text:
BGE pressing space bar while in play mode isn't running script
I'm new to bge, reading a tutorial on matrix, I downloaded the linked file, a very simple task, I'm supposed to go to bge, press P then press space in order to run the script. the problem is, it's not, I googled it to search for other examples, I thought may be I'm doing something wrong, but everywhere it says that this his how you do it, can someone please enlighten me.I'm attaching the .blend

This code is from pre 2.49. I'm pretty sure it runs into an error.
Always have the console window open when running the BGE with python code. Otherwise you will not see errors caused by Python code.
Convert the above sample to (BGE 2.5 and Python 3):
import bge

controller = bge.logic.getCurrentController()
owner = controller.owner

rotation_matrix = [ [0,-1, 0],
                    [1, 0, 0],
                    [0, 0, 1]]

sensor = controller.sensors["space"]

if sensor.positive:
    owner.worldOrientation = rotation_matrix


text:
LuxBlend light groups
I just installed LuxBlend, LuxRender for Blender, in order to test it, and I'm very new to using it. I made a simple scene with a couple of mesh lights "plane objects", and assigned emitting materials to them. I'm trying to get two Light Groups, one for each mesh light, but it looks like something is missing. The Light Groups panel in Render Layers tab is empty. I tried to add it in the light material with no luck, for light materials, I chose Null, for material type, and checked LuxRender Light Emission check box, "as I've seen in a tutorial." There's a tutorial on the Luxrender website that explains how to do it, but I'm sure it's for a different version, because there's a Material Type called "Light", which makes sense. Why choose "Null" for a light? But in the version I have, there's no such material type! I'm using Blender 2.77a, LuxBlend 27.

Maybe it's a dumb question... but you do have Lux selected as your renderer in the pull-down at the top of the screen, right?

@Matt, Yes, otherwise I wouldn't have the materials and all other panels in that I attached in my question.

Okay, cool. I wasn't sure if that's why they showed up, or if they were just part of the plugin.

I uninstalled the version I had, reinstalling the experimental version, just to check if this is a bug in the version I have, or something I'm doing wrong, or I don't know how to do.

After fiddling with this issue, I found out this is a bug. I uninstalled Luxrender, removed the add-on from Blender, restarted my machine and installed a different version. Using Luxrender 1.6 test version No OpenCL, I have the Light Groups available in Render Layers panel. The Materials Panel preview is still black. I couldn't find a Group Node (maybe just because I'm unfamiliar with Lux), but if I don't use Nodes, I can create Light Groups in Render Layers panel and assign light materials to the Light Groups.

Support for Group Nodes is not implemented in LuxBlend yet (I don't know if it's already possible with Blender's Python API, I fear not).
If your material preview is black, check Blender's console after a fresh start, there are probably errors importing the pylux/pyluxcore modules. Ask in the Lux forums for further help in that case, and make sure Blender and Lux are the latest versions.

You need to click "Add LuxRender Material Node Tree" in your material. Blender is currently trying to cram the data from the original Blender material into a LuxRender material, and that doesn't work very well.
Once you click that, it should start making more sense.
You can find more information here.

When I click "Add LuxRender Material Node Tree." All the panels in the Material tab disappear except for Preview and Emission. Nothing shows up in the Node Editor!

It doesn't look like the image I just added?

Yes it does, but clicking the drop down menu beside in Light Emission does nothing. How can I use this?

I'll be out for a few hours. In the meantime, make sure "Use Nodes" is checked and press the "home" key and.or the "period"  on the number pad while you're hovering over the node editor to zoom to any nodes that are present, just to make sure.

...make sure that you're scrolled all the way down. Sometimes when you expand panels, they go off the screen without telling you.

It works, I can see the node, I had to check an icon that looks like the Material icon in the Node Editor, called "LuxRender Material Node", but I still can't make light groups, the "LuxRender Light Groups" panel in the Render Layers tab is still empty.

Ok, so I uninstalled Luxrender, removed the addon from Blender, redownloaded the test version, Luxrender 1.6 and restarted my Windows, and I can see the Light Groups, so this was a bug, I will delete this question tomorrow.

No need to delete the question. Others also need to know that it's a bug, not a user error. You should just add an answer that explains that it's a bug, and then accept it.

source: Stack Exchange

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

sort: votes


text:
Issue with running blender player over ssh
I have a blender simulation which uses Blender Render and Blender Game Engine. I execute the following script(Renderer.py) from a python file(simulation.py) using "./blender -b compress.blend --python Renderer.py" to run a simulation on my machine.
import bpy
import math as m
import random as rand
import divider as d
import COM
import vol

def del_existing():
    del_obj = [item.name for item in bpy.data.objects if item.type == "MESH" or "LAMP"]
    for obj in del_obj:
        bpy.data.objects[obj].select = True
    bpy.ops.object.delete()

def makeMaterial(name, diffuse, specular, alpha):
    mat = bpy.data.materials.new(name)
    mat.diffuse_color = diffuse
    mat.diffuse_shader = 'LAMBERT'
    mat.diffuse_intensity = 1.0
    mat.specular_color = specular
    mat.specular_shader = 'PHONG'
    mat.specular_intensity = 0.5
    mat.alpha = alpha
    mat.ambient = 1
    return mat

def setMaterial(ob, mat):
    me = ob.data
    me.materials.append(mat)

def add_lamp(lname,srctype,location):
    scene = bpy.context.scene
    newl = bpy.data.lamps.new(name=lname,type=srctype)
    objl = bpy.data.objects.new(name=lname, object_data = newl)
    scene.objects.link(objl)
    objl.location=location
    #print(list(bpy.data.objects))
    bpy.data.objects[lname].select = True
    bpy.data.objects["hemi"].data.energy = 0.9

def add_camera():
    cam = bpy.ops.object.camera_add(view_align=True, location=(0.0,34,8.0),rotation=(m.radians(80), 0.0, m.radians(180)))

def my_handler(scene):
    bpy.data.objects["Cube.001"].location.x += 0.2
    bpy.data.objects["Cube.002"].location.x += -0.2
    print(scene.objects.get("Cube.002").location)
    print(scene.objects["Cube.001"].location)

def create_some_object(ii,y_co,mass):
    if ii % 5 == 0:
        x_co = 8.1
        name =  "obj_torus"+str(ii)
        bpy.ops.mesh.primitive_torus_add(location = (x_co,y_co,2))
        selobj = bpy.context.active_object
        selobj.name = name
        selobj.game.mass = mass
        selobj.scale = (1.5,1.5,1.5)
    if ii % 5 == 1:
        x_co = 3.5
        name =  "obj_cube"+str(ii)
        bpy.ops.mesh.primitive_cube_add(location = (x_co,y_co,2))
        selobj = bpy.context.active_object
        selobj.name = name
        selobj.game.mass = mass
        selobj.scale = (2,2,2)
    if ii % 5 == 2:
        x_co =-1
        name =  "obj_cone"+str(ii)
        bpy.ops.mesh.primitive_cone_add(location = (x_co,y_co,2))
        selobj = bpy.context.active_object
        selobj.name = name
        selobj.game.mass = mass
        selobj.scale = (2,2,2)
    if ii % 5 == 3:
        x_co = -5.4
        name =  "obj_sphere"+str(ii)
        bpy.ops.mesh.primitive_uv_sphere_add(location = (x_co,y_co,2))
        selobj = bpy.context.active_object
        selobj.name = name
        selobj.game.mass = mass
        selobj.scale = (2,2,2)
    if ii % 5 == 4:
        x_co = -9.0
        name =  "obj_monkey"+str(ii)
        bpy.ops.mesh.primitive_monkey_add(location = (x_co,y_co,2))
        selobj = bpy.context.active_object
        selobj.name = name
        selobj.game.mass = mass
        selobj.scale = (1.2,1.2,1.2)

def create_logic_bricks():
    sensors = bpy.context.scene.objects['Cylinder'].game.sensors
    controllers = bpy.context.scene.objects['Cylinder'].game.controllers
    actuators = bpy.context.scene.objects['Cylinder'].game.actuators
    bpy.ops.logic.sensor_add(type='ALWAYS', object="Cylinder",name="sensor1")
    sensors['sensor1'].use_pulse_true_level = True
    bpy.ops.logic.controller_add(type='PYTHON',object="Cylinder",name="controller1")
    controllers['controller1'].text = bpy.data.texts['pistonMover.py']
    sensors['sensor1'].link(controllers['controller1'])
    bpy.ops.logic.actuator_add(type="GAME",object="Cylinder",name="actuator1")
    actuators['actuator1'].mode = "QUIT"
    controllers['controller1'].link(actuator = actuators['actuator1'])
    bpy.context.scene.game_settings.logic_step_max = 50
    bpy.context.scene.game_settings.physics_step_max = 50
    bpy.context.scene.game_settings.physics_step_sub = 5

def get_volume_params():
    positions = {}
    for item in bpy.data.objects:
        if item.name == "Cube":
            positions['h1'] = item.location.z
        if item.name == "Cube.003":
            positions['h2'] = item.location.z
        if item.name == "Cube.002":
            positions['b1'] = item.location.x
        if item.name == "Cube.001":
            positions['b2'] = item.location.x
        if item.name == "Cube.004":
            positions['l1'] = item.location.y
        if item.name == "Cylinder":
            positions['l2'] = item.location.y
    return positions

