How to create an arch with bridge edge loops consistently

Edit: This is now a confirmed bug: Bridge Edge Loops operation has inconsistent results

You need to duplicate the objects in Object Mode and join them.
Duplicating them in Edit Mode gives weird results.

Duplicated in Object mode and joined. Works as expected.

Duplicated in Edit Mode. Gives weird results.


Blender Python - Call function when face is newly selected in edit mode?

I couldn't find a way to do this. So I presume there isn't an easy way. But the next best thing is to do add a keymap that triggers when MOUSESELECT is pressed. Here is an example of that.

# store keymaps here to access after registration
addon_keymaps = []

def register():

    # handle the keymap
    wm = bpy.context.window_manager
    km = wm.keyconfigs.addon.keymaps.new(name='Object Mode', space_type='EMPTY')

    kmi = km.keymap_items.new(ObjectCursorArray.bl_idname, 'SPACE', 'PRESS', ctrl=True, shift=True)
    kmi.properties.total = 4

    addon_keymaps.append(km)

def unregister():

    # handle the keymap
    wm = bpy.context.window_manager
    for km in addon_keymaps:
        wm.keyconfigs.addon.keymaps.remove(km)
    # clear the list
    addon_keymaps.clear()`


How do I render image only without shading

It looks to me that what you were trying to eliminate was the apparent 'lines' in the mesh, and that might actually be a matter of applying 'shade smooth' to the mesh before render. The geometry will show like that if there is no smoothing, regardless of renderer used.


Are there more standard patterns besides diamonds which will preserve quad only meshes?

Usually one can catch such topologycal tricks by watching
the vertices (poles) neighbour count. In your example there
is a cube which has one vertex with 5 neighbour and another
with 3. The following example shows one where these poles
are neighbours. As Hount House notet in his comment,
sometimes they are called N-poles and E-poles.

When avoiding triangles, you can reduce or increase edge amount
somewhere by the cost of doing it somewhere else. In your example
on the same side you loose one and another edge. In my example I
added a new edge in the right side, and had to redirect the loop
Flow to the top. When simply removing an edge loop, you take
one edge from one side and one from the front side.

Generall, when using only quads on manifold meshes, every sub-mesh
of it (for example strangly subdivided planes like these) must have
even number of border edges (only one face connected). So a hole
with odd number of edges cannot be filled with quads.

Maybe I am getting too wild now. I am currently
working on a trees retopology, where you can see,
that I mostly only have the usual poles or E-poles.

A similar example to yours (two edges taken
from bottom side), but with another loop Flow:

Must note the tutorial in this related
question. I Recommend to watch all episode.


I found a CUDA driver for Mac's on this site of NVIDIA

This solved the problem.


You could use the Follow Path constraint to do it the way you want.

Here is the procedure:

First, create a Bezier Curve, and place it along the object's local Z axis (in your exemple, the Cube).
Next, reset the camera position (ALT G)
Then add a Follow Path constraint to the camera, select the "BezierCurve" for the Target, and tick Follow Curve, as well as Fixed Position. Choose -Z "Forward axis" and Y for "Up axis".
Finally, parent the curve to the object.

The camera is now dependant of the position and rotation of the object (the cube), but you keep the ability to rotate the camera freely, while the animation curve is a single control: the Offset setting in the Follow Path constraint panel of the camera.

And, even better, when you reset the rotation of the camera, it should always points towards the object!

Here is the result:


copy linked materials nodes to local material

So I finally made it myself again after several hours of playing with the code (see I am actually FLASH ActionScript2 guy so it took me like 2 weeks to understand syntax of Python, its objects etc. and get used to it but now I have fully working script!!!).

The right solution is this:

# ...some quite long code here and now:
for r in _mNews.links:
    _mOld.links.new(_mOld.nodes[r.from_node.name].outputs[r.from_socket.name], _mOld.nodes[r.to_node.name].inputs[r.to_socket.name])


Anyone know why my reflection is appearing noisy/weird

Without looking at the nodes for the floor it's hard to be sure, but it looks like you gave the floor material a little bit of Roughness, which creates noise that becomes "blotchy" when the Denoiser tries to fix it.
Options you can try:

Set Roughness to zero (unless you really really wanted it)
Increase the samples of your render (if you can wait)
Stop using the built-in denoiser and use the compositor Denoiser instead (if you can't wait AND need the roughness to stay the way it is)


Select objects in a specified region with python

Look into this answer, as it is similiar.

My example will handle an XYZ bounding box with perpendicular edges only. Otherwise look into batFINGER's suggestion.

object_matrix_world
to_translation

Paste the code into Blender's Text Editor and press "Run Script".

import bpy
from mathutils import Vector

# checks if a supplied coordinate if in the bounding box created by vector1 and vector2
# vector_check           the vector which is compared against the bounding box
# vector1                     the vector defining the start of the bounding box
# vector2                     the vector defining the end of the bounding box
def IsInBoundingVectors(vector_check, vector1, vector2):
    # if vector_check is either bigger or smaller than both other, it does not lie between them
    # in that case it won't be inside the bounding box; hence return false
    for i in range(0, 3):
        if (vector_check[i] < vector1[i] and vector_check[i] < vector2[i]
            or vector_check[i] > vector1[i] and vector_check[i] > vector2[i]):
            return False
    return True

def SelectObjectsInBound(vector1, vector2):
    # deselect all
    bpy.ops.object.select_all(action='DESELECT')

    # cycle through all objects in the scene
    for obj in bpy.context.scene.objects:
        # check if the object is in the bounding vectors
        # if yes, select it
        # if no, deselect it
        if(IsInBoundingVectors(obj.matrix_world.to_translation(), vector1, vector2)):
            obj.select = True
        else:
            obj.select = False

SelectObjectsInBound(Vector((0, 0, -5)), Vector((10, 15, 15)))


You really only need to use a color ramp node, but I have added some math nodes to control the contrast. Instead of these you could use a Color Curve node.


i have 2 textures, how can i turn one the textures on and off?

One simple method is to add a Maths 'Add' node between your texture and the color ramp. This allows you in set an offset to the texture to raise or lower it so it's more towards one texture or the other - ie, negative values will be more one texture, 0.0 will be an even mix, positive values will be more of the other texture (with larger values pushing the mix more in that direction).


how to vertex parent an object to a quad face and not a tri?

You don't have to "make tris" (if you meant divide your quad), you just need to parent to 3 of the 4 vertices of your quad. Your object will rotate, but it will only follow 3 vertices.


Is it possible to get a wide camera shot without warping?

In both the physical world and the computer modeled sense, yes.

While it is vastly more complex to achieve it with a physical camera, it is possible with precise optics. The term typically is referred to as rectilinear distortion when it is unintended. Unintended because some lens optics are designed to deliver a spherical image such as fisheyes, while others deliver cylindrically compressed imagery such as anamorphic.

In the case of your question, it is unclear whether you are referring to physical optics, which may suffer from rectilinear distortion, or computer generated work, which will only have perspectival distortion typically.

In the simplest of senses, the field of view is a byproduct of lens length with gate size.

So while it is tricky judging your desire from your question, you can achieve your goal from within Blender by adjusting your field of view and your gate / sensor dimensions.

Remember, optics are optics and a wider lens with a smaller gate size will exacerbate the perspectival vantage. Longer lenses will compress the perspectival components. To disable the perspectival aspect, you could also consider an orthographic camera.


How do you get an object's position and rotation through script?

You can access an object's transformations through the relevant properties (location, rotation_euler -  for Euler XYZ rotations, and scale) this way:

>>> object.location
Vector((-2.609607696533203, -3.618044137954712, 1.8581657409667969))

>>> object.rotation_euler
Euler((-0.6668576598167419, 0.697817325592041, -1.8853096961975098), 'XYZ')

>>> object.scale
Vector((1.2768771648406982, 1.4246054887771606, 0.6418209075927734))

Do note though that these values represent the object origin. If your origin is not at the center of your object, you might get unexpected location values.

Move the origin to the geometry (Ctrl+Alt+Shift+C > Origin to Geometry) first on all your objects to avoid this.

Or pythonically:

bpy.ops.object.select_all( action = 'SELECT' )
bpy.ops.object.origin_set( type = 'ORIGIN_GEOMETRY' )

On a more general note though, I'd like to mention some great sources for documentation and examples for Blender python scripting that will help you find answers more quickly next time (since finding object location and other transformations is probably one of the most basic and best documented things you can do in scripting, I'm assuming you're not familiar with these sources):

Blender API official documentation (with useful search bar)

Scripting quickstart document

Blender python scripting Code Snippets and Cookbook


Is there a hot key that automatically makes a group of vertices into a circle?

You can also use the To Sphere function for that.
When used with a 2D mesh it makes a circle.

Mesh > Transform > To sphere
Shortcut: Shift+Alt+S and press 1 for a full circle.


Import coordinates from CSV and create sphere at each position

It has been a while since I have done any scripting, but the below should work based on your description. Note that the CSV file I made for testing included a header row, and the creation of objects for ease of testing was bpy.ops.mesh.primitive_uv_sphere_add()

bl_info = {
    "name": "Blank1",
    "author": "Your Name Here",
    "version": (1, 0),
    "blender": (2, 79, 0),
    "location": "View3D > Tools panel 'T' > Blank1 > Blank2",
    "description": "",
    "warning": "",
    "wiki_url": "",
    "category": "",
    }

import bpy
import csv
from bpy.types import Operator
from bpy.types import Panel

class MeshGenTool():
    @classmethod
    def main(cls, context):
        scene = bpy.context.scene
        objs = importCSV(scene['CSVFile'])
        for obj in objs:
            bpy.ops.mesh.primitive_uv_sphere_add(size=obj[1], location=obj[0])
            MyMesh=bpy.context.object
            MyMesh.name = "MyMesh"

class MeshGenButton(bpy.types.Operator):
    """Execute generation"""
    bl_idname = "object.simple_operator"
    bl_label = "Generate"
    def execute(self, context):
        MeshGenTool.main(context)
        return {'FINISHED'}

# This is based on CSV file having a header row with the descriptions 'x', 'y', 'z', 'd'
def importCSV(CSVFile):
    obj_loc = ()
    obj_dia = 0
    obj_data = ()
    objs =[]
    with open(CSVFile) as csvfile:
        reader = csv.DictReader(csvfile)
        for row in reader:
            obj_loc = (float(row['x']), float(row['y']), float(row['z']))
            obj_dia = float(row['d'])
            obj_data = (obj_loc, obj_dia)
            objs.append(obj_data)
    return objs

class VIEW3D_PT_Blank1_Blank2(Panel):
    bl_space_type = 'VIEW_3D'
    bl_region_type = 'TOOLS'
    bl_category = "Blank1"
    bl_context = "objectmode"
    bl_label = "Blank2"

    def draw(self, context):
        layout = self.layout
        scene = bpy.context.scene
        row = layout.row()
        col = layout.column(align=True)
        scn = bpy.context.scene
        col.label(text="Blank2")
        col.prop(scene, "CSVFile")
        col.operator("object.simple_operator", text="Add items", icon='MESH_ICOSPHERE')

def register():
    bpy.utils.register_class(VIEW3D_PT_Blank1_Blank2)
    bpy.utils.register_class(MeshGenButton)
    bpy.types.Scene.CSVFile = bpy.props.StringProperty(
        name = "CSVFile",
        description = "Path of CSV File to read from",
        default = "",
        subtype = 'FILE_PATH')

def unregister():
    bpy.utils.unregister_class(VIEW3D_PT_Blank1_Blank2)
    bpy.utils.unregister_class(MeshGenButton)
    del bpy.types.Scene.CSVFile

if __name__ == "__main__":
    register()


Change Object Relative Position to Origin

There are several ways of changing an object's origin to a specific place.

Place the 3D cursor where you want the origin of the object to be.  This can be done by either modifying it's position directly under the 3D Cursor roliout of the N toolbar in the 3D view, or by selecting something and pressing Shift+S > 3D Cursor to Selected.   Then select the object and hit CtrlShiftAlt+C > Origin to 3D Cursor.
You can set an object's origin to the world origin by applying its location with Ctrl+A > Apply Location.


Camera view range [Clip start and end not working]

Cameras have their own clipping, independent from the view.


Refraction bending with planar surfaces in Cycles (2.78b)

On first look it might seem that refraction on planar surfaces will not distort the image, but just linearly bent it or zoom it:

In real world there are very few examples where the distortion is clearly visible, one of them being refraction on water level:

(Thanks to @RichSedman for pointing this out and patiently making me dig deeper to find the truth and how it works.)

Refraction follows the Snell's law. This means that for every IOR value there exist a critical angle after which the ray won't be refracted but reflected:

We can see this in the above pictures, where the refraction is surrounded by the reflection of pool or sea bed. We will return to this (in Cycles) later. What we also see is the distortion of those refracted rays, so lets tackle the distortion first:

It's best to start with reflection analogy. Reflection is much simpler - the angle of incidence is the same as angle of reflection - their relationship is linear (unlike with refraction). By tracing the reflected rays, we can construct a single(!) virtual viewing point B, from which we see the reflected image:

Doing this with refracted rays (and drawing them in CAD with Snell's formula) reveals, that the rays do not intersect into a single virtual viewing point, but into infinitely many of them (because the relationship between incidence angle and refracted angle is not linear). This means that every piece of the refraction we see from different perspective and that is the reason for the distortion (every 2 rays create a virtual viewing point in different location):

Now let's see how this behaves in Cycles - left how it changes with distance to camera (single refractive quad with IOR 1.3) and right how it changes with IOR (1.0 to 2.0):

This is physically correct behavior. By knowing this you are now able to create a panoramic fish-eye lens camera from simple perspective camera and a refractive quad (if the engine can do refractions but has no such camera option:)

But what Cycles doesn't do on it's own is to change the ray from refractive to reflective after the critical angle just with the Refractive shader (naturally) - it is just black. For this there is the Fresnel node that after the critical angle gives 1.0 mixing factor to mix in Glossy shader:

The glass shader has all this already build in.


You can use a conbination of Mesh Deform and Cloth simulation with proper settings.

Create a grid plane to cover the whole net;
Add Cloth Simulator to it, then Solidify modifier;
Tweak settings of them;
Add Mesh Deform modifier to the net object. (use higher Presision value if necessary, then Band)
Then play or bake the final shape. Delete the grid mesh (optional).

Example File


Have blender automatically monitor textures for changes?

Blender doesn't have this kind of feature (or at least I never heard of it). A quick google search however brought this as a result:

External Paint Autorefresh

I haven't tried it but it surely sounds interesting...


A mixamo animation, in order to work, has to share the same exact names between its channels and the bones of your rig.
In order to work well as expected the rotation rest pose of your rig should be the same as the rotation rest pose of the original Mixamo rig.
If this is not the case you have to perform a "retargeting", which is too complex to explain in a short answer (there are tutorials, addons, end even manual procedures to perform).
When you reach theese conditions you can stack the mixamo animation on top of your previous animation with the NLA editor, turning off or overwriting the arms channels on your animation and turning off (or deleting) all non arms related channels in Mixamo animation.


How to check if Blender is installed on computer

You are talking about windows machine, I suppose.

The answer is here: Detecting installed programs via registry

The only thing specific to Blender is what to look for in registry:

HKEY_CURRENT_USER\Console\paths_to_blender_executables - you will find here entries for ALL Blenders (versions installed or only executed from .zip archives). There is no assurance that Blender is still on the system though, just that it was in some point in time
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts.blend - here is the Blender reference to .blend file. Also can be misleading if Blender was not uninstalled properly.
HKEY_LOCAL_MACHINE\SOFTWARE\BlenderFoundation\ or HKEY_CURRENT_USER\Software\Blender Foundation\ - both are what you are looking for


With Blender 2.80 the use of the Edge Split modifier is deprecated in favor of new custom normals.

Custom Normals allow precise tweaking of normals beyond what auto-smooth can do

There's a lot more information in the Normals section of the recent documentation site. Although I'm not a big copy-n-paster, this is what it has to say about Auto-Smooth:

  The Auto Smooth option is a quick and easy way to combine smooth and faceted faces in the same object.

In addition, when you use custom normals:

  This has the side effect of enabling Auto Smooth, as that is necessary to use custom normals. Once you have custom normals, the angle threshold of the Auto Smooth behavior is disabled – all non-sharp-tagged edges will be considered as smooth, disregarding the angle between their faces.

Which brings us to the link to the documentation for Auto-Smooth:
https://docs.blender.org/manual/en/2.80/modeling/meshes/structure.html#auto-smooth


Get obj export settings (properties) from ExportOBJ class shown in the UI in python script

Window manager methods

Prior to running python console code below I have exported the  scene to wavefront obj, set a filepath and chosen use selection.

>>> wm = C.window_manager

>>> props = wm.operator_properties_last("export_scene.obj")

Running auto-complete props.CtrlSpace

>>> props.
          as_pointer(

          ... cut for brevity...

          use_normals
          use_nurbs
          use_selection
          use_smooth_groups
          use_smooth_groups_bitflags
          use_triangles
          use_uvs
          use_vertex_groups
          values(
>>> props.

Can get any property value

>>> props.use_uvs
True

This is the default value for use_uvs

If however we iterate over items, will get those values last used that are non default.

>>> for k, v in props.items():
...     k, v
...
('filepath', '/home/batfinger/Desktop/untitled.obj')
('use_selection', 1)

To run the operator again using the same properties from code could simply make this a dictionary and pass it to the operator as kwargs

>>> d = {k : v for k, v in props.items()} # or d = dict(props.items())
>>> bpy.ops.export_scene.obj(**d)
Progress:   0.00%
    (  0.0003 sec |   0.0000 sec) OBJ Export path: '/home/batfinger/Desktop/untitled.obj'
Progress:   0.00%
Progress:   8.33%
Progress:  16.67%
Progress:  25.00%
Progress:  33.33%
Progress:  41.67%
Progress:  50.00%
          (  0.0044 sec |   0.0034 sec) Finished writing geometry of 'Cube'.
Progress:  50.00%
Progress:  50.00%
Progress:  50.00%
      (  0.0058 sec |   0.0051 sec) Finished exporting geometry, now exporting materials
Progress: 100.00%
NO NODES!
      (  0.0074 sec |   0.0067 sec) OBJ Export Finished
Progress: 100.00%
Progress: 100.00%
Progress: 100.00%
Progress: 100.00%

{'FINISHED'}


Set the object physics to dinamic.

In logic editor add:

always sensor > AND > Edit object suspend Dinamics

collision sensor > AND > Edit object Restore Dinamics

Note: i used delay sensor to test but you need an collision sensor as in the next img.

With Python script:

add an always and collision sensor to a python controller.

Text.py

from bge import logic

def main(controller):
    colsen = controller.sensors['Collision']
    if not 'init' in controller.owner.getPropertyNames():
        controller.owner.suspendDynamics()
        controller.owner['init'] = True
    if colsen.positive:
        controller.owner.restoreDynamics()

main(logic.getCurrentController())

Related Documentation


For Blender 2.80, you need to adjust The clip start down.  This is found in the View section of the transform panel.


This is trivial to achieve using normal based effects like Fresnel.

You can use it both for the color gradient, and the shader transition from glossy to emission shader.

A layer Weight Node should give you both the Facing socket for the colors and a Fresnel socket for the shaders.

Drive it through a Color Ramp node to control the color progression gradient, and link the Fresnel socket to a Shader Mix node for shader mixing, between say an Emission node and Glossy, or Emission and transparent if you will.


My trees are being blown too fast and my grass is not affected by my wind physics after a few seconds

As your file is not added so I cannot tell much but still i can give you some idea. I hope your grass is using a particle system and it it is true then you can just increase the strength of wind on grass instead of increasing it overall and for that just go to field weights in particle(Hair) settings and increase the wind strength to 5 - 10 or as high as you need.
Let me know if this works for you.
If not then comment it down and i will try to give you another fix


How to get topographical contour lines like shown in manual? Analogous to Rhino3D functionality?

Simple node setup that uses the separated Z texture coordinates and modulo to drive a repeating color ramp.

Use the green cursor on the ramp to change thickness of lines.
Use the Z Scale to adjust line space
For the ground, same texture but using the X texture coordinate component.


You can't "join" a camera with an empty, join (ctrlJ) is to make 1 object from several, what you probably want to do is parent: Select the child, then the parent, then ctrlP


Use the local space.
The default plane in blender has local coordinates where x and y range from -1 to 1 and z is zero.
>>> me = C.object.data
>>> for v in me.vertices:
...     v.co[:]
...
(-1.0, -1.0, 0.0)
(1.0, -1.0, 0.0)
(-1.0, 1.0, 0.0)
(1.0, 1.0, 0.0)

With this arrangement can consider only the x, y coordinates effectively making it 2D within the plane z=0.
Hence any point with x and y randomly chosen from that range will be on the plane.
Simple test script, with an object that is the default plane "Plane" with any arbitrary global transform, and it will add an empty on its surface.
Multiplying this local point by the objects matrix world will ensure it is at a global location on the surface of planes current position.
import bpy
from mathutils import Vector, Matrix
from random import uniform
context = bpy.context
scene = context.scene

plane = scene.objects.get("Plane")
if plane:
    vec = Vector((uniform(-1, 1), uniform(-1, 1), 0))
    bpy.ops.object.empty_add(
            location = plane.matrix_world @ vec,
            )

Will re-iterate this relies on the plane having its original local or mesh coordinates in range explained above, making it a simple task to place an empty on its surface.
Via Parenting.
Another way to use local coordinates is via parenting. In this case need only set the local location of the empty within range above to have it on the plane. This will have the effect of aligning the axes of empty to plane.
if plane:
    vec = Vector((uniform(-1, 1), uniform(-1, 1), 0))
    bpy.ops.object.empty_add()
    mt = context.object
    mt.parent = plane
    mt.location = vec

To make the influence of the parent planes scale to empty unity for any subsequent children of the empty,.   Does a child object inherit the matrix from the parent?
if plane:
    mw = plane.matrix_world
    _, _, scale = mw.decompose()
    S = Matrix.Diagonal(scale.to_4d())
    vec = Vector((uniform(-1, 1), uniform(-1, 1), 0))
    bpy.ops.object.empty_add()
    mt = context.object
    mt.parent = plane
    mt.matrix_parent_inverse = S.inverted()
    mt.location = S @ vec

For an arbitrarily un axis aligned plane it is a bit more complex. https://stackoverflow.com/questions/42352622/finding-points-within-a-bounding-box-with-numpy


Custom float property used in a driver need manual UI modification to work

Ok I have figured out a solution.

If I save the file and reopen it, the drivers are working perfectly fine with what I have done with my script.

Might be an update issue with the property UI I don't know.

I could add a save/reopen at the end of the script, that would be an easy work around for now.

If anybody know how to instantly make it works please do tell so. Posting my answer anyway in the case someone else is encountering the same driver issue.


What is a good file type for campatibility with blender

I think Wavefront .obj is what you're looking for: https://en.wikipedia.org/wiki/Wavefront_.obj_file

As far as I know, Blender imports an obj file as one single object, so you may have to separate them later.


You are now in Solid view, where materials don't appear.
Switch to Material Preview or Rendered preview, and your colors will be there.

You can also set a color for Solid view only, in Material > Viewport display options.


You have two problems:

The first one is that you have set the subsurf modifier to a very high number of subdivisions for rendering.

You have to be careful when using the subsurf modifier, as it increases the number of vertices exponentially. Using a large number of vertices will require more RAM and will use more computing resources.
I doubt you need 6 levels of subdivision ever. With 6 levels of subdivision your very simple scene needs 6.5GB of RAM to render.

Use a more reasonable number. Read: Blender render crash when using subsurf modifiers.

The second problem is that you are trying to use depth of field on the camera, but have set the focus distance to zero, so your scene is completely out of focus, and it renders all gray.

Set the focus  to the distance of the object , or select the object as your focus target.

Read:

Rendered image is just grey


Blender screwing up normal maps from Substance Painter?

Unfortunately, we can't see your image texture nodes, which makes me think you don't know there is an important setting there, that you need to set up properly depending on the kind of map you're using. But as I can't see, maybe it's not the answer either.

As explained in the Blender Manual - Image Texture Node:
You have to set the color space to "non-color data" when your texture doesn't output color info for your material. Normal maps must be set as non-color data (as well as metallic, specular and roughness).

If you're curious on understanding the difference between "color" and "non-solor data" color spaces and why use one or the other, I suggest you read this topic.


I would check the transparency blend mode settings of the material in the Properties Editor, Material tab:

You don't have these settings visible if you have Cycles selected as the render engine, but EEVEE is used to display stuff in the viewport, so just in case they are not there, just switch the render engine to EEVEE temporarily:

Also check face orientation:

Red would mean that normals are inverted.


You set several of the roof pieces as rigid bodies. To delete the rigid body and all of the motion calculated from it Select the roof pices, then in the physics tab of the tool bar press remove.

You can also get to the physics settings in the physics tab of the properties window.


The closet tool I can think of is Checker Diselect.
Select all of the faces/edges/verices you want to affect and go to select->Checker Diselect  (or press the space bar and type checker)

To further refine your selection activate the tools options by pressing F6


Translate area mouse coordinates to the the Node Editor's blackboard coordinates?

this'll solve it for you:
def invoke(self, context, event):
    region = context.region.view2d
    ui_scale = context.preferences.system.ui_scale
    x, y = region.region_to_view(event.mouse_region_x, event.mouse_region_y)
    self.x,self.y = x /ui_scale,y/ui_scale
    return self.execute(context)

Then when you want to use it:
def execute(self,context):
    new_node.location.x = self.x
    new_node.location.y = self.y

    return {'FINISHED'}


Share Object data between two scenes, but no materials

Yes this can be done. First, you need to create the two scenes where the Object Data is linked, but the objects are not. After that, you can setup the materials in a way so they are different in both scenes.

Start off by creating the second scene using 'Link Object data'. This will copy the object, but link the mesh data. That means, when you edit a mesh in one scene, its shape updates in the other as well.

Blender allows you to choose if the materials are linked to your Object or the Object Data. By default it links to Data, that means that somewhere in the datablock where the mesh is stored, the information which face receives which material is stored as well. Since both scenes share the same mesh data, the materials would always be the same in both of them.

In your case, you will need to set the Link to Object instead, like in the screenshot here:

Now the information which face has which material is stored in the Object. Again, for the two scenes, the objects are different, only the data is shared.

Note that when you switch your material link from Data to Object, the material slot will be emptied. Click on this Icon to browse through a list of materials to link it back:

In your 'Blender Render' scene you can now assign completely different materials to the same mesh. However, keep in mind that if you delete a material slot, it will disappear in both scenes!


I'd like to scale something up to mark seams, how would I scale it the equivalent down?

You would scale it by 1/50 which equals 0.02


Ok, i chose those faces and unjoined from rest of mesh and tried again. This time it worked. So it must be faces, next to them, causing the problem. But when i unjoined and extruded those faces, shading looked alittle weird. Also i didn't want to apply solidify to the whole mesh to prevent from unnecessary polygons. In the end, this is what i made.

I made over the mesh.

1.I applied solidify on a basic cylinder

2.Then gave details to outer face only and my problem seems to have fixed


Logic Editor - only selected objects of Layer 1 are showing

To be able to select/link objects from layer 1 and 2 for example, both layers must be active.
You can select multiple layers by holding down the SHIFT key and selecting individual layers to toggle them on/off.
Use the same SHIFT method to select individual objects to link logic-bricks to and fro from the desired objects.


To get zoom independent snapping you need to keep the displayed grid from subdividing. As described here (Grid: disable auto subdivision) to keep the grid from subdividing go to "View" -> "Properties" -> "Display" -> "Subdivisions" -> *set the value to 1*. To change the size of the snap, change the "Scale" value in the same section.


Blender VSE 40 minutes for a 3 min proxy rebuild? Is there no way to make a proxy for only a single strip?

According to the documenation:1 "Storage: Defines whether the proxies are for individual strips or the entire sequence. Per Strip: Proxies are stored in the directory of the input." So, the "Per Strip" option really does only specify where the proxy is located.
AFAIK, I think your problem is with the "cut". You imported a 1-hour video and cut it to 20 min. This does not implicate that the strip is only 20 min. It only shows 20 min in the timeline. Dragging the handles will easily extend the strip until its original length.
So, you have to cut your video in a separate application like handbrake or ffmpeg and save the result as a new video. This is essentially what you did in your second attempt (adding a 20 min video).


I switched it to replay and it worked! I am going to just do it in final mode as well because that works too. for some reason modular doesn't work.


How Can I create wings with auto rig pro

The problem was that my Auto Rig Pro was just outdated


Generally, a high view factor between your scene and the lamp you use makes sampling smoother and less noisy, but also reduces the contrast in your scene.

Therefore, point lamps and sun lamps are relatively inefficient, meshlights and other lamps with a significant and homogenous surface area are more efficient and ambient light from an environment map (that has a low contrast or at least not only small points of light on it) is the most efficient lighting source.

While the lamp choice has relatively significant effects on the noise produced in combination with glossy and glass surfaces (especially with caustics enabled), the influence is smaller with matte surfaces.

The "Multiple Importance Sample" option in materials and lamps optimizes the sampling for small view factors and thereby (partially) compensates for the inefficiencies created by them.


Particle hair growing in a weird direction

The hairs grow from the faces of the two rings in the direction that the normals are facing.  If you view normals in edit mode (by turning on the overlay

and setting the normal length) I suspect you will see something like this:

You want the normals from the top ring to face down.  To do that select all of the faces in the top ring and type SHIFT-N to recalculate normals.  If they're still facing up, open  the action box (in the lower left of the 3d view) and enable inside:

and you should see something like this:

Now your hair should grow down from both rings


How to make an object go through a plane but the plane deform with the face of the object?

One way to achieve this is with Cloth physics.
Start by animating your object raising up through a flat plane (keyframe it starting below the surface and then 'rise up' until it protrudes). Add physics Collision to both the plane and your object.
Create another plane and position this above the first. Heavily subdivide it so that the cloth can suitably drape over your object and add Cloth physics to it.
Run the animation and you should have something like the following :

(note that I artifically reversed the same frames to go back to the start of the animation - that isn't possible with the cloth physics!!)
You might want to tweak the cloth physics paramters to get the effect you're looking for.


