How to display custom panel in two spaces?

Subclasses and inheritance

Code based on this answers and updated for 2.8x according to API changes:

class MY_PT_CustomPanel(bpy.types.Panel):
    """A Panel to show in many places"""
    bl_label = "My Tools Panel"
    bl_region_type = 'UI'

    def mydraw(self, context):
        # do nothing here so each class can add it's own thing'
        pass

    def draw(self, context):
        self.mydraw(context)
        row = self.layout.row()
        row.label(text="Hello world!", icon='WORLD_DATA')

class MY_PT_Viewport(MY_PT_CustomPanel):
    bl_space_type = 'VIEW_3D'

class MY_PT_ImageEditor(MY_PT_CustomPanel):
    bl_space_type = 'IMAGE_EDITOR'

    def mydraw(self, context):
        row = self.layout.row()
        row.label(text="For the Image editor")


can i use cloth simulation to create clothing


How do I set a background image while I am editing?

See Cannot find Background Images feature in Blender 2.8 if using 2.8.

Background images are gone in Blender 2.8, at least in the traditional pre-2.7# sense. The old system was aging and prone to failure ... and it has been retired due to inherent limitations.
Information was stored as User Interface data, as such if you opened a file without the Load UI option ticked they would appear to be missing, and any previously assigned background images mysteriously absent.
Saving the file would then silently erase them, permanently eliminating without warning or explicit user intervention.

As an alternative to Gwenn's answer, you can also use an empty. Empties in Blender now have an image type.

This is very useful as it gives you more control over positioning your references and users coming from other software can use this method as it is the norm for them. (most Max users I know use frozen planes with textures when modeling).
Control the image object properties in the "Object Data" tab:

Once added, you have a lot of control over the reference. You can adjust the opacity, scale it, rotate it etc. Much more flexible than the common way using the N panel in the other answer. You can also lock it so it behaves the same way. Another advantage this has is that it's visible in both orthographic and perspective views.


Lattice modifier deforms object as soon as an object is selected

Changes to the lattice while in edit mode will be used to deform the mesh. This applies even if you alter the lattice before linking with the modifier.

Also selecting and scaling all points in edit mode, like you would with a mesh object, will add an odd out of proportion scaling effect while scaling the lattice in object mode.

To prevent this you need to scale the lattice in object mode to get it to the starting position that you want before making any changes in edit mode.


Character rigging: Blender keep offset is not working

Here are some things you may have done wrong:

1- try selecting the bone that you want to be the child FIRST.

2- ofset effect will ONLY work in POSE mode

3- make sure ALL the bones are in the SAME metarig otherwise it won't work as you are trying to do

Wrong way:
If they are like the ones above, try joining them and repeat the process of parenting

Right way:

I Hope this helps.


How to toggle grid lines that are displayed in wireframe mode?

What you see is the Subdivision Surface modifier effect on your mesh. Disable its visibility, or, as Frederik Steinmetz suggests, enable the Optimal Display option, but in that case keep in mind that you won't see the real mesh but its deformation through the modifier.


How can I fix the streaking on the side of this cube in Blender 2.83?

It appears as though either: 1. you are not using the UVmap you created, 2. there a different materials applied to different faces, or 3. The object is not unwrapped correctly.
First, make sure that in your node setup you have the UV output on the Texture Coordinate node connected to vector input socket on Mapping node.
Second, make sure that all your faces have the same material assigned. Select all of your faces in edit mode and in the materials tab, choose the correct material and click assign.
Third, try unwrapping again. Go into edit mode. select all of your faces. choose UV Unwrap.


I hope there is a better way to do this, but here is a workaround I used:
I copied 'normal' normals to a uv layer via script. Two layers to be exact. While I could have compacted them into a single layer, it would have increased shader complexity
import bpy

ob = bpy.context.object

for loop in ob.data.loops :
    normal = ob.data.vertices[loop.vertex_index].normal
    ob.data.uv_layers["XY"].data[loop.index].uv = (normal.x, normal.y)
    ob.data.uv_layers["ZW"].data[loop.index].uv = (normal.z, 0)

Then in shaders I plug the combined value into fresnel normals input.
Here are sample results form left to right:

Default monkey with default fresnel
With normals edit and custom normals plugged to fresnel
With normals edit and default fresnel

The artefacts (sharp white areas) are due to lousy normal edit, which I bet you will not have in your model. Otherwise the normals carried over from UVs appear to be near identical to original smoothed normals
EDIT: As noted by Heinrich Tester, the normal from UV must also be transformed from object to world space before use


Is there a way to hide the path that a hook modifier draws on the 3D view?

Those paths are called 'relationship lines', and can be toggled on and off here:


Get frame to frame object location Blender 2.81 +

Object.matrix_world.to_translation()
Recommend using the matrix world,  of the evaluated object. Which is calculated for  each frame of blender. What you see in the UI, is the matrix basis.
Does a child object inherit the matrix from the parent?
Note the local matrix can be gained by multiplying the matrix world of an object, by its parents inverted matrix world. (link above shows how this relates to matrix basis, which is what we set via its components (rot, loc, scale) in the UI)
Here is a quick test script to output the global location of the cube, and evaluated cube for each frame.
There is no need to clear and add a handler for each frame.  Do make sure to clear handlers if running script multiple times as they will accumulate.
import bpy

names = ("Cube",)
def frame_change_post(scene, dg):
    f = scene.frame_current
    for name in names:
        ob = dg.objects.get(name)
        if ob:
            print("dg", ob.name, ob.matrix_world.to_translation()[:])
        ob = scene.objects.get(name)
        if ob:
            print("scene:", ob.name, ob.matrix_world.to_translation()[:])

bpy.app.handlers.frame_change_post.clear()
bpy.app.handlers.frame_change_post.append(frame_change_post)

scene = bpy.context.scene
for f in range(scene.frame_start, scene.frame_end + 1):
    print(f"frame {f} ------------------")
    scene.frame_set(f)

Output of running script.
Here I've run the script above directly from the text editor. The cube has an arbitrary follow path.  Note no difference here between result of un or evaluated object.
frame 1 ------------------
dg Cube (-0.4548962712287903, -7.230154037475586, 0.0)
scene: Cube (-0.4548962712287903, -7.230154037475586, 0.0)
frame 2 ------------------
dg Cube (-0.9097925424575806, -7.199532985687256, 0.0)
scene: Cube (-0.9097925424575806, -7.199532985687256, 0.0)
frame 3 ------------------
dg Cube (-1.357460618019104, -7.115467071533203, 0.0)
scene: Cube (-1.357460618019104, -7.115467071533203, 0.0)
frame 4 ------------------
dg Cube (-1.8044718503952026, -7.026542663574219, 0.0)
scene: Cube (-1.8044718503952026, -7.026542663574219, 0.0)
frame 5 ------------------
dg Cube (-2.238593101501465, -6.889674186706543, 0.0)
scene: Cube (-2.238593101501465, -6.889674186706543, 0.0)

Rendering animation.
dg Cube (-0.4548962712287903, -7.230154037475586, 0.0)
scene: Cube (-2.238593101501465, -6.889674186706543, 0.0)
Saved: '/tmp/0001.png'
 Time: 00:00.42 (Saving: 00:00.01)

dg Cube (-0.9097925424575806, -7.199532985687256, 0.0)
scene: Cube (-2.238593101501465, -6.889674186706543, 0.0)
Saved: '/tmp/0002.png'
 Time: 00:00.31 (Saving: 00:00.01)

dg Cube (-1.357460618019104, -7.115467071533203, 0.0)
scene: Cube (-0.9097925424575806, -7.199532985687256, 0.0)
Saved: '/tmp/0003.png'
 Time: 00:00.34 (Saving: 00:00.01)

dg Cube (-1.8044718503952026, -7.026542663574219, 0.0)
scene: Cube (-1.357460618019104, -7.115467071533203, 0.0)
Saved: '/tmp/0004.png'
 Time: 00:00.34 (Saving: 00:00.01)

dg Cube (-2.238593101501465, -6.889674186706543, 0.0)
scene: Cube (-1.8044718503952026, -7.026542663574219, 0.0)
Saved: '/tmp/0005.png'
 Time: 00:00.33 (Saving: 00:00.01)

dg Cube (-2.238593101501465, -6.889674186706543, 0.0)
scene: Cube (-2.238593101501465, -6.889674186706543, 0.0)


(v2.90) What are these thicker blue lines, and how do I quickly remove them?

Those edges are marked "sharp". To remove, select all (or just the ones you want to clear) in edit mode and then select "clear sharp".


Do something when check/uncheck checkbox Python

actually your code is running... but you must open your blender with the cmd (console)

after that you can see the prints in the cmd

/**** update

you should check enter link description here

I clean the code....

bl_info = {
    "name": "tester",
    "description": "",
}

import bpy

from bpy.props import (StringProperty,
                       BoolProperty,
                       IntProperty,
                       FloatProperty,
                       FloatVectorProperty,
                       EnumProperty,
                       PointerProperty,
                       )
from bpy.types import (Panel,
                       Operator,
                       AddonPreferences,
                       PropertyGroup,
                       )

# ------------------------------------------------------------------------
#    store properties in the active scene
# ------------------------------------------------------------------------
def update_func(self, context):
    for obj in bpy.data.objects:
        if (self.my_bool == True):
            #print ("Property Enabled")
            obj.hide = True
        else:
            #print ("Property Disabled")
            a = obj.hide=False
            print(a)
def update_func_1(self, context):
    for obj in bpy.data.objects:
        if (self.my_bool1 == True and obj.name=="Cube"):
            print ("Property Enabled")
            obj.hide = True
        else:
            print ("Property Disabled")
            obj.hide = False

class MySettings(PropertyGroup):

    my_bool = BoolProperty(
        name="Enable or Disable",
        description="A bool property",
        default = False,
        update = update_func
        )
    my_bool1 = BoolProperty(
        name="Enable or Disable",
        description="A bool property",
        default = False,
        update = update_func_1
        )
    my_int = IntProperty(
        name = "Set a value",
        description="A integer property",
        default = 23,
        min = 10,
        max = 100
        )

    my_float = FloatProperty(
        name = "Set a value",
        description = "A float property",
        default = 23.7,
        min = 0.01,
        max = 30.0
        )

# ------------------------------------------------------------------------
#    myTool in the image editor
# ------------------------------------------------------------------------

class UV_OT_my_panel(Panel):
    bl_idname = "UV_OT_my_panel"
    bl_label = "My Tool_modify"
    bl_space_type = "VIEW_3D"
    bl_region_type = "TOOLS"
    bl_category = "Tools"

    def draw(self, context):
        layout = self.layout
        scene = context.scene
        mytool = scene.my_tool

        # display the properties
        layout.prop(mytool, "my_bool", text="hide everything")
        layout.prop(mytool, "my_bool1", text="only hide cube")
        layout.prop(mytool, "my_int", text="Integer Property")
        layout.prop(mytool, "my_float", text="Float Property")

# ------------------------------------------------------------------------
# register and unregister functions
# ------------------------------------------------------------------------

def register():
    bpy.utils.register_module(__name__)
    bpy.types.Scene.my_tool = PointerProperty(type=MySettings)

def unregister():
    bpy.utils.unregister_module(__name__)
    del bpy.types.Scene.my_tool

if __name__ == "__main__":
    register()


How to see bundles and back projecting points of different colors?