if __name__ == "__main__":
    del_existing()
    plane_mat = makeMaterial('planemat', (0.7,0.7,0.7), (0.5,0.5,0), 1)
    plane_mat2 = makeMaterial('planemat2', (0.6,0.1,0.1), (0.5,0.5,0), 1)
    plane_mat3 = makeMaterial('planemat3', (0.0,0.5,0.0), (0.5,0.5,0), 1)
    plane_mat4 = makeMaterial('planemat4', (0.0,0.0,0.5), (0.5,0.5,0), 1)
    ''' Make a box for compression '''
    #BASE CUBE
    bpy.ops.mesh.primitive_cube_add(location = (0,18,-0.5))
    bpy.data.objects["Cube"].select = True
    selobj = bpy.context.active_object
    selobj.scale = (50,50,1)
    setMaterial(bpy.context.object, plane_mat)
    #COMPRESSION CHAMBER 1
    bpy.ops.mesh.primitive_cube_add(location = (-11.4,-18,0))
    bpy.data.objects["Cube.001"].select = True
    bpy.ops.transform.rotate(value=m.radians(90),axis=(0,1,0))
    bpy.ops.transform.resize(value=(0.5,28,5))
    bpy.ops.transform.translate(value=(0,28,5))
    setMaterial(bpy.context.object, plane_mat3)
    #COMPRESSION CHAMBER 2
    bpy.ops.mesh.primitive_cube_add(location = (11,-18,0))
    bpy.data.objects["Cube.002"].select = True
    bpy.ops.transform.rotate(value=m.radians(90),axis=(0,1,0))
    bpy.ops.transform.resize(value=(0.5,28,5))
    bpy.ops.transform.translate(value=(0,28,5))
    setMaterial(bpy.context.object, plane_mat4)
    #PLANE ON THE TOP
    bpy.ops.mesh.primitive_cube_add(location = (0,11,11.01))
    selobj = bpy.context.active_object
    selobj.scale = (11.5,28.5,0.5)
    blue = makeMaterial('transcube', (0.16,0.05,0.8), (0.5,0.5,0), 2)
    #setMaterial(bpy.context.object, blue)
    bpy.data.materials["transcube"].use_transparency = True
    bpy.data.materials["transcube"].transparency_method = 'RAYTRACE'
    #bpy.data.materials["transcube"].raytrace_transparency.ior = 1.5
    bpy.data.materials["transcube"].alpha = 0.2
    #Piston Frame
    bpy.ops.mesh.primitive_cube_add(location = (0,37.2,5))
    bpy.data.objects["Cube.004"].select = True
    bpy.ops.transform.rotate(value=m.radians(90),axis=(1,0,0))
    bpy.ops.transform.resize(value=(10.3,0.5,5))
    setMaterial(bpy.context.object, blue)
    #Piston Handle
    bpy.ops.mesh.primitive_cylinder_add(location = (0,47.7,5))
    bpy.data.objects['Cylinder'].select = True
    bpy.ops.transform.rotate(value=m.radians(90),axis=(1,0,0))
    bpy.ops.transform.resize(value=(1,9.8,1))
    #MAke the handle and plate one object i.e. Piston
    bpy.data.objects['Cube.004'].select = True
    bpy.data.objects['Cylinder'].select = True
    bpy.ops.object.join()
    #PLANE ON THE BACK
    bpy.ops.mesh.primitive_cube_add(location = (-18,-18,0))
    bpy.data.objects["Cube.004"].select = True
    bpy.ops.transform.rotate(value=m.radians(90),axis=(1,0,0))
    bpy.ops.transform.resize(value=(-11,4,5))
    bpy.ops.transform.translate(value=(18,-4,5))
    setMaterial(bpy.context.object, plane_mat2)
    bpy.data.objects["Cube.004"].select = False
    box_dim = []
    obj_list = []
    for item in bpy.data.objects:
        if item.name.startswith('Cube') and item.name != 'Cube.004':
            temp_dict = {}
            temp_dict['x'] = item.location.x
            temp_dict['y'] = item.location.y
            temp_dict['z'] = item.location.z
            temp_dict['mass'] = item.game.mass
            temp_dict['name'] = item.name
            box_dim.append(temp_dict)
            obj_list.append(temp_dict)
    com = (COM.COM(box_dim))
    print("COM_before::"+str(com))
    obj_masses = d.divider(d.create_random_list(51))
    pos1 = 0
    pos2 = 0
    y_co1 = com['y'] - 4.3
    y_co2 = com['y'] + 4.3
    for ii in range(0,51):
        if ii % 2 == 0:
            try:
                create_some_object(ii,y_co1,obj_masses['list1'][pos1])
            except IndexError:
                pass
            pos1 += 1
        else:
            create_some_object(ii,y_co2,obj_masses['list2'][pos2])
            pos2 += 1
        if ii % 10 == 0 and ii!=0:
            y_co1 -= 4.3
            y_co2 += 4.3
    #bpy.ops.mesh.primitive_cube_add(location = (com['x'],com['y'],com['z']))
    add_lamp("hemi","HEMI", (0,0,6.9))
    add_camera()
    bpy.context.scene.use_gravity = False
    bpy.context.scene.frame_end = 150
    bpy.context.scene.render.engine ='BLENDER_GAME'
    itemtypes = ['Cube.001','Cube.002','Cube.003','Cube', 'Plane.001','Cube.004']
    for item in bpy.data.objects:
        if item.type == 'MESH' and item.name not in itemtypes:
            item.select = True
            bpy.data.objects[item.name].game.physics_type = 'RIGID_BODY'
            bpy.data.objects[item.name].game.use_actor = True
            bpy.data.objects[item.name].game.use_collision_bounds = True
            if (item.name).find("cone") >= 0:
                bpy.data.objects[item.name].game.collision_bounds_type = 'CONE'
            elif (item.name).find("cube") >= 0:
                bpy.data.objects[item.name].game.collision_bounds_type = 'BOX'
            elif (item.name).find("sphere") >= 0:
                bpy.data.objects[item.name].game.collision_bounds_type = 'SPHERE'
            else:
                bpy.data.objects[item.name].game.collision_bounds_type = 'CONVEX_HULL'
        item.select = False
        if item.name.startswith('obj_'):
            temp_dict = {}
            temp_dict['x'] = item.location.x
            temp_dict['y'] = item.location.y
            temp_dict['z'] = item.location.z
            temp_dict['mass'] = item.game.mass
            temp_dict['name'] = item.name
            obj_list.append(temp_dict)
    bpy.data.objects['Cube.004'].select = True
    bpy.data.objects['Cube.004'].game.mass = 500
    bpy.data.objects['Cube.004'].select = False
    bpy.data.objects['Cylinder'].select = True
    bpy.data.objects['Cylinder'].game.mass = 150
    bpy.ops.object.origin_set(type='ORIGIN_CENTER_OF_MASS')
    com_with_obj = (COM.COM(obj_list))
    positions = get_volume_params()
    print(positions)
    print("VOL_before "+str(vol.volume(positions)))
    #print("COM_before "+str(com_with_obj))
    create_logic_bricks()
    bpy.context.scene.render.engine = 'BLENDER_GAME'
    bpy.ops.wm.blenderplayer_start()

This works fine on my machine and it gives me results correctly. I tried to run the same script over ssh on another machine and it works fine except the last line "bpy.ops.wm.blenderplayer_start()". The blender player is not starting and I do not get the results from this part of simulation.
I have looked at the answer for the question
Blender via ssh? but it did not help to answer my question.
My question is, why does my script stop only at the last line. Does is have to anything with X11 or the way I am invoking the blender player?
I have also checked whether service X is running on remote machine and configured the /etc/ssh/sshd_config to forwardx11trusted yes. All I want to do is to run blender animation of remote machine and capture the text results given by my script( just the way I am doing on my local machine). I am planning to do this to see if there will be any improvement in the performance of the simulation when I run on a machine with multiple cores. Can someone throw some light on this please. Thanks in advance.

This is less an BGE more a Blender thing. I can only guess that the blenderplayer needs a canvas to render to. A text terminal does not sound sufficient.

Don't think this as a blender problem. Check that you can start any gui app remotely, even start blender remotely without the script. With ssh you need to enable X11Forwarding, ssh -X the forwardX11trusted -Y option then allows X11 forwarding to bypassing security controls. Search for general X11 forwarding over ssh how-to's.

Thank you sambler. Using -X in my case helped resolving the issue.

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


text:
Having added a Custom Property in Editor, how do we assign an Update function?
When creating a custom property via e.g. bpy.props.FloatProperty(), we can specify a user-defined function to be invoked every time the value of said property changes.
Once the property exists, e.g. added via the Properties Editor, how do we assign or re-assign the update function?
The Properties Editor (Blender 2.74) does not offer that, and, in Python, I don't know how to access the property itself, as opposed to merely its value.

Changing the callback function after registration isn't possible, unless you re-register the property. A dev once mentioned, that doing this might leak memory, but in my test that wasn't the case. You shouldn't re-register stock properties to add a callback however, it can crash Blender.

Re-register? Crash? Is this something that refactoring, and dependency graph, gurus are looking into these days?

Don't think so. It crashes because you cross the boundary between Python and C code I think. It's kind of undefined behavior. What seems to happen if you re-register Object.name for instance, is that a 2nd property with same name is created and interferes with the original.

Thank you!
The thing to do, then, is to register the name of the custom property and of its update function, as suggested by @martinlindelof, and subsequently edit the function as ideas evolve. My motivation is separation of concerns: e.g. define a custom property called "smirk", to be used by moving a slider from 0 to 1 (or, -1 to 1) without having to be, during use, aware of whether it is being implemented by shapekeys, or bones, or what.

I am looking into it myself atm.
some_value = FloatProperty(default=1.0, update=onupdate)

and then I have a function that handles the update
def onupdate(self, context):

it's important that the function handling has self & context as arguments, and returns none.
You can read more here.

Aha! Thank you.
Have you confirmed that this actually works?
Has something changed between Blender 2.74
and the so-called "massive" update 2.75?

The very basics I can assure you works in 2.75 I am using it, by very basics I mean, when you create your FloatProperty in your case, you can set update= a function that is called each time the value changes. but if you can re-assign it later I am not sure.

...if you can re-assign it later I am not sure...

When in "use" mode, you don't want to have to remember whether that custom property causes an empty to rotate, or what; when in "improve" mode, you try to optimize the technical details behind the scenes, and, for that, a Python script looks handy, doesn't it? But that's why you want to assign or re-assign an Update Function at any time!

I'm thinking of using a custom property with a name like "smirk" to specify a complex set of adjustments to a (hopefully, realistic) humanoid figure.

Use drivers!
Drivers act as an update function and are calculated in every frame of the animation.
Suppose you have a Custom Property obj["prop"] that you need to control frame by frame, and a function pyFunction(self, targetName).
To set it up, you first need to add a simple line in your py code:
def pyFunction(self, targetName):
    obj = bpy.data.objcts[targetName]
    #Your code here
    return x #where x is the value you want the driver, and therefore your ["prop"], to have

    #this line lets Blender know that the pyFunction can be used in driver expressions
    bpy.app.driver_namespace["pyFunction"] = pyFunction

then you can create a driver on the ["prop"] property, and write in the expression field pyFunction(self, targetName), or whatever your variables are.

Note that all variables in that function must be initialized in the driver itself, so for "self" you need to tick the "Use self" checkbox, and for the others you need to create variables with the driver GUI (as a tip, if you want to put an object as a variable, create a single property variable in the driver and write "name" in the data path field, then in your pyFunction remember to get the object from the name, as I did in the code snippet before).

In alternative, you can create the driver on another property or object (like a hidden null). If you set it up this way, it doesn't matter what you put in the return of the pyFunction (it only controls the driver's value), but you need to change the property in the function, something like:
target = bpy.data.objects[targetName]
control = bpy.data.objects[controlName]

#links the Custom Property to, for example, an object's location, however this can be any number you want
target["prop"] = control.location.x

#the return is not mandatory here, the driver will just have the value 0

In any case, the driver calculates the pyFunction every single frame as an update function, and execute the pyFunction's commands every frame

Thank you!
Would this solution have worked in 2015?
It certainly deserves that I try it.  ˆ_ˆ

@TomTelos I don't know, I started coding only a few months ago ;P

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


text:
Selecting GPU with Python script
Alright, so i have a slightly strange system configuration. I'm running Zorin OS 12, which is roughly equivalent to Ubuntu 16.04. I am also running Mesa, but i use AMD's OpenCL. It works just fine with various miners i tested.
Now i want blender to actually render on the GPU. Blender detects it when i use the split kernel, but for some reason, whatever i do, it always falls back to the cpu.
Here's the script i use:
import bpy, _cycles
bpy.ops.wm.open_mainfile(filepath="/home/xxx/xxx.blend")

for scene in bpy.data.scenes:
    bpy.context.scene.render.engine = 'CYCLES'
    bpy.data.scenes["Scene"].cycles.device='GPU'
    bpy.context.scene.cycles.device = 'GPU'

bpy.context.user_preferences.addons['cycles'].preferences.compute_device_type = "OPENCL"
bpy.context.user_preferences.addons['cycles'].preferences.devices[0].use = True

bpy.ops.render.render(True)
img_path = "/home/xxx/Bilder/test_1.png"
rendered_image = bpy.data.images["Render Result"]
rendered_image.save_render(filepath=img_path)

I am really at a loss here, but i think this could work. I mean even if the GPU for some reason does not work, it should not just fall back to the CPU, but give me some sort of error, right?
uname -r
4.15.1-041501-generic

clinfo
 Platform Name                                   AMD Accelerated Parallel Processing
 Platform Vendor                                 Advanced Micro Devices, Inc.
 Platform Version                                OpenCL 2.1 AMD-APP (2527.3)
 Platform Profile                                FULL_PROFILE
 Platform Extensions                             cl_khr_icd cl_amd_event_callback cl_amd_offline_devices
 Platform Host timer resolution                  <printPlatformInfo:5: get CL_PLATFORM_HOST_TIMER_RESOLUTION : error -30>
 Platform Extensions function suffix             AMD

EDIT
For reasons unknown to me, installing Radeon RenderPro for Blender has fixed the problem!
https://pro.radeon.com/en/software/prorender/blender/

For reasons unknown to me, installing Radeon RenderPro for Blender has fixed the problem!
https://pro.radeon.com/en/software/prorender/blender/

Right now, I am using Blender 2.90. Here is my Python code to detect and use GPU in Blender.
import bpy
bpy.data.scenes[0].render.engine = "CYCLES"

# Set the device_type
bpy.context.preferences.addons[
    "cycles"
].preferences.compute_device_type = "CUDA" # or "OPENCL"