How to mix 2 shaders depending on distance from camera

Set up the nodes as pictured below. Add Camera Data node (Add [Shift+A]-->Input-->Camera Data), then Math Node (Add-->Converter-->Math). Optionaly you may add the Color Ramp node (Add-->Converter-->Color Ramp).

With the Math Node set to Substract try to experiment with its value (the closer to the object camera is the lower value should be).

Use Color Ramp node to make the transition between colours/ textures soft or sharp.

Edit:
For smoother transitions you can use other math nodes in combination. For instance put a logarithm node between the Camera Data Node and Subtract node. Change the color ramp to Cardinal and also change the direction of the ramp. Set the bottom value of the Logarithm to 15.0 and the bottom value of the Subtract to .250. Subtract becomes an offset of sorts.


It's possible to do this without python by changing the Frame step in Render settings > Dimensions > Frame range:


2.8 Shortcut to turn on/off "Emulate 3 Button Mouse"..?

Blender's keymap requires an operator to execute when the shortcut is pressed. Currently there is no operator to toggle the Emulate 3 Button Mouse option from the preferences, but this can be solved by writing a little add-on.

The following add-on creates an operator that allows to toggle the preference option and can therefore be added as a shortcut into your keymap. Copy & paste the script into a file and save it with the .py file extension.

bl_info = {
    "name": "Toggle 'Emulate 3 Button Mouse'",
    "author": "Robert Guetzkow",
    "version": (1, 0),
    "blender": (2, 80, 0),
    "location": "Edit > Operator Search",
    "description": "Operator for toggeling the 'Emulate 3 Button Mouse' option.",
    "warning": "",
    "wiki_url": "",
    "category": "Preferences"}

import bpy

class PREFERENCES_OT_toggle_emulate_3_button_mouse(bpy.types.Operator):
    bl_idname = "preferences.toggle_emulate_3_button_mouse"
    bl_label = "Toggle 'Emulate 3 Button Mouse'"

    def execute(self, context):
        context.preferences.inputs.use_mouse_emulate_3_button = not context.preferences.inputs.use_mouse_emulate_3_button
        return {"FINISHED"}

classes = (PREFERENCES_OT_toggle_emulate_3_button_mouse,)

def register():
    for cls in classes:
        bpy.utils.register_class(cls)

def unregister():
    for cls in classes:
        bpy.utils.unregister_class(cls)

if __name__ == "__main__":
    register()

You can install the add-on in Edit > Preferences > Add-ons.

Once it's installed you will have to enable it. You can find it in the Preferences category.

Then switch to the Keymap in the preferences and add a shortcut referencing the operator from the add-on. You'll have to decide what key binding you'd like to use.


Bones don't appear in Action Editor at all

In the Dope Sheet you've enabled the Only Selected Objects option, so you'll only see the tracks and keyframes of the bones that are selected (if keyframes have been created for these bones! as pointed out by Batfinger). In the video he also has this option enabled but he has selected all his bones.


How can I etch a perfectly straight line into a sculpted model?

you can also use: crease + space with stabilize strokes in sculpt mode or strokes lines


Currently the Python API can't handle opening and closing panels (it's not exposed).

Related: Is it possible to expand/collapes all panels in a region with a keystroke or shortcut?

The only thing you can do with python is to toggle by calling operators:

bpy.ops.view3d.properties()
bpy.ops.view3d.toolshelf()

They need the right context though, so they need to be called from the 3dview area or the context needs to be overwritten. This will toggle all panels in all 3d_views inside window:

for area in bpy.context.screen.areas:
    if area.type == 'VIEW_3D':
        context_copy = bpy.context.copy()
        context_copy['area'] = area
        bpy.ops.view3d.properties(context_copy)
        bpy.ops.view3d.toolshelf(context_copy)


Dissolve or disintegrate part of mesh while it is animating?

I think you are looking for the Build modifier.

The build modifier erases your mesh, then animates it being "re-built" face-by-face.  Just add a Build modifier to your object, set the Start frame and frame Duration to the desired amounts.  Then check Reversed to have it progressively take away geometry instead of building it from empty.

To get a more dissolve-like effect I would also check Randomize, this makes it randomly choose faces to take away, instead of sequentially doing connected adjacent faces.  Here is a side by side comparison, with Randomize checked on the left and unchecked on the right.


Set origin to Matrix_world bottom center of Lego bricks's bound box

guys. I get the answer about the question. Thanks for the help from Martynas Žiemys
this is the code:
def origin_to_bottom(ob):
if ob.mode != 'OBJECT':
    bpy.ops.object.mode_set(mode='OBJECT', toggle=True)

d = ob.data
m = ob.matrix_world

bounds_center = (sum((m @ Vector(b) for b in ob.bound_box), Vector()))/8
difference = m.translation - bounds_center
local_difference = difference @ m
for v in d.vertices:
    v.co += local_difference
    m.translation -= difference

difference = Vector((0,0,0))
bound = min((m @ v.co).z for v in d.vertices)
difference.z = m.translation.z - bound

local_difference = difference @ m
for v in d.vertices:
    v.co += local_difference
    m.translation -= difference


Short answer just to point you to the direction of cloth simulations.

Start with a large circle in the position of the highest point of the canopy, with a "triangle fan" face fill.
Remove one vertex along the circumference, to make an opening
Subdivide many times, minimum 6 but possibly 11-12.
Assign the central vertex to a vertex group.
Set up a Cloth simulation and enable pinning on the newly created vertex group.
Make the canopy holder ring using a simple torus mesh and enable collision.
Enable collision on the bed (or on a cube representing the bed's proportions, if your bed isn't ready yet).
Bake a cloth simulation
Choose a frame that looks right, and "Apply" the Cloth modifier.


Using Python to add object with specified number of vertices?

To do this:

Press Shift+C to position your cursor at the origin (0,0,0)
Follow this answer to create a mesh with a certain number of vertices


How to list (dump) context content in debug purposes?

Via Context.copy()
Conveniently there is a copy() method that returns context as a dictionary.
>>> print(C)
<bpy_struct, Context at 0x7f771bd250c8>

>>> c = C.copy()
>>> for k, v in c.items():
...     k, v
...
('active_annotation_layer', None)
('active_bone', None)
('active_editable_fcurve', None)
('active_gpencil_frame', None)
('active_gpencil_layer', None)
('active_object', bpy.data.objects['Text'])
('active_operator', <bpy_struct, Operator("TEXT_OT_run_script") at 0x7f771304bd88>)
('active_pose_bone', None)

etcetera, etcetera

('visible_objects', [bpy.data.objects['Lamp'], bpy.data.objects['Camera'], bpy.data.objects['Text']])
('visible_pose_bones', None)
('weight_paint_object', None)
('window', bpy.data.scenes['Scene']...Window)
('window_manager', bpy.data.window_managers['WinMan'])
('workspace', bpy.data.workspaces['Scripting'])


Since it's symmetrical, you can use Mirror Modifier.

Create bottom right part of the X stretcher (I used Knife project tool to cut the end part)
Position origin to the center of the table
Use mirror modifier on X and Z axis


The least troublesome way to transition from one computer to the next is to copy the contents  of all folders used for your blender projects in the same file structure you had in the old computer.
As you learned already images used as textures are not saved as part of the blend file unless they are packed. But even if the textures are packed, any link or reference to other blend files will be broken if the file does not exist in the specified place.
That is also true for the cache files for physics and other simulations. If the files are not found you will need to bake them again.
Note as well that for video files and image sequences and audio files there is no way to pack them into the file either.
A partial solution is to use relative paths, where the file structure doesn't have to be the exact same, as long as the assets are all all within the same folder as the blend file. But again, all relevant files have to be copied over to other computer.
A different approach would be to remove the drive from the old computer and make it available to the new one as an external drive.
As a last resort, if you don't want to copy all of the files, you can use the old computer as a network drive, through which you can access your files directly without having to copy them over. But the access will be slower.


Using 2 Texture-Atlas for UV Mapping a Mesh , How do I setup same Configuration in Unreal Engine 4

if you have different material slot for reference to this atlases - just make 2 materials with different textures. if slot one - you can multiply two textures or make some lerp by mask


Blender exporting incorrect uv map for .obj

Found the issue sigh. OpenGL reads the uv coord (t) backwards. Blender exported the obj correctly I just forgot about upside-down textures in OpenGL.


In game engine, all texts change color to white

Set Object color in Properties panel > display
If you want text look similar as in the 3D view just convert the text to mesh. Alt+C > Convert to mesh


Make Flames stick close to the surface instead of rising upwards

Final result:

Wrapping up:

I'm working with Metric Units (Unit Scale: 1). Result may differ when using other sphere sizes and some tweaking will be needed but I'll explain them later on.

Also, Fire or Plasma is transparent so it will be less visible in bright/white areas, just like fire in real life.

Objects:

We will need only three of them. Sphere as a Flow object, Domain, and Force field which gives us noise to the flame.

Start with empty scene and Shift+A > Mesh > UV Sphere. Keep everything as is.
With Sphere selected hit Space and type Quick Smoke. Select it.
Now we need a Force field. Shift+A > Force Field > Turbulence.

Domain settings:

Select Smoke Domain in the scene or in the Outliner and go to Physics tab.

Smoke tab

Resolution. We will leave it now at default value, but for final bake set it to 64.
Time. Crank this up to have faster moving flames.
Temp Diff. It's important one. Set it to 0 so flames will not go in any direction.
Vorticity. Higher = more noise, lower = smoother flames.

Smoke Flames tab

Speed. I've set it to 1. It will be connected to Force field settings (strength).
Smoke. Set it to 0. We don't need any smoke.
Vorticity. Same as Vorticity in Smoke tab.

Smoke Adaptive Domain and Smoke High Resolution tab

Check Smoke Adaptive Domain.
In Smoke High Resolution set it to 2 Divisions.
Lower Noise Method to 1. You can try and play with it. Low setting will give smooth flames and really high make them raving.

Sphere (Smoke Flow) settings:

Select our Sphere, you should see settings right away in the same place where Domain was.

Smoke tab

Change Flow type to Fire.
Flow rate is really fun to play with setting. Low value gives us really gentle flames, and high values will create total destruction.

Force field settings:

Select Force field (or Field in Outliner) and go to Physics tab (same as other objects).

Strength. Set it to 35 or lower if you want shorter flames.

Note: If you set it to low value, flame will be shorter but also slower. Consider changing in Domain settings Time scale and Flame speed.

Noise. Max it out. You can keyframe Seed to have even more noise.

Materials:

We will need materials for our flame - this will be Domain, and for Sphere, to simply hide it.

Domain or Flame/Plasma material

Select Smoke Domain and go to Node Editor.
Delete everything there besides Material Output.
Add Attribute node. Shift+A > Input > Attribute and type in it flame.
Add Color Ramp. Shift+A > Converter > Color Ramp. Add there couple of colors you want, place as you want but remember to set last one (right one) to Alpha 0 and set color to it as well.
Add Emission Shader. Shift+A > Shader > Emission.
Connect everything as in picture above.

Sphere or Flow material

Just add Transparent BSDF to it. Nothing more.

Final thoughts:

Now you can play or bake (under Domain > Smoke cache settings) scene. Remember to set for final render Resolution to 64, and to have dark background.

Save a lot. I mean it. A lot.

Setup is really flexible, so don't afraid to test other settings.

I didn't achieve good stutter or flicker effect. The only thing I've come up was adding Brightness/Contrast node between Attribute and Emission and keyframing Brightness value, but this is horribly slow process. Maybe F-curves will help but I'm not good in animation.

Blend file:


What are the implications for having Python scripts or add-ons licensed GPL incompatible?

I think law.stackexchange.com would be the best place online for an accurate answer, the following should be consider when formulating an answer and not taken as legal advice.

The issue comes from how python works, a python script is often viewed as a simple text file (or interpreted script) by most people, technically it is a source file that gets compiled into bytecode -

  bytecode
  Python source code is compiled into bytecode, the internal representation of a Python program in the CPython interpreter. ... This “intermediate language” is said to run on a virtual machine that executes the machine code corresponding to each bytecode.

The action of compiling a script means python scripts are a source code file used to generate a binary code that then links to (or dynamically calls) functions within blender, this means they could be treated as derivative works the same as adding a source file to the blender code base, this makes blender the library file that the python script links to. As well as a plain python script linking to blender, an addon script is compiled into code that blender calls, which would make an addon closer to a derived work than a plain python script used to automate a task.

It could therefore be said that any user that adds an addon to blender is building their own custom variation of blender. Placing the addon in a location that blender can find it, or installing with the install from file button in preferences, causes the compilation of the addon, then enabling the addon links blender and the addon into a derived work.

The LGPL was created specifically to allow a program to link to covered code without having to be released under the same terms as the code being linked to.

In contrast a shell script is read at run time to invoke external programs to execute with given parameters and retrieve the result output from the program. This means a shell script does not generate binary code that links to other code so does not get considered as a derivative work.


Add dimensions like in technical drawings

You can use an addon called MeasureIt

https://www.youtube.com/watch?v=OoMwmUrOhdc

It comes with Blender and you will find it in addons


How can I choose randomly from five Mix RGB nodes?

As mentioned, if you can combine your color choices into one ramp, you can plug the Random output directly into that.  To do this with this level of control, you need to do some math to convert the random output into a straight 0 or 1 over a given range.  I've done this with a compare node.

The bottom compare node is everything in the range of .8 to 1.0, which, at the end of this group, is the same as the top color input (in other words, that top input is "everything that's not caught by these other compare nodes").  That's why it's not connected to anything.


Why blender rendering objects to block/cut each other? And how to avoid it?

It seems to be a problem with the camera end clipping.

As you see it
 the left cube is renderer with a proper camera clipping while the right one is rendered with a too low end clipping

As you see it

you can change the camera clipping in the properties menu while the camera is selected.

Try to increase the camera end clipping


Can I run bpy scripts without all of blender in background

Generally the answer is "no", blender cant run as a standalone module except if you build it on your own (never tried that to be honest).
Blender python : where is bpy module located in windows 10
A working guidance for building blender as bpy python module?
What I would suggest instead, is to run Blender on the background and load your scripts and your 3d mesh, do all the processing and export your file as needed.
Here you may find all the possible and useful args for your commandline
https://docs.blender.org/manual/en/latest/advanced/command_line/arguments.html
it will take some more tweaking in order to set your custom scripts either on the blender startup or as additonal arguments on the commandline before the execution.


How can I create and project a symbol/rune on a sculpture? (like Blizzard's games)

Symbol preparation

You must draw the shape of your symbol in black with a sharp brush with a white background and add spikes. Use a big resolution to get less compression. If you are bad at drawing you can create the symbol in a 2D mesh in Blender. You can also use a text font, preferably that looks like the Unreal Engine font with spikes: https://www.dafont.com/

The silhouette should look like the U of the Unreal Engine logo:

For this demonstration I will download the Blender logo to show you how to convert it into an image you can project.

Here is the source image, like I said we must use an high resolution:

With a color ramp invert the image by inverting the sliders' position, then move the black slider to the position 0.01 and the white is at 0. Now we get a completely black silhouette on a white background. To make it more like a Blizzard rune sharp claws must be painted with sharp black and white brushes to make the peaks look like claws. As a reference you can imagine that you are converting it into a Shuriken weapon while keeping the initial symbol recognizable. This is the hardest part if you are bad at drawing.
Then use the Inner Glow technique that you can see here: https://blender.stackexchange.com/a/121470/23134, a Filter > Dilate/Erode in Threshold mode with both values at 50, this value depends on the thickness of the lines, resolution and the result you want. This effect allows to perform an inset on the symbol to improve his projection and the normal map baked from it.
Add a Color > Gamma node at 2.2, to convert it to Linear to have a flat slope when the image is projected.
Finally use a slight blur to avoid getting lines, this is especially useful if the resolution of your image is low to avoid getting aliasing.

Save the image, it is important that you save it in 32 bit float to avoid compression on the Inner Glow effect and Blur, otherwise the surface won't be smooth, so choose the OpenEXR format in Float (Full).

Projecting the symbol on a mesh

The symbol will be projected in Sculpt mode. You will need an high polycount to get as much details as possible. You can create a plane, in edit mode do W > Subdivide until you reach 1 million triangles.

In sculpt mode choose the Inflate brush
In Texture click on New and in the property panel at the right import the symbol. In Brush Mapping choose Stencil.
Set Sample Bias to -1 to avoid that the white background pulls the geometry, at the default 0 the middle grey doesn't move the geometry.
In Stroke choose Anchored.
In the Curve menu set it to the maximum effect, it must have no falloff, use the latest preset.
In the 3D view place the stencil on your image, hold Shift + right click to scale it. If you rotate it by mistake click on Reset Transform, then on Image Aspect.
Go in orthographic view, left click at the center of your stencil and drag the mouse to the exterior so it envelops the entire stencil. In perspective check the depth, you can adjust the strength to dig more or less.


Trying to recreate an effect that envolves emission and cant get it right at all

You can do this with Volume Scattering.
In the world tab (icon of globe), under "Volume", select "Volume Scatter" from the dropdown and set up the Density and Antisotropy to be similar to mine (feel free to tweak but this should work well):

This brought my emission object from this

To this:

Again, feel free to play with any of the values shown to get it to look as you imagine!


Using a Normal map together with a Bump map

This is the correct setup to combine normal and bump maps.

If you use a normal map, you can't use the displacement material output, you have to plug it directly into the BSDF. The normal map must go first, and then you can add bump mapping on top of it.


How make a frame of cloth simulation into a permanent object?

The cloth button in the physics tab creates a modifier linked to it.

Apply the modifier, your cache will be lost. It will be applied on the current frame.


How to update a custom property value modified by script?

You might have to force a frame change to get it to update.

   bpy.context.scene.frame_current += 1


Partial transparency in viewport (cycles)?

Try to unselect "Limit selection to visible" in the 3D View header bar.
This works only in edit mode on the selected object...
I don't know if it's enough for your purpose.


Physics object with force field render oddly shaped and jagged

The order of the modifiers was the cause of jagged shape!

Changed the subdivision modifier after the cloth simulation.


Try using different blend modes in the MixRGB node. Can't tell which one will help for sure. There's a good explanation of all blend modes but in Photoshop: https://youtu.be/i1D9ijh3_-I


What snapping technique to scale edges out to be exactly upright in this case?

While this is no general answer to how to solve the snapping problem and might not work for more complex shapes, in this particular instance I think it's easier to not rely on scaling but instead use Loop Cut and Slide, cut exactly at the bottom and then manually move the added edge loop upwards. For the upwards translation you could use exact numbers or vertex snapping (while restricting the movement to the Z axis) to end up at the height of your existing loop.


It would be easier to see with the blend file here... but looks like all the bones in the Character are aligned to the normals.

Look in the Outliner if you can separte it from the geometry and try to build a armature scheme native from blender.


How do you take baked textures and apply them to a Blender Render/ Game Engine Object

After reading more about baking, and playing with it some, I found that my error was trying to bake the materials and textures from my cycles render to an image, and then putting that image on a blender render.

To take materials and textures from a cycles render to a blender render or game engine, first you must bake them and apply them over the object in the same file in cycles render. Then you can change to blender render or game engine and go to nodes. Create a new materials node and connect the normal and vector slots between the nodes.


It looks like you have to modify the vertices, you could try the smoot tool, select the veetices in the bend and smooth them, if that dows not work you could try using the sculpt mode and smoot a little with the smoothe brush.
If it does not work a would sujest using curves with a bevel object i is usually easier to achive curvy "tubes" with them.


Hiding a part of an object in the Object Mode

you can  use the mask modifier for this task :

create a vertex group of the vertices that you want to hide
add a mask modifier  and assign the vertex group
you can click beside the vertex group to switch the effect
the mask will also has effect in the render you have to uncheck 'show in render'


How you denoise renderered images in Blender?

The Denoising Feature is only available for rendered images as it takes information from the unrendered scene as well as the pixel data of the rendered image to "guess" the right values of each pixel.

So unfortunately the denoiser isn't available for external images. There are a few compositing solutions available though. Here are some node groups you can use.


Particle children "simple" stop showing on certain frame

Just found out, the culprit is the Boolean.
Tweak translation of intersecting objects to make it work.


Too big addon list, what should I do? How expand names and keep it all?