Those red and green colored points are available only after you have successfully solved the scene.
To make them visible, enable the overlay in clip display > Marker Display > 3D markers

(for 2.79  enable 3D Markers on the Marker Display Tab.)

The dots show the difference between the tracker and where blender is actually laying the points in 3D space. It is a visual reference to help you identify problems and further refine your track to get a better camera solve. The colors reflect to the "reprojection error" If the rerpojected points are close to the original tracker they will show green,

Otherwise they will be red. Notice how the dots are away from where the tracker is.

Sometimes you can make the reprojected points fall closer to the original trackers by moving the optical center on the camera presets .

But if your reprojection errors are too high you might be dealing with errors on the focal lenght, the optical center or the radial distortion coefficients. So solve the scene again using those options in the refine section.
For more info on the last step see:
How to determine lens undistortion values for motion tracking?


try select all you want to simetrize and with right button chose "names" > left-right, and what you don't want to simetrize and choose "names" > top-bottom. So select the left-right bones and simetrize will use the top-bottom bones as reference.


Image Texture is fine in Render View but renders distorted

It definitely looks like z-fighting. Likely caused by a copy of the object on top of the one you want to render. You cannot have two surfaces that overlap and use the exact same point in space, the 3D engine will not know how to render that and display one surface or the other randomly.
Check if you don't have a copy of the object. Delete it or disable it for render.
See:
Avoid rendering hidden objects (blender 2.8)
If the mesh is duplicated as part of the same object, then enter edit mode and do Mesh > merge by distance to get rid of duplicated vertices


Does a game engine runtime work on all operating systems?

No, the output is dependent on the OS that you called it from (Blender 2.6 Doc)

If you executed make runtime on Windows, then the output is a Windows executable (and various DLL files). This package will only work on Windows.

Running the same function on the Mac will give you a Mac .app file, etc.


Normal map baking - All clean blue (no color variation)

Normal maps are not showing elevation of the faces, only normals angle (faces angle of high poly relative to low poly model), in your case all the normals facing low poly model exactly at the same angle, thats why you do not see any changes on the normal map.

In an example below you can see that faces that are 90 degrees to low poly model are not visible.


Lighting in Cycles is not working properly

On the top right corner there is a play button:

This enables/disables viewport rendering, clicking it should start previewing your viewport render on cycles


Faces move slow / not fully connected to bone

The problem was that the edge was also being controlled by another bone and by changing the weight of the other bones it worked


How to let people see message in add-on preference?

Type your text in add-on preference script:
bl_info = {
    "name": "Example add-on",
    "author": "Your name here",
    "version": (1, 0),
    "blender": (2, 92, 0),
    "location": "Your location here",
    "description": "Your description here",
    "wiki_url": "",
    "tracker_url": "",
    "category": "Development",
}

import bpy

class AddonPreferences(bpy.types.AddonPreferences):
    bl_idname = __name__
    def draw(self, context):
        layout = self.layout
        col = layout.column()
        #Type your text
        self.layout.label(text="Your text here")

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

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

Finally I got this


A couple of things:

Your TowerTexture.png file is very small --  4 pixels x 2 pixels -- and was not assigned as the material's texture. More on that in a moment, but here is how you can see the size of your texture file:

I took the .blend file you uploaded and did a couple of things: I unwrapped the tower and applied a color grid as an image texture. This is a feature you can use within Blender to add a numbered grid as a new image texture:

I also made the new image 1024 x 1024, which is a standard size... but you can use larger or smaller.... It helps to size them as pow3ers of 2, like computer RAM:  512, 1024, 2048, 4096. 4096 would be pretty big... but I am just showing you the powers of 2. This is not mandatory, but speeds rendering.

I then applied the color grid file to your model:

The numbered grid lets you see if your texture file is being squashed or stretched... There are a couple of ways to deal with scaling your image, but here is one:

I also turned your lamp into a "sun" type lamp and pulled the camera further back to get a full view of the tower. I am not sure those changes were critical, but I wanted to note that I did this. I uploaded the file with these changes and you can download it below.

Also, when you are assigning an image to a material in Blender Internal, specify "Image or Movie" in the texture "Type" dropdown:

Then select the file to wrap onto your model. But make sure you are specifying that the image is applied as a material texture here --

I believe you had accidentally assigned it as a brush texture (the checkered box to the right of the material box...)

Anyway, once you see the color grid in place, you can replace it with the real texture you want to use.... And you can make your tower more than on material and image texture, but I hope this helps.


Look at the HDRI below the horizon. Many of these HDRI's have a black 'ground'. Glass will refract all light, so the black ground as well. That is probably where those dark shapes are coming from. Remember, glass only exists because of reflection and refraction, both of which depend heavily on the environment. If something is wrong with the way your glass behaves you probably need to tweak the environment.


hello yes there a little hack for doing this, but in this weird way...

select some vertices and extrude them to the axis to point the edge loops, then flatten with S+Z+0 and again S+Y or X+0, and then enable automerge and split edges option, and enable snapping with edge center, and then move the vertices and snap them and click for applying, and then repeat the same in the other edges...
then set snapping to vertices, and manually snap and apply each vertex in the last intersections...
and then add some loopcuts with CTRL+R and manually select 2 edge loops vertices and press CTRL+J to connect them, and repeat the same for the remaining things to clean up...


What causes rendered frame "flickering"?

It is most likely Z-fighting.
Break down the scene and look if there are any planes in the exact space of orientation.
1 - Could be a hidden object in viewport but still enabled in rendering

2 - Maybe it is an object that is hiding in a different layer.
3 - It could also be 1 object with 2 overlapping faces in the exact same location. (go into edit mode and pull away some edges to check)


Here my how-to:

In UV/image editor select "keep UV and Edit mode mesh selection in sync"
and Face select mode:

Now select in 3D view needed face, and you will see it in UV/image editor:

And finally, use C or B to select all faces in that position:


Flat shaded normals, have weird shading artifacts

TL:DR press Set From Faces in the Shading tab of the Tool Shelf.

What's happened is your normals have got bent out of shape in a weird way that the usual Ctrl + N make normals consistent doesn't see as a problem.

They're all facing the right way vis-a-vis inside/outside, but they're all over the place in terms of direction. So you just tell Blender it needs to force all normals to be perpendicular to their corresponding face.

I still have no idea how this problem occurs in the first place, though. It foxed me for a good few days.


How to trim this cylinder where it meets a box

The Boolean is less destructive, but for a one-off, leaving more options in some cases:

Object Mode, CtrlJ combine the components if not already one object.
Edit Mode, all selected CtrlF Face Menu > Intersect (Knife)
Adjust Last Operation panel > Self Intersect

Followed by removing the faces you don't want, and AltM merging the selection of vertices you want to, By Distance.


With a boolean modifier
You had it right with either of these solutions. I would use the first one. But as you noticed, the cube mask hides the part you want to show. Select the cube and go into object properties and set the viewport display to "Wire". also don't forget to uncheck "Render" in the visibility so it doesn't appear in your animation.

Then Select the road object, add a boolean modifier set to "intersect" and pick the cube mask.
Now you can either move the mask or the road to get the desired effect.

With a custom shader
You can limit the visibility of the road with a custom shader. You then don't have to use a mask object, and you won't have boolean artifacts, but the drawback is the mesh doesn't get "cut" on the edges of where it needs to stop displaying.
Select the road, go into the shading editor and add a new shader. Let's say you want the
road to display between y = - 1 and y = 1.
Add this setup to visualize the alpha of the material (1 is white, meaning the material is opaque. 0 is black, meaning the material is transparent):

Plug it into the alpha input of a principled bsdf shader and connect the bsdf to the material output. In the right hand side panel, go to options and set the blend mode to "Alpha Clip".

Result :


Can't draw on my texture in texture paint mode

You have your destination texture loaded as a brush texture, so you are trying to paint on the image with itself. Turn that off, and switch from Dots to Space in the stroke type, and I am able to get paint to drop onto the new image I used since the file doesn't seem to let me open the one you are using.


Redraw Texture Based Off Disfigured Mesh

I think you can use a bake process to do that.

Let's say we start with this dragon (anyway, it does not know at all it is not) :

And you for instance want to separate the horns from the head :

You here want to remap these UVs like that which does not match the initial texture :

Create a new material and a new texture for the head
Go to node editor and add a texture node to it (with the corresponding texture). Keep this node selected as below (this selected node indicates to Cycles where to bake to) :

Do the same for the horns part (new material, new texture and same node setup)
As we will bake and bake uses environment light, set it to full white (RGB = 1, 1, 1) and a strength of 1 : this will keep the same colors as the original

We begin with a bake for the head
Set the new head at the exact same place as the original
Select the original RMB
Then select both the new head Shift+RMB
Go to the bake section in the render panel
Click 'selected to active'
Adjust a little bit the 'ray distance' in order to avoid artefacts (this may be tuned depending of your mesh)
And click 'bake'

Do the same for the horns :

Instead of doing that piece by piece, you can also rejoin all your meshes once you have recreated each UV map and each material (eventually remove doubles after the join) and bake them all in one time.


Mesh causing abnormal results with subsurf modifier

Short answer:

Bad topology.