# Set the device and feature set
bpy.context.scene.cycles.device = "GPU"

# get_devices() to let Blender detects GPU device
bpy.context.preferences.addons["cycles"].preferences.get_devices()
print(bpy.context.preferences.addons["cycles"].preferences.compute_device_type)
for d in bpy.context.preferences.addons["cycles"].preferences.devices:
    d["use"] = 1 # Using all devices, include GPU and CPU
    print(d["name"], d["use"])
```

Looks like you have multiple scenes in your file. To cycle through them and set them all use:
for scene in bpy.data.scenes:
    scene.cycles.device = 'GPU'

bpy.context refers to the to the area of blender which is currently being accessed by the user, not the script loop. If you don't have the file open, I would avoid using bpy.context calls and instead access bpy.data.

Right, that makes sense. I changed the script to do that, but sadly the gpu still is not being used. It always falls back to my cpu.

@user3922088 Then the problem must be in setting up the devices in UserPrefs. Your system config is very rare, it will be hard to help. Are you able to run Blender normally on that system with GUI and setup it manually with everything working? I don't see why the script wouldn't work.

I can run it normally, but not when i use this specific OpenCl configuration. Is there no way to set the device via Python? I mean it must be possible on render farms, right? They don't run the gui either. I realize it's rare, but the thing is that the Mesa drivers are superior to AMD's in all regards BUT OpenCL.

@user3922088 you would use the command line arguments when rendering remotely for what is needed to set (https://docs.blender.org/manual/en/dev/advanced/command_line/arguments.html). The system setting in UserPrefs is persistent when saved so there is only need to set it once. What do you mean with: I can run it normally, but not when i use this specific OpenCL configuration?

I am running Blender with a custom LD_LIBRARY_PATH to access AMDs OpenCL. If i print the availible devices via Python it shows me the processors and the gpu. I just don't know why it does not let me select it.


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Sculpting brushes other than the grab brushes aren't affecting most of my mesh
All of the blue and red/orange brushes aren't doing anything when applied to the upper part of my hair object mesh. I've tried flipping the normals and recalculating them, didn't change it. Trying it with dynamic topology off also didn't fix it. The brushes seem to occasionally work on the bottom part of my mesh, and I went inside of the mesh once and the inflate brush worked from the inside out.
blend file uploaded to google drive

I uploaded a picture of the mesh but unless I made a gif of the issue happening there really isn't anything of value a still image could add, other than if someone wanted a picture of a specific settings menu or statistics.

Go to object mode, select the mesh, press Ctrl + A, then choose Scale.
here more info: https://docs.blender.org/manual/en/2.79/editors/3dview/object/editing/transform/clear_apply.html#apply-object-transformations
Why is it important to apply transformation to an objects data?
this is the problem: negative scale (and not uniform)

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


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Mesh mirror itself without a mirror modifier
as the title says "Mesh mirror itself without a mirror modifier".
I had a mirror modifier on but not anymore but the mesh keeps mirror itself and i don't know what is causing it, in my modifiers tab i only have and armature and subdivision modifier. Any idea what is causing it?
I have applied the mirror but the problem is that any new change i make it mirror it

My english is not that good sorry

I don't have auto mirror and i tried older versions of my model that had the mirror on, i apply it and it keeps happening the same

I wouldn't care if it wasn't because i want to make some shape keys

A cache folder/file lurking somewhere perhaps?  In the project folder or Blender's temporary folder?  Usually named "Blender_Cache" or similar.  Save & exit the project, delete any cache files/folders you can find, then reload.

Duplicate of Why does mesh behave like mirrored in Edit mode without Mirror modifier?

You may have enabled the "X mirror" option, which is an Edit mode option rather than a modifier. It's located in the tool shelf (T) of the viewport under the "Options" tab. The first one here:


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How To Make A Board Game Piece With Vector Displacement
My final outcome will be a flat plane with a displaced board game piece that I can move around. I started by making a cylinder come out of the plane.

Then I wanted to use RGB curves to shape a board game piece.
I tried for a while to turn this all into a vector I could use, but I just don't know how.

I'm using this less than and clamped add to make the plane under the cylinder full white so it doesn't change with the base of the game piece
P.S. I've tried putting my final b&w texture into the x and y sockets on a Combine XYZ node, and I've tried doing that but multiplying the combine to the vector I'm working from, every solution I've conceived always makes a cone shape, despite the RGB curve shape. I had some weird problems like this on another project where the outcome is pretty much not related at all to the nodes

Hello, it's hard to see, did you actually use a vector displacement node ?

I didn’t, I was watching a lot of tutorials where they didn’t and I didn’t really think to. If i did, how should I integrate my texture? Also I should I put the vector displacement mode before or after subtracting the original texture coordinates?

On DefaultCube's YT channel there are two interesting tutorials that might help you with this, there's this one called The Romans Are Jealous where he uses RGB curves as well for shaping and which comes close to what you do. The other is The ONLY Vector Displacement Tutorial. I think in both he doesn't use a Displacement Node, it's just manipulating the normals and feeding them into the displacement socket of the output node.

@Gorgious You don't need a Displacement Node if you're manipulating normals directly instead of converting a height map or something similar to normals.

I cannot edit my first comment anymore... so I think my linked tutorials are unnecessary because it seems like you already followed them to create this, I guess.

Looking at the second screenshot it seems like the RGB curves only contribute to the Viewer Node, they are not in any way connected to the Displacement Output Socket.


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Python How to make pose bone rotation toward a point?
I have the pose bone at a location and I would like for it to rotate to face a point
Code:
Pos1 = Vector(bone.location)
#The point location (local)
Pos2 = Vector(10,10,10)
diff = Pos2 - Pos1
quat = diff.rotation_difference(pos1)
bone.rotation_quaternion = quat

But it doesn't seem to line up

Matrices
The rotation difference returns how much to rotate from direction to direction. The result needs to be applied to current direction.
Setting the direction absolutely from the rotation difference result will only work for the case when initial value is 0.
By using matrices, will work for whatever rotation type the pose bone has.
Test script. Rotates the context pose bone to point to the head of the pose bone named "Target".
import bpy
from bpy import context
from mathutils import Matrix

rig = context.object
target = rig.pose.bones.get("Target")

pb = context.active_pose_bone

v = target.head - pb.head
bv = pb.tail - pb.head

rd = bv.rotation_difference(v)

M = (
    Matrix.Translation(pb.head) @
    rd.to_matrix().to_4x4() @
    Matrix.Translation(-pb.head)
    )
pb.matrix = M @ pb.matrix

Emulating the constraint.
Can roll the bone around its Y axis in result above and it will still point to target.
POSE space is one of the more "tricky" spaces since it is defined by the head, tail and roll of each bone as set in edit mode.
To get but one roll result
q = v.to_track_quat('Y', 'Z')

makes a quaternion from vector v that points its $Y$ direction to vector with $X$ axis up.
There is a handy convert_space method available on all objects.
>>> rig
bpy.data.objects['Armature']
>>> rig.convert_space(
convert_space()
Object.convert_space(pose_bone=None, matrix=((0, 0, 0, 0), (0, 0, 0, 0), (0, 0, 0, 0), (0, 0, 0, 0)), from_space='WORLD', to_space='WORLD')
Convert (transform) the given matrix from one space to another

What do mean by get one roll result? Do I need to get the rotational difference between the current quaternion and the roll quaternion?

Thank you for your thoughtful answer. People like you are amazing :)

In Pose Mode select the bone that is supposed to rotate, then in Bone Constraint Properties tab (1) add (2) a Track To (3) constraint. Choose a target (4) - if it's another bone, the target should be the Armature containing it; once you select the Armature, you will be able to specify the Bone (5). You may need to tinker with other properties to orientate the bone properly (particularly the Track Axis and Up properties).


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Object Moves Away From Original Position When Using Grab
I haven't had this problem so far, but for this particular object, whenever I press G to grab the object to move it along some axis (by selecting x,y, or z) the object shifts from its original position before I select the axis and also doesn't clip back to the spot when I select the axis

maybe because you've enabled the Snapping option (magnet icone?)

@moonboots Yup that was it. But I still don't understand why that was the problem

because it sticks to the face of the cup I guess?

@moonboots Ohhu, okay I get it now. Thank you :)


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Particles floating above procedural surface
I am trying to add particles to a surface over which I have added a texture and they look like they are floating in the air. I know this is because they are sitting on the actual model but is there a way to get around this?

This is interesting. I don't think the particle systems can get access to this kind of information. Given the "simpleness" of the displacement, you could use an actual pre-rendered wave texture inside a Displace modifier, which in turn can be accessed by the particle system. You can also use a Wood texture for instance and tweak the settings ?

As Gorgious says, it seems like the particle system can't take the Displacement node into account, in that case what you can do is baking the current displacement setting:

Unwrap you object with the Smart UV Project option
In the Shader Editor plug the wave texture only
Create a new Image Texture node, create a new 32-Bit Float image, keep the node selected:

Bake with Bake Type > Emit:

Here is what you should get:

Create a Displace modifier, put it above the ParticleSettings modifier, choose Coordinates > UV:

Load your texture:

In the Shader Editor, replug only the Principled BSDF:

It should work:


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Why does texture fades away on the surface?

So I was making an interior scene and when I added the floor texture I got this:

I used a node setup that BlenderGuru uses so I don't know if it's because of the HDRI or something else. I first thought that the plane was too big and was out of my view so I made it smaller. But that did not fix the problem.
Does anyone know how to fix this?

Could you post your material node setup for the floor?

I just did ! :)

Check if it's not z-fighting, so make sure it's the only one plane there.

It was not z-fighting but i just discovered the plane had to be flipped -_- lol.Thanks for the reply though !

The plane's texture was fading on my screen (The right one) the left one is how it should be. :
And that is because a plane has 2 different sides one that is made to be facing the camera (Left one) and the other side has to be facing away from the camera (right one).
Now to fix this problem you need to select the face that is facing the wrong way in edit mode (The right one) then press ctrl + f and click on flip normals.
That will make sure that the face is facing the right direction and then you won't get the fading effect.
I would explain it better with pictures but I can't because I don't have more than 10 reputation points.


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UV Mapping a spinned object
So I'm creating roads for my game.
When I create 90 degrees turns with the Spin tool, the road spin perfectly and everything, the only thing is that the texture gets stretched out, and I was wondering how I could fix it by saving time. I know how to fix it if I take 2 verticies and straighten them up and doing this with all the others, but I was wondering if I could save time by doing this.
Here is where I want to start the UV mapping :

http://prntscr.com/fesnhl
Any short-cuts or anything I could use to do this fast and easy ?

Please use built-in possibility to insert images. As to UV map either UVSquares or QuadUnwrap addons should do it fast (not to mention you could do it manually).

Related: https://blender.stackexchange.com/questions/65565/straighten-the-series-of-vertices-in-uv-editor


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Wierd artifact on my mug
Can someone explain why i got this strange "artifact". I'm following a tutorial.

have you checked this? https://blender.stackexchange.com/questions/3606/why-are-some-faces-in-my-mesh-darker

Use built-in facility to include images please so they are in the question body, see https://meta.stackexchange.com/questions/75491/how-to-upload-an-image-to-a-post as your post relies on information from image completely

It looks like it may be extra geometry. Tab into Edit Mode and press ALT + "H" to un-hide everything to see if there is unwanted geometry there.


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Start & End Cap not working in blender, any ideas?
For some odd reason I thought that just adding a start and end cap object would be easy with the Array modifier but I guess not. Any ideas?

The array start and end caps are placed using the same offset distance as each repetition.
The geometries position relative to the object origin plays a part in the positioning. Using a plane with each repetition spaced at 1.1 we can see that an end cap with an origin in the centre will match up with the array while a start cap with the mesh starting at the object centre will be disconnected from the array. Also note that if the original objects mesh is not centred around the origin it can also move the extremes of the final mesh which will require adjustments for the end caps to match up.


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NLA Animation: Where is the Extra Animation Data Coming From and How do I fix this?
So I recently tried my hand at non-linear character animation. I set my character up in a way where I wouldn't need to rig it and made both a walking animation and an idle animation. Each of the parts has their own animation data and this character is supposed to be exported into Unity.
The problem I'm running into is instead of 11 animations getting made there's somehow 66 animations and most of them affect the whole setup rather than a single part of the setup. Only a small handful of them are relevant to what I made and the rest are completely irrelevant, in the 2nd example you can see the head is missing and the arms are out of their place.
If it helps everything is parented to the torso in some way (the sword and shield parented to the arms which are parented to the torso.) These 11 animations work in Blender but get turned into 66 animations with random results in both the 3D viewer (which I am using to test this .FBX file) and Unity. So like the title of this post says I want to know why there's 55 extra animations I never made (and some missing) and I want to know how do I fix this problem.

If you have all these tracks in the NLA it is because you've pushed them from the Dope Sheet into the NLA, you can remove the tracks you want by selecting them and pressing X

I am having trouble understanding what you mean, I've selected every strip and pressed X but nothing happened. Really the only tracks I have are the 11 in the NLA editor (excluding empty data I added to make selecting what animations play easier.) The extra 55 are random animations generated, parts are displaced and at random locations and changes made, one of them is literally just an upscaled floating head that takes the place of the torso, sometimes the legs are horizontal and moving like they're arms. Animations I've never made before have been generated and I don't know how.

It's impossible to know how it happened, to remove the tracks you need to put your cursor on the track (not the strip) and press X, to remove the strip select the strip and press X. If you want to use the NLA, select the action in the Dope Sheet (in Action Editor mode) and push it down, don't push all the actions. If you struggle with the NLA maybe follow some tutorials on NLA?

So how do I push it down? Like click and drag it down? Also the only tracks in the NLA editor are the ones assigned to the knight. There's nothing else. However my boss did have me import rover model at some point just so I can see the animations and demonstrate what NLA is to me. Though I have deleted that from the project entirely. Is it possible the NLA strips assigned to the object that doesn't exist anymore still exist in the project and are getting applied to my knight? I definitely will watch some tutorials but I'd need to know what to look up as I don't know what this problem is called

the actions of an object that has been removed still exist but you can't see them, unless you've given them to another object them pushed them into tne NLA. To push an action into the NLA you have 2 possibilities, either select the action in the Dope Sheet (in Action Editor mode) and press on the Push Down button, or press on the down arrow button of the NLA track. If a NLA strip exists it's because it has been pushed a way or another into the NLA, it can't exist otherwise

Ok I think I understand now. So basically the problem I'm having is from the removed object's NLA strips still existing somewhere in my project and because they exist they're getting added to my knight upon export. If that is the case I know how to delete them and push them to the NLA but how do I find the data that? I've basically restarted this because a friend suggested I rig the knight and animate via the bones but currently that has yielded far less results than this, as it seems the animation data for my objects won't export at all when rigged.

the NLA strips will be removed when you'll remove the object they have been assigned to, but the action are still present in the blend file if they have been marked as Fake User (F in front of the action name), you can definitely remove an action by going into the Outliner, switch it to Blender File mode and under Action remove all the actions you want. Is is what you want to do? I'm a bit lost in your problems to say the truth...

Ok here's my problem, that first image is all the animations visible in my .blend file. It's all the animations that I have made/need, all of that works perfectly fine in blender. However when I export it out as is there's 55 animations that I've never made before, there should only be 11 animations, 1 on the head and 2 for every other body part including the torso. If I remove all my animations and rig the model and remake them Microsoft's 3D viewer won't load the model and everything is displaced in Unity. All I need is a way to get only the animations I made out of Blender and into Unity.

do you want to bake what you see in Blender into one action? You can do it in the NLA

That actually might help out, how do I bake in the NLA editor? (Also it would be more like 2 actions, a walking animation and an Idle animation.) Maybe if I bake all of the animations relevant to eachother out as one action before I export it'll fix this problem and if not it'll be far easier to find the relevant animation to use in the mess that has been getting exported out.

I guess you need to mute all the tracks you don't want in the NLA, then in the 3D view top menu > Object > Animation > Bake Action, it creates a brand new action from the actions that are not muted

So without knowing exactly what the cause is the solution is somewhat out of reach, but I think the problem is a mix of different issues that snowballed into one big thing. To quickly go over it, the first issue was a lot of my objects hadn't had transformations applied to them before I started animating which would affect how they would come out on export. I had also imported a mesh with NLA strips to see it's animations and hadn't properly deleted it so there is likely leftover data affecting the project. Finally the animation setup itself was flawed, I had designed the mesh to be animated without the need to rig it, putting the limb's pivot points inside of the torso so I could simply rotate the objects themselves and move them up and down, which on paper sounded like a good idea but didn't work in practice.
However after getting some help from a friend troubleshooting this I can conclude that the best solution is to 1. Revert to an older save before any animations were made and before anything was imported (if you imported anything at all.) 2. Add bones to your mesh and make sure the transformation data is applied before animating. 3. Animate via the bones and not the objects. Following these 3 things should get you a mesh that can be exported out with animation data using NLA strips.


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Specific style using shader editing nodes
I am trying to play with the shading nodes and wondering if anyone knows how I could achieve some sort of airbrushed or styled effect on my renders.
The below image is the kind of style I am after if anyone has any knowledge or insight of how I could get started I would greatly appreciate it!

Still, or animated?

Just a still image, I'm trying to achieve this saturated blurred effect.

For the grainy effect, well actually you could use the Cycles render engine and keep the Sampling value very low, for once you'll be glad to have grains. I don't know if it's doable in the Compositor. You can do it with an image editor (Filter > Other > Random Noise in Krita for example), or fake with your materials with some Noise nodes, like that:

I'm not sure it was part of your question but for the smoke itself, you can create a bezier curve, bevel it, play with the vertices Radius and Tilt values (shortcuts AltS and CtrlT):

Give it a mix between a Diffuse and Transparent node, use a Noise as factor, the Texture Coordinate UV output will allow you to follow the curve shape, use the Mapping node Scale values to stretch the noise along the good axis. In Eevee don't forget to choose Material > Settings > Blend Mode > Alpha Blend so that the smoke is transparent:

Wow so helpful! I will defo give this a try.


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Does Changing F-stop Affect Render Time?
I am rendering an animation. It is taking a lot of time even though it is being rendered in EEVEE. I think is that it is because of the f-stop value being too low.
My question is, does the f-stop value affect the render time dramatically or should I take into account other things as well?

Hello :). Yes, lower f-stop values cause more of your scene to be out of focus, which can lead to longer render times.

Thanks for your reply. I would also like to know how much impact does it have? Like can it increase the time by a 100 times?

Hey :). The impact is rather small, at most a few percent for complex scenes. I don't think it's worth to worry about it too much :).

Have you rendered without depth of field for a qucik check if it gets a 100 times faster? This would be the easiest way to find out if there are other things than the f-stop slowing down your render...

Yes for frames with high f-stop value the render time was around 2 seconds. But where the f stop value was low like 20-30 the render time for each frame was around 2 minutes. I think it was the f-stop value increasing the render time. I couldnt find any other factor


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Image will look broken when using image texture
If you use the E key to apply the image texture to the increased mesh, the image becomes forced to increase width or height.
Resizing the image or mesh deployment in the UV editor will not change anything.

As shown in the attached image, it doesn't matter to change the size of the mesh, but only if you expand it through E key, the texture is broken like that.

You need to manually fix the UV map. Extrude does not modify the UV map...

This is one of the features that has been addressed in 2.9

yea, if you use blender 2.9, the UV should adapt to your extrusions.


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Is There a Good Way to Change Many Joined Meshes in Order to Make One Mesh With No Inside?
I'm attempting to kitbash a number of different models together to make a new one. The problem that I now have a lot of badly joined together meshes. Ideally, what I would like to do is to join them on the correct vertices (So I can do things like sculpting). Also, it would be great if it removed all of the vertices which were inside the model.
Is there anything we can do to do this automatically, like a plug-in or some other  option? Or do I need to do this by hand?

No garantee it will work but you could try to boolean.
First make sure you don't have holes, select all in Edit mode and Mesh > Clean Up > Fill Holes (set the values in the Operator box):

Then select all your meshes except one and press CtrlF > Intersect (Boolean), and again choose the right settings in the Operator box. If the meshes are closed it should delete all inner vertices:


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How to Reassign Input Strip in Blender? (Linux)

I want to recycle my already made transform strip but the program wouldn't let me. I can't find any clear help. Using 'Swap input strip'/'Reassign input strip'/... gives me errors.

I think you can follow the procedure as outlined in this video. In summary, you have to duplicate your original strip with its transform strip attached. Then, change the source of the duplicated strip to the one that you want the effect to be copied on.


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Scale the Skin Modifier on a Specific Axis
I'm trying to learn how to use the skin modifier effectively, and realized that it would be beneficial to understand how to scale the modifier on specific axis, instead of in general, without having to select the radius properties in the N menu. I know that it can be done, based on what I've seen in videos floating around, but I don't quite understand how to do so.
Ive tried doing Ctrl+A + X (or Y) but neither of those had any affect
How do I scale the skin modifier on a specific axis with hotkeys?

Yeah, I see what you mean, when I try so scale on only Y for example, it scales on the Y and the Z. I think it has something to do with how the skin modifier works, because I cannot manually scale on Z axis at all. Could be similar to how you can't scale a flat plane on the Z. I could be wrong, though, I will upvote in case someone who knows more has a better answer.

What version are you using? In 2.91 pressing x/y works for me.

@HISEROD
Im using version 2.91, when i press x, it deletes the vertice or worse, and when I press y, nothing happens

Oh sorry, I meant pressing Ctrl A then (before confirming) pressing x or y.
Btw Blender displays the options at the bottom of the window. (but only the X,Y,Shft,Ctrl keys should be visible for this particular tool. Probably a bug.)

@HISEROD before confirming? I never get the choice to confirm or not, i thought it just automatically scaled, it never brings up a menu or anything for me to confirm

The left click is the confirmation.

What left click? I never get the choice, i just press ctrl a and then the effect takes place

@HISEROD
Sorry I see what you mean now. That actually works perfectly, my issue is that I was pressing ctrl+a+x all at the same time, not pressing ctrl+a and then pressing x. Thank you so much for the help!!

Hiserod in the comments was able to help me
My issue is that I was pressing ctrl+a+x all at the same time, not pressing ctrl+a and then pressing x/y/z separately from that.


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Workbench Outlines not appearing when rendering animation from command line
The "Outlines" feature of the Workbench render engine Properties / Render Properties / Options / Outline provides the expected results when rendering an animation from the UI Render / Render Animation (Ctrl + F12).
Using the command line (for something like blender -b myfile.blend -a with proper paths) on the same file gives a result which seems to completely ignore the outlines.
I tried this with multiple projects and Blender versions 2.80, 2.83, 2.91 & 2.92 alpha on a Linux Mint 19.3 environment, all with the same results.
Searching online for bugs and/or implemented features returned nothing of relevance.
Any information on this? Maybe a setting I might have missed? Or a plug-in interfering?

I ran into the same problem today, and I found a solution by using the OpenGL render in a python script as such:
import bpy

# Most cited way of rendering via python:
#bpy.ops.render.render(animation=True)
# Produces no outline as by using blender -b myfile.blend -a

# Render with OpenGL:
bpy.ops.render.opengl(animation=True, view_context=False)
# Produces outlines as in the GUI

This can be used from a terminal like so:
blender myBlenderFile.blend --python myPythonScript.py

Note however that I omitted the background flag -b due to that OpenGL does not support Blender running in the background. So depending on why you want to render from a terminal this solution might not be valid.
It worked well for me, however. Furthermore, it also resulted in a render speed increase as it seems like it better utilized multiple CPU threads.
"Standard" example where outline doesn't take

OpenGL example where outline works


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Missing textures in linked files using Botaniq/Graswald Addons
I am working on a pretty massive file, therefore I have broken it down into different files, all linked into one main file.
I am using the Botaniq and Graswald addons in most of these linked files.
I have saved the main file which has all the linked data and tried to open it on another machine, only to find the dreaded pink textures of missing files.
Everything else is fine, since I have a dedicated Texture folder. But anything created with the addons just doesn't show up and I cannot for the life of me figure out where Graswald and Botaniq save their texture data.

Likely something set in an addon pref in blender user prefs. Otherwise addon should have their own docs of some kind, but I have never heard of these addons.

If memory serves you have buttons in the panels of these addons that will look for broken data links. Does this help ?

@Gorgious Thanks for the input! Yes, they do. The problem is that is not working, since i am transferring the file on to another machine. So it cannot find the missing files :/ I was wondering if there was a way to get a folder where all the textures from the addons could be stored/found.


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Blender Cycles Render solid black, but works fine in preview
At some moment my scene just stopped rendering, and now produces just a black(blue) solid screen after press F12. Blender version 2.9, tried in 2.8 as well, nothing works.
A couple of days ago all was fine, but then somthing has changed and I have been struggling to find a reason. The scene is quite complicated, got compositing for bloom effect.
I have tried to switch off compositing, gives no effect, all materials on preview look good.

maybe keep only one object of your scene and share the file? https://blend-exchange.giantcowfilms.com/

It is strange, I deleted all objects , created a cube and it works fine... Never heard of smth similar. Looks like there is smth with my render settings or some objects.. Tried to create new cameras and it still does not work


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child objects don't move as expected
My scene has a number of child cylinders that have a plane parent object.  When I rotate the parent (plane), all the child cylinders move as expected - as if they are attached and resting on the plane.  When I try to move one of the child cylinders, it instantly moves off to a seemingly random position.  Not sure what I'm doing wrong.
My .blend file can be found here:

Could you provide a .blend file to be able to help you?

Gladly.  But I see there isn't a way to upload a file.

Forgot I had a dropbox account.  Hopefully you can access it.

I've downloaded your file and I was able to grab and of the cylinders and position it any place I want as shown here http://pasteall.org/pic/index.php?id=110848 what version of blender are you using?

Currently using version 2.78a

Well, I don't understand what happened - I tried myself and the objects are moving as you described - so I don't know if I changed something or if something in the animation has something to do with it.

That appears to be the problem, the animation.  If it is not at frame 1, then it behaves unexpected when I move a parent object.  Thank you for checking into it.

not a problem, I'm glad I was able to help. I've added an answer so if you can accept and upvote it :)

Looking into your file, this is caused because there is an existing animation starting from frame 1.


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Why is my blender file now not rendering the current frame
My file
http://www.pasteall.org/blend/38528
keeps rendering the old image, not the changes I've made. A similar questions was answered at
Came back to a blender file, now not rendering ,
but I can't find where the problem lies.

Did you change a texture by painting? If that is the change, then I know the answer.

I didn't on purpose, but I may have hit a hot key by accident.

was the head rendered as narrow? It's supposed to be wider.

This is the wrong render, the face should be much wider http://www.pasteall.org/pic/94129

I'm running mint. Here, take a look at the wide skull. http://www.pasteall.org/pic/94130

old question, I guess you figured out meanwhile, but here is the answer
You have a shapekey Shin that you must set to 0 :
in edit mode it will show you only the active key that you are editing, as soon as you leave Editmode, the final model taking in account the overall shapekeys mix will be displayed (and rendered in your case)


text:
How to add a checkbox to a pie menu?
I have a simple pie menu and I have it setup to allow the user to change a custom property value. But I don't want the user to have to choose a value, I want it to be an ON/OFF. So I want to make a checkbox and have it shown in the pie menu, then when they select that, it will change the custom property value to what I need it to be. I have tried going through this but its pretty confusing for me. Could someone show me how to do this?
My current code:
import bpy
from bpy.types import Menu

from bpy.props import BoolProperty

# spawn an edit mode selection pie (run while object is in edit mode to get a valid output)

iSight_Camera_Indicator = BoolProperty(
    name = "iSight Camera Indicator Toggle",
    description = "Turns the iSight Camera Indicator ON and OFF",
    default = False
)

class VIEW3D_PIE_template(Menu):
    # label is displayed at the center of the pie menu.
    bl_label = "Macbook_Controller"
    bl_idname = "Object Mode.mc_pie_menu"

    def draw(self, context):
        layout = self.layout

        pie = layout.menu_pie()

        """
        pie.prop(context.object, '["00_iSight Camera Indicator"]', text="iSight Camera Indicator Toggle")
        pie.prop(context.object, '["01_Dirt and Dust"]', text="Dirt and Dust Toggle")
        pie.prop(context.object, '["03_Menubar and Dock"]', text="Menubar and Dock Toggle")
        pie.prop(context.object, '["04_Screen Rotation"]', text="Screen Rotation")
        """

        pie.prop(Macbook_Controller, "iSight_Camera_Indicator", text="iSight Camera Indicator Toggle")

def register():
    bpy.utils.register_class(VIEW3D_PIE_template)

    wm = bpy.context.window_manager
    km = wm.keyconfigs.addon.keymaps.new(name = "Object Mode")
    kmi = km.keymap_items.new("wm.call_menu_pie", "E", "PRESS").properties.name = "Object Mode.mc_pie_menu"

def unregister():
    bpy.utils.unregister_class(VIEW3D_PIE_template)

if __name__ == "__main__":
    register()

    #bpy.ops.wm.call_menu_pie(name="VIEW3D_PIE_template")

Why the linked post is confusing?

I don't understand how to put it into my pie menu...

The boolProperty needs to be registered to a particular type.  In the example below I've associated it with a camera (data) type.
bpy.types.Camera.xxx = BoolProperty()

To assign a property to an Object type would use
bpy.types.Object.xxxx = BoolProperty()

Then all objects in the blend file will have the xxxx property.  Use bpy.types.Scene for scenes.. etc.
I used code from https://blender.stackexchange.com/a/40793/15543 for the keymap, it's mapped to Alt-E
Restrict bl_idnames to lowercase, no spaces, only one period . for example "object_mode.xxxx_yyyy" not "Object Mode.xxxx_yyyy"
import bpy
from bpy.types import Menu

from bpy.props import BoolProperty

class VIEW3D_PIE_template(Menu):
    # label is displayed at the center of the pie menu.
    bl_label = "Macbook_Controller"
    bl_idname = "object_mode.mc_pie_menu"

    def draw(self, context):
        layout = self.layout
        # get the camera, use a poll method to check no cam
        scene = context.scene
        camera = scene.camera.data
        pie = layout.menu_pie()

        pie.prop(camera, "iSight_Camera_Indicator", text="iSight Camera Indicator Toggle")

def register():
    # register the property to a camera (data) type
    bpy.types.Camera.iSight_Camera_Indicator = BoolProperty(
                    name = "iSight Camera Indicator Toggle",
                    description = "Turns the iSight Camera Indicator ON and OFF",
                    default = False
                                            )
    bpy.utils.register_class(VIEW3D_PIE_template)

    wm = bpy.context.window_manager
    km = wm.keyconfigs.addon.keymaps.new(name = "Window",space_type='EMPTY', region_type='WINDOW')
    kmi = km.keymap_items.new("wm.call_menu_pie", type = "E", alt=True, value = "PRESS")
    kmi.properties.name = "object_mode.mc_pie_menu"

def unregister():
    bpy.utils.unregister_class(VIEW3D_PIE_template)

if __name__ == "__main__":
    register()
    bpy.ops.wm.call_menu_pie(name="object_mode.mc_pie_menu")


text:
Kind of asset selector
I'm beginning in blender, addons development
I want to create simple add-ons who's creating some asset
And I got a file with some assets, and I want to present them in a panel like the one in the picture.
I have seen that is created by the function template_icon_view()
But how could I link my file and this panel
Thanks you i'm stuck very hard

    def draw(self, context):
    layout = self.layout

    data = # There is the problem

    # Spawn Button

    row1 = layout.row()
    row1.template_icon_view(data,show_labels=True, scale=8.0, scale_popup=6.0)
    row1.scale_y = 2.0

Are you planning on using images saved on disk, images saved in the blend file, or dynamically generated icons ?

I will use images saved on my disk,
Something like a folder with some images


text:
Faking acurate reflections with an environmet texture on a model with a normal map

So, I've tried making cubemap-like reflections on a model with an environment texture (the ones that come with blender for now).
The sphere on the right has just the regular reflection from the viewport shading.
The sphere on the left is basically the same but with the environment texture imported and layered on top of it.
As you can see, the flat part of the texture lines up perfectly with the actual reflection but the parts that are distorted by the normal map don't match up.
Now, I'm really bad at math, so I'm already glad that I got this close but I still wanted to ask if you can help me get closer to accurate reflections.
Thanks in advance for any reply.
(how do you end stuff again?)
Uh, Love you. Bye.

I believe this node setup can help you. I myself was looking for this exact issue recently, and have stumbled upon this.
This node setup is the same as the reflection vector from the Texture Coord input, with the geometry normal replaced with a normal map node.
The only issue seems to be that it looks wonky from a orthographic view, probably
tied to the camera view and fixable with some other kind of math wizardy.


text:
Step pyramid scale equally?
I am having a problem that I am sure is something that I just don't understand. Very much still learning.
I have this step pyramid (from the "extra mesh addon") and I want to scale the edges in straight to keep the lip but to add an angle faces. See photos
As you can see when I scale it is not equal at all.

Scaling requires an origin point to compute the steps. The closer the vertex is to the origin the smaller the step will be, that's the whole point of scaling.
Thus becoming uneven in this case.
Here we don't really need scaling, what we want to do is "move" the vertices evenly toward the center.
One solution would be to:

Select all the edges as you did before
press "G then G again", it will trigger the "move along edge" feature.
Then move all your selected edge along the corner edge which point to the center of the pyramid

Example:

Thank you. I know I was missing something and I won't be forgetting it for a long time too.

...just because it's fun: Here is the solution for Geometry Nodes:

(Blender 3.1+)


text:
Where are Collections stored from Geometry Nodes?
i am trying to find a Collection that is used from my Geometry Nodes (Collection Info), but it is not shown in the outliner. Where is it stored? Added by an Add-on

AFAIK the collection must be stored in the same blender file as you are working in, for -> so it must one of collections or sub-collections in the outliner. You just need to find it. Or the nodes might be trying to link to a collection that doesn't exist in which case the output of collection info node should be empty.

If the collection hasn't been linked to your current scene, you can find it in the Blender File view of the outliner.
Click on the second button from the left in the top left corner of the outliner, choose Blender File and navigate to the collections container, and you should find your collection there. Then you can either instance the collection in the scene or link the collection to the scene from there using the right-click context menu. Go back to the regular View Layer mode afterwards.


text:
Rendering many overlapping parallel lights
In my situation, I want to render many narrow spotlight all overlapping in mist.

You can see in this image how all the spotlights overlap. The rendering I'm trying to produce is a simulation, and therefore I want to keep the geometry mostly as it is.
I've tried a few approaches:
Use spotlights into a volume
The issue here is that the minimum angle of a spotlight in Blender is 1 degree, which is still too large for me! (My spotlight should be 0.5 degrees)
Blender Render / Volume emit cylinders + Scattering volume

The main issue with this approach is that in areas of very strong overlap, some bits are even darker than background. I.e. where there's lots of light crossing over, the result is shown as dark.
Perhaps the 'emit' object are also casting a shadow.
Cycles Render / Volume emit cylinders

Get a better result (the areas of most overlapping aren't the darkest). But still getting some black parts.
For Blender Cycles, I also tried disabling Ray Visibility settings on each beam object for

Transmission
Volume Scatter
Shadow

but the result is largely the same

Not a real answer, but did you try to apply a boolean to all your objects to avoid intersecting geometry?

Hi Pyos - no sorry i haven't tried yet as it's non-trivial (needs a script to union them all in pairs). And I have the same presumption that it would have an undesired effect (areas of high overlap wouldn't be differentiated in terms of output intensity).

For the Cycles volume emitters, have you increased the number of transparancy bounces to a suitably high value? Could be that you're maximg out on bounces.

@Rich - yes this gives a marked improvement. Thank you for the tip! There's still some visual glitches where too much geometry overlaps (shows as white blotches) but this is a different issue

An idea for the spotlights into a volume - you can get spotlights to less than 1 degree in Cycles by manipulating the intensity of the lamp based on the Normal - similar to this answer https://blender.stackexchange.com/a/80007/29586 but imagine a small circular image instead of the test grid. Taking it further you could use a Dot product node of the Normal with itself to calculate the distance from the centre and to generate a circular spotlamp of any size - instead of using an image. Hipe this helps - can write as an answer but not for quite some time as limited internet connection at moment.

@Rich - that's fantastic! I've been trying to create video projectors in other physically based renderers without success. (I'm still Blender beginner, but feeling the investment of time paying off)

For Cycles volume emitters you need to ensure that the number of bounces in the Light Paths panel is set sufficiently high - otherwise the rays cannot travel through all of the surfaces.

The Transparency Max and Min values determine how many transparent surfaces rays can pass through. Increasing both values will allow rays to pass through more transparent surfaces unaffected.

Specifically Transparency bounces helped, could you mention that in your answer? Thank you


text:
Trying to Move 1 Selected Object in Blender Drags Other Faces It's Touching
If I create or duplicate an object that's touching other faces on objects in edit mode, it drags the faces it's touching with it. This just started happening in the middle of me making a haunted house model. Here's a video with the problem:
https://www.youtube.com/watch?v=YsuNEOsiB40&feature=youtu.be
Any help would be appreciated.

Disable the Proportional Editing button on the bottom horizontal menu bar (a blue sphere icon)


text:
3D Builder won't accept meshes made from Particle System in Cycles Render
Basic Background
So, I was in very early stages of some modeling I was creating as a favor to a company called "Atomz Lab". I was to create and 3D print their mascot (A young boy wearing an atom T-Shirt, holding a graduated cylinder full of a orange substance).
It was essentially something I could add to my portfolio.
But very early on, while I was still working on the basic shape and detail of the head, I ran a quick test, to see if the hair would export like in material mode, or how it did post render.
The Problem
After converting the particle system into a mesh and exporting it as .obj and .mtl files, I loaded it up into 3D Builder, only to find just the head. My hair object was gone. After several other attempts, I finally gave up and decided to post this for answers.
I believe the problem could either be contributed to the limitations of 3D Builder, or that Blender exports converted meshes from hair particles in some sort of format only it can read.
Here's some screenshots:

After exporting the .obj and .mtl files, I opened them up in 3D Builder.
This is what I found:

The hair disappeared!
I really need some help. If any of you know the answer, on how to bring converted meshes into 3D Builder, please let me know.

Hair particle system based hair does not generate actual real geometry, and thus is not exportable by any means. See https://blender.stackexchange.com/questions/57531/fbx-export-why-there-are-no-materials-or-textures You can try to convert to mesh first

Looking at the reference image I'd say it could be better to model that hair via simple mesh without any particle system. This way is often used for hair in some styles of 3d and 2d art, it allows to avoid possible slowdowns of particle system as well.
As to converted particles probably you used Path option as how particles are rendered in the Render layout of the particle system settings.

After applying Particle System modifier they become simple lines (edges with no thickness) which can't be printed because they are non-manifold geometry.
One way is to make that geometry manifold is to solidify it using Skin modifier on converted particles.
Select object with converted particles (note that you might want to leave particle system undeleted but hidden in case some changes are needed).
Add Skin modifier to it. By default modifier will solidify only one of converted particles because it marked a vertex as root for only one edge while it needs one root vertex for all the connected pieces of geometry. As per manual:

Mark Root
      Marking a vertex as root causes that vertex to be used for calculating     rotations for connected limbs. [...]
      Each set of connected vertices should have one root node.

The easiest way to mark one vertex for multiple edges of the converted particles is to enter Edit mode, select all and press Mark Root button. It will find one vertex itself to mark so no need to deselect anything.
Once done all the particles will have thickness and become manifold, all-quads geometry. Make sure to apply modifier if exporting mesh.

Another simple and working a bit differently solution is to
set Object as how particles are rendered in Render rollout instead and give it some thin and long cube as object to be used as hair particle to make particles based on it. See underlined option on the 1-st screenshot, change it to Object and choose cube you created. No need to make follow it anything, it will be done automatically.
Make sure to rotate base mesh accordingly so it's oriented accordingly (e.g. outside of the mesh, typically you will need to rotate it along X axis).
This way is less flexible and gives slightly different result as it doesn't allow e.g. Brownian Motion setup to change particle orientation along its local X and Y axis, only along Z, and other options which allow to randomize  particles.

Okay, so about the Object hair particle. How do I do that? I made the thin cubes, but I could only select one. I made them a group and swapped to group, but the hair still didn't follow the cubes in any consistent matter I could find. I even created a bezier curve of the hair, converted to mesh, joined the vertices, made a face, and extruded them out.When I selected it, it just made a really weird hair style that didn't even fit on the sphere. None of my courses covered mesh hair, so I haven't the slightest clue on how to use them. YouTube isn't much help, either. @WKG

@DanielEverhart no need to select more than one cylinder, one is enough for particle system. I added some details into the answer for this method and added another one with Skin mod.


text:
Blender 2.79: Issue with Texture Painting
The previous model I did had no issues with texture paint, it worked normally, but this time. . .not so much. I've looked through other solutions on here and various websites but I can't seem to fix it.
I've already:

Unwrapped and created an UV Map
Set up my nodes (crtl + T and Shift + crtl + click for textures) and
hooked up my UV map to the Image Texture node. Made sure everything
to the left of that node was set up appropriately. Followed a tutorial to
make sure this was right
Made sure the texture in Tools tab in Texture Paint is off.
Checked slots tab and made sure everything was set up fine.

I can still paint directly on UV Map and when I try to fill the 3D model itself, nothing happens. The oddest thing that just cropped up is that when I paint the UV Map, the preview area becomes completely white. Never had that happen before.

Blender file here.
Any help would be greatly appreciated as I've been trying to fix this for the past day with no luck. I'm also working with the top half, the human half, only.

It worked fine for me. I saw two problems, You have 2 materials applied one with nothing connected to the material output and another that you have only the viewer node on. I would just erase both materials and start over. Go to uv editor create new Image to paint on to, then make sure Image Texture node is highlighted before going into texture paint mode.

What do you mean by "2 materials applied one with nothing connected to the material output and another that you have only the viewer node on"? Also, I have reset and started over twice today and several other times yesterday with no success. As for the last bit, didn't help either. ^.^"

Found the problem area (due to some help on another forum), which was a slight overlook:


text:
Modelling a mechanical spring for a bike
I am currently modelling a bike based on a Norton 961:

I struggle with modelling a proper mechanical spring. It should look like this, I think:

I really don't know how to make it look flowing and natural and having enough "layers".

See https://meta.stackexchange.com/questions/75491/how-to-upload-an-image-to-a-post on how to upload images and use that facility please, as great part of your question depends on them and if they go dead so the question with them

Activate the Add Curve: Curve Extra Objects addon in the user preferences if you haven't yet.
Then just add a new 3D object with Shift + A Add > Curve > Curve Spirals > Logarithmic or Archemedian in you prefer.
Adjust the desired height and number of turns as required.
Adjust curve bevel factor from the Properties Window > Object Data (Curve) as desired and set the Fill option to Full.

You can then manually add the "flat" end loops manually by joining in a bezier curve circle object afterwards in Edit Mode.


text:
Blender 2.79b (and RC 2.80) require opengl32.dll be present before Blender will open (Windows 10)
Blender 2.79b and 2.80 does not load unless I place the opengl32.dll file in the Blender directory. I've gone through all of the drivers I know to update but still no luck. Even placing the opengl32.dll file in the directory does not allow me to load previous .blend files.
Windows 10 Home
V 10.0.18362
i7-8750H CPU @ 2.20GHz, 2208 Mhz, 6 Core(s), 12 Logical Processor(s)
NVIDIA GeForce GTX 1050 Ti
Update on 7/19.
Went to Nvidia website (thank you) and downloaded the latest driver. Ran the blender_debug_gpu cmd from 2.80 with exactly the same result. The results:
Switching to fully guarded memory allocator.
Blender 2.80 (sub 74)
Build: Thu 07/11/2019 09:59 AM Windows
argv[0] = blender
argv[1] = --debug
argv[2] = --python-expr
argv[3] = import bpy; bpy.ops.wm.sysinfo(filepath=r'C:\Users\xxxxx\AppData\Local\Temp\blender\debug_logs\blender_system_info.txt')
read file
  Version 280 sub 39 date unknown hash unknown
Error   : Unrecognized Exception
Address : 0x00007FFC3FC7A839
Module  : C:\WINDOWS\System32\KERNELBASE.dll

This is a new computer so I'm almost to the point of returning it if I can get this figured out. Thanks for everyone's help.

are you trying to use a 32bit build? Try a 64bit one.

Using 64-bit build Tried 32-bit with same result.

Copying/Moving .dlls around is very, very wrong. When you say it doesn't run, are there any errors displayed? In the install directory of 2.8 you should find blender_debug_log.cmd. Please run this to create a debug log and add the results to your question.

@rjg "Copying/Moving .dlls around is very, very wrong" pasting opengl32 dll file into Blender directory is not wrong, it is recommended way to diagnose if problems are caused by graphic card (or its absence / unavailability).

@MrZak My bad, yes the softwaregl test using (https://download.blender.org/ftp/sergey/softwaregl/) is valid. I thought he has moved it there from somewhere else on the system. Looks like OpenGL can't be found or not in a suitable version. I'd take the following steps to see what's wrong 1) In case you haven't already updated the driver of your graphics card, update it https://www.nvidia.de/Download/index.aspx?lang=en  2) If that doesn't work start Blender using blender_debug_gpu.cmd and look for errors regarding OpenGL (post updates) 3) Repeat the previous step but with the softwaregl.

Updated the entry. No change with updated graphics driver and running the blender_debug_gpu.cmd. Exact same text output.

@Tom is your graphics card working/detected by the OS? Please run dxdiag.exe (either by opening a command prompt or searching for it the start menu) and check the display tab. Does it display your GPU and/or any errors?

Really appreciate the help @rjg. I figured out the problem. After running dxdiag it did not show any reference to my Nvidia graphics card. A couple of USB devices but that's it. Then it dawned on me that I am using a USB docking station so I can have multiple screens. For whatever reason, it wasn't accessing the graphics card. Once I unpugged the docking station I was able to start up Blender without any problem. I have used  the docking station successfully in the past with other laptops so I'll have to sort through how to fix that. But Blender is working A-Ok! Thanks again for the help.

@Tom You're welcome. Glad I could help.

And for future reference - the issue appears to be a Windows 10 bug. I had to Disable the onboard Intel graphics card to force Windows to use the NVidia card. This solved the problem:  https://support.plugable.com/t/ud-3900-and-nvidia-geforce-920mx-with-hdmi-connection/11183

@Tom You can post this as an answer to your own question. It makes it easier to find for others with a similar problem.

I had the same problem. Here is how I solved it.
The PC has two graphics cards: one built-in Intel and one NVIDIA. By default, Windows (10-pro) recognizes and enables both. However, Blender default will work only with one of them. If you happen to use the other one instead, then Blender will close on start up.
Solution: Disable the graphics card which you are not using. Blender will go with the other one. It should work.
(Actually my experience is with Blender 2.90.1. Blender closes/crashes on loading/start up)


text:
Select only backfaces?
Is there any way to select only backfaces in edit mode in blender? When editing models for mods/games I've noticed a lot of the time there are double vertices for faces, and because of this simply recalculating normals doesn't always fix backface issues. It would be much faster than enabling backface culling and selecting every face if there was some automatic way to do this, is there?
EDIT: Sorry guys, my question was not super clear. I would remove doubles from the model but the way the model is made there are some vertices that overlap so certain parts of the model are "loose parts." If I remove those vertices the model won't work properly with the animations.

Welcome to the site. I'm confused with your question as whether are you going to select back faces of a solid model (located on another side of the mesh) or faces with normals orienting inside and located in the same place as faces with normals orienting outside. From "double vertices for faces" part it seems to me you should try selecting all and W > Remove Doubles

Not sure to understand the question, but it could be about selecting faces having similar orientation (normal). To do that, select a face and use Shift+G then "normal" or "coplanar". Once done you can tune the selection in the operator panel (threshold)

You could select front faces and invert selection then. The Limit selection to Visible button in the header should be your friend here.

@Tiles Yes THANK YOU. This is exactly the solution I needed, I didn't realize such a button existed. If you post this response again as the answer, I will put it as the solution so you can get points.


text:
Getting the curve modifier to work
I have been using Blender for about a year and I sill don't know much. I was recently messing with the curves and watching tutorials when I stumbled into something weird. When I added the curve modifier to my shark and binded it to the curve the shark turned into a whole new shape, and when I tried shrinking it, but then my shark was 2d. If anyone knows anything please help me.

Actually I got it to work by redoing the curve, but I ran into a different problem.

The secret to following curves is to ensure both the shark and curve share the same origin point.  Also using CTL-A on a rescaled object can cause distortion problems.  Best to try it without this first.

Possible duplicate of Problems with Curve Modifier

https://blender.stackexchange.com/questions/64579/why-does-adding-a-curve-modifier-move-my-object-to-the-center-of-the-curve also https://blender.stackexchange.com/questions/51909/mesh-deforming-when-add-bezier-modifier

please share your file: https://blend-exchange.giantcowfilms.com/ when an object has a Curve modifier it's deformed. Also, perhaps your curve vertices have been twisted or scaled, in that case select them all and alt T, and W > Set Curve Radius

Thank you I figured it out, i just deleted and re-did the curve


text:
How do i set a object with particles to the background and keep another object in front in composition?
Hello guys iv got a sphere that has particles (stars) and im putting some blur on them how do i set that image as a background? and keep the ship in front of it ?
the particle system is connected to the sphere the ship is inside of it and the camera is too. the particle system is on another layer. im rendering them separately and in the compositor view adding blur to the stars.
the ship is not a single object.
id like the stars not to be visible in front  of the ship. as seen in the render view (bottom left)
And my plans are going around the ship with the camera.

is there a reason you didn't position the spaceship in front of the sphere?

or make your sphere bigger so both the ship and camera are inside it.

Assuming your rendered image has an Alpha channel then simply change the last Add node in the chain to ‘Mix’ and use the Alpha as the Fac. This will mix between your shapceship and the stars based on the alpha.
Note that if you don’t have an alpha (if you haven’t rendered with transparancy enabled) then you can use the Depth as a filter instead as it will be very high for points on the background behind your spaceship (1000000000 or similar - effectively ‘infinity’) and much lower for points on it - pass the Depth through a Greater Than maths node to compare it with, say, 10000000 and the output of that can be used effectively as an alpha.

This resulted in a final solution (from @IvanVujacic) as follows :

Thx the alpha tip helped. i noticed after adding the alpha to the factor in the add node the stars were visible only on the ship so i used a invert node and in the end the stars were only visible around the ship. i needed them on separate layers because i was adding blur to the stars and making thme + shape. a mod deleted my old msg...

Thanks for the feedback - glad to help. I’ve edited the question to include your image.

A simple way is to create a very large sphere and place your camera inside the sphere.
You could put the star field on a plane and place that behind your main scene. This implies you have made an image out of your particle system.
You could also consider setting a star field as a world background. This also implies that you have made an image out of your particle system, but you should also be able to find suitable images (check the licence for allowable uses) on the internet. There are some HDR images out there for star fields.

the particle system is connected to the sphere the ship is inside of it and the camera is too. i should add that to the question.


text:
Blender 2.91 - Half of my objects are not appearing on render
I've been setting up my scene and tried to render to check how the noise looks on the sunbed. Render looks like a total disaster - resolution on moon surface is way worse than it should be (displace is set to 7 on render and 5 on viewport), my glowing guy and the sunbed just vanished.
Have no idea what's going on, all objects are checked to appear on render.
pics:

rendered in cycles
EDIT: I checked every possible cause in the answer and it didn't change the result. My question is about not rendering certain objects and rendering lower resolution moon surface than in viewport even though it's set to higher.

How to upload an image to a post

https://blender.stackexchange.com/questions/53632/render-result-is-completely-blank

Seems like the surface of the moon is inflated in the render. I suspect it might be covering the other objects. There is probably something wrong with displacement. If you shared the file, it would be a matter of seconds for pretty much anyone here to determine the problem and provide you with a solution. You did not share the file however.


text:
DecalMachine problem with decal creation

When I try to create decal this error appears.
How can I fix it?

Ask the creator of the addon? - It's not built in to Blender.

Same issues, did u solve it


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Can I add transparency to a joined object?
I used the 'join' function to make a large object (made up of many smaller objects with their own materials)
Now I want to do a global transparency although the only way I can find so far is to go into each object and adjust the alpha blend manually for each one. Surely there's a better way!?
Can anyone help with this?

I don't believe there's a way to batch edit the materials, but if you don't have many reflections, you could try using compositing. If you add the (large) object to its own view layer you can mix it back with the original and change the factor to change its "transparency."

Thanks Tim. Some of the materials do have reflections, although (on reflection) I guess I could just render the object as it's own layer and use the opacity setting in premiere..


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Normal Bake Problem
I have this wierd problem. My mesh is clean. dont have double faces and my normals are correct and blue. and the problem is just on first picture. The rest of the model is correct!!!

this is a picture of wired normals in that area of weapon. dont know how to fix that.

hello, maybe share your file? https://pasteall.org/blend/

@moonboots sry. its for a project and need director premision.

share only the part with the problem

@moonboots sure. I will split this and share it as a blend file for you just tell me where can i share this.
and I posted new picture of my problem. a picture from normals on this post.

Problem fixed.
It was not mesh but UV problem. My UVs overlapped.

oh ok, great then....  ;)


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Creating a transparency mask using a texture and blending with shaders
I want to give my ship's wings a kind of glitched holographic effect using a texture. I'm struggling with making a mask with a texture and making it so that the texture only affects,

The blue part of the wings
Only affects the edges.

I've tried just creating a simple gradient transparency using a color ramp with mapping+coordinates, but I think since the blue and white stars are separate shaders connected to a mix node with a color ramp controlling the factor it's not giving me the results I want. I'm not sure how to go about this though?

Here's how the wings look now and a concept of what I have in mind.

And here are my nodes

Use a gradient to control the mix of textures https://blender.stackexchange.com/questions/45866/making-vertical-gradient-then-make-top-half-transparent and https://blender.stackexchange.com/questions/199669/linear-environment-gradient/199814#199814

I think I can point you in the right direction.

You need to define a wave texture and apply it along a gradient, so we'll need a wave texture node, and if you use a separate XYZ node you should be able to find a direction that gives you the gradient you need.  For this object it's the Z axis.

I'm going to use a Color Ramp to invert the Z gradient and give us a little more control if we choose to exercise it, a Math node to bump up the value, and then subtract out the wave texture.  I've clamped the last operation, but maybe it's not necessary.

If we use this map as the factor of a mix shader between the blue emission and a transparent BSDF, we can assemble the rest of your shader behind it and we get very close to your desired effect.

From here I think you can find something you like.  The way I chose to do this was to animate a 4d noise texture mixed into the coordinate space, and then move the minkowski voronoi texture along the Z axis.


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Blender Batch Rename Collections not working?
i want to Batch Rename multiple selected Collections. But it does not work. I get a message "Rename 0 Collections". With Objects it is working fine. What am i doing wrong?

You appear to be trying to replace 'Vase 1' with 'Vase 1'.  That would result in 0 renames.  Did you mean something else?

Cursor should be in the outliner then you press Ctr+F2, so that Blender knows, that you want to run this command in the outliner, not in the 3D viewport.

IDK if your hotkey is set differently but I think the default shortcut for batch rename is Ctrl+F2. Alt+F3 does nothing for me.

Yep. thanks for pointing that


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Manipulate camera track motion
I'm jumping from motion tracking in After Effects to learning motion tracking in Blender, and I've run into a problem.
Following this tutorial (https://www.youtube.com/watch?v=lY8Ol2n4o4A), I've tracked my handheld footage and placed a camera into the scene. The camera is moving around the scene perfectly.
I want the camera to stop moving at the beginning and end of the shot. How can I do this?
In After Effects, an object with the tracked motion applied will have transform keyframes that can be manipulated. However, in Blender, it looks like the transform keyframes (Object Properties tab) are separate from the tracked motion applied on the camera.
Essentially I want to animate the camera, then have it follow the tracked handheld motion, then back to being animated. I assume the only way to do this is to remove the handheld motion at the beginning and end of the shot.

I found the answer:
Camera > Animation > CameraAction
Object Constraint Properties tab
I keyframed the Influence value, setting it to 0 when I wanted the handheld motion turned off.


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Remapping specific textures in same material
I've downloaded a photogrammetry model of a street. I want to use this tutorial to add puddles to the street (https://www.youtube.com/watch?v=oojlF0m8KSE), but because the texture mapping is all over the place, the puddles don't show up neatly (texture below).
Is there a way to remap JUST the puddle texture to map flat across the street? So the two textures can neatly comp together?
Thanks!

You should just use a second UV Map. Like this

Yes there is a way.
You can have 2 UV maps.
go into the object properties of the terrain and add a second uv map -

now select the second uv map and unwrap it in the uv editor in a way that would make it easy to add the puddle but would probably break the textures.
(you don't need to unwrap the whole model, just select the mesh you want to put a puddle on.)
Now create / get the texture you want to overlay on top. and replace the original picture with a node tree matching the following -

this works like adding a layer in photoshop or gimp or any other image editor for that matter.
Notice how in the puddle texture i set the third option to clip instead of repeat so you don't have a bunch of puddles.
example usage of this node setup -
if i set the top texture to this

and the bottom texture to

i will get the following image with the smiley face layered on top -

So set each image to use a different uv map and you're in business

Thanks for the response!


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How to change the edges lines in edit mode after smooth?
I am using Blender 3.0.1. I created a humanoid model.
I used subdivision surface to smooth the whole model. Then I want to edit the model again after the smooth. But in edit mode, the lines are still in poly (before using subdivision).
My question is how can I change the "edit mode" lines into the smooth surface model???

You need to apply the modifier first.

Please clarify your specific problem or provide additional details to highlight exactly what you need. As it's currently written, it's hard to tell exactly what you're asking.


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how should I install blender Shelfy add on?
I have been using maya for sometime and I found that they have something called shelves, you make a shelf and you add buttons that you use regularly in it.
I found a add on called Shelfy and I tried to install it.
I downloaded the zip file and extracted it from this repo https://bitbucket.org/cgarhivator/shelfy/src/master/
I opened blender 3.1.2 and went to edit -> preferences -> Add-ons and I installed it by pressing install and choosing the __init__.py in the directory.
I then searched on shelfy in the community Add-ons and found "3D view: shelfy addon" and I enabled it

still shelfy still doesn't appear in blender view port I would be happy to know where I went wrong.

Don't unzip the file.  Blender does that for you.  Install from the zip file.

Author of "shelfy" here, im glad someone is using it (i hope you made it work) Btw, im working on new version which will be much more user friendly, stay tuned

Don't unzip and select the __init__.py
Just select the zip file and click "Install Add-on". That will install the addon successfully