Do you really need all those addons?
That seems neither productive nor beneficial for performance. Having many addons may eventually have a significant toll on responsiveness and available resources.
Features are often grouped for certain steps or stages of a project. You may notice you only need certain addons for certain tasks or worflows, maybe even use a few of them simultaneously in groups, but not at the same time as some other.
If that is the case you can set up workspaces dedicated to certain tasks where you will pick a few addons you generally use in tandem relevant for that task (say modeling, animating, shading etc.).
Once created you can take advantage per workspace addon filters. In the 3D View Toolshelf, (expand it with the N key) go to the Tools tab, Workspace panel, activate Filter Addons.
There you can pick which addons are active for that specific workspace. Choose only the relevant ones for those particular tasks you generally do in that workspace.

Also see related Addon to customize tabs


how to bake texture from multiple overlayed uv Islands to individual uv islands

Create a second UV map on your object in Properties > Object Data and unwrap it so it has individual islands (or however you want)

Blender Internal

Add your existing texture to the object and select the appropriate UV map in Properties > Textures > Mapping > Map:

Create a new image in the UV/Image editor by pressing AltN or Header > Image > New

Select the new UV map in Properties > Object Data and then select the new image in the image editor, so that the individual islands UV map is displayed over the new image.

Press Bake in Properties > Render > Bake:

Cycles
To do the same in cycles, you can use attribute nodes:

Add two attribute nodes and enter the names of your UV maps. You can now use the Vector output of these as those UV coordinates.

Create a new image in the image editor and add it to the node setup with a texture node. Plug the mapping you want into that texture node and select it.

With that texture node selected, press Bake in Render settings > Bake.


Packing multiple objects for 3D Printing

I think there's not (yet) such addon, the only 3d printing related one (included by not enabled by default) has not this feature, but I guess it also depends on some printer spec, like the printing area shape, maybe other things, like the printer type (a powder sintering printer can print things in a very different way than a fdm printer, eg).

The only thing you can do now in Blender, if it helps you, is to use the UV map "pack island" tool to simulate the best layout from the objects you have in the scene, maybe.

If you can find out what is the shape for each object that has to fit (it could depend a alot on the objects shapes), you can create a plane for each object shaped like its limits.

Then merge those separate planes together, in a single object and then UV unwrap them. The UV/image has a "pack islands" that can optimize the UV maps on the texture space.

Here I did it with some basic shapes, just to get you the idea:

I just used the largest horizontal face for each separate mesh. I know it could not be realistic, is just to give you the idea.

If you can consider the texture space as your printer printing bed (ie: only square print beds), the UV can be optimized to fill it (you can also scale them).

then the "pack islands" could help you to find the best way to pack them in that space. eg going from

to

then, of course you have to replicate that layout in the 3d view to get the same suggested placement. If this helps you you can also export the uw layout as .svg and then import tht svg into blender, to help you as a reference (eg: snapping)


BPY how to detect what mode is the current mode in 3D View

To store the mode which the active object is in you can use:

current_mode = bpy.context.object.mode

to store the mode in the variable current_mode. In order to set that mode again use the following line:

bpy.ops.object.mode_set ( mode = current_mode )


How to set color_mode to RGBA using script?

To set the color mode to RGBA for the current scene, use:

 bpy.context.scene.render.image_settings.color_mode ='RGBA'

color_mode is a member ImageFormatSettings, which is in turn a member of RenderSettings. The render settings of a scene are accessible via Scene.render.

See here for an explanation how to find out the access path:Blender/Python API Reference Usage: examples of how to use the API reference docs


You have to click on the armature for it to show in the upper right tab where you can select "Pose mode" and then rotate your mesh however you want (depending on the armature)


Transparent Background
In general - Render Properties - Film - Transparent works (viewport and render)

To Save render with transparency - Render Properties - Output - File Format - PNG and Color - RGBA has to be set (or any other format that supports alpha channel).

Hide Background
For viewport you can hide background image in Shading properties by changing World Opacity set to zero.

Notes:

Works for Eevee and Cycles
HDRi is file format, but important in terms is that background in blender use equirectangular texture type. It doesnt has to be necessarely HDRi that refers to a high dynamic range image.


What are common causes for Blend files growing in size?

In each instance the cause of growing file size may be different.

Common causes include:

Groups of objectsCause: Objects in a group might not exist in any scene.Solution: Check groups in the outliner, if you want you can add an empty scene and RMB in the outliner to instantiate all group objects in the scene to check all the objects you have in groups.
Physics cacheCause: Objects with internally stored physics cache may accumulate cache in the blend file.Solution: Clear the cache for your physics objects, you may want to use external cache files too.
Auto-packed texturesCause: Texture auto-pack is a feature, stored per-blend file, that will pack all your textures when saving.Solution: Check that you have auto-pack disabled in the menu: "File -> External Data -> Automatically pack into .blend".

feel free to suggest extras in comments - or add own answer :)


I helped to add a thickness to my window since I made a window from plane. Also i helped to change paramert IOR to 1.000. Maybe normals were flipped too.


How to copy BGE logic from one object to another using script?

To copy game logic from one object to one or many others:

Select the other object (or multiples using shift) first (object you would like to copy game logic nodes to)

Select the object you want to copy from (using shift to select)

Click Object->Game->Copy Logic Bricks

( or script as bpy.ops.object.logic_bricks_copy() )

Can be done for Properties as well as Physics properties.

Is this the type of copy you are looking for?


Need help with animating textures using AnimAll (texture moving is somehow visible during animation)

By default blender will use Bezier interpolation mode between keyframes, creating a smooth transition from one keyframe to the next.

In this case you want no interpolation, you need the placement to remain constant and then make a sudden change from one keyframe to the next.

In the dope sheet editor (or the graph editor), select all of the keyframes for the texture and set Interpolation Mode to constant (the shortcut for interpolation menu is T):


sharp creases on the edges between the mirror and the model

There could be a face inside the mesh, right where it gets mirrored. That often causes some weird stuff to happen if you add another modifier


I have had similar issues with Bsurfaces and it is difficult to pin point what triggers the error. The solution that works for me is making sure the automatic join is not ticked.

For the record: The error, when it happens, generates a number of overlapping files which essentially corrupt further work - specifically 4 files. In my case here only the Plane [green] can be considered not corrupt and the only one worth saving. I would advise that the other items be deleted, your file saved and Blender restarted.


Movie set as image texture not playing in cycles?

Well, you should enable auto-refresh in the image texture node so the image is refreshed every frame. Other than that I have made the experience before that I additionally had to set the frame range, start frame, etc. in the image editor for the corresponding texture.


It looks like the model is made using technique similar to metaballs in blender. To Create metaballs, in object mode Add > Metaball > Ball, and Add > Metaball > Plane for the surface
That kind of material can be achieved usin position from Geometry node, adding Separate XYZ, plugging z output to Math node set to "modulo" with unconnected socket at 1, and then plugging the output to color ramp. The color can then be plugged into whatever kind of shader you want to use (diffuse, glossy, emissive etc.)
In this i added the multiply node; by changing the value of it you can alter the band width. In color ramp, it is important to notice the interpolation set to constant.
If you create the metaballs used to make the scene in Object mode (not edit mode) they can be animated as any normal object (position/rotation/scale)

Here i animated two metaballs on a metaplane only in z position and two keyframes each.


To make particles collide on the plane, add Collision Physics to it and set the stickiness to 1. Perhaps also add some friction.

The particles will now stop on the plane, but they won't pile to a mountain as you want. That is because particles don't collide with each other. See here for particle self collision.

Instead of particles, you may also try rigid body physics or water simulation (with enorm viscosity, don't know if that one will work though).


the armature doesn't move the mesh and i can't unparent the mesh for it to work

You have vertices overlapping. In Edit mode, select all the vertices and press AltM > Merge By Distance. Play with the value in the Operator box in the bottom left of your 3D view (but the default value is ok). The parent With Automatic Weight. You'll have to make some corrections though.


Centre every object in relation to each other

Either select all objects, center the cursor with Shift + C and then use Shift + S > Selection to Cursor (offset); or if that doesn't work:

Select all objects with A
Clear their relations by removing parenting with Alt + P
Center objects origins with Shift + Ctrl + Alt + C > Origin to geometry
Now select all objects again with A and then Shift Select one last large object (like the ground or the scene background or whichever you want to be at the exact center of the world) by clicking on it to make it the active object
Press Ctrl + P to parent all other objects to that one
Now you can move that active "main" object to the scene's origin with whichever method you like more without breaking objects relative positions.

Either With Alt + G or with Shif + S > Object to origin or by manually entering or clearing coordinates.

You can then release the parenting if you no longer need it afterwards.

Edit: Have in mind that this may break any meaningful relationships you might previously have between your objects

P.S. Offtopic: Kudos for having Vivaldi browser installed ;)


Rescaling rig with same key frame animations

You are applying the scale to the rig but not the mesh. This leaves them at different sizes and breaks the alignment used when attaching the rig to the mesh.

You can either use the rig to make the mesh smaller (like you had before applying the scale) or apply the same scaling to the mesh object.


Fake user ON by default in Blender materials and textures

You can use an app handler to set use_fake_user to True right before saving. The following addon does it for materials and textures:

bl_info = {
    "name": "Save unused Materials and Textures",
    "author": "CoDEmanX",
    "version": (1, 0, 0),
    "blender": (2, 63, 0),
    "location": "(none)",
    "description": "Enable fake user to rescue unused materials / textures automatically before saving",
    "warning": "Make sure this addon is enabled by default!",
    "category": "Material"}

import bpy
from bpy.app.handlers import persistent
from itertools import chain

@persistent
def enable_fakeuser(scene):
    for datablock in chain(bpy.data.materials, bpy.data.textures):
        datablock.use_fake_user = True

def register():
    bpy.app.handlers.save_pre.append(enable_fakeuser)

def unregister():
    bpy.app.handlers.save_pre.remove(enable_fakeuser)

if __name__ == "__main__":
    register()

Make sure this addon is really enabled (best make it enabled by default and do that whenever you update Blender).


How can I fix brush lag in Texture Paint?

Changing the Window Draw Method to Full under User Preferences seemed to fix the lagging in my case, even though I'm not sure how this could impact other things. But after changing it once, I was able to set the draw method back to Automatic and still be able to paint without lag.
Hope it helps.


