If you grab the bottom corner of the top window you collapse the top timeline and you get rid of your 2 problems:

I may be wrong but for the moment it looks like if you have sticking windows, you can only get rid of them with the creation of a new one (or directly collapsing 2 windows but you'll need to recreate the one you had):


Can Blender be used on an Android device?

Sorry, there is no Android support at this time, and probably not ever. It would involve a massive coding effort for support and because blender is very cpu/gpu intensive, the devices that run it would make for a poor experience indeed.


no tiles while rendering, picure builds from bottom since i edited file on an old laptop

It sounds like the "progressive refine" option is checked.

Progressive refine will render the entire image one sample at a time similar to how the viewport does it. This does not affect the quality of the output, but it does affect the speed as progressive refine is slower than rendering all samples per tile.


Problem with positioning object relatively to another object

I finally found what causes this problem.
The object origin was not right for both objects.
https://docs.blender.org/manual/en/dev/editors/3dview/object/origin.html

For each object :
Panel:  Tool Shelf ‣ Tools ‣ Edit ‣ Set Origin
Menu:   Object ‣ Transform
Hotkey: Shift-Ctrl-Alt-C
-> Origin to Geometry

However I am still curious if there is a smarter way to specifies that 2 faces should be on the same plan.


Need Help with Python in Blender Game Engine

Okay,

I'll give you an example of what you could do.

Add the collision sensor as you normally would, the way you want it, but named "Collision" and set to true pulse triggering, and connect that to a python controller with your script (eg. "Text.py"). You also need a text object, named "Text", with a Game Text Property.

Collision Sensor -----> Python Controller

Then, inside the script (eg. "Text.py"), type the following:

from bge import logic

cont = logic.getCurrentController()
own = cont.owner
sce = logic.getCurrentScene()

collision = own.sensors["Collision"]
text = sce.objects["Text"]

if collision.positive:
    text["Text"] = "Wrong Way!"
else:
    text["Text"] = ""

Tell me if you need any more help.


Quicktime is a container.

On version 2,79 you have to choose FFmpeg video to reveal the encoding options.

There you can choose quicktime as Container and the codec.


If you want to do this effect with metaballs, then the accepted answer to this question shows how you can have a lot of metaballs in a certain shape: Why is there no option to convert a mesh to metaball object?

However, I wouldn't do it with metaballs. It shouldn't be too difficult to set up a shapekeys-based animation on a mesh object, with full control over the details.

HISTORY I gave the following answer when the question was formulated "Is it possible to use metaballs for something more interesting than just a ball?" It received two upvotes, so it seems that it was useful to some people.

The metaballs are not just balls, they are balls that melt into each other when they are close enough.

They can be used to simulate rain droplets on a window, and similar things, but in general they are not very useful. Just like NURBS surfaces, they are outdated technology, and are not used much these days.


Cannot set value 'RGBA' to color_mode in Blender by script (Python)

Little mistake :-)
I haven't set output format. There was set JPEG and it has no transparency.

When I put this line (before RGBA assignment):

rndr.image_settings.file_format = 'PNG'

script works.


this is a starting point (not 100% correct, but you can play with these nodes):


Blender Cloud texture settings: How to get from 0 alpha partial transparency in render?

You can use the Value from the cloud texture to get transparency.
Enable nodes, and in material nodes connect the value of the cloud texture to the Output's Alpha.
You can fine tune the amount of transparency by adding a color ramp in between .


Can a Blender script stay in memory and listen to a socket?

Since neither Blender nor Python deal with threading very well.. one option is to use async-IO to handle the network socket, and hook bpy.app.handlers.scene_update_post to have your script called periodically.

When your handler is called, you would both process async events on the network sockets, and perform whatever operations were requested by the network. Each interation of your handler should run for a relatively short time, or you'll block the UI.


It's because the mesh and the curve haven't got the same origin point. Select the curve, press Shift+S-->Cursor to Selected. Then select your mesh and press Shift+S-->Selection to Cursor.


Blender 2.8 Grease Pencil displays [Report ERROR: Nothing to erase or all layers locked] when trying to draw

I had the same problem on my XPen Deco03.There is a button on my pen Pen/Eraser.
I accidentally pressed it and turned on the Eraser. Just toggle it back to Pen by one more click


Mirror model in editmode without breaking UVs?

This seems to be a fixed bug (T80623 https://developer.blender.org/T80623) already on the list for potential candidate 2.90.1 https://developer.blender.org/T80396
As a workaround you can use the mirror-modifier and apply it.


How do I make animation nodes drive the vertices of my object?

Best to start by breaking down your problem:
- You want a node tree setup to control vertices of mesh
- Sound to drive the vertices

Check AN Templates for those two:
* Simple Sound Controller
* Random Vertices Offset

The YouTube demo is cool, but if node is missing, you probably can try to look for similar node.

Try a simpler setup first like maybe have a LINE and try to drive the vertices of the line by using sound.


The Subdivision surface object modifier

There are two things that I've identified in your screenshots that need to be improved. One is a fix, and one is the modifier.

Mesh Topology

Tab into Edit Mode and key A once or twice until everything is selected. Key Alt + J to convert Tris to Quads (triangular faces to quad faces). You can also key Ctrl + F to open the Faces menu and manually select Tris to Quads. Lastly, you can go 3D Viewport > bottom menu > Mesh > Faces > Tris to Quads.

Ctrl + F menu:

Mesh > Faces menu:

Subdivision surface

The Math

This will use the Catmull-Clark algorithm to create new faces between two imaginary points in the center of each current face.
From Wikipedia:

  Catmull–Clark surfaces are defined recursively, using the following refinement scheme:

  Start with a mesh of an arbitrary polyhedron. All the vertices in this mesh shall be called original points.

  For each face, add a face point.

  Set each face point to be the average of all original points for the respective face.

  For each edge, add an edge point.

  Set each edge point to be the average of the two neighbouring face points and its two original endpoints.
  For each face point, add an edge for every edge of the face, connecting the face point to each edge point for the face.

  For each original point P, take the average F of all n (recently created) face points for faces touching P, and take the average R of all n edge midpoints for (original) edges touching P, where each edge midpoint is the average of its two endpoint vertices (not to be confused with new "edge points" above). Move each original point to the point:

         This is the barycenter of P, R and F with respective weights (n − 3), 2 and 1.

  Connect each new vertex point to the new edge points of all original edges incident on the original vertex.
  Define new faces as enclosed by edges.

The Modifier

Go to the Properties panel > Object modifiers tab and add a Subdivision surface modifier. The two values you should care about are the View: and the Render: values. The View: value determines the number of subsurf levels, or iterations, displayed in the 3D Viewport. The Render: value determines the number of subsurf levels in a rendered image or animation. The Render: value should generally be higher.

The Subdivision surface modifier:

Subsurf levels 0, 1, 2, and 3 on a Suzanne:


you should be able to use the line select tool and scale up more so it covers the whole image, But Im not too shure :D


How to show transforms of Child Of or Copy Transforms constraint

I found the solution it was an answer in this question: Is there a way to convert a constraint to a keyframe?

You have to use Bake Action and then tick "Visual Keying" and probably also select the bone you want to bake the action for. This will make keyframes for any visual transforms.

Also in Pose Mode you can select bones and hit Ctrl+A and then use Apply Visual Transform.

I think you can insert keyframes for it with I -> Visual Transform too.


It looks like some stray edges.  Go into edit mode and press ctrl+shift+alt+m to select the non manifold geometry and then press x delete it. This can't be done in face select mode.


Removing an object from specific lighting

Method 1: The most simple or common way would be to use multiple files instead of one. 1 file with the background, one with the logo. Render out each animation as image sequence. Then perhaps in a third file load the two image sequences and render out the combined result.

Method 2: If you're using Blender Internal Render, another way would be to limit lighting for your materials to a specific lamp group:

Method 3: You could put your special object and its special lighting to a different layer as everything else. Then set the render layer not to render the layer for the special object. Create a new render layer and set it to only render the layer for the special object. Enable Compositing, and use nodes for compositing. Add another render layer node. Set it to the render layer for your special object. Combine the two render layer color outputs with a color mix node. Make sure you're rendering with transparency and that the color mix node is set to use the transparency of the second input. (This method is basically method one, but all-in-one)


How to plot 1/x^x in Blender using Z function surface

You can wrap your expression in parens add a .real or .imag to get the real or imaginary part, e.g. (1/(x**x)).real.


Is it possible to rotate two textures on the same object in opposite directions using the same Empty?

After much fiddling with nodes and materials, I couldn't get the direction of rotation to change. What I ended up doing was creating an empty and adding inverted copy rotation and child of... constraints as shows below. The primary control is "CTRL_TextureRotation" and then the material is setup as you have shown, with one texture coordinate driven by the empty and the other by the controller.


Bounding Box Size

I may guess is caused by a different bounding box size between the objects.

When there is no vector input in a texture node, Blender automatically use Generated coordinate type. As stated by the Blender manual page:

  Automatically-generated texture coordinates from the vertex positions of the mesh without deformation, keeping them sticking to the surface under animation. Range from 0.0 to 1. 0 over the bounding box of the undeformed mesh.

The hull certenly looks less tall than long, causing a "compression" of the values upon the Z-axis.

See in the image above the different mapping caused by a different bounding box's size.

And here you can see the values that the noise texture is passing to the Voronoi node. Notice how the mapping range is the same (0,1) but as is placed on object who has different sizes, the results don't match.

That's not probably your case, but remember that each kind of geometry is taken in to account for bonding box calculations, even loose vertices:

If you would like to spread the texture homogeneously upon the objects, I would suggest to use a Object Texture coordinate instead, maybe pointong not to the object itself (changing its scale would affect the texture size too) but to an Empty like in the example below:


how to speed up a video sequence in blender 2.8?

Speeding up the video framerate (which is what I believe you mean by video speed) can be done the same way in 2.8 as it can be in 2.79 and before. In the render settings, switch the default 24 FPS to whatever is faster than that. It should speed up the video speed.


You'll want to look at bpy.data.libraries.load(), which allows you to open a Blendfile and select which datablocks (objects, meshes, materials, etc.) you want to append or link. The API documentation also has examples.


You can use animated shape keys for it. To avoid too much stretching of the texture, you can use object coordinate.Like this:


Bezier Point Radius - Set Multiple by Absolute vs Mean Value

You can control curve radius proportionally with Alt+S or the Curve Shrink Flatten operator as you already know. This will proportionally scale all vertex.

So set an absolute value for all selected vertex use the operator Set Curve Radius either from the tool shelf, or the space bar search menu, and enter the desired value.


I think this might work. In edit mode delete faces 1 and 2. Select all the vertices of 1 and 2. Hit 'w' and select Bridge Edge Loops from the list. Hope this works.


It's caused by lack of bleeding in UV set, which will show poor result when sampling.

To solve this, just leave some room for the border pixel with the same color (that's what bleeding used for).


Here is a simple node set up that should get you close to what you are looking for.

Also you need a light to reflect, so I added a plane and put an emission shader on it.


How to iterate an image texture and save the iteration with python

I recommend you compute your filepath using a function like this:

from os.path import isfile

def next_file_name(pattern):
    i=1

    if (pattern%1) == (pattern %2):
        raise Exception("bad file name pattern")

    while isfile(pattern%i):
        i=i+1
    return pattern%i

print ( next_file_name("/var/tmp/blender/voronoi-wave/%04d.png") )

( thanks, https://stackoverflow.com/questions/82831/check-whether-a-file-exists-using-python )


Blender is genereally faster if you do not view the UVs of a high poly object while at the same time working with the mesh in 3d. UV mapping a high poly object might not be necessary, it is better to avoid doing that at all and work with UVs only on the lower poly versions that you bake the normals for. You can also hide parts of the mesh while working - in edit mode h to hide selected, Shift+h to hide unselected, alt+h to unhide. You can hide objects you do not need to see in the object mode as well it might be easier to do this from the Outliner or use local mode(Numpad /) to concentrate on one object. Spliting your object into smaller objects where possible and working on parts at a time might also make a difference. Obviously viewing objects in textured or material modes is slower than in solid or wireframe modes.

It's worth considering that the best cure for slow hardware might still be upgrading the hardware - no matter how much we don't want to hear that. If it's earning you money it's worth it, if not, than do you really need to work with such high poly meshes or is it possible to settle for less?..


How to change the Viewpoint Shading like in older Blender versions

You seems to be correct - with Flat type Lightning you can use Texture or Vertex Paint only, if you want use Workbench.
I wanted to use Material type, but it reflects only Viewport Display setup (single RGB Color).
So the only one way I see is use Eevee material.
Plug Vertex Color node and Image texture node into Mix RGB node, than directly into Output without any shader.
To see colours untouched you should change Color Management > Standard.


Grease Pencil why are black strokes gray, and how to make them black for a rendered image?

With your Grease Pencil object selected in Object Mode, go to the Modifier tab in the Properties Panel and click on Add Grease Pencil Modifier at the top.

You will see a few options. One of them is Opacity. Choose it and select your Grease Pencil's current material under the Material dropdown, and then its Layer under the Layer dropdown.
Increase the Factor by more than its current value of 1.

The result is a completely opaque render (Before and After)

I don't know why this works, nor why it's needed in order to achieve this. But I wasn't able to get an opaque render result any other way.


How do I create an 8 sided die from one object?

In user preferences (ctrlaltu) go to "Addons" and enable "Add Mesh:Extra Objects".

Back on the 3D viewport press ShiftA Add->Mesh->Math Function-> Solid

and select Octahedron from the toolbar.


Go to the vertex group panel and choose Copy Vertex Group (from the drop down menu) for each group you want to mirror. Then select the copy and choose Mirror Vertex Group.


Is there a way to store a workspace with a scene & auto-recall it when changing to that scene?

This used to be the default in Blender 2.7x, apparently they removed the function entirely, Here is a workaround:
How to assign different scenes for workspaces in Blender 2.8?
He creates a new window and instead of switching workspaces, he switches windows (ALT - TAB)


Firstly open your Command Processor.

  Windows(Command Prompt)
  Linux(Terminal)
  Mac(Command Line).

For Windows:

In cmd first type set path="C:\Program Files\Blender 2.80" replace it with path were your blender is extracted or installed. And press Enter.
Now we to locate the folder where you save your Blender files.
So in cmd, type

cd yourpath

If you didn't get what to type after cd than make a folder named Blender Projects on your Desktop and move the .blend files in it, and in cmd type

cd desktop\blender projects

and press Enter.
You are in the expected location,
Now,
If you want to animate,
run
this command,

blender -b yourfilename.blend -a

Rendering Single Frames

blender -b file.blend -f 10

-f 10 describes which frame you wish to render, in this case single 10th frame will be rendered.

You can also set start frame and end frame for animation just add this block in your animation command

-s 10 -e 500

-s refers to start and -e refers to end, replace numbers with yours.
You can also refer the documentation provided by Blender Foundation.

  Editing is greatly appreciated to this answer for Linux and Mac users.

Hope this information may be helpful. All the best.


how can I use both Color and Alpha for the ColorRamp

To have the alpha properly control the transparency of the volume you need to multiply it into the density before plugging it into the strength of the emission shader.

Click to enlarge


You can use face selection masking or vertex selection masking to select only vertices or faces, that You wanna paint on.This are options located on the bottom bar of 3D view port.


Operators: Updating a CollectionProperty using the exec() method

The type parameter of CollectionProperty is expecting a subclass of bpy.types.PropertyGroup. So you would need something like:

class MyBool(bpy.types.PropertyGroup):
    bool = BoolProperty()

Then in your operator, you use that type in your CollectionProperty:

my_list = CollectionProperty(type=MyBool)

You add to your collection by using add():

mybool = self.my_list.add()

...which gives you an instance of the PropertyGroup and the properties it contains. Here is an example that makes a list of booleans based on the selected vertices in the active object and prints the list:

import bpy
from bpy.props import CollectionProperty, BoolProperty

class MyBool(bpy.types.PropertyGroup):
    bool = BoolProperty()

class SimpleOperator(bpy.types.Operator):
    """Tooltip"""
    bl_idname = "object.simple_operator"
    bl_label = "Simple Object Operator"

    @classmethod
    def poll(cls, context):
        return context.active_object is not None

    my_list = CollectionProperty(type=MyBool)

    def execute(self, context):
        obj = context.active_object
        for vert in obj.data.vertices:
            mybool = self.my_list.add()
            mybool.bool = vert.select
        for b in self.my_list:
            print(b.bool)
        return {'FINISHED'}

def register():
    bpy.utils.register_module(__name__)

def unregister():
    bpy.utils.unregister_module(__name__)

register()


hit STRG-ALT-NUMPAD0 to set the selected object as the active camera. Currently you have an object as the active camera. The small triangle above the camera tells you whether it is active or not (filled triangle = active, triangle with just contours = currently not active)


Where is the samples setting for the Cycles render

You can change the number of samples for Cycles under the Sampling rollout of the Render Properties panel.  The Render spinner adjusts the number of samples used for the final render, and the Preview spinner adjusts the number of samples used for viewport rendered mode.


Model seems to shine in ways it shouldn't

It's a problem of normals that can happen with some imported objects, you need to go in the Properties panel > Object Data > Geometry Data, and Clear Custom Split Normals Data:


Joining 2 objects in Blender 2.8 loses UV mapping on 1

If more UV maps are linked to an object, the materials used by that object need to have an Input > UV Map node attached to the Vector socket of their textures, specifying which UV Map to use, so either of these:


UV textures not applying to skin modifier

You must Apply the skin modifier to be able to unwrap the mesh. Once applied, you will get acces to the generated mesh. Just press the "Apply" button in the modifier parameters.


Bezier Curve for some reason seriously messing up

You can enable viewing the curve's normals in edit mode using the overlay dropdown.

If your curve is twisted, this will show up clearly in the angle of the normals:

Unfortunately the only way I know to fix it is to select individual control points and either change their vector type to automatic (by typing VA) or by rotating the control point until the alignment looks good.


Emission material not showing in render EEVEE

You can use the bloom pass and composite it in the Compositor.


How can I make this surface in blender...?

There is basic support of NURBs surfaces in Blender. Basic is the keyword here. Check docs for detailed information about them: https://docs.blender.org/manual/en/dev/modeling/surfaces/introduction.html

In this example I've started with Surface NURBs Curve (marked as 1., red color) after moving and subdividing to achieve desired shape I've Duplicate it and made its reflection on X axis - S>X>-1. Than I've selected both Curves and made a segment - F. After some more tweaking individual vertices, subdividing surface and selecting Endpoint on V this is a result.

Also I've added Subdivision Surface Modifier.

In conclusion, it is possible, but it's really painful in Blender as it is lacking many mesh modeling tools. Read the docs and maybe you will be happy with them.


First keyframe is 1, not 0.
Make frame #1 your start one and then you have 30 frames like <1, 30>. Move start to #10 and it ends at frame #40.


WindowManager.invoke_props_popup(operator, event)

Operator popup invoke (show operator properties and execute it automatically on changes)

Code based on How to call a confirmation dialog box?, I just  replaced invoke_props_dialog by invoke_props_popup to diplay the popup without confirmation option:

import bpy

class SimplePropConfirmOperator(bpy.types.Operator):
    """Really?"""
    bl_idname = "my_category.custom_confirm_dialog"
    bl_label = "Do you really want to do that?"
    bl_options = {'REGISTER', 'UNDO'}

    prop1: bpy.props.BoolProperty()
    prop2: bpy.props.BoolProperty()

    @classmethod
    def poll(cls, context):
        return True

    def execute(self, context):
        self.report({'INFO'}, "YES!")
        return {'FINISHED'}

    def invoke(self, context, event):
        return context.window_manager.invoke_props_popup(self, event)

    def draw(self, context):
        row = self.layout
        row.prop(self, "prop1", text="Property A")
        row.prop(self, "prop2", text="Property B")

class OBJECT_PT_CustomPanel(bpy.types.Panel):
    bl_label = "My Panel"
    bl_idname = "OBJECT_PT_custom_panel"
    bl_space_type = "VIEW_3D"
    bl_region_type = "UI"
    bl_category = "Tools"
    bl_context = "objectmode"

    def draw(self, context):
        layout = self.layout
        layout.operator(SimplePropConfirmOperator.bl_idname)

def register():
    bpy.utils.register_class(OBJECT_PT_CustomPanel)
    bpy.utils.register_class(SimplePropConfirmOperator)

def unregister():
    bpy.utils.unregister_class(SimplePropConfirmOperator)
    bpy.utils.unregister_class(OBJECT_PT_CustomPanel)

if __name__ == "__main__":
    register()


BGE: "Record Animation" for just one object

Animations are recorded only for objects with Physics Type: Rigid Body & Soft Body. If you don't want to record animations, you can use Physics Type: Character.


Try pressing Alt-C to convert your text to a mesh object. I have found Cycles doesn't render text properly as text objects, as opposed to meshes. You could also try this shadeless material:

This should make your text be exactly the color you had picked without affecting any other objects in your scene.


Delete/merge mutliple vertices on the same spot

Select every vertex with A, hit W and select remove doubles .
 you may have to adjust the merge distance if they are not exactly on the same spot.

To make vertices that are on the same location merge automatically, enable automerge.

Another option is to select all the vertices again with A then press Space to open the search, then type Remove doubles (Or for saving time, just "dou")

Then press enter or click on it.


How do I add a specific number of loop cuts?

You can do this simply by typing the desired number (1 then 5) after pressing Ctrl+R and before left-clicking to complete the operation.


You can't just render the mist pass on its own. Blender always renders the combined pass (even if you check it off on the Data passes for the view layer).
You will need to render again.
Enable mist on the data passes for the view layer

Then use the Mist ouptut of the render layer to save your image.

What you should do in the future:
Avoid PNG and save as OpenEXR multilayer.
Use a File Output node, set the output to the desired format and create all of the inputs you need:

That way you can save the image with other different passes. Think of EXR as an exact copy of the render layer.
Then import the file back in blender and the layers should be available for you in the compositor.


Well facial rigs can be hard, it's better to learn simpler rigs first. For the model you're attempting, I would recommend joints, they work quite well. Remember that he is a rigid character so apply bones to mesh parts with "Bone" not any others as it wont distort different sections but rotate like using R on the object.

Blender cookie has great tutorials on facial rigging, especially David Ward's tutorials.


Python change of bone rotation is not update when export .bvh file

the scrip is active.

""""""""""""""""""""""""""""""""""""""""""""""""

for f in range(sce.frame_start, sce.frame_end+1):
    sce.frame_set(f)
    if f == FrameNumber:
        keyFrame = context.scene.frame_current
        keyInterp = context.user_preferences.edit.keyframe_new_interpolation_type
        print('key interp: {}'.format(keyInterp))
        for pbone in ob.pose.bones:
            if pbone.name == BoneName:

                lastMode = pbone.rotation_mode
                pbone.rotation_mode = "XYZ"
                bpy.ops.object.mode_set(mode='POSE')
                pbone.bone.select = True
                pbone[pbone.name].rotation_euler.x = math.radians(ValueX)
                pbone[pbone.name].rotation_euler.y = math.radians(ValueY)
                pbone[pbone.name].rotation_euler.z = math.radians(ValueZ)

                bpy.context.scene.update()
                pbone.keyframe_insert(data_path="rotation_euler" ,frame=keyFrame)
                context.user_preferences.edit.keyframe_new_interpolation_type = keyInterp
                bpy.ops.object.mode_set(mode='OBJECT')
                pbone.rotation_mode = lastMode


Creating a new particle texture using python scripting

after run:

import bpy
bpy.ops.texture.new()

you can see the "new" texture from:

/// update

*///////////////**

you can change the current texture to the "new one" with a simple code.. in this case my material name is 'Material', and after that you can change anything, for example I apply the new texture and change the type from CLOUDS :

import bpy

D = bpy.data
ob = bpy.context.active_object

bpy.ops.texture.new()
text =bpy.data.textures[len(bpy.data.textures)-1]
mat = bpy.data.materials['Material']
slots = mat.texture_slots
for slot in slots:
    try:
        slot.texture = text
        bpy.data.textures[text.name].type = 'CLOUDS'
    except:
        print("empty slot")

ACTUALLY , you have some better options to add textures, as texture slot add:

mat = bpy.data.materials['Material']
tex = bpy.data.textures.new("SomeName", 'IMAGE')
slot = mat.texture_slots.add()
slot.texture = tex


The way I did it was by writing serial information to the usb port from the arduino and reading it from inside blender with pyserial.

I did run this in the Blender's game engine, which may or may not be what you want. The Blender side looks something like this (code is not very clean, I just hacked this together quickly for fun, but hopefully to gives you some idea of how you could implement it):

from bge import logic
import serial
from mathutils import *
from math import *

def startup():
    ser = serial.Serial('/dev/ttyUSB0')

    scene = logic.getCurrentScene()
    object = scene.objects['Suzanne']
    print('startup')

    logic.globalDict['serial_bus'] = ser
    logic.globalDict['main_object'] = object
    logic.globalDict['light'] = scene.lights['Lamp']

def loop():
    ser = logic.globalDict['serial_bus']
    object = logic.globalDict['main_object']
    light = logic.globalDict['light']

    # this is where the data is actually read from the serial interface
    data = ser.readline().decode()
    pot, var, phot = data.partition(";")
    print("pot:", pot, "phot:", phot)

    object.localOrientation = Euler((-.31,0,radians(float(pot)))).to_matrix()
    light.energy = 10 - float(phot) * (10.0/800.0)

The Arduino side is just Serial.printing numbers separated by semicolons.

How exactly you want to animate objects in blender depends on your usecase. If it's for a real time demo, you probably want to use the BGE (or use another game engine entirely, such as godot). If you want to use it as a secondary input device in Blender's viewport (e.g. a sort of DIY 3D mouse), you'll probably want to look at writing an addon.


Your troubles come from the fact that some gloves vertices weights are assigned to vertex groups unuseful (i.e. the thumb one): remove all assignements to unuseful vertex groups and assign some weight to the forearm bone only.


How do I connect these faces up without adding too many quads using retopology?

Hi, this is the "usual" workflow how to proceed from a low-poly to high-poly (or vice-versa) and keeping quads - You could repeat the process multiple times so there is no problem to start with 2 quads and finish with 8 or more. Try it if it will work for You cause I dunno how "dense" your original mesh is so maybe this could not fit properly (too many steps needed).

Hope it helps, Buddy.

Sincerely, Jan


Which is the best way to model a low poly coat?

For low poly clothes you could start by blocking out the shape with just vertices and edges. Begin with a simple plane delete two vertices, add a mirror modifier and start extruding vertices around your model with E and connecting vertices with F.

Then when you get something like in the picture, you can start connecting those edges and pairs of vertices to make faces around your model using F in edit mode.

When you get a simple geometry that works you can add loops to refine the model with Ctrl+R. Then you can add a solidify modifier and play with the thickness parameter to give volume to the cloth.

For the details as it's a low poly model you'd have to texture them, but you can simplify the process by sculpting first then baking the results and applying a normal map or displacement map to get volume.


A bit of googling lead me to Metric & Imperial Units in Blender.

@DemonFate's answer, made me try manually setting the scale to 0.0254, which is 1 inch expressed in metres. I assumed the scale was a conversion from BU to whatever unit I wanted. But from the link above, I realised that when Blender is set to Imperial, the scale is a conversion from feet to whatever unit I want. Hence setting it to 0.08333 does the trick. To get the best precision, type in 1/12 and hit Enter, and Blender is smart enough to calculate it.

There are drawbacks, but I can live with them. The Scale and Location values in the Object tab and in the Properties panel now increments in thou, and all values typed in manually when grabbing or extruding are now taken as inches.


You have defined a RNA property, it will be available on any instance of this class( all scenes will have this property ) , to access this property use the following line  :

XX = context.scene.XX
# in the UI
row.prop(context.scene, 'XX')

you can also define an ID property which will be available only on this scene :

context.scene['XX'] = 10.0
print(context.scene['XX'])
#in UI
row.prop(context.scene, '["XX"]')

To learn more about this Topic refer to this DOC page : RNA properties versus ID properties


How do I make a glass with a thicker bottom than top?

You can for instance use a solidify modifier set to vertex group, