much for any help you'll provide.
Cristiano

Hello and  welcome to Blender.SE :). Please share images of your current progress, and specify where exactly you're stuck. Without that, it's hard to help you :).

@Merlin if you believe that to be the case, you can edit or vote to close the question in addition to the DV.   Modelling with good topo only looks easy. As an example of well received q but  Not the same shape

Here’s my best crack at it. I used Curves to create edge loops which I then bridged, subdivided, creased as needed, and mirrored.
https://www.youtube.com/watch?v=xjdiLHzDEVY&feature=youtu.be
I would highly recommend watching a car modeling tutorial (or better yet, invest in a true hard-surface modeling course) to understand approaching difficult shapes like these which you’ll encounter many times in the future.
Good luck,
John

Hi John! I think your walkthrough is very cool! In general, though, we tend to keep most of the information that is useful to answer a question within this site, and use external links only for further reference. I believe you could provide a much nicer and accessible answer by expanding a bit the «I used Curves to create edge loops which I then bridged, subdivided, creased as needed, and mirrored» part, using bullet points and screenshots (for instance, taking screenshots of the 3D viewport -- no need for the entire screen -- from the video itself)


text:
Why the Emission on Hair Particle System is disable?
I need to edit the NUMBER of EMISSION, but it disabled after I use WEIGHT PAINT with VERTEX GROUPS.
How can I edit emission after this?

You have to "Delete Edit".

Thank you for the answer FFeller, is the issue that I tried to avoid, but that's it. I thought that I'm doing something wrong, becouse every time that I deleted it, I needed to adjust the hair mesh with COMB again, it's been a headache

You have to switch to Object Mode and Delete Edit, only after that, can you re-edit simulation properties again.


text:
Make the wall of a UV sphere collide-able in untiy?
i followed the tutorial in this answer to make the hemisphere.
but when i added it to unity and generated the colliders , the BASE of the sphere had a collider on it.
(imagine if hemisphere had like a cover under it).
i want the collider to just cover the thickness of the walls of the hemisphere , not the bottom of the sphere.
[edit] i just want to add that when importing it to unity and enabling to generate collision, it doesn't worth either, i have to enable the convex option for it to work.

For anyone still having the same issue, just simply go to blender, select all vertices while in the Edit mode, go to Mesh,Normals and then invert the normals.
and then import it in unity as an obj file.


text:
When dragging a mesh onto a rig, the rigging menu with "with automatic weights" option won't appear
I'm using the basic meta rig produced by using the Rigging plugin. I aligned the rig's bones to my model and when i parent the go to rig it the menu with options like "with automatic weights won't appear"

Did you try to apply the rigging in edit mode or object mode? The rig with automatic weights only works correctly in pose mode. Also, you can not select "with automatic weights" in object or edit mode by going to the object tab, because it will not parent the bones correctly. I make this mistake often.


text:
Where i can find animation in .fbx?
I imported the .fbx file with animation from wowmodelviewer, but I can not find how to enable its animation in render

Do you mean you can't play it in Blender?

This model of wagon can walk and run in wowmodelviewer. Can i use this animation in Blender? the wagon rides along the purple road.


text:
Render OPTIX on T4 GPU
T4 GPU is an RTX GPU, in the nvidia documentation it supposed to support OPTIX.
But when I try to render using OPTIX on that GPU, blender renders on CPU.
I tried to retrieve all available GPUs and what I get is only CPU and CUDA.
Is there a way to enable OPTIX on T4?

If the GPU is properly detected as CUDA device by Blender in Edit > Preferences > System, then it seems the check in device_optix_info (device_optix.cpp) fails somehow. Not sure why this would happen though, since the compute capability of the GPU should be high enough. Make sure that you're using a recent graphics driver version.

It's NVIDIA Driver Version: 450.51.06, CUDA Version: 11.0. Just as stated, this should work but doesn't.

You may want to ask about this on DevTalk or blender.chat where you can get in contact with the developers involved in the Cycles development.


text:
How can I check if the active object is a mesh and selected?
I want to check if the active object is a mesh before I UV unwrap it. Here's my code and for some reason the execute runs even when a mesh is not selected. What am I missing?
@classmethod
def poll(cls, context):
    our_case = False
    selected = context.selected_objects
    object = context.active_object
    if object is None: return False
    if object.mode == "OBJECT" and all(obj.type == "MESH" for obj in selected):
        return True
    return our_case

def execute(self, context):

    bpy.ops.uv.smart_project(angle_limit=30, island_margin=0.06)
    return {'FINISHED'}

because 'all()' returns true if the iterable is empty?

additionally, an object can be active despite it is not selected

Here's what I ended up with that worked:
@classmethod
def poll(cls, context):
    obj = context.active_object
    objs = context.selected_objects
    if len(objs) == 0: return False
    if obj.type == 'MESH': return True
    return False

Why the variable when using the reference one time?


text:
Are addons written in python compiled at runtime?
Or, are the interpreted each time they are executed? If not compiled (JIT?) then how much slower is their execution than native code?

@BlenderBlackened Python is a language, there are multiple interpreters/runtimes available for it.

Python is by default an interpreted language. Blender bundles and uses the default python runtime (CPython), ans therefore python code in blender is interpreted.
However there is a catch. Most of Blender's API is actually written in native code (C) and is then exposed to the Python runtime through generated bindings.
Relative performance is trickier, as this is dependent on many many factors. And there are other issues here as well, in particular the GIL, which prevents the CPython interpreter from being truly multithreaded. Efficient use of the Blender API and the Numpy library (bundled with Blender) can bring most performance issues to acceptable levels. It is best to start with those anyway, and only look at other alternatives when you actually run into issues (i.e. avoid premature optimisation). You may find that the main performance bottlenecks are things other than code execution speed anyway (e.g. file handling).

As already explained, while your script is interpreted, much of the work may be done with code already compiled into blender.
However there are other alternatives, a blender addon is a python module, it can be written is C/C++ and compiled the same as any other python module. There are some requirements to being a blender addon, such as having a bl_info dictionary and register/unregister methods.
An easy method to make a compiled binary addon, would be to use Cython, which will turn python code into C/C++ that is then compiled. For examples, have a look at Cubesurfer  or Animation Nodes. You can also use cython as a starting point to generate the framework that you then fill in or link to your C/C++ code.


text:
How to fill a cube volume with random flat planes in Geometry Nodes?
So, I want to create something like this but I want to randomize the aspect ratio of the little planes.
Most the answers I find are using older Geometry Nodes configurations with deprecated nodes. Can anyone help? Thanks!

Here's a group that, given a cuboid, can randomly distribute planes in its volume, randomly scale the planes to specified limits, and clips the collection of planes to the cuboid.
In steps.. 1. Distribute instances in the given box:

The 'Count' input sets the number of planes. Since we can limit their depth, later, the planes may as well be cubes.

Randomly scale instances to within specified limits:

Realize the instances, clip them to the dimensions of the box:

Just for illustration, here, this example stores the instance ID on each vertex of the realized instances. This uses the Mesh Islands node available in Blender 3.1a. It can be done in 3.0 by using the hack in this answer, but that's a bit of a faff... This group..

.. normalizes the instance ID's to floats between 0 and 1, and stashes them on the vertices of the realized instances..

... so they can be passed out of the modifier, and used by a shader:

Thanks for explaining this method.

you could use this node setup:

Raycast
Here is one approach. The default cube will be the container object.  Everything outside of the raycast area, we want to trim.
In the GN editor, the Mesh Line node is instanced on a Grid Node.  On the points of the mesh line we also instance smaller grid nodes.

In order to give the instances of the planes random values we can use scale, rotate, and translate instances nodes.  These can be plugged directly into random value nodes.

We can use a raycast node with the target of our default cube.  The hit area output is connected to a math node set to less than.   This goes to the selection input of the delete geometry nodes.

In the delete geometry nodes, If we set these to "only faces" we can see what is being deleted outside our default cube:

When adjusted everything satisfactorily, we can turn it back to "all".

Here is one idea.
I have just connected the group input so that it can control the distribution in the modifier tab.

That's not a volume and the planes don't have random widths/heights


text:
Just want to set viewport to wireframe from script
Not sure how best to do this...
I have a very simple question. When I click on the solid view icon in the window I see the console shows:
bpy.context.space_data.shading.type = 'WIREFRAME'

But when I add that to the Text Script window:
import bpy
bpy.context.space_data.shading.type = 'WIREFRAME'

It of course doesn’t run because it doesn’t have the proper context.
I also tried:
import bpy

prev_type = bpy.context.area.type
bpy.context.area.type = 'VIEW_3D'
bpy.context.space_data.shading.type = 'SOLID'
bpy.context.area.type = prev_type

which doesn’t throw an error, but doesn’t work either. I know it must be something simple, but how to fix this? Thanks!

Screen is divided into areas.
An areas active space, matches area type.
2nd script will set the 3d view in that space to solid shading, change text editor to 3d view to confirm.
To set 3dviews  in context screen, find them first
spaces3d = [a.spaces.active for a in context.screen.areas if a.type == 'VIEW_3D']
for s in spaces3d:
    s.shading.type = 'SOLID'

If there are more than one view 3d open, you may wish to only set the largest area, can sort the list by area area (a.width * a.height)

This question could benefit from this answer too.

Cheers, did a cursory search, ,  close enough to dupe to mark as dupe don't you think

Thanks, how would I use only one (any one) of multiple VIEW_3D areas? Do I set a counter and check it in the for loop, or is there a simpler way?

spaces3d[0] is the first.  s = spaces3d.pop() is the last "popped off" the list.  See python docs on  list type.


text:
How to set the dimensions of an object without it's modifiers?
I'm trying to set the size of an object without it's modifiers. So, in a script, I turn off the visible modifiers, then set the scale, then turn them back on. Why doesn't it work?
It does shrink the room and set correctly if I comment out the last:
show_modifiers_master_room(True)

But, when I turn the modifiers back on, the object's scale includes the modifier dimensions (I have a simple Solidify modifier on the object "Master Room"). It appears as if Blender is applying the dimensions after the modifiers are turned back on.
def show_modifiers_master_room(p_bool):
    ob = bpy.data.objects['Master Room']
    for mod in getattr(ob, "modifiers", []):
        mod.show_viewport = p_bool
    print ("show mods: " + str(p_bool))

def room_dim_changed_v(self, context):
    show_modifiers_master_room(False)
    bpy.data.objects['Master Room'].dimensions = (4.0,2.0,2.0)
    show_modifiers_master_room(True)

Very likely same issue as here.  https://blender.stackexchange.com/questions/234020/exporting-data-looping-through-objects-gets-wrong-data-for-very-last-object

or via https://blender.stackexchange.com/questions/212926/how-to-get-the-base-dimensions-of-an-object-ignoring-all-of-its-modifiers/212929#212929

C.scene.objects.get("Master Room")

Setting dimension requires a view layer update
As outlined in Exporting data: looping through objects gets wrong data for very last object  call view_layer.update() after using dimensions, to set the scale.
Get the dimensions from the mesh
Borrowing from both
How to get the base dimensions of an object (ignoring all of it's modifiers)?
How do I get the bounding box of all objects in a scene
can get the unmodified global sized bounding box of a mesh
import bpy
import numpy as np
from bpy.props import FloatVectorProperty

def np_matmul_coords(coords, matrix, space=None):
    M = (space @ matrix @ space.inverted()
         if space else matrix).transposed()
    ones = np.ones((coords.shape[0], 1))
    coords4d = np.hstack((coords, ones))

    return np.dot(coords4d, M)[:,:-1]

def get_mesh_dims(self):
    if self.type != 'MESH':
        return None
    me = self.data
    coords = np.empty(3 * len(me.vertices))

    me.vertices.foreach_get("co", coords)

    x, y, z = np_matmul_coords(coords.reshape(-1, 3), self.matrix_world).T

    return (
            x.max() - x.min(),
            y.max() - y.min(),
            z.max() - z.min()
            )

bpy.types.Object.mesh_dimensions = FloatVectorProperty(
        name="Mesh Dimensions",
        get=get_mesh_dims,
        subtype='XYZ',
        unit='LENGTH',
        )

Now having run script above every object has a mesh dimension property. Here is a test run on default cube with default subdivision surface.
>>> C.object.mesh_dimensions
Vector((2.0, 2.0, 2.0))

>>> C.object
bpy.data.objects['Cube']

>>> C.object.dimensions
Vector((1.6790125370025635, 1.6790125370025635, 1.6790125370025635))

>>> C.object.mesh_dimensions
Vector((2.0, 2.0, 2.0))

>>> d = C.object.mesh_dimensions
>>> C.object.scale = 4 / d.x, 4 / d.y, 4 / d.z
>>> C.object.scale
Vector((2.0, 2.0, 2.0))


text:
Why can I not set bpy.context.scene.light_direction?
Trying to set:
bpy.context.scene.light_direction = (-0.0796555, 0.0730634, -0.994141)

and I get the error:
AttributeError: 'Scene' object has no attribute 'light_direction'

But, when I use the light direction interface sphere shown below, it shows in the info console:
bpy.context.scene.light_direction = (0.538462, 0.519231, 0.663671)

Try bpy.context.scene.display.light_direction. Don't know why the Info window is wrong.

It's now bpy.context.scene.display.light_direction
I don't know when this was changed, or why there's a mismatch between the python in the info pane and the python interface. I was able to find it by tab autocompleting in the python console. Probably worth filing a bug.


text:
How do I move all children objects away from parent empty (by scaling the empty) but NOT scale the children?
I have a bunch of boolean modifiers on a cube. I want to move them all off the cube by just scaling the empty they are parented to. But, I don't want the child objects scaled. Is there a way to do this (non-python)?
I am happy to use drivers or other techniques to achieve the same result: namely moving the booleans off the cube in a direction as if they were scaled. Thanks!

Possibly related: Scale Space Between Multiple Objects

If this is the same problem i had, and you are using version 2.81, try this:

No idea where you got that popup form. And I'm not sure why affect only parents would work-- as these are children, not parents that are moving.

@chippwalters You can also find those settings in the Tool tab of the N panel (under Options >Transform). I'm not sure about Affect Only Parents, but Affect Only Origins sounds like what you're looking for.


text:
Where can I find the source code for the translate/grab tool
You see I'm recreating the grab tool for a game engine based on LUA.
Problem is, I can't seem to figure out how exactly it works
Would be great if somebody could link me to the source code of the translate tool

I'm voting to close this question as off-topic because it has been decided that questions about Blender's source are (sadly), off-topic. Try asking on the #blendercoders IRC channel on Freenode.

This question appears to be off-topic because it is about Blender C/C++ source code.
These questions are considered outside the scope of this StackExchange as defined in the help center. Development questions should be asked of the developers directly instead, see the contacting developers page of the blender wiki.


text:
Why can't a linked group be used as a dynamic paint brush?
I have created a character for my 30second short that is my final in my Blender Graphics 3D Design class in a separate blend file from the landscape it resides in.  I am trying to make it so the character is carving out a path in the landscape, but where I have linked this character group it will not allow access to all of the physics options.  I'm using Cycles Render to get a more life like effect.
Am I going to have to go into the original character file in order to make it into a dynamic paint brush, and if I do will it work with having the dynamic canvas in the blend file the character file is linked to? Or is there another way around this issue?

Have your tried linking as individual proxy objects instead of linking as a whole group?

I feel like an idiot right now.  I ended up answering my own question after taking a breather and searching through similar questions.  I ended up linking the group then duplicating it, after making it local, so it could act as the digital paint brush.  The answer I found most helpful was http://blender.stackexchange.com/questions/46945/change-linked-object-to-appended   The first answer to it was most helpful for my distraught soul.


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When was the Cycles renderer introduced?
I am wondering when did the Cycles renderer introduced to Blender, 2010 or 2011? And how stable is it?

It was in 2011 (Summer).
Today, it's just more stable (6 years, it's pretty long), and more complete.


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Interpolated Hair Cuts Through Mesh
I'm trying to give a character two braid pigtails - which works out relatively well, except some of the interpolated hairs are cutting through the mesh of the body rather than going around it to reach the parent hair. This is happening particularly badly in the back.
I've tried moving the parent hair (it is a single parent hair) forward, backward, left, right - but I am constantly getting the particle hair cutting through the mesh, rather than deforming around it
Any ideas?


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Missing Physics Tab? [Blender 2.78]
I'm just wondering if anyone else is missing the options in the physics tab of their Blender program with the new 2.78? It was released yesterday. I knew I should have waited before downloading it...
I've tried scrolling up, but there's absolutely nothing there. At all.
Ideas? Help? Anything?

Some screenshots of Properties editor ? Do you have any object selected (I couldn't resist of asking) ? How many tabs are avaible there ?

scrolling up... what? there...where? physics tab is the last on the right in the properties editor... sorry, I have opengl 1.4 at home, can't install 2.7/2.8 here.

I had an object selected, by I guess the program didn't download properly the first, third, or fifth time - by sixth reinstall, physics options returned.
Thanks everyone!


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Weird texture bug not going away
So I've had this issue randomly happen before and I would just tab out and back into sculpt mode and it would fix the issue, but this time it doesn't. Any ideas how to fix this?
Note: I am a beginner at sculpting, so I wasn't messing with anything other than sculpting.

Flipped faces, maybe? In edit mode try selecting the whole mesh, then from the options at the top of the viewport, pick mesh > normals > recalculate outside. Although, that won't help if it's a genuine "glitch".

Unfortunately that didn't work :(

Yeah, I don't know then. If it's happening inconsistently (fixed by a tab switch) it does seem more like some kind of "glitch" than a problem with your mesh. Do you experience any other graphical glitches? Maybe try updating your graphics drivers?

I have had these issues also at times and have just had the same answer of "your drivers are not up to date" which is potentially the case for some but says that older computers are being forced to be "outdated" by Blender themselves.  Pot luck.  They fix some things but mostly keep adding features and don't fix glitches as they go along because theyre too busy adding new features all the time. It's annoying.

Ahh. My pc is a new build with up to date drivers :(


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Can't find the "Default" tab usually located next to "Compositing"
I am a new user of blender. I want to know how to find the "Default" tab usually located next to "Compositing". I cannot seem to find it. Thank you.
(I am using Blender 2.8)
Have a great day.

Hello and welcome :). You don’t really need it. Maybe you deleted it by mistake. Just rearrange your panels the way you want. The tabs are there just to save time with rearranging panels, you don't lose any functionality if you delete a tab :).

However, if you really really want it, just open a new Blender document, and it will be there :).

Thank you. It was required for me to use it as I was inserting something. Have a wonderful day.

Yes. It is the tab you always start with, and if you really think you need it, then you can restart Blender.

I would suggest watching an absolute basics(Navigation and changes most 2.7 tutorials still work with 2.8 just somethings moved around ) video.

Hi and welcome to Blender community :)
You can use the 'Layout' view as default. The things that changes is that are shown by default some tools focusing on each type of work you will be doing. For me, 80% of my time I use in the 'Layout' tab. Script and Sculpting are for more specific works. But if you feel lost you can go over this '+' icon right next to the other tabs and add the tab you are looking for. Hope it helps


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Using a vertex as pivot point with multiple vertex selected
I am try to transition to Blender 2.8 from Maya. Would love to move but running into so show stoppers for me. Am mostly doing modular assets so grids and snapping are essential.
Example. I have a modular wall piece. I need all the vertices on the left and right to be snapped to grid so I can easily snap the modular pieces together later. At current the vertices at the left side are off grid. However I need to keep the interior vertices of the wall looking symmetrical with the right side. The interior vertices won't be on the grid and do not need to be.
In Maya I can select any number of vertices, activate move /rotate / scale, press D, select a vertex, edge or face to use as my pivot, and then if I move the selected vertices with grid snapping on the vertices will all stay in the same relative location compared to each other but the vertex used as pivot, plus any vertices on the same exact axis position, will snap to the grid even if they were off grid to begin with.
I can't replicate this behaviour in Blender.
I can select a vertex, snap the 3D cursor to it and then use that as my pivot, but then when I move my vertices the 3D cursor being used as the pivot is in a fixed position so my vertices move in grid units, but do no actually snap on to the grid.
I know there is a snap to grid command but in this scenario I only want the outside vertices of the selected vertices to snap to grid, so from what I can tell this won't help me as it will snap all of them.
If I were to just selected the outside vertices and snap them I would then have to try and eyeball moving the other internal vertices that I wanted to move with my original snap so would likely not end up with symmetry . I could maintain symmetry by halving the model and mirroring it, but this assumes the center vertices are on grid, which the might not be and might need to not be, and is a lot of steps for a simple task.
I could lessen the severity of this road block by ensuring my outside vertices were on the grid to begin with. But I can't find a way of having the edgeloop or knife tool snap to grid during the process of creating my loops and cuts.
I have found the settings for ensuring the knife tool cuts in a straight line but not how to keep that straight line on grid during the cut. I have also found the tool for straightening vertices so I can easily straighten my edge loop vertices, but again now ensure they on grid to begin with.
I have to make my loop / cut as close as I can get it and then try and use the method above to get the outside vertices on grid, which I am failing to do.
Am I missing or misunderstanding a tool(s)?
Thanks

Add a screenshot or a .blend file as this is too long and hard to understand.

ok this looks like more then one question can you divide them to smaller questions? I don't know what you want exactly. I can tell you if you want you could set up a custom grid and use that.

That's a lot of information, but I dare to guess: try putting your cursor where you want your "wall" to be, use it as pivot and eg press S -> X -> 0. Now all your vertices share the same x value. You can do this along the normals of their combined faces as well, and with a little more fiddling, you can specify your own direction as well. If that isn't the answer, I concur with the 2 comments above. Lukasz-40sth and Mobin.


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making 3d surface using list of vertices coordinates
i want to animate a changing 3d surface (i.e. an ocean wave). the surface cannot be defined with a single z function and instead I have been defining as a list of coordinates that lie on the surface. when I use matplotlib the software is able to make a smooth surface based on coordinates easily, but on blender I cant figure out how to add faces.
I use a bmesh to plot the coordinates which I give in the form [(x, y, z), ...]. However, I can't figure out how best to add edges and faces to make a complete surface. I would like to make the faces square so each square's corners are marker by the four closest vertices.

here is a surface made up of individually plotted vertices on a mesh. If I use the 'make edge/face' option it adds one big face bounded by every single vertex as far as I can tell.

is there a way to achieve what I want without having to manually add faces to each group of four vertices? preferably in a way that might be efficient enough to animate quickly.

https://blender.stackexchange.com/questions/76535/create-model-from-xyz-data-points

@batFINGER that is perfect, thank you!


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How do i get rid of these black marks
The wing flaps are 2D planes that i applied a solidify mod on them. how do i remove these black marks/seams?

Shadows in this case are due to some errors in geometry, hidden / internal faces or custom normals or else something. As there's Subsurf modifier in stack internal faces would be first thing to check, in Edit mode switch to Edge selection mode and run Select All By Trait > Non-Manifold

Add more diffuse light, or lights from other angles, so that ripples don’t make such harsh shadows.

Lighting won't help in this case since they aren't rendering anything, that is solid mesh is shown on the screenshot.

You need to edit your post to supply more details and information.  All I know is the low-res screen shot, and they look like shadows from a harsh light source on a wavy material.

If you switch to "flat" rather than "smooth", will the black show?
If you switch to " flat" and the black disappear, the solution will be to make more "subdivision" in the "edit mode" and then switch back to "smooth"

Is this supposed to be a community wiki post?

Use Edge split modifier and try changing angle
Try Applying Subdivision surface modifier
if this does not work apply solidify modifierand go to edit mode and re-calculate normals by pressing "Shift + N"


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Is there a particle/array combination?
So basically what im asking, is if it is possible to create an array with multiple objects (like a particle system). Because I think it would be useful for say... a boardwalk, where you would want some of the planks to have hole in them or cracks, but dont want to manually place/edit the planks of wood.

You can have an array emit a particle collection .. see for example here or here

I'm going to answer by assuming what you are trying to achieve because it isn't really clear.

Add a collection and model your planks inside it.

Outside the collection, add a plane object, then add an array modifier to it. In edit mode scale it along the y axis so that is is about the width of your planks.
Add a particle system to this plane. Set it to "Hair", check "Advanced". Set the number to the number of planks you want to have.
Right click the "Number" field and choose "Copy as new driver". Go back to the array modifier and right click in the "Count" field and choose "Paste Driver". Now you don't need to touch the array modifier again, it will be modified every time you want to add or retrieve planks in the particle settings.

 - Go back to the particle settings. Set the instancer to collection and choose the planks. Uncheck "Show emitter" (twice). Don't forget to check "Pick Random" to add variety. :

Modify it to look like this. You can tweak the "Randomize" fields to add a bit of variety in size and rotation. :

If you add a curve modifier between the array and the particle system, you can even go 3D !


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Dynamic paint not working
I'm making an animation of a stencil paint against a wall. I'm trying to resemble the graffiti painting whit dynamic paint over a logo. But I can't make it work. Assuming the issue was sited at the logo material, I tryied setting it to: 1 - transparent BSDF 2 - diffuse BSDF 3 - image texture. None of them gave me the key. Also tried applying or not dynamic paint on modifiers, and had no succes. When changing canvas mode from paint to wave, it worked. Might that give a clue?
This is my project:
https://drive.google.com/file/d/0B48XSxEO28GMNTZaSHBmUTlETEhKWTFtSV9Ga21kQm50cWZZ/view?usp=drivesdk
This is a closely related question I made about the same project: Spray paint simulation

Possible duplicate of Spray paint simulation

how is this different then your other question?

In this question, I'm talking about the animation of the wall receiving paint. The other question asks about the paint flying through the air, emmited from the spray can.


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How to model 14,16 and 18 sided dice?
I've already modeled the 4,6,8,10,12 and 20 sided dice via regular solids (tetrahedron, icosahedron, etc...) and the 10 sided following a tutorial.

Now I need the 14,16 and 18 sided ones, but I don't have a clue of how to get them...

Has anyone a clue of how to model them?

@cegaton Hehe.... exactly the approach I was thinking of taking.. except I was wondering if there was some combination of forces that could achieve this in Blender physics?

Equal distribution on sphere
Using the script from This answer
Need to alter the parameters. Here is what I used for the 14, 16, 18 side die. (where n is number of sides.  Had to run the 16 side twice, as it didn't find solution the first time, kill the script by hitting ⎈ Ctrl C
 over the system console.  The rat value determines the size of the hole. Too small 0.8 and the holes overlap, too big 0.999and the holes will be too small
# parameters
n = 18  # number of points on sphere
rat = (n - 1) / n # how far along the radius to bisect
u_segments = 32  # UV sphere settings
v_segments = 32
thickness = 0.2  # solidify thickness
TOL = 1e-7

14, 16, and 18 sided die, ret = (n - 1) / n
To make the die "solid" remove the solidify modifier, and grid fill each circular hole.
Solid Version
Here is an edit to create a solid version, where the holes can overlap. The holes are filled with an ngon. Poke it to make tris.

14, 16, 18 sided solid, where ret = (n - 2) / n.
Edit update for 2.8x for prior see revisions
import bpy
import bmesh
from mathutils import Vector
import random
from math import pi, asin, atan2, cos, sin, radians

# parmaaters
n = 23  # number of points on sphere
rat = (n - 2) / n # how far along the radius to bisect
u_segments = 32  # UV sphere settings
v_segments = 32
thickness = 0.2  # solidify thickness
TOL = 1e-5

points = [Vector((0, 0, 1))]
for i in range(n - 1):
    theta = random.random() * radians(360)
    phi = 2 * asin(random.random() * 2 - 1)
    points.append(Vector((cos(theta) * cos(phi),
           sin(theta) * cos(phi),
           sin(phi))))

while True:
    # Determine the total force acting on each point.
    forces = []
    for i in range(len(points)):
        p = points[i]
        f = Vector()
        ftotal = 0
        for j in range(len(points)):
            if j == i: continue
            q = points[j]
            # Find the distance vector, and its length.
            dv = p - q
            dl = dv.length
            dl3 = dl * dl * dl
            fv = dv / dl3
            # Add to the total force on the point p.
            f = f + fv
        # Stick this in the forces array.
        forces.append(f)
        # Add to the running sum of the total forces/distances.
        ftotal = ftotal + f.length

    fscale = 1 if ftotal <= 0.25 else 0.25 / ftotal

    # Move each point, and normalise. While we do this, also track
    # the distance each point ends up moving.
    dist = 0
    for i in range(len(points)):
        p = points[i]
        f = forces[i]
        p2 = (p + fscale * f).normalized()

        dv = p - p2
        dist = dist + dv.length
        points[i] = p2
    # Done. Check for convergence and finish.
    if dist < TOL: # TOL
        break

context = bpy.context
view_layer = context.view_layer
scene = context.scene
coll = context.collection or scene.collection

# make one point north pole.
R = points[0].rotation_difference(Vector((0, 0, 1))).to_matrix()
points = [R @ p for p in points]

bm = bmesh.new()
#bmesh.ops.create_icosphere(bm, diameter=1, subdivisions=5 )
bmesh.ops.create_uvsphere(bm,
        diameter=1,
        u_segments=u_segments,
        v_segments=v_segments)

for p in points:
    ret = bmesh.ops.bisect_plane(bm,
            geom=bm.faces[:]+bm.edges[:]+bm.verts[:],
            plane_co= rat * p,
            plane_no=-p,
            clear_outer=False,
            clear_inner=True)

    # fill the holes
    bmesh.ops.contextual_create(
            bm,
            geom=[e for e in ret["geom_cut"]
                  if isinstance(e, bmesh.types.BMEdge)]
            )

me = bpy.data.meshes.new(f"{n} Sided Dice")
bm.to_mesh(me)
ob = bpy.data.objects.new(me.name, me)
coll.objects.link(ob)
view_layer.objects.active = ob
ob.select_set(True)
ob.location = scene.cursor.location

Super awesome! Thank you very much! The script worked like a charm!!!!!


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Texture not shown in UV/Image editor
I don't know how to make my texture appear in the UV/Image Editor view so that I can transform my unwrapped mesh in order to fix it. I am rather sure that there is a simple button that I did not press but I couldn't find it so far.

Is this what you're looking for?


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Simulate a panorama using 6 cube faces
I have the 6 cube face images required to render a panorama. I am trying to see if it is possible to use Blender to use these images as the textures for a cube and then place a camera inside the cube to generate a video of the panorama (by rotating the camera). If this is possible, I intend to use Blender's Python API to automate this.
Full disclosure: I have no prior experience with Blender.

I dont know if its possible to automate it
But It can be done manually by
Making the Normals face inwards,
UV unwrapping the cube,
mapping the textures
move the camera to the center
and render a 360 panoramic
http://regusmartin.deviantart.com/art/Panoramic-Rendering-in-Blender-468232790

If your question is: Is it possible?
Can't help you with the scripting but it's definitely possible to model the scenario.
You should easily be able to find out how to make a box and unwrap it. You may need to adjust the UV's to get the textures right. It may be easier to make a big texture of the 6 images.
Make sure you flip the normals to point inwards.

Thank you! I chose @eromod's answer because it linked to a guide (which contained pictures :D).


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Joined objects causes program to slow down in blender
So I was just using blender 3D modelling and I decided to take 6 objects and join them together using CTRL + J and suddenly the program just slowed down real hard.
What is the cause of this please and is there a way to fix this? Do I have to delete my object again?

Do some of your object have any modifier?

http://prntscr.com/azulx2 This is a screenshot of 6 objects which I joined into 1. All It had was a subdivision surface

You can see at the top of the page that the scene has like, 41 million verts. you've done something to make this happen. It is possible that one of the meshes you joined has a really dense topology already. This, combined with the level 4 (!!!) subsurf is giving you unnecessary detail, and your lag.

If you look at the info shown at the top of your window, your scene has 40 million vertices, that is why things are slow.

You probably had a subsurf on one object but when you joined them together the subsurf then became active on the new denser mesh.
As you have a subsurf division setting of 4, that means you have about 150,000 real vertices or 25,000 vertices in each original object. With the subsurf at 4 divisions on only one of them, you would have had 6.8 million vertices before joining. That jump from 6.8 million to 40 million will be the reason for the performance difference.
Solutions:
A subdivision setting of 4 is high, dropping it to 2 will give a similar visual result with only 2.5 million vertices.
From what I can see of your object, 157,000 vertices for each item is extremely high. I would expect to use less than 200 vertices for a shape like that. Adding a subsurf with a division of 4 on 6 of the lower poly objects would leave you at about 300,000 vertices which will be very fast to work with.

40 million :o? Thats over 9,000!!!!

I see. I think best solution here is to remove the sub surface and use smooth instead. It has a similar effects and there isn't much change to the object. Thank you very much every1 for your feedback. I found it helpful :) and yes I shouldnt have done a subsurf of 4 that was stupid of me. I just never knew that sub surf would create such lag


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When importing svg from inkscape, losses of color and definition
I'm trying to compose a cone in Inkscape, embedding text, image (after converted in vectors):

But, after importing in Blender, here is what I get:

You see then that something went wrong, but I don't know what.
Please your advise is welcome !
JF

It isn't exactly clear what exactly you want to achieve. Could you give a better description of your end result?

Blender being a 3D modeling application doesn't really work like a 2D vector drafting application like Inkscape, there is no Z ordering or layers to tell what stays above what, like one would in an illustration program.
What you see in you image is not loss of color or definition, nothing is wrong with your shapes, what you are seeing is simply the imported shapes overlapping each other at Z=0 height and causing faces to glitch.
This is a well known issue with rendering 3D scenes with overlapping geometry often called Z-Fighting, where coinciding or almost coplanar surfaces cause a myriad of visual artifacts and glitches.
Think how these shapes would be built in the real world, there can't possibly be two objects be occupying the same physical space. You simply have to "subtract" or remove the shapes from each other so there are no overlapping parts.
For example make a copy of your "yellow logo" part and joint it with Ctrl + J to the white "cone base" part, so there is a whole there with the same outline, where the yellow logo can be seen through. Same for all other parts, purple background should have a whole in the center shaped like the white cone, and so on.
Another option that may work in some situations is to actually displace the shapes in the Z direction so they don't overalp anymore, giving them an actual Z height difference between them, much like they'd hav different Z depths in an 2D illustration program. This distance may be imperceptibly small (but non zero), as if to simulate an inherently bidimensional illustration, or more pronounced if the model supports it.
Before you proceed consider this:
Are you planing to make this cone three dimensional with an actual cone shape?
Have in mind that you will have a very hard time doing that from a bezier curve object, or even from a mesh object created from those imported SVGs. Blender doesn't deal with that very well at all because of how bezier curve geometry is generated.
Consider exporting your design from Inkscape as a PNG image and using that as a texture on your cone instead. Model a cone from a mesh in Blender directly, it will be a lot easier and produce better results.

Yes, he could, but my comments assumed the user is planning on making the cone actually three dimensional, an actual cone, which I understood is what the the user is probably wants. Otherwise he could do that just in Inkscape.

Well, inkscape does in fact have layers and they even get exported to inksape's own version of svg. Apart from that I'd go with your Idea of exporting the logo part to png.

Jean-François, I would start to create a cone in Blender, give it a white material, unwrap it and bake the diffuse color to a texture.
Then I would isolate the logo part of the svg in inkscape, delete the rest and export the logo to png (Menu - File - Export Bitmap - Selection. You can chose the resolution in the Bitmap size area of the export window).
After that I'd go into gimp, open my texture image then open my logo image (which should have an alpha channel already due to isolating the logo) and combine the two.
Last step would be reloading the texture in Blender and if you've placed the logo correctly you should have your cone with the logo.


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Apply Texture only on parts of Object with nodes
I'm trying to model a beer bottle and I'm almost finished now. The only thing I still need to do is to apply the labels to the bottle. In Cycles I already mixed the Shaders for the glass and the label. My Problem is that the texture is applied to the whole bottle... It looks like this:

I want to apply the Texture only to the body and the neck, because only these parts are unwrapped. I want the areas where usually no label is applied (in the image, you can see many tiny labels in these areas) , not to be textured!
this my node setup:

Hope you guys can help me. Thanks in Advance!!

You could achieve this in two different ways

Either use two very similar materials, one with a texture other without, then use two distinct material slots for each. One for the parts with the logo the other for the parts without.
Reset and clear your UV coordinates for all faces of the bottle you want to keep without images. just enter edit mode, select all the faces where you don't want your image to appear and clear the UV coordinates. You can easily set them to X0,Y0 for example, in the UV editor by setting the cursor to 0,0 coordinate by pressing . and scaling them all with a factor of zero.

I have an easier way on doing that, but it only works if you don't use UV unwrapping.
You can just select parts of the mesh and in material settings hit assign, then you can select different parts of the mesh, chose new material and assign it to different part of the mesh. This meted is a lot easier and I use it a lot.
Also you can color the bottle and add labels later by assigning png images to the plane mesh and curving it as you need.


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BGE: Import Error No Module Named "Tkinter"
I want to add some GUI without simulating 2D Controls in 3D, and I think Tkinter module is easy enough to use. I set up a simple scene to try my idea, but it seems not work.

Neither import tkinter nor import Tkinter, as I tried out, works probably. Any suggestions? Thanks.

@root how to make blender use a certain environment?

@root should I try to add /usr/bin/env to PATH?

@root Sorry, I am rendering an animation, I don't want to interrupt it, I will try out this method after it is finished.(it seems to be work). Thanks.

@root Recently, I found I can install python package into my workplace with pip3 install --target <directory> <package-name>. That will take away more spaces from disk maybe, but it is more convenient to share projects with others.

Tkinter will freeze your game and create a popup window, which is probably not what you want. You could install it, but I wouldn't suggest it.
I've found that making simple interfaces is harder in code (eg tkinter) than it is in BGE with objects. Of course, by the time you want combo boxes, you probably want a GUI library. And these libraries do exist.
There is a nice one called BGUI you should look into. This writes into openGL ontop of BGE, so it won't freeze your game or create external windows.


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Cycles: make a bouncing ball with physical simulation
I want to make an animation of some ball which have horizontal initial velocity bouncing on floor. I tried to add Rigid to the ball (dynamic) and floor (static). But the ball dropped to the floor without a bounce. I googled for answer but what they do are move the ball to approximate position and set a key frame, don't care much about physical rules. I do believe blender can deal with such a easy simulation.
Any suggestions? Thanks.

You must set the ball to rigid body, and increase the bounciness value for both the ball and the floor.

@Anthony Forwood Exactly where might I find this "bounciness" value???

@InternetWarriors Properties -> Physics -> Rigid Body Collisions -> Surface Response -> Bounciness


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How do I programmatically query the state of the timeline "record" button?
I have a frame handler that should set keyframes if the record button is set. How do I check whether it's enabled via Python?
Thanks!

If you place the mouse cursor above the record button, you will see:
bpy.data.scenes["Scene"].tool_settings.use_keyframe_insert_auto


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How to wrap a spiral around an object?
I'm trying to make a spiral wrap around a bent object. Or at least, bend the spiral itself to be placed and scaled accordingly.
The example here is of the tights, two seperate spirals mirrored and merged, wrapping around this characters leg.

Is it for a still or animate character? Here is a way to do it for a still character, I hope someone will give you a solution if you need to animate your character:

Model your character.
Create a bezier curve that loosely wraps around the shape of the leg. Put the bezier origin point on its bottom vertex, check its direction so that it goes up.
Give your bezier a Shrinkwrap modifier with the leg as Target, enable the fourth displaying option of the modifier (Apply this and all preceding deformation modifiers...).
Create a cylinder, subdivide it horizontally and put it on the origin point of the bezier.
Give it an Array and a Curve modifier, enable the Merge option of the Array, and choose the bezier as the Object of the Curve modifier. Play with the parameters so that it follows the bezier correctly. Give also your cylinder a Subdivision Surface modifier.
Play with the Offset of the bezier Shrinkwrap modifier to tighten the pipe along the leg.


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how to animate a gradient moving over an object
Improving on this tutorial, is there a way to animate the gradient so the colours move across the object?

if I have configured the material of the cube as described above, how do I execute the animation?
Unfortunately I can't get the colors to move. Many thanks for the help !


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Is there a way to colour meta objects without turning them into meshes?
Reason being I want to animate them as blobs - once they’re meshed they lose their blobbine nature. I'm interested in creating this sort of dripping effect, applying it to this character made out of metaobjects - the intention to have certain meta objects running through the rest to create ooze effect. Ideally I'd like it coloured but doesn't work unless they're meshes.

I'm not an expert but Metaballs can have materials and colors, so what limitations have you met exactly?

Wow ok I couldnt add colour to metaballs. Figured that wasnt possible unless they were meshes. You just proved me wrong. Not sure what was happening before but gracias!

You can even give them bumps with the bump node. It would be interesting if you show the result and how you did it, maybe as an answer.


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Problem installing Blender 2.8.1 via Apple Remote Desktop
I've been tasked to install Blender 2.8.1 onto multiple Macs (50+) running Mojave.
Our normal method is to simply copy the .app into the applications folder on the devices using Apple Remote Desktop (ARD) and users will run the file from there.
However this is not working with the new version.
App file copies over fine, however when trying to run it, I get an error that the file may be damaged or incomplete.
Permissions set to read for everyone.
Hope someone can help?
Thanks

Deployment questions are probably off-topic for this site.  If you are using blender commercially you should consider paid support.  Are you sure there is no corruption of the download, i.e you tested it locally.  The file extension would normally be .dmg.  Here's the 2.81 download for MacOS

Can you recommend where to get support for this?
I work in an educational institution for non profit.

Can I add that I am sure there's no corruption in the download. I can run Blender on one account, but when I try to run it via another account, it states it's corrupted.

I think you need an ARD expert, but it sounds like a permissions issue maybe.  Read the ADR manual don't skip anything, the lightbulb usually appears after third reading.  If all else fails call Apple.

Also, this question really belongs on [SF] as this is really a deployment problem rather than a blender one, I can't migrate it though I'm afraid.  I'll talk to the moderators.

Thanks, the reason why I have posted to Blender is that I haven't had this issue with other Apps. I can copy and paste them into Applications and run them no problem, not with Blender however.

Understood, it's a tricky one and I do think it is useful here, however I am sure there are more ARD experts there, this is more for using blender than deploying it.  One of the shortcomings of Stack Exchange is solving cross-topics like this one.

If you are still stuck then you can always try https://blender.chat , https://blendernetwork.org or dare I say it resort to twitter, which has a lot of active blender users.

Did you get anywhere with this?

Same issue here, i just rolled back to the previous version.I had just deployed to 400 macs without testing (stupidly). It seems the permissions on the app require you to be an administrator. The person who installs locally has read/ write access, everyone has no access and there are no groups listed in the permissions. I will do some more testing tomorrow changing the permissions. I did give everyone full access but that didn't work.

Have you reported this back to blender?


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I am seeing both blender 2.8 and blender 2.81 in my program list. So can I uninstall blender 2.8?

I have previously installed Blender 2.8 and today I have updated to Blender 2.81 by downloading and installing it from blender website. I see 2 blender programs in program list, one Blender 2.8 and Blender 2.81 which seems awkward. I thought it would rewrite the previous version which I already have but instead it creates a new blender program, although the desktop icon is still single and refers to Blender 2.81
So can I uninstall Blender 2.8 without uninstalling whole blender?
And is Blender 2.8 taking extra unwanted space in my hard drive?
and
How to update Blender the right way efficiently?
Can I update Blender without downloading the whole software again?

Welcome @Ankit927 to [blender.se] on Stack Exchange.  Please read [ask] and [tour].  It would be helpful to others if you can rephrase your question in a form that is easily searchable e.g. "Multiple Versions of blender installed on Windows after update", as this may be useful for earlier or later versions also.  Also we encourage a single question be asked, there seems to be a family of questions here, but I'm sure that that the answer you receive will be full and cover many of the concerns you have raised.

You can uninstall 2.8. Every version of Blender doesn't rely on other versions.
Updating Blender is usually done exactly how you're doing it. This is because Blender doesn't automatically update. Sometimes new versions break old files or addons, so it's up to the user to update the program by downloading it. It can be useful in certain cases to have multiple versions installed, although it's rare.
The only way to automatically update that I know of is if you install through Steam, although my understanding is that Steam basically does what you did just in the background.


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Object Appering in preview mode but not in renders
I'm Trying to render a box on top of a video that ive tracked in the 3D viewport everything looks fine but when I render the frame using f12 the geometry is missing from the rendered image.

I'm Pretty new to blender especially 2.8 so if there is anything missing please ask me and im going to put it in the post.

In the Outliner (in the top-right of the screen, in the default workspace), is the "Disable in Renders" icon (a little camera) next to the cube Enabled or Disabled?

Per my comment above, you should first check if the Disable in Renders toggle is Enabled or Disabled. You can find this in the Outliner, which will appear in this area (circled in red) of the default workspace:

If the Disable in Renders toggle indicates that the object should be rendered, then the problem may be more complicated. This seems like the most likely problem, though.

I've checked thatand everything in the Outliner sould be rendered. But I Just realized that the cube is transparent for some reason.


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How do i get rid of wrinkles in a subsurf
I have been modeling a dagger. I've just finished doing the rough profiling. I've added a subsurf modifier to smooth it out a bit but i cannot figure out how to get rid of these wrinkles. can any of you guys help me out? Thanks in advance.

Here's the Blend File: https://www.dropbox.com/s/b6u1lf41x9vujwd/Dagger.blend?dl=0

By 'wrinkles', do you mean that you want it to be sharp rather than smooth at certain transitions, or that you have unintended unevenness in the diameter of the mesh cross-section?

yeah was talking about the uneven-ness

I'm not sure if this is what you mean, but if your goal is to selectively convert some of the smooth transitions to sharp transitions, you can do this either by adding additional Geometry (often through loop cuts, as shown here):

(note: sharpness depends on how close the new loop cut is to the old loop cut, because the subdivision surface adds geometry between them -- hence, if there is no or little space between them, the subdivision surface has little or nothing to smooth)
Which results in:

And/or by using Mark Seam: Sharp

(result not pictured)
If, instead, you want to remove some of the undesired unevenness of the mesh or something else, a different answer/solution will be needed.

Thanks! In the end I just removed some of the geometry to stop it being so condensed.