Compositor - File Output - PNG compression ratio issue

The difference comes from the dithering. This post-process is not applied on the viewer node but is applied on the render. You can find more info on dithering : https://docs.blender.org/manual/en/dev/render/output/settings.html#dithering

  Dithering is a technique for blurring pixels to prevent banding that
  is seen in areas of gradients, where stair-stepping appears between
  colors

Dithering adds noise. It explains why file sizes are not the same (noise is harder to compress).
Below, the first image does not have dithering and the second one does have dithering (maybe you need to zoom in to see the difference).

To get back to my initial question, the image saved with the File Output node via the Compositor has dithering and the image saved from the Viewer Node via the Image Editor does not have dithering.

I get the info from developers on ticket I opened :
https://developer.blender.org/T74071


Houdini's "explode node" in Animation Nodes

If I understand you correct, what you essentially need is a way to store the initial transformation of objects.

Fortunally Animation Nodes (AN) has an in-build system for that. It is called the ID-Key system (the name comes from the fact that it can theoretically work with all types of ID-Objects in Blender)

Using it is relatively simple - if you know about it:

Select all objects whose transformation you want to save in an ID Key.
Go to the AN tab in the toolshelf of the 3D View and open the ID Keys panel. There you have to click the "From Current Transforms" button. This will store the location, rotation and scale of each selected object in custom properties. You can also see them in the object settings.

Open the node editor, insert a Object ID Key node, click Choose Key and select Initial Transformation. Now you can get the initial location, rotation, etc of the object you have as input. The Initial Transformation of an object does not change unless you press that button again.

The ID-Key system is a generic solution to the underlying problem of storing values per object that are not changed by your nodes.

The same system is used by the Separate Text Object node. If you look at the template, it also uses the Object ID Key node. Also it does not only store the initial transformation of a letter but also the inital text-value.


Looping background (png image) in Blender for a car chase scene

That's not too hard actually:

I just move the UV coordinates around.

Create a seamless background image. Left and right borders should match.
UV-Map it on a plane that fills your background.
Use the Node Editor for the material and create this node setup:

The texture coordinates are provided to a Vector Math node. There, I am adding both vectors together, animating the yellow, formerly static one. Just click the button, set the X value, exist and set a key frame. It simply creates an offset for your UV coordinates, shifting the image around the plane.

As many frames as you want later, crank the value up and set another key frame. With the node selected, go into the Graph Editor and set the interpolation to linear in order to get a nice and smooth motion.

I deleted the other two channels since the motion is only in one axis.

Only drawback is that motion blur won't work with Cycles. You could blur the texture though.


Equirectangular option is only available when using the Cycles Rendering engine. If you are using the old "Blender Render", it will not be available.


How can i make the track to constraint track on x axis using location transformation instead of rotation?

You would almost certainly prefer a damped track.  Here's an example:


Standard combined with a transparent background solved the issue. World material was changing the colours of the objects in the scene


just drag and drop the blend file into unity assets folder, and open the file, then drag the armature to controller. thats all...


Made a mistake weight painting now i cant reset weight values of bones to the automatic ones

You can remove all the vertex groups from the object then try automatic weight.
You can select a vertex group and press the "-" button or press the "special button" (marked red) and select "delete all groups".


Difference between visual and normal keyframes

The following cube has a limit location set to (0,0,0) when you move the cube its position in the viewport don't change while the location info in the transform panel shows this change:

this is the case for all constraints they won't change what is displayed on the properties panel while they change the visual properties ( loc, rot, scale)

so you if you keyframe the location you'll store (1.938, 0.411, 1.286) for the current frame
while if you keyframe the visual location you'll store (0, 0, 0)


When importing a video, you have to use the same frame rate. If you don't, the lenght of the video will change, but the audio will keep the same, resulting in a difference between audio and video.

25FPS video import with 25 FPS in render settings : audio and video have the same length

25FPS video import with 30 FPS in render settings : video is shorter (same number of frames but 5 more every second)


Can you please share the picture of the object you are trying to model?

One of the cons of using curves that i experienced is you cannot make the thickness randomized or uneven.. like in branches of a tree they are not the same thickness throughout. so by using curves you cannot achieve the same thing..


Missing 'Generate' button in Rigify Buttons tab

The Generate Button is only available in Object Mode. The screenshot you posted shows that you're in Edit Mode Press Tab then the button should appear.


Easy solution first: Avoid loading the UI saved in the file, un-check the box shown in the picture below:

Shows the top right corner of the open file browser.

Click on the little cogwheel/options icon and you can un-check the "Load UI". Results in opening all data but leaving your User Interface untouched.

Longer solution for completeness sake:

If you have no properties and outliner area, you can hover with your mouse over the separation between the 3D View and the Menu, as they are essentially 2 different areas. Your mouse will turn into the 2 sided arrow and you can right click and select "vertical split", then split the 3D View where you want the new area to start. After that you can do the same again along the line separating the 2 areas and this time split horizontal. Afterwards you can simply switch each area to which ever type you want.

Easier to understand visually:


Align view to axis during modal operator?

Short answer: Nope. Sorry.

Explanation: As you correctly state, such functions are modal operators, which are a type of operator. You cannot run two operators at once. Technically, such functions as Numpad7 are operators: the operator, in this case, is bpy.ops.view3d.viewnumpad(type='TOP'). Even if you could see the View, Object, and Select menus, you wouldn't be able to do anything.

The problem's not the shortcut. It's the concept.

It would be nice for an operator to be able to be designated as AMODAL or DUAL or something like that, for an operator that does something like manipulate the view or snap the cursor to the center (another thing you can't do) so that it could be run during a modal operator's RUNNING state. Maybe one of the developers could implement this, but as of 2.68.0 r58537 it's not present.


How can I get a smooth rounded shaped normal map?

Tangent space normal maps give transforms of normal values relative to the face normal, if the face normals are not smooth then it doesn't follow that the normal map will be either.

In this case it looks like your face normals are discontinuous on the cylinder's 'curved' edges, and thus so is the normal map. This will probably render fine.

If you do want a continuous normal map, you could set these faces to be smooth shaded on the lower poly.


Small black triangle appears during subdivide in combination with Sub Surface

It seems that you subdivided, just this edge. The result is a n-gon which will cause problems with the subsurface modifier. It even looks like the resulting vertex is not connected to both faces, so the subsurface-modifier sees this vertex as a corner and rounds it. Go into vertex-editing and find the 5th vertex (it's exactly where this weird triangle is) and dissolve this single vertex, by deleting it and choose the dissolve vertex option. After that find out if the face over and below that edge are connected, the easiest way to find out is to just move the edge, if both faces follow you are good, if not you will have to merge the faces with on common edge between. I hope I could help you with that. All the best Marco


why are my cylinders stretched if i use this geometry setup

This is happening because you're doing the operation (in this case add on x-positions) after instancing the cylinder. So, you're modifying the x-position of each vertex of the instanced cylinder instead of the x-position of the points that you used for instancing.
Thus, you have to first modify the x-position points then use them for instancing of cylinders,


Why is this texture repeating when its set to clip?

This is the way "object" coordinates work: it takes into account the bounding box of the object, puts the texture in a plane that goes through the origin and projects the same color value onto every face wich has the same XY (UV) coordinates, so the image can get repeated if two zones share the same XY coordinates (and maybe have different "height") in the bounding box world.

If you want  a single position you have to use UV coordinates instead.


I had to change the frame rate from 23.8 to 24 to back to 23.8 fps....


Ok here is the box you need to change. I think you got it wrong way round when you explain your issue too. You went from material to solid mode ... not the other way round I guess.

Basically, what's happening here is that. The solid mode is an opengl operation so it uses a different color operation for showing color on screen. Where material mode takes the material color into consideration. Solid mode are usually usually a quick way to set up simple color to work on the models before heading onto material creation.

And here is the same file with the colors changed!


If this is what you want to obtain :

Starting from a grid like in (1)
Inset I the faces (2)
Remove the top center point and, eventually, align the top (3)

At this step, the smooth makes a non sharp angle and some faces to 'correct' in the bottom part :

Separate V the bottom center vertex and move it down a little (4)
Ctrl+E then edge slide both sides to mark the angle (5)

Here the shading is not good :

This is due to the inner triangles which are badly oriented :

Have a look (6), with Ctrl+T (triangulate)
And correct it (7), Ctrl+E then rotate edge CW (clockwise )

Come back to quads, selecting the faces and Alt+J (8)
Sharpen the angle if you need, like previously with edge slide (9)

The topology is more or less tolerant to subsurf (which seems ok) or to bevel (which is not so ok). So, depending on what you want, you may need to adjust it :


Good approach to make planks for a barrel?

There undoubtedly lots of ways of doing this. Here's one of them:

Array modifier

Use an array modifier with an object offset to duplicate one board object around radially. This way all the boards can be easily tweaked later on by editing just one; changes will be copied to the other boards.

Create the board object. If you want a certain number of boards (say, 16), then you'll want to be sure the board's width is 1 16th the circumference of the desired circle. The easiest way to do this is add a circle with 16 sides:

Add a circle (⇧ ShiftA) and set the sides to 16 in the redo panel.
Extrude (E) it into a barrel shape. I used a loop cut (⎈ CtrlR), beveling (⎈ CtrlB), and scaling (S) to quickly make a basic barrel shape.
Select one face loop (⎇ Alt RMB) and invert the selection (⎈ CtrlI), then delete faces (⌦ Delete, F)
With the remaining face loop selected, extrude (E) and press Esc to cancel the transform. Scale along the normals (⎇ AltS) to give the board some thickness.

Setup the array modifier

Add an empty and rotate it 360/16 degrees (R, = 360/16 will do the math in place and rotate the empty 22.5°)
with the board selected, add an array modifier, disable Relative Offset, and set the Count to 16.
Set the empty as the Object Offset.

Optionally fatten up the board object (⎇ AltS in edit mode) to reduce the size of the cracks between the boards.

Result:


Apparently KX_PolygonMaterial doesn't exist anymore.


turns out i needed to use the alpha of the main texture (not the mask texture) to the alpha of the principled BSDF. I think the suggestion from @blunder to use alpha mix also helped (but i had to use alpha clip)


I use sheepit too!
This error comes up when you are missing image files, caches, or other external sources which are required in the rendering process. In this case, I would check the box in Blender under File > External Files > Automatically pack into .blend.
This should do the trick.
If not, then you would have to take the image files and pack the into a .zip file with the blender file. You would have to make sure that the image directory in Blender for the images is set to local in the file, so that it would find it on any computer. (Which is how sheepit works.)


How to select/extrude all the upper faces of a lot of buildings in one only step

Your problem is that your buildings seem to have already been extruded once, instead of being flat 2D shapes as in the tutorial.

Either delete all but the bottom faces and star over. Select one of the top faces then use Shift+G > Normal option to select all faces pointing up. Then use Ctrl++ once to grow the selection and add include side faces too. Then delete them with X and extrude as per tutorial instructions.

Or select only the top faces for extrusion, don't select side faces like you did in your video or you will end up with a very bad dirty topology and a model full of errors.

Select one of the top faces then use Shift+G > Normal option to select all faces pointing up, then extrude


You could parent the child object to 3 vertices of the soft body object: Select the child, shift select the soft body object, go into Edit mode, select 3 vertices, press CtrlP > Make Vertex Parent, and the child will follow:


Workflow for animating a linked armature with bone constraints?

Blender's proxy system is designed to handle this situation.

By creating a proxy of the armature you can animate the rig while it is linked from an external file. It is common to have the rig and mesh belong to a group so that you import the group and create a proxy of the rig.


There isn't direct way to inset a face without taking into account proportions of the parent face, however you can use addon to workaround that.

After inset use Circle option of the LoopTools addon (addon comes with Blender by default; addon should be activated in User prefs). Operator will likely rotate the face, you will need to rotate it back so that it fits parent face (if the resulting face is oriented unevenly in the global space you should rotate it around its normal to avoid distortions).

If in 2.79 this will be in W menu > LoopTools. In 2.8 it depends on preferences you set for selection mouse button (right or left). By default, it should be in the Right click menu.

Note that Circle operator isn't generally designed for equalizing proportions of faces rather it does what its name suggests - converts selection to circle. As the face in this case consists of 4 vertices it works as expected. If you were insetting Ngon this way would created a circle.


Does decimate an object helps cycles rendering faster in blender?

Sure. Just like always in computer science: the more data you have, the longer it takes to calculate and the more memory it takes as well. However, it's not that much as you'd probably expect since the lighting needs to be calculated anyway.

Original Geometry vs. Decimated Geometry

Quick comparison of rendering a high-poly model (3.519.529 faces) and its  decimated version (35.224 faces ~1%) in a static scene using a simple backdrop and 3 area lights:

Render Time: 10:07.97 | Faces: 3.519.529  | Memory: 447.2 Mb

Render Time: 07:37.17 | Faces: 35.224 | Memory: 6.5 Mb


Yes, there are some ways to make custom macro buttons or a panel of operators that you define yourself. In the Scripting editor, there is an option to look at the python script templates that ship with blender - there is one that is called Simple Operator. If you have already seen some of the videos on Youtube or elsewhere about scripting in python in blender, then you might be familiar enough to follow a tutorial and copy the commands you want to reproduce into the Simple Operator script template and rename it to a specific name of your own.
example for simple panel with operator https://www.youtube.com/watch?v=OEkrQGFqM10
More info on the ways to take advantage of the python in the interface
https://www.youtube.com/watch?v=vFoh3S8MLBI


Strange stretching of mesh when using automatic weights

The automatic weights didnt paint the entire mesh the way you want it.

You can manually weight paint the mesh
here is a youtube tutorial:
https://www.youtube.com/watch?v=S0VS0IVylzg

Or just try changing the "bone envelope" and parent the bones to the mesh with automatic bone envelopes

here is a tutorial:https://www.youtube.com/watch?v=wBLv6oa60_k

But either way you will probably want to tweak it to make it perfect by manually weight painting a little


Wire it up in a setter.
Touched on this in answer to How to Update NodeSocketString Value inside a node group in a attribute node using python
As noted in question self.id_data is the node tree, not the node, and self is the property group.  Even without being defined a property group has a name property.
Will use this to, when trying to set a value, look over the node tree first and assign any emmission shader's name to its "myaddon" pointer property name, then use this to look up what the node is.
Sounds confusing? have added a simple example and tested in py console.
import bpy

def wire_up(node_tree, nodetype):
    nodes = (n for n in node_tree.nodes if n.type == nodetype)
    for n in nodes:
        n.myaddon.name = n.name

def update_color(self, context):
    print("Updating Value")

def get_node(self):
    print("Getting Value")
    return self.get("color", (1.0,1.0,1.0,1.0))

def set_node(self, value):
    print("Setting Value")
    wire_up(self.id_data, 'EMISSION')
    self['color'] = value
    node = self.id_data.nodes.get(self.name)
    if node:
        print(node)
    else:
        print("Node not found")

class MyEmissionSettings(bpy.types.PropertyGroup):
    color: bpy.props.FloatVectorProperty(
        subtype='COLOR',
        min=0.0, max=1.0, size=4,
        default=(1.0,1.0,1.0,1.0),
        #update=update_color,
        get=get_node,
        set=set_node,
        )

bpy.utils.register_class(MyEmissionSettings)

bpy.types.ShaderNodeEmission.myaddon = bpy.props.PointerProperty(type=MyEmissionSettings)

Test Run
>>> mat = bpy.data.materials.new("Test")
>>> mat.use_nodes = True
>>> mat.node_tree.nodes.new("ShaderNodeEmission")
bpy.data.materials['Test'].node_tree.nodes["Emission"]

>>> mat.node_tree.nodes.new("ShaderNodeEmission")
bpy.data.materials['Test'].node_tree.nodes["Emission.001"]

>>> en1 = mat.node_tree.nodes['Emission']
>>> en2 = mat.node_tree.nodes['Emission.001']
>>> en1.myaddon.color[:]
Getting Value
(1.0, 1.0, 1.0, 1.0)

>>> en1.myaddon.color = (1, 0, 0, 1)
Setting Value
<bpy_struct, ShaderNodeEmission("Emission") at 0x7fa0bddf8c08>

>>> en1.myaddon.color[:]
Getting Value
(1.0, 0.0, 0.0, 1.0)

>>> en2.myaddon.color = (0, 0, 1, 1)
Setting Value
<bpy_struct, ShaderNodeEmission("Emission.001") at 0x7fa096f38e08>


Don't feel bad about understanding all of this, it can be very confusing and it takes a while to get.

There are a lot of bases to hit here, and they are all deep enough to be a full paying job in their own right.  Hopefully, this info should help you ask more targeted questions with this info, so here we go:

UV Maps are just a way of relating 2D information (like a picture) to a 3d object (such as a model).

Blender can generate these for you by going into edit mode, selecting everything (a), and pressing u for the unwrap menu, and choosing "smart unwrap" (results are sub-optimal, but "good enough").  Unwrapping models are an art to themselves, because where cuts are added to the model to allow the UV's to be made flat can be noticeable.

Once you have a UV map, textures can be applied to your model.  The simplest one is Diffuse, as this the model's color (the rainbow example pictured above).  There are other maps that you may use that will affect how those colors are shown further, depending on renderer and shader, such as Gloss, Emission, Specular, or even Transparency (to name only a few).

A Normal Map is an extremely special kind of texture.  This is a way to fake geometric detail into a model that doesn't have the geometry itself to pull it off.  Someone usually does this in order to preserve detail from a high poly sculpt while still being able to use the model in a game or animate with.

You will usually know you are dealing with a Normal Map (sometimes referred to as a Tangent Map) if it is mostly purple with fluorescent reds and greens here and there.

The usual way to generate a Normal Map is to take a high-poly model and bake on the details to a lower detailed model, Blender is capable of doing this.  There are also programs that let you draw directly on Normal maps, but as far as I know, Blender is not one of them.


How to make freestyle lines stay the same size?

Yes, it is possible. Here is how:

First change the Line Thickness parameter under Properties tab > Freestyle to Relative (1)

Next go to the Render layers properties, or just click the icon in the Freestyle panel (2). Then go to the thickness tab (3), and then Add a Distance from Camera modifier (4) .
You then have to check the invert box (5) to that the lines decrease in width over the distance. You will see a parameter slider box called Range Max (6) , this value should be the distance of the farthest object away visible in the shot.You can use the Fill Range by selection, or do it manually. In my case the object is about 100BU away. Value Min (7) and Value Max (8)  control the ending width and starting width, respectively.

Note:

For animations you might have to set keyframes for these values
You can ignore the Base Thickness parameter
The Distance from Object modifier can achieve similar results and may be more suitable for animations.
Lines are drawn based on edges. One long cube is only going to have the same width through, regardless of the modifier.

Final Result:


Blender gets very slow to draw a scene having large number of plane?

Dupli objects
Try using Dupliverts (instances):

Create/import the point cloud as a mesh with only vertices:

Create a single tri by adding a plane (ShiftA> Mesh > Plane) and merging one edge with AltM:

Parent the tri to the point cloud by selecting both objects with the point cloud active (last selected) and pressing CtrlP.

With the point cloud active, enable Verts in Properties > Object > Duplication:

Add a track to constraint to the tri with the camera object as the target so that all the tris face the camera:

This has performed fine for me with point/vertex clouds of over 7000 vertices.
This will work with both BI and Cycles.
Halos
Another method for rendering point clouds is to use a Halo Material:

Create/Import a point cloud as vertex only mesh (no edges or faces):

Create a Halo material:

Note that this only works for BI.


How to fix obvious connection line between meshes?

It look like you use 2.79 on one screenshot.
If you want to output it then somewhere from Blender - bake normal maps from models where all parts attached and vertices merged to each separate part. This normal map will be baked with taking in to account normal differences so it will compensate it and make detached parts look similar to full head.
If use just in Blender - use Normal Edit modifier on detached parts where pick full head model with merged vertices as reference object. Like on GIF - 2 separate sphere parts, " normal Object " is full sphere.

I mean use modifier for " non destructive " things. You can also just apply this modifier and not bake any normal maps.


Adding geometry (Ctrl+1) does not work as expected

By pressing Ctrl 1 you added a Subsurf Modifier with one subdivision. The default subdivision agorithm is Catmull-Clark, which tends to round off the geometry, hence the roundness you see in the ghosted image. On the modifier you can change the subdivision from Catmull-Clark to Simple.