Longer answer:

You have here some non-manifold geometry as internal edges, badly made faces (one face across 3 prepared quads), ngons and for some parts you will need support geometry (to eliminate shading issues and hardening edges). Subdivision Sufrace modifier don't play along with those. You will need to have quad based topology with proper edge flow.

As for this particular question there is too much to cover on how to repair every broken part, I would encourage you to have a moment to redo the whole mesh having in mind quad based topology. Also, use Mirror modifier so you will not need to make changes on both sides (there are some differences now).

Look for example at this topology:

Also you can learn something from here: http://topologyguides.com/


Setting up a rooftile system with controllers

Though I'm not an expert, I tried for fun a (very) simple driver setup that you could try to adapt-

I created two shapes roughly resembling yours above, here shown with two different materials to help visualization.

(Note that I locked all "manual" rotation and location transform for those shapes, because I wished to hide the transform tools when they were selected!)

the top brown cylindrical has an array that allows for X replication (fixed count), and has a driver using the X location of a "controlling" mesh (a blue cube, named cube.001, here hidden in another layer)

the side yellow square shape had two array modifiers, allowing replication (fixed count) on its X and Y local axis, with a driver for each (always to the blue controlling cube, on its X and Z), and also a driver that allows for the rotation on its X, based on the X rotation (limited by constraints) of the blue cube.

You can add those drivers right clicking on the "count" property, and choosing this menu voice:

You'll find (for a selected object) this new driver settings in the "graph" editor, selecting "drivers" mode, instead of the default "f-curve"

Here is the overall setup:

Now, revealing the blue cube (separate layer) allows for "roof tiles" editing: the cube is in  its initial position

grabbing it along its X, allows for the roof X "expansion"

then, grabbing the blue cube down on its Z, expands the roof tiles on their Y direction:

and finally, rotating the blue cube on its X axis allows the roof tile to rotate in the same way, as needed:

here is an animation showing how it works, and how you can reset it using clear location (altG) and clear rotation (altG)

and here is the file I used (just a simple example)

Note: drivers need to automatically run python scripts, so you need to load the file using the "trusted source"


How do I animate influence of follow path

This can be done by animating the influence slider at the bottom the the constraint.

Most interface elements in blender can be keyframed by pressing I while hovering over them.


Ocean displacement map not showing waves

The circle does not have enough geometry.

Displacement in Blender works by modifying existing geometry on the object. Your circle definitely does not have enough existing geometry to make displacement visible. This is an easy fix, just apply a subdivision surface modifier, or select all the edges and subdivide them in the edge context menu.

Additionally, I see that you are in Texture Preview mode. Note that displacement will only show as bump in that mode, and in order to actually displace the mesh you need to switch to rendered view mode in cycles and make sure that displacement and bump are both rendered.


Import and render 3d objects with python

I believe this is possible and not too difficult. The trick is: Do one iteration manually by clicking in the menus etc. and Blender will create most of the code for you. Then you just switch to the Scripting layout (or change one of your panels to Scripting -> Info type) and there is the code Blender used to perform your operations.
For example I just added a camera in my scene and I see this line:
bpy.ops.object.camera_add(enter_editmode=False, align='VIEW', location=(0, 37.462, -0.0662922), rotation=(1.5708, -0, 1.5708))

You then need to change the numbers into variables and make some for-loops and you are done in no time.


How can I have an entire island move when selecting a portion of it?

Enable Proportional Editing in the UV editor, setting it to Connected and Constant. Then after selecting just move the island as close to the relevant pixel you can, ensuring the Proportional Edit is mousewheeled out (down on windows) enough to move the entire island.
If you need to be perfect, I guess move a randon, probably still-to-be-unwrapped vertex to the cursor with Snap>Selected to Cursor. The select your island, and with Proportional editing above, Change "Type of Element to Snap to" to Vertex (icon next to the Magnet). Assuming Snap during Transform is off, G to move your island, and if you hold Control, your island should snap to the vertex at the cursor when you get near.
Just remember to to move the "spare" / "cursor" vertex out again by a combination of inverting selection or some such.


You can find that Attributes on the official Page for the Attribute Node:
Attribute Node - Blender Manual

Or on the Stack Exchange Thread: All Possible Attributes - Stack Exchange


It looks like you have different materials assigned, got to the materials tab in object properties to see your materials.

When in edit mode you should see options to assign selected vertices to materials, you can use this to assign everything to the correct material slot. You can also use the select options here to see which vertices are currently assigned to that material.


Eeevee only supports box-shaped volumes. To increase the resolution bump up the tile size and samples in rendering/volumetrics.


Your question doesn't tell us for which application you need this effect - a rendered animation I guess. (Or a game?)

If you don't need it to be live input, you can just do the following:

Set your camera to the desired position. For every frame the camera is 'active' as the portal is deployed, you have to be in camera view.
Now, just render the animation in this time period (as png's).
Next, go into photoshop/gimp/whatever, and put the portal on it like a border. Everything outside it should be alpha. (To achieve an animated portal you should use different portal borders, a static portal looks quite boring...)
Finally, back in blender, add a plane the size of your portal (you can also use the add-on "images as planes") at the place you want to let the portal appear.

Animating the Texture:

As this is complicated to explain just take a look at this video, which explains the process in detail.

If what I said wasn't visual enough, I could help out with sceenshots and a blend file.


My model is not reflecting any light / looks dark

It's a problem you may find with some imported files, you need to go in the Properties panel > Object Data > Geometry Data, and close Clear Custom Split Normals Data.


Reconstructing vertices and uv separate from polygons

I was putting skip into triangle when skip was already the triangle face re-ranged


Enable Use Nodes:

and make sure you are not on the Material Node Editor, but on the Compositor:


First enable the Rigify Addon in Menu: File / User Preferences

Now you can add the whole human rig to your scene in Object Mode Shift-A

In Edit Mode align all bones with your model. When done parent the model to the rig Ctrl-P (With Automatic Weights).

And create the Meta-Rig.

After that you can create Actions and arrange them in the NLA editor. Importing to Unity is best done by Import New Asset from the Asset Menu.

A more detailed description with removal of unneeded bones is available in the Unity documentation: http://docs.unity3d.com/Manual/BlenderAndRigify.html

If you don't want to animate a humanoid then chose Animation Type: Generic  in the import settings of the rig:


Can I change default folder to save startup file (startup.blend and userpref.blend)?

To save Blender user preferences in Blender's own installation folder, also known as a Portable Install, start by navigating to the place where you installed or unpacked the Blender archive.
Method 1 - Easy and simple
Once there open the Blender folder and search for the version number folder (commonly 2.## ) inside the root directory, and inside it create a new directory called Config such that it stays Blender\2.##\Config.
If you now run Blender from this location and press Ctrl+U startup.blend, userpref.blend, bookmarks.txt, and recent-files.txt will be placed under this config folder by default.
New addons will now be installed alongside default ones currently shipped with the installation Blender\2.##\scripts\addons or Blender\2.##\scripts\addons_contrib
If you already had any previously customized config files under your Windows profile you can manually copy them from the default profile location (generally under C:\Users\\\$USERNAME$\AppData\Blender Foundation\Blender\2.##\) to this new location to bring back your previously saved preferences.
Method 2 - Safe and maintainable
Blender supports several launch variables, a few of them are BLENDER_USER_CONFIG and BLENDER_USER_SCRIPTSwhich allow overriding the default folders for user configuration (where startup files are saved) and the folder for users scripts and addons, where third party installed addons, presets, keyconfigs and scripts are installed.
The trick is to launch Blender from a batch file that sets this to your custom desired location.
In a plain text editor like Notepad paste the below lines of code and save them to the same folder as Blender.exe, give it a any name like "Blender_Portable" but make sure you specify the file extension as .bat not .txt.
SET BLENDER_USER_CONFIG=%~dp0Portable_Data\Config
SET BLENDER_USER_SCRIPTS=%~dp0Portable_Data\Scripts

if not exist %BLENDER_USER_CONFIG% mkdir %BLENDER_USER_CONFIG%
if not exist %BLENDER_USER_SCRIPTS% mkdir %BLENDER_USER_SCRIPTS%

start Blender.exe

This will ensure any custom addons and scripts installed will be placed in a separate directory from default shipped ones, making this "portable install" easier to update for future releases without loosing your custom installed addons or having to install them and configure again.
Notes
When using any of these methods make sure Blender is not "formally installed" into one of the default protected system locations like C:\Program Files or C:\Program Files (x86) or any other place in the file system with restricted access that may require administrator privileges to write to, otherwise saving preferences may trigger UAC prompts or fail entirely.
These method are more suitable if you install Blender in some secondary internal drive, removable media like a thumbdrive, external HDD, USB device, memory cards, or similar, and useful if you jump around computers frequently (between work, home or school). This way you can keep you settings and user preferences with you, and carry them around wherever you go, without changing system installed or local defaults.


How to update the connection shortest line between the vertice of a cube and an Ico sphere?

Using the animation system

Result of making an "edge object" parented to cubes zeroth vertex to the closest vertex point on the ico sphere. A cone is constrained to tip of edge and tracked to the cube.  Its motion path has been calculated and displayed for 100 frames
Set Up
Set up your scene, blender rotation unit is natively radians,  Using Q code and for this example adding keyframes to rotate cube one revolution in total_moves plus one frames.
import bpy
from math import radians

bpy.ops.mesh.primitive_cube_add(
        size=0.51,
        location=(0,0,0))
cube = bpy.context.object
bpy.ops.mesh.primitive_ico_sphere_add(
        radius=3,
        location=(0,0,0))
ico = bpy.context.object
wfm = ico.modifiers.new(name="wire", type='WIREFRAME')

total_moves = 100

cube.rotation_euler.z = 0
cube.keyframe_insert("rotation_euler", frame=0)
cube.rotation_euler.z = radians(360)
cube.keyframe_insert("rotation_euler", frame=total_moves + 1)

Add the "edge" mesh
Next will set up the shortest edge mesh. Contend that instead of creating an edge mesh for each frame can create a single edge mesh and move it.  (would also note its possible that all verts of cube are equally close to a vert on ico,)
Make a two vert one edge mesh, both coords at origin (0, 0, 0)  For use later have added one vertex to vertex group "Tip".
Consider all variables to be "as above" if not defined.
verts = [
    (0, 0, 0),
    (0, 0, 0),
]

edges = [
    (0, 1),
]

me = bpy.data.meshes.new("Edge")
me.from_pydata(verts, edges, [])
edge = bpy.data.objects.new("Edge", me)
vg = edge.vertex_groups.new(name="Tip")
vg.add([1], 1.0, 'REPLACE')
collection.objects.link(edge)

Parenting
Parenting can be our friend here. If we parent the edge to the cube, then the location of the edge can be set using local coordinates of cube.
Instead I'm going to use vertex parenting. The example below parents the edge to the zeroth (index=0) vertex.
edge.parent = cube
edge.parent_type = 'VERTEX'
edge.parent_vertices = [0, 0, 0]

Could set the location (and or parent) to cube vertex and the location of other vert of this one object using code in question in a frame change handler for example.  See https://blender.stackexchange.com/a/183688/15543 re handler code using (non vertex) parented edge object to cube.
Shrinkwrap
Instead I'm going to put up the idea of using shrinkwrap.
swm = edge.modifiers.new("SWM", 'SHRINKWRAP')
swm.target = ico
swm.vertex_group = "Tip"

Image shows the result. The closest point on the wireframe ico is a halfway point on an edges (Since the verts are on sphere surface, a straight line to another cuts into the sphere...)  Motion trail from tip to vert (gif above) displays the vert chosen.
Make a disc on vert shrinkwrap target
Make another ico with arbitrarily small faces at its verts.
from mathutils import Matrix
import bmesh

bm = bmesh.new()
for v in ico.data.vertices:
    co = v.co
    M = v.co.to_track_quat('Z', 'Y').to_matrix().to_4x4()
    M.translation = v.co
    bmesh.ops.create_circle(
            bm,
            cap_ends=True,
            segments=16,
            radius=1e-6,
            matrix = M
            )

me = bpy.data.meshes.new("IcoSpots")
bm.to_mesh(me)
ico2 = bpy.data.objects.new("IcoSpots", me)
ico2.matrix_world = ico.matrix_world.copy()

collection.objects.link(ico2)

This object can now instead be used as a target of the edge objects shrinkwrap modifier.
Notes.
This is put forward by way of concept. It is only creating the one edge object and parenting it to one vertex by way of demonstration.  I also didn't use the modified ico mesh to make the "spot" mesh.
To display the shortest would be tempted to add an edge for each cube vert, and drive its visibility based on other lengths.


I have never needed to work with text blocks so I have no idea yet. Let's find out.

If you press Tab after writing something in the Python Console, you can see all the available options from auto complete like this:

We can see that it is possible to access lines text.lines so if we want to read the 4th line for example we carry on with auto complete:

and see that it has body, that's probably the thing we need here then:

It's a string. That's it.


How to get object's world rotation around z axis

Without seeing the rest of your code, or even an example of your output, I'm assuming the result does not make sense because they are displayed in radians. Blender uses radians at it's core so all raw rotational data is in radians.
To get the Z rotation of an object, use import mathutils and to convert to degrees from radians, use import math
import bpy
import mathutils
import math

matrix = bpy.data.objects['Cube'].matrix_world # assign Cube matrix
eul = mathutils.Euler(matrix.to_euler('XYZ'), 'XYZ') # create an Euler from the matrix using mathutils
print (math.degrees(eul.z)) # print the Z value from the Euler converted to degrees via math


I might be wrong but I thinks it's as simple as you first have to click on the "principled BSDF" otherwise blender doesn't know where you want to add the principled set-up.

So just click on the node to make sure it's highlighted and try again!


Here is just an example about doing something like that with booleans, as I stated in my comment above...

starting form a shape like this:

and then from a copy object, using a cylinder as duplivert (faces), later converted to real object, like this:

then using booleans to subtract the second from the first, to obtain this:

As said, this would require some more regular base mesh topology, and could not be applicable to your model, at least as it is now, but could give you some inspiration to find a setup that works...


Adding random noise to a mesh -- programmatically (bpy.ops.mesh.noise)

Ugh, found it:

bpy.context.active_object.active_material

bpy.ops.mesh.primitive_plane_add()
bpy.ops.object.editmode_toggle()
bpy.ops.mesh.subdivide(number_cuts=subdivisions)

bpy.ops.object.editmode_toggle()
bpy.ops.object.editmode_toggle()

#mat = getOrCreateMaterial()  Does not work
mat = bpy.data.materials.new("Material")
mat.texture_slots.add().texture = getOrCreateTexture()  #works

bpy.context.active_object.data.materials.append(mat)
bpy.context.active_object.active_material = mat

bpy.ops.mesh.noise(factor=0.5)

Had to look in the C source code for clues.


Grab data from every frame with Python API? without using bpy.context.scene.frame_set(frame)

You can read the keyframe points of F-Curves directly, which doesn't require frame changes. Instead, the x-coordinate of a point is the time / keyframe, the y-coordinate is the value.

To find the right F-Curves, iterate over Object.animation_data.action.fcurves and check their data_path and array_index properties.

Related:
http://www.blender.org/documentation/blender_python_api_2_71_release/info_quickstart.html#animation
(See the low level example)


How to scale along the local axis of an object?

When you are in edit mode, select the desired vertices, press S, and then press either X, Y, or Z twice in a row.

After the first press it will transform along the global orientation as usual:

After the second press it will use the transform orientation selected in 3D view > header, which is set to local by default:

If the orientation is set to global pressing the axis key (X,Y,Z) twice will still use the corresponding local axis.

This solution does not work if the vertices were rotated in edit mode. For that you may have to change the transform orientation to normal, and manually move the edges.


Texture, Material problem when exporting to three.js

Set the diffuse color to full white.

Blender internal materials do not overlay the diffuse color over the texture (blending) while depending on your application / three.js shaders probably do take diffuse color into account as a color overlay.

Als make sure to set the intensity to 1 as that might change the RGB values upon export. Blender default materials have a gray value and intensity 0.8 as default, so you could write a little script to update all the materials:

import bpy

for material in bpy.data.materials:
    material.diffuse_color = (1.0, 1.0, 1.0)
    material.diffuse_intensity = 1
    material.specular_intensity = 1

A neutral white should therefore produce the proper result.


How can I get a new random seed for every object using the same geometry nodes?

The geo-node-network containing the random height functionality is executed only once per instance. So if you're instantiating the buildings from a single object mesh or collection instance it will be all based on the same random value.
I had a simular issue and solved it by creating a collection of instances and letting the point instantiate node pick random items from that list. I used the location of the instance to select a height value, but you can also use it as a seed value.

To get the position of the object within the associated geo-node-network:

Add an empty object at the world origin
Add an Object Info node to your network
Set the offset toggle to Relative
Add a Vector Math node and multiply the location by -1,-1,-1


Animation Nodes Using Time/Frames to affect Objects Materials

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

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

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

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

import bpy
from datetime import datetime

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

"""

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

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

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

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

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

# Note: pass_index is 0 by default.

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

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


I got this solved, in a kind of sad way.

The cause was that I had the mouse locator on. This over took the keyboard input of my Ctrl key.


Each scene in a blender file is separated from each other, using it's own settings.

The data in a blend file can however be shared between scenes, this may be an object, mesh data, material etc. For example when you selecting a material, every material in the file will be listed and show up the same in every scene. When you use the same data block in multiple scenes then changing the item in one scene will also change it in other scenes.

The easiest way to tell if an item is unique is by the name, data blocks linked between scenes will have identical names. Here you can see that Suzanne is the same object linked between scenes, while Suzanne.001 is a different object that is only in scene.003.

If you want to use the same object in multiple scenes select it and press CtrlL and under Objects to Scene choose which scene you wish to link it to.

So the answer to your question will depend on how your file is setup, this should help you find out and to setup your file as you want.


Efficient Rendering of Many volumetric particles

The best solution I found is by utilizing the point density node in the cycles materials. First, I placed a material with vertices - this method was described in my original post. Then, placing a cube around the coordinate extremes and assigning the vertex group as the first mesh. There are some toggles (resolution and radius), these are assigned to match the grid-size as defined by the simulation. Then the remaining of the problem is found in: Is there an easy way to make volumetric clouds for Cycles?.

edit:

The result of said manipulation is as follows


This is most likely caused by your brush being limited to the boundaries of the UV islands. You have 2 ways to fix that :

increase the Bleed value in the Tool Shelf > Options tab
paint on a transparent background and once you're done painting, save the image, import it in the compositor and feed it through an Inpaint node

the latter being the best in complex models and textures but in your case the first is certainly sufficient.

However no matter how simple or complex your model is, you always need margins between your UV islands, even bigger ones if you're using bleed since without a big enough margin it can overlap to another island (which doesn't happen with Inpaint but still a small margin is obligatory).


How to ensure accurate rigid body simulation with many small objects

I believe your problem is due to the Collision Sensitivity Margin - although you shoul dalso ensure you always Ctrl+A, 'Apply Scale' on your objects (if you have rescaled them) prior to running any simulations.

I've replicated a similar situation to drop a multitude of small cylinders into a box :

In the above image you can clearly see that the cylinders are separated from the surface. This is due to the default collision Margin of 0.04 on the Cube. The collision margin generally helps with generating a more stable simulation by providing a 'buffer' with the surface to prevent objects from intersecting. However, the default may be too large for some simulations - especially with objects at a small scale.

Here's the same simulation with the margin set to 0.001 :

As you can see there is now no noticeable gap between the container and the cylinders.

Note that the smaller the 'margin' the closer objects are allowed to get before they are considered to have collided. However, the tooltip on the margin does suggest that better results are obtained when set to non-zero. Therefore, you should generally set it to a value for your scene that is just small enough to not notice a gap between colliding surfaces.


To install this add-on you don't need to unzip the folder.

Go to the Add-ons tab in user preferences and navigate to your add-on zip location and double click on it, then once it is installed make sure to tick the checkbox to activate it.

Steps:

Download Zip Folder

Go to File -> User Preferences

Then choose install from file

Navigate to the downloaded add-on zip or simple copy the path of the zip folder and paste it in the path text box as shown below then select the zip folder and click on the install from file button
 checkbox

Select your Object then in the Tools Menu you will find a new tab called Sculpt click on it


Automation for baked rigid body dynamics baking, creating armatures, and transferring to armatures

https://blendermarket.com/products/ossim
This tool provides almost exactly what I am looking for.


Displace a grid.

By nature  moving an imported obj by the noise result is going to look voxelated.
Could instead simply displace the matching z coordinates of a grid by the noise. (Akin to using as a displacement texture)
import numpy as np
import bpy

def interpolant(t):
    return t * t * t * (t * (t * 6 - 15) + 10)

def generate_perlin_noise_2d(
        shape, res, tileable=(False, False), interpolant=interpolant
):

    delta = (res[0] / shape[0], res[1] / shape[1])
    d = (shape[0] // res[0], shape[1] // res[1])
    grid = np.mgrid[0:res[0]:delta[0], 0:res[1]:delta[1]] \
               .transpose(1, 2, 0) % 1
    # Gradients
    angles = 2 * np.pi * np.random.rand(res[0] + 1, res[1] + 1)
    gradients = np.dstack((np.cos(angles), np.sin(angles)))
    if tileable[0]:
        gradients[-1, :] = gradients[0, :]
    if tileable[1]:
        gradients[:, -1] = gradients[:, 0]
    gradients = gradients.repeat(d[0], 0).repeat(d[1], 1)
    g00 = gradients[:-d[0], :-d[1]]
    g10 = gradients[d[0]:, :-d[1]]
    g01 = gradients[:-d[0], d[1]:]
    g11 = gradients[d[0]:, d[1]:]
    # Ramps
    n00 = np.sum(np.dstack((grid[:, :, 0], grid[:, :, 1])) * g00, 2)
    n10 = np.sum(np.dstack((grid[:, :, 0] - 1, grid[:, :, 1])) * g10, 2)
    n01 = np.sum(np.dstack((grid[:, :, 0], grid[:, :, 1] - 1)) * g01, 2)
    n11 = np.sum(np.dstack((grid[:, :, 0] - 1, grid[:, :, 1] - 1)) * g11, 2)
    # Interpolation
    t = interpolant(grid)
    n0 = n00 * (1 - t[:, :, 0]) + t[:, :, 0] * n10
    n1 = n01 * (1 - t[:, :, 0]) + t[:, :, 0] * n11
    return np.sqrt(2) * ((1 - t[:, :, 1]) * n0 + t[:, :, 1] * n1)

def generate_fractal_noise_2d(
        shape, res, octaves=1, persistence=0.5,
        lacunarity=2, tileable=(False, False),
        interpolant=interpolant
):
    noise = np.zeros(shape)
    frequency = 1
    amplitude = 1
    for _ in range(octaves):
        noise += amplitude * generate_perlin_noise_2d(
            shape, (frequency * res[0], frequency * res[1]), tileable, interpolant
        )
        frequency *= lacunarity
        amplitude *= persistence
    return noise
# lightweight test
#p = generate_fractal_noise_2d((16, 16), (2,  2), 3)
p = generate_fractal_noise_2d((256, 256), (8, 8), 5)
print("-" * 33)
i, j = p.shape
scale = 0.5

bpy.ops.mesh.primitive_grid_add(
        x_subdivisions=i,
        y_subdivisions=j,
        size=10,
        )

grid = bpy.context.object

for v in grid.data.vertices:
    v.co.z = scale * p[v.index // i][v.index % j]

Please note, have used a loop by way of example, in a rush (off to the vet)  and will get back
Far quicker to  use
grid.data.vertices.foreach_set("co", flat_array)

and set with  a ravelled list of coordinates
[x0, y0, z0, x1, y1, z1, ....]

eg making x and y with linspace or meshgrid, then slicing in z as shown in https://blender.stackexchange.com/a/172973/15543 is according to stackoverflow link quickest way to ravel.
Note blender has a perlin noise generator as well, will also try and find link re this.


Transfer settings to new version of Blender

You can always use the new Blender Cloud Sync addon. It requires a Blender ID (free) and the addon (free). It allows you to upload your preferences to the cloud, and download them anywhere in Blender.

(Image from cloud.blender.org)


Triangulation using X, Y, Z data file to create an elevation model

raster to csv to 3d surface

in a CSV all you need to provide are the z-heights per column / row. Decide on a formula to convert pixel intensity (RGB) to the z-height. You do not need to specify x,y components associated with the z-height, because they are implied by the position of the z value in the csv row/column.

At most you need to provide the spread distance between rows and columns, once. Given you are working from a raster image, and assuming the pixels are square, usually the spread_x and spread_y are the same value.

raster direct to 3d surface

If you can import the raster as a png or other supported file format, it is possible to convert straight from the image to a mesh..

import bpy
from math import floor

scalar_z = 2.3    #  amplification in z direction
scalar_xy = 1.0   #  amplification in xy

def generate_face_keys(num_x, num_y):
    faces = []
    verts_per_side_x = num_x

    for i in range((num_x - 1) * (num_y - 1)):
        x = (i % (num_x - 1))
        y = floor(i / (num_x - 1))

        level = x + (y * verts_per_side_x)
        idx1 = level
        idx2 = level + 1
        idx3 = level + verts_per_side_x + 1
        idx4 = level + verts_per_side_x
        faces.append([idx1, idx2, idx3, idx4])

    return faces

def geometry_function(image_name):
    img = bpy.data.images[image_name]
    num_x = w = img_width = img.size[0]
    num_y = h = img_height = img.size[1]

    # work on copy only
    pxls = img.pixels[:]
    num_pixels = int(len(pxls) / 4)

    verts = []
    add_vertex = verts.append

    # generator expression
    gen_obj = (i for i in pxls)

    for idx in range(num_pixels):
        y = int(idx / w) * scalar_xy
        x = (idx % w) * scalar_xy
        r = next(gen_obj)
        g = next(gen_obj)
        b = next(gen_obj)
        a = next(gen_obj)

        # height-map, would be grayscale, so z can be set to r*scalar
        z = r * scalar_z
        add_vertex((x, y, z))

    faces = generate_face_keys(num_x, num_y)
    return verts, faces

def generate(func, image_name, geometry_name):
    verts, faces = func(image_name)

    mesh = bpy.data.meshes.new(geometry_name + "_mesh")
    mesh.from_pydata(verts, [], faces)
    mesh.update()

    obj = bpy.data.objects.new(geometry_name, mesh)
    bpy.context.scene.objects.link(obj)
    obj.select = True
    obj.show_bounds = True

generate(geometry_function, "wvb_flat_2b.png", "3d_Surface_Object")

produces:


Yeah,, you can actually do it follow this video: https://youtu.be/qSafYNQrodk?t=1330

But here you have a simplified node setup to do it:

The color ramp is used to choose the steepnes you want to select, the white parts are what is selected, so maybe you'll need to inverse the color ramp colours.
The "Average Node" of the video is actually the "Vector Math" node with the average option choosed, I don't know why he used it, the simplified node setup that I shared works equally.

How this works? I really don't know, I only know that you use the perpendicular normal axis (in this case the Z) to get the stepness in said axis and the ramp to set the threshold.

With three points (black, white, black) in the color ramp and the ease mode you can customize more the selection.


Cannot Create Multiple Copies of Two Objects

If you want a copy use copy()
To get a copy with same object level properties use
copy = ob.copy()
copy.name = f"Target{i}"

and link that to the collection.  It will have the same data linked as the original.
Using question code you were losing all object level properties of the original by simply making a new plain jane default settings object with just the data part of original.
How to duplicate an object in 2.8 via the Python API, without using bpy.ops.object.add_named()


What is "Read Render Layer" actually for?

Quite frankly never heard of that before.
According to the Blender manual it is used to read cached render buffers from disk, possibly after writting them to save memory
From the Python API manual

bpy.ops.image.read_renderlayers()
Read all the current scene’s render layers from cache, as needed

It is probably used with the Save Buffers option under the Performance tab of the Render panel in the Properties Window which according to the manual:

Saves all render layers and passes to the temp directory on a drive,
and read them back after rendering has finished. This saves memory
usage during rendering, particularly when using many render layers and
passes.

Haven't figured out how to restore image after using it, I'm afraid it is lost, though I don't really fully understand the purpose of this nor how to use it.


I'm using objects as particles but the objects have hair. Why is the hair is all going sideways?

The answer has two parts.  First was that I had used a (hilariously) small amount of Gravity for growing the hair for just a touch of realism.  It is truncated in the UI to three decimal places.

Secondly, when I rotated and applied the rotation, my object was ready to be used as a particle, but it was on its side in scene space, and the hair system on the object still respected gravity in scene space.  In other words, the hair now understood gravity to be something that pulled to the side, in a sense.
But afterwards you can freely rotate an object, and as long as you don't apply the rotation the change won't be reflected in instanced objects.
So I simply rotated my reference object back 90 degrees on the X axis such that it was reaching for the sun like a good wheaty, and everything is fine.

Reintroducing phase randomization.


How to disable wireframe for a second 3D view when in edit mode?

A quick workaround for achieving such a work-space might be to make use of the 'Render preview' option in viewport shading. Given that the speed at which the window updates will depend upon the complexity of your scene and your system specs. But it could be useful as it does hide the vertice/edge/face data that can be seen in edit mode. Here's a screenshot of a similar scene:


The item you tagged as (1) is the objects data block and can be changed via python with

bpy.data.objects['3745'].data.name = 'newName'

Instead of referring to an object directly by name you can access the active object's data block with

bpy.context.object.data.name = 'newName'


Blender Units of scale and solidify modifier

The scale of your object is all over the place:
[![enter image description here][1]][1]
Apply the scale with CTRL-A in Object mode and try again.
[1]: https://i.stack.imgur.com/yL8Ni.jpg


How do you draw in multiple colors with grease pencil?

First, make sure that you are in material preview shading or rendered shading (unfortunately you cut the top of the viewport on the image on the question, don't do that).

Color will not appear in solid view.

For Material.
Set the material for the stroke and fill in the material properties window.

For vertex color
Set the color directly either on the top color selector on the screen.

Or use the tool options in the properties window.


Project from view multiple times from different angles

It sounds like this is what you are looking for unless I misunderstand the question.

Once you've unwrapped everything once you can then use -> UVMapping -> Project From View on selected faces without changing what has already been mapped out.


Can object index be used as driver variable?

import bpy
bpy.types.Object.index = bpy.props.FloatProperty() #Create new property 'index'
obs = bpy.context.selected_objects
i=0
for ob in obs: #Object created last will be in the first iteration and so on
  ob.index=i   #Assign value for selected objects in reversed order of creation
  i+=1


On appended character keyframes are semi-visible and not saved

Click the F to save the animation in the Action Editor. It stands for Fake User. Blender will discard data that does not have a user when you save a file.


Scaling: What’s the difference between Ctrl+A and S?

CTRLA while in Edit Mode changes the vertex radius; nothing else.
Only things like modifiers that use that property of the vertex to change something are affected. It's a nondestructive and indirect way of control since it only affects functions that read that value from the vertex.
Scaling on the other hand, at least in Edit Mode actually changes the mesh. It moves stuff to or away from the current pivot point. It is direct manipulation of the mesh.


New cube linked to the old object, how to make them separate?

It looks like you added the little cube while you were in "Edit" mode, so it became part of the same mesh as the chair. You will need to go back into "Edit" mode, select all the faces of the little cube and delete them.

"tab" for edit mode
"alt"-a deselect all
"3" for face mode
select click a face on the little cube
"Ctrl"+l for all linked faces
"p" to separate to new item


How to make 3D hollow cuboid objects and cut holes out of it

You can model this object quite easily this with a boolean modifier, and 3 array modifiers as well as a solidify modifier.

As for the actual shape of the holes in the image posted in your question, you can do this with a cube that is subdivided twice, then bevel the edges with Ctrl+B to round the shape and the mousewheel to adjust the cuts. Scale the object on the Z axis to finish it off.

For the rest of the object:

Add a cube, scale on the x or y axis to the desired length,
and apply scale with Ctrl+AScale. Then delete
the faces at the ends with X in edit mode.
In object mode add a solidify modifier to the cube, and adjust
the thickness to the desired amount.
Place your beveled cube where one of the holes should be. Scale it down accordingly.
Add an array modifier to the small cube with an offset and count
that is  appropriate across the top of the larger cube.
Add a second array modifier to the small cube to move the copies to
the opposite side.
Add a third array modifier to move the first two to base, and apply
all in the order they were added.
Add a boolean modifier to the larger cube set to difference with
the small cube as the target object and apply.

You can delete the beveled cubes, they are no longer needed.


You should observe what effect Subdivision Surface modifier has on different geometry. In this case the topology you modelled is just not good for it. If you have concave faces in your model the result of Subdivision Surface modifier will often be undesired:

This problem can only be fixed by modelling correct geometry for the modifier. You can have the modifier added and model things with it visible to see what results you get in real time while modelling. In some cases adding edge loops(ctrl + r) will help you, in some cases joining some vertices(j) or using the knife tool(k) in order to avoid concave faces might improve the situation. I cannot describe all the possible scenarios in this answer because of how many of them can be so my advice would be to experiment and see for yourself. Don't forget that you do not have to use Subdivision Surface modifier at all and can also achieve the same results using other modelling techniques. In many cases modelling inorganic shapes one can get better results simply using bevel(ctrl+b) operation.


Set the horizon to white
Turn on freestyle
Set freestyle visibilty to QI Range
Set the objects material fully transparent.


strange shadows and artifacts on cycles render

It looks like you are having duplicated meshes intersecting each other on your mesh, if not then it should be normals that are not represented correctly. Try to removing double and recalculate your normals and see if it helps. Also select all your face and apply smooth shading.

Attaching a portion of your mesh would let us help you diagnose the issue too. You could just leave the nose portion in the file where the artifact is showing up.

Preliminary Probe

Probing into the file, I found that you have meshes that have all the edges "mark as sharp"
to unmark the meshes. Go into edit mode, select all the edges ... hit CtrlE and select "Clear Sharp".

After which, I also found out that your faces are not joined as a single mesh ... to solve that.
Do this ... With all the faces selected , Hit W select "remove doubles". This will weld all the triangles into a single mesh and remove vertices that takes up the same 3d space.

At this point I apply "shade smooth" with the W "special meun. This mess up the normals. Then I proceed to add a modifier "Normal Edit" under then modify column. The strange shadows are gone but some harsh edges still persist.

Solution

Note
You can read about why this happens here. http://www.blenderartists.org/forum/showthread.php?370090-Cycles-Glass-render-Black&p=2864146&viewfull=1#post2864146


Here is something I put together to answer this q about a month ago, noticed it active and dug it up.

Before running script set up a scene with a sphere named "Sphere" and a cone named "Cone", give the cone a track to constraint to make it face the sphere.  The Cone is given a speed custom property.  Animate the sphere and the cone will track it.  This is done with frame change handlers.

NB: Need to fix for when the speed is zero, the track to constraint has no effect, (simple driver) 1 if speed > 0.0 else 0 and what to do when the objects collide.

import bpy
context = bpy.context
scene = context.scene

obA = scene.objects.get("Cone")
obA["speed"] = 0.01

obB = scene.objects.get("Sphere")
preloc = obB.matrix_world.to_translation()

def getloc(scene):
    global preloc
    preloc = obB.matrix_world.to_translation()

def setloc(scene):
    global preloc

    # set location for frame 1
    if scene.frame_current == 1:
        obA.location = (10, 10, 10)

    loc = obB.matrix_world.to_translation()
    v = loc - preloc
    if v.length > 0.000001: # it has moved
        print(scene.frame_current, v)

    # move object A towards B
    dv = loc - obA.location

    speed = obA["speed"]
    print(dv.length)
    if speed > 0.000001 and dv.length > 0.000001:
        obA.location += speed * dv.normalized()

bpy.app.handlers.frame_change_pre.clear()
bpy.app.handlers.frame_change_pre.append(getloc)
bpy.app.handlers.frame_change_post.clear()
bpy.app.handlers.frame_change_post.append(setloc)


This is probably due to viewport display settings.

Select the concerned object and in its properties panel,

go to 'object properties' tab
then 'viewport display' section
and uncheck 'wireframe' check box


How to avoid "Cycle of dependency" when rigging a mechanical model

You can work well using IK. See for detailed structure.


Exposure in the viewport is drasticly different than the render

Found it! Thank you, @cegaton!

I had two area lights from testing the system previous to putting on the hdri that were turned off from preview (eye icon) but on in the render (camera icon) in the outliner.

Life is in the details!


What are these items that are showing up in the viewport render

To render just your model without any lights, cameras, empties, or armatures getting in the render; simply turn on Only Render.

The Only Render  checkbox is in the Properties panel N under the Display category.


How to increase glare strength of just emission map?

Since you are using over exposed Emit pass as a mask, there is no way to get proper pixel mix with rendered image. Even more because of border's pixels contaminated by background color (on antialiased edge). Also in your answer I can see edge in your render. Probably a bit better because of differences on Multiply values rather than mix type.

What I would try is to add Dilate-Erode node on "mask" to get rid of border pixels. This also brings all edges of mask highlighted because over exposed glare node. To compensate these appeared pixels I tried isolated only "glare" object color (can be done many ways, luminance is not probably the best way) and bring this part a bit darker to original, so pixels can be mixed more smoothly into final.

Note: I disabled Denoise node since produced worse result and was extremely slow. I also add Multiply after Glare, but your "before" is probably better you don't work with such low values, but result should be mostly the same. Environment texture was not attached so I used blender's Environment "studio.exr" texture.

These mixing of border pixels is always very sensitive for input, so its always quite a lot of tweaking. It's not like one group node you can attach anywhere.


Try going through the following checklist:

Check to see if the problem might be caused by Modifiers.
Try turning off or deleting Shape Keys on the Object Data tab.
Clear out any Keyframes
Clear displacement and rotation of bones
Try removing the armature from the object


Objects are disappearing during a boolean subtraction

As Dale Cieslak explains, the Shear tool is very convenient. But you can force a 45° with the knife tool. Press K to activate it, press Z to cut through the mesh, and press C to cut orthogonally and 45°. So now go orthogonal top view and use it.

After that, delete, dulicate, mirror, snap with merge vertices, etc.


I've never had much joy combining two curve modifiers - not even sure what your set is - perhaps curve following path? As curves do essentially modify, they work fine with things like cables and planes, but will distort objects especially around tight corners.

The example below I set up with a Nurbs curve with three Hooks: One to hold the centre form and the other two to animate. There is not much animation just a bit of rotation and placement. If you wanted the scroll to open more, you could just scale it on one axis.

Maybe not the answer you were looking for but think it could be usable...


How to move the handles of a sequence via scripting?

You can reference the sequence object immediately when creating it:

seq = bpy.context.scene.sequence_editor.sequences.new_image("coolName", "somePath/img.PNG", 4, 1)

Then you can edit the frame_final_start and frame_final_end to edit the sequence start and finish, same as the handles:

seq.frame_final_start = 10
seq.frame_final_end   = 50


OK, so I figured it out. Apparently autosmooth in rigs doesn't work very well when animated with motion blur. Turned off motion blur and fixed my geometry w/  holding loops and everything is fine.


Can’t move hierarchy to collection or parent in outliner

An object(A) in a certain collection (lets call it Collection 1) can be parented to an object(B) in another collection (lets call it Collection 2), while it(A) remains in Collection 1.
So what you are experiencing is normal/intended behavior.
If you want the child(A) to also be in the same collection as its parent(B), simply select the object(A), press M to move it to another collection, and choose the one the parent is in (Collection 2).


Opening up a dope sheet window allows you to view all keyframes that you've made, accidentally or otherwise. You can hit A to deselect all the keyframes while hovering over the dope sheet; all frames are automatically selected. Hit B to select the frames in question and then delete them.


It turned out that I was using the Solid shading instead of the Material Preview viewport shading.


Insert keyframe for rigid body properties for object python script blender

You have to use the correct datapath.

bpy.context.active_object.keyframe_insert(data_path="rigid_body.kinematic",frame=100)

Select the object, make it active.
Enable the animated (rigidbody.kinematic) property and keyframe it.
Disable the animated property on the frame you want to have the object start simulating and keyframe it.

This script assumes there is an object called Cube in the active scene.

import bpy

obj = bpy.data.objects['Cube']

start_frame = 100

# make the object the active object
bpy.context.scene.objects.active = obj
obj.select = True
bpy.ops.rigidbody.object_add()

obj.rigid_body.kinematic = True
obj.keyframe_insert(data_path="rigid_body.kinematic",frame=start_frame)
obj.rigid_body.kinematic = False
obj.keyframe_insert(data_path="rigid_body.kinematic",frame=start_frame+1)

Look at the python tooltips.


I can not get an object to rotate around its local axis whit animation-nodes

Record the initials transforms of the object using an ID key, then multiply that transformations by a rotation matrix that hold the rotation data you want.


There's an orange dot with a black outline that is more visible when you are in object mode. That's your object's origin. The mirror modifier reflects over that origin point. If you'd like to change the origin point, you can do so a few ways. The way I'd do it is to select the top-most vertex alone. Shift+S and select Cursor to selected. Then go back into object mode and hit Ctrl + Alt + Shift + C and select Origin to 3D Cursor.


See the NLA editor capabilities for this.  Repeat Loop. Let N1 and N2 be positive integers. So action can be repeated N1 times.  Then a period of no movement.  Then again an action can be repeated N2 times.
Consider this as a quick note on NLA possibilities How to generate a full sprite sheet automatically
Tutorials on NLA can be searched here at BSE or yoootooob or similar site on your selected search engine. This is not a tutorial on NLA.
Insert keyframes for position on your Follow Path Constraint position. If the object moving happens to be an organic character then use keyframes on the motion of legs of character.


The stripey effect near the corner (known as z-fighting) would indicate multiple faces in the same location.

In edit mode select all vertices then remove doubles. You can find remove doubles in the specials menu W or in Mesh -> Vertices -> Remove Doubles


no matter what I do, the hair net addon doesn't work (Blender 2.9)

HairNet version
For Blender 2.90.1 you need HairNet 0.6.3. Version 0.6.2 is for Blender 2.90.0 (and older) and you will get this "mouse_event" error when you use it in a later version of Blender.
Sheets
A common mistake with the sheets is to use a sheet with only 2 "strand edges". The add-on needs at least 3 strand edges to work. Else you get this misleading "no seams" error.

Additionally

make sure that Location, Scale, and Rotation  is applied to the hair objects and to the head (Ctrl+A in Object mode).
make sure that you don't have accidentally checked the HairNet option [_] Emit Hair on Self when you have a head (sheet and head for example). Check both objects because the setting is not global but stored in the objects.
select the head/emitter object last (orange selection color)
the HairNet 0.6.3 (or Blender) has a bug the makes all hair of a random existing hair particles system move down on the z-axis if you add another hair particle system from sheets, curves, etc. You can prevent this if you turn off the previous particle systems in the viewport with the "monitor" icon before you add another one with the add-on.
don't forget to increase the number of Strand Steps (5) in the Viewport Display* settings for a better shape
and to "touch" the created particle guides in Particle Edit mode with a minimal strength brush as described in the manual


What about using a mix node with the lighten blend mode?

If you want more control, then you can generate a grayscale map and use that to set the alpha with a set alpha node:


How can I make my animation video repeat several times so it is a loop?

Open the VSE (Video Sequencer) window, import you images with ShiftA > Image/Sequence, it will create a strip, duplicate the strip with ShiftD, render.


Apparently there was something wrong with my mesh (although it looked completely fine in edit mode). I activated the Mesh: 3D Print Toolbox add-on and then used the Make Manifold button on my mesh. After that all the smoothing tools (Smooth modifier, Smooth sculpt brush) began to work properly.


How can I get my texture to show in render?

Your lights are disabled for preview... (eye icon)

Turn them on.


How to find active brush in Image Editor context?

I've found it

context.tool_settings.image_paint.brush


How to expand and contract the current selection in Edit mode?

The key combinations to expand and contract the selection are CtrlNumpad + (to expand) and CtrlNumpad - (to contract). Like this:

Note: I'm not using an English keyboard, and the < and > may work on an English keyboard. I honestly don't know


To switch two points on a graph select them and press S X -1

And to scale to 0 (as pointed out by @gandalf3)  S Y 0


Any way to simulate a material to look like the viewport?

Make Your Own MatCaps Render Cycles

In the Render Layer Node ( you just have to recharge the scene you're using )

Remember save file on .PNG


bpy.context.screen is a shorthand, but read-only.

You can set a screen via the Window object, which actually holds the screen reference:

bpy.context.window.screen = bpy.data.screens['UV Editing']

http://www.blender.org/documentation/blender_python_api_2_70_release/bpy.types.Window.html#bpy.types.Window.screen

There's also an operator to change screen by a number, relative to the currently active screen:

bpy.ops.screen.screen_set(delta=1) # select screen after current from list

This is what CtrlLeft and CtrlRight trigger (with a delta of -1 or 1 respectively).


Found it! For anyone else having this same issue, press N for the right side toolbar and click on the "tools" tab, then under the "workspace" drop down arrow, toggle "filter addons" off.


how does one install "audioanalyse0.1.1" module in blender?

Assuming you mean Audio Analysis v1.1.0 this script was developed for Blender 2.43 (around 2007) and is unlikely to work with the latest releases.

Meanwhile there was an addon Import_Movement_From_Audio_File which could be a better starting point. Unfortunatly it seems that it has been removed from the current distribution (the documentation refers to 2.64.9).

You could get an older Blender version from here.


If I were you I would have used "veins texture" and blend it with an orange background. Also use Subsurface scattering for the organic look. That's how I would try to make it. Good luck!


Blender can't figure out what to do with that big, oddly-shaped face on top.  You can see that even with a simple cylinder:

A few extra cuts on that face will make it smaller and convex, and it solves the problem:

That said, you should try to avoid large faces with more than 3-5 edges (preferably 4 edged quadrilaterals), which will give you the best results for subdivision.

Also, your initial model is very high-poly for a model you intend to subdivide.  Your UN-subdivided model is high-poly enough that it'd probably already work for most uses.

For subdivision modelling, I always try to economize the amount of quads before subdividing. Here's a quick wrench I did that uses a pretty small number of vertices:

...but it still subdivides quite nicely:

Hope this is helpful!


Sequencer's OpenGL render crashes with Grease Pencil

While the bug report you show has been resolved, it hasn't been included in a blender release. You will need a recent daily build (after nov 2016) or build your own from source to get that bug fix.

Note that the bug fix won't help, the solution to stop crashing was to disable grease pencil display in the VSE preview renders. I expect your solution will be to do an OpenGL render from the 3dview and then add the files to the VSE.


Child of Constraint influence value doesn't recorded as keyframe

It's looks like you set the transform keyframes. To set a keyframe for influence, hover the mouse cursor over the influence value setter and press I.
Another way to do this - press dot icon over the influence value.
If the keyframe is setted, the value slider turns yellow.

Important: make sure, that final medium supports Blender's constraints


In Edit Mode subdivide your Icosphere one time

Select all, and Split, Faces by Edges with ⌥ Alt + M

Change pivot point to individual origins and S to scale a bit smaller.

Add Solidify and Bevel modifiers in object mode.

Result:


You can activate the Snap option to make the vertices of your walls stick together, it will also work in Edit mode. As Yash said, you could also use a Boolean modifier to merge some walls, but it won't always give good result. But as AzulShiva said, maybe the best is to model your walls within only one object, it will simplify your work, unless you have a very particular reason to separate your walls.


Is there a way to make a one way mirror? (Cycles)

You have to use the Geometry node to make difference in the face sides. Here is the guide what I've seen before: Backface culling in cycles

You can set the camera to orthographic in the camera settings in the properties tab.

I made a native file for this: https://blend-exchange.giantcowfilms.com/b/6020/


How to efficiently instantiate object with memory-hungry modifiers?

Make a group of your object(s) with Ctrl + G and name it (in the tool panel)
In the add menu, go to "Group Instance" and pick the group you want to instantiate.

If you append/link such an object, select "instance groups" on the links before appending/linking.

This allows you to render billions of polygons on a 4Gb computer with precise positioning and also saves space on your hard drive as well.


Extruding, right-clicking, then scaling moves some vertices to the wrong place

In the Tool panel (on the left of your 3D View window, activated with T) > Options tab, deactivate the Mirror option.


What's better: adding new primitives or extrude from existing?

I am not an expert, but:

Using only one mesh (extruding from an existing mesh) is absolutely needed if you need deformations, because all geometry is linked, and also can keep vert/poly count lower... it is the better choice in most cases, in my humble opinion.

Using separate mesh (adding a new primitive) could allow to keep independent mesh parts separated, for some reason (e.g.: to split them later while modeling), but also allow you to treat them as a single object in animation (without deformation).


You can change "wire" or "wire edit" colors in the preferences:

To clarify, "wire edit" is the color for the editable part of the mesh.
For instance pink here (as this color does not or few overlap with others):


I think what you are looking for is Texture Atlas

It says it can

  Create one UV Map for all objects (non destructive making)

Which sounds like what you need to do.

As far as combining textures, I think you may have to do that manually. In the future I'd advise you to join your UV's first.


Given the answer of troy_s in this question here How to measure the dynamic range of an HDRi?, he states in the first paragraph that:

  An F-Stop is a halving and doubling of light, relative to the exposure
  referenced.

Now from my own trial and error testing in Blender, that's exactly what happens when you change the exposure value in Blenders color management settings:

If we now apply this thinking as a formula, for each color pixel this would mean to do the following for each color channel:

Pixel(x) = x * math.pow(exposure_value, 2)

Transferred into nodes, this could look like the following Node setup:

In a world node tree, you would now have something as easy as this if you transfer it into a node group:

You can find this node group, and also a similar one for the compositor to doodle around, in this Blend:


In Edit Mode you can mark the polygons you want to separate and press P , then Separate by Selection.

Pressing L while hovering over a mesh in Edit Mode will select connected mesh parts.


Operator doesn't work when invoked from Panel, but works when invoked using the spacebar

There are two issues with your code, and I presume your button doesn't actually call this code, but an older version of your operator:

bl_idname = "load.pointCloud" is an invalid name, only lower-case characters are allowed. Bad naming will make the operator registration fail.
The path to your .ply file contains backslashes, but you didn't escape them. You can use a raw string (r"C:\path\to\file.ext") to avoid lots of \\.

class LoadPointCloud_Button(bpy.types.Operator):
    bl_idname = "load.pointcloud"
    bl_label = "Load Point Cloud"
    bl_description = "Load the point cloud"
    bl_options = {'UNDO'}

    def execute(self, context):
        bpy.ops.import_mesh.ply(filepath=r"C:\sfmoutput\pmvs\models\option-0000.ply")
        return {'FINISHED'}

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

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

if __name__ == "__main__":
    register()


Cube Emitter: the cubes emitted pass through the ground plane instead of rest on it

This answer is just regarding your ground plain and having objects stick to it. I am assuming that this is a particle system. For your ground plane will need to have:

A collision modifier added, then
In the physics field to make them "stick" an option is that you could set Damping to 1 and Friction to 1. However, play around with the fields.

Note, this image is just using default particles with no mods.

After downloading your blend file I did the same and it worked as expected. Again noting this is only the getting the cube to 'stick' the other part is a bit vague for me.


Hexagon is distorting on x axis, when scaling on y globally

Here is why it stretch on the x axis : the scaling is done the world space (orientation ) and it gets projected to the local space of the object to be applied (since axis are not aligned world Y axis get projected on local X and Y axis) , the vertices has to keep their location the local space ( hence you see the distortion ) :


Best way to unwrap angle without stretching?

Solved by adding this triangle part to other part of UV. If you have any recommendations would be happy to see them.


Why isn't the textures with their patterns rendering in the correct places?

I don't play that game nor know the extraction software, Collada DAE is quite fine as an export format, something must be wrong with either the Ohana exporter or the Collada plugins, or both.

Jumping through many applications is a recipe for certain trouble, a million things could go wrong, not the very least, bad implementations, unsupported features, or even a plain bug. It's impossible to tell from the file alone.

Rule of thumb is: import the geometry, remake the materials, export file formats never deal well with materials.

Looking at the Blend file it seems that there is some trouble with the mesh symmetry and the texture.

Scaling the mesh 200% in the UV image Editor seems to partially fix the problem and vaguely align the geometry with the texture features. I would advise deleting half of all meshes, and applying a mirror modifier to them so UV are also mirrored automatically.

Enter edit mode on all objects composing the model, select all faces, go to the UV image editor, press . (Period Key) to transform about the 2D cursor location, make sure the 2D cursor is at the origin, press S to scale, press X to scale about the X axis, press 2 by a factor of 2.

Then optionally in the 3D view erase half the mesh with the wrong texture coordinates, and add a Mirror modifier to the object.

Optionally change the Material Specular Shading from Phong to Blinn to eliminate the shading artifacts.

I have no clue what it is supposed to look like, if that is not the intended appearance, then you might have to either import again with different settings or manually fix the UVs by unwrapping again.


Why won't the material node displacement work in cycles

Change the displacement type found in the Properties window under Object Data from (the default) Bump to True.
Note that this is an experimental feature and you must change the feature set from Supported to Experimental in Properties > Render Settings > Render.

True Displacement: Mesh vertices will be displaced before rendering, modifying the actual mesh. This gives the best quality results, if the mesh is finely subdivided. As a result this method is also the most memory intensive.
Bump Mapping: When executing the surface shader, a modified surface normal is used instead of the true normal. This is a quick alternative to true displacement, but only an approximation. Surface silhouettes will not be accurate and there will be no self shadowing of the displacement.


half animal has a mirror. Can I move the tail from one side to the other?

Another alternative is to keep the mesh symmetric with the tail in the center, and then add an Armature with bones to control the tail and then pose the armature to make the tail off-center.

The order of the modifiers (mirror and armature) are probably important.

Edit:  is a .blend file illustrating the technique and proving that it is possible to pose a mirrored mesh without applying the mirror modifier (leaving it as a modifier).


Rendering flat faces shows too many tris!

Ah found the answer:

"Set smooth shading and add an edge-split modifier with the Edge Angle set to 0 degrees"

https://blenderartists.org/t/making-mesh-render-faces-as-quads-not-triangles-in-sculpt-mode/518770/7


Can not make proper selection to make a face

i think you are hitting ALT as stated above, try this ... go to EDGE SELECT and select the two edges (easier then selecting 4 vertices anyways) then press F key


Figured Out I Need To Combine It With A Larger Object, Apply The Boolean, Separate The Objects, Then It Works.


Curve Editor — Move 2 Handles the same time

To select and move 2 curve handles at the same time you can use simple way which means selecting everything first, and then deselecting what shouldn't be moved.

Select all the curve points which should be edited, set the curve handles type to Free with V > Free.
With MMB deselect curve points and those curve handles which should stay untouched.
Move only one half of curve handles, not moving another.

This works in a similar manner as with editing Bezier curves in 3D View. You can scale, grab those handles etc.

The disadvantages:

It may be hard to tell exactly which handle belongs to which curve point so in order to select / deselect them correctly.
In case of many curve points to process this may be inefficient.


Animation Nodes - How to Instance multiple objects/collection

You may use the Object Instancer node to instance a group of empties, then you can set their instance_type to COLLECTION and set their instance_collection to whatever collection you want. For instance:


Hide Objects(Collection) used as an particle from render in Blender 2.8 EEVEE

You also clicked the computer screen icon. Click the eye and camera icon, but keep the screen icon.


To get the result you want with smooth sides and better geometry there are a lot of steps necessary, but I can show you how this is achieved. For most of the following actions it's easiest or most comfortable if you use Vertex Select in Edit Mode.

Select everything with A, then press X > Limited Dissolve. This gets rid of several vertices you don't need anymore.

From the menu choose Mesh > Clean Up > Split Non-Planar Faces.

It's important that the side faces are split at the vertices where they bend towards the front, so make sure the Max. Angle value in the split options is set low enough so that there appear new edges between those vertices marked in the image.

For the following steps you need to set the Snapping to Vertex. You can also enable the Snap Tool (the magnet symbol) or later hold Ctrl while moving things to temporarily enable snapping.

Now you have to make cuts in all front faces of each step (except for the smallest one). You do that with the Loop Cut and Slide tool. Enable it by pressing Ctrl+R, then move your mouse to one edge of the front face of the higher step behind the smallest step. Make sure you're on an edge above the small step to definitely cut the higher front face, not the backface of the small step. Click to cut the face, then slide the cut up to the corner vertex of the small step.

With the Snap tool enabled (or holding Ctrl for temporary snapping if the tool is disabled) make the loop cut snap to the corner vertex and left-click to place it there. Now you have to repeat this for each following higher step.

For the following actions make sure you have Options > Auto Merge enabled. Next, select all six vertices between a smaller and a higher step that are supposed to be more or less aligned vertically (see left side). A good way to do it is to use the X-Ray or Wireframe mode, go to the Top View and select the very close vertices with Box Select or Circle Select.

To align them all, hit S to scale, then Shift+Z to constrain scaling to X and Y axis, hit 0 to scale to zero and left-click or Return to confirm. The vertices are aligned now but kept their distance vertically. You have to repeat this for all rows of vertices where the back and front of two steps meet.

After aligning all vertices like that, the Auto Merge option ensures that where two vertices shared the same location, they got merged into one. The only problem left now are the remaining inner faces that were on the backside of the steps. Deselect everything with Alt+A or double-tap A, go to the menu, Select > Select All by Trait > Interior Faces.

This selects all faces hidden inside the mesh. To delete them hit X > Delete > Faces. You can now go back to Object Mode.

Switching back to Solid View everything's shaded flat. Right-click the staircase > Shade Smooth.

Now the staircase looks terrible although you have Auto Smooth enabled. The problem is you have set it to 105°, which means Blender smooths even over the sharp 90° corners. To correct this, set the value to something that is in any case below 90°, usually the default 30° are sufficient, maybe go up to 45° if that doesn't seem to be enough. Et voilà, it's finished.


Curve weight and tilt smoothing has been added in r58575.
Will be available in the 2.69 release or any recent build.


How to make a bannister for a spiral staircase?

One way is to just add some cylinders to your stair object:

Add the cylinder meshes while in edit mode with the stair object selected.
Line up the geometry on the end of each cylinder (snapping is useful here, as it leaves no doubt about which vertex should be merged with what):

What I did in the gif:

Note the Z rotation of the array empty (this is only needed for the initial setup, it will be done automatically later), then enter edit mode and rotate the end to the cylinder the same amount (in my case, ~3.1)
Enable apply modifier to edit cage on the array modifier (inverted triangle icon).
Ensure the snapping type is set to Vertex and Self snapping is enabled in 3D view > Header.
Select any part of the horizontal cylinder, then press CtrlL (select linked) CtrlI (Invert selection) H (Hide selection) to get a clearer view and make snapping easier.
With the rotated end of the horizontal cylinder selected, press G and then hold Ctrl with your mouse cursor over the other end of the cylinder in the next array element.

Now enable Merge in the array modifier to merge those vertices together, resulting in a sub-serfable railing:

By using hooks parented to the main empty, you can keep the merged parts in the right locations, no matter where you move the main empty:

To do this, select the end of the horizontal railing cylinder and press CtrlH> Hook to new object. This will automatically add a vertex group, an empty, and a hook modifier. The hook modifier will bind the location of the vertices in the vertex group to the location of the empty.
Parent the newly created hook empty to the empty controlling the array (CtrlP> Object).

Repeat the hook+parent for the bottom edge loop of the central column.

See this example .blend to explore it yourself :)


In the mirror modifier you most likely have it set to mirror on the wrong axis. It could be set to X when it needs to be set to Y or maybe to Z. Just experiment with the different axis settings to see which one works. Also, If you want it to join at the center of the two sides which is great for modeling, use the clipping setting. Hope this helped! ;)


Use your 2d object as bevel object of a bezier circle object.

If 2d object is a mesh, convert it to curve, Alt+C > Curve from mesh.


How do I set a vertex color material in Blender 2.8?

Here is Attribute node with Color output and Col parameter according your Vertex Color name.

Updated:

List of all what can you call from the attribute node


You've probably already solved this by now, but it looks like you're in "Edit" mode.  Try selecting the drawing in "Object" mode (by hitting ↹ Tab), then try moving it.


"Failed allocate render result, out of memory" on render - Cycles Blender 2.79b

Sorry guys !
I just saw I put "1000 %" on the render size instead of 100% ! That was the cause !


Why are objects visible when set not to be?

For anyone that had this issue, I just made our prop "active" set to true by default. I do not know why this is the case, but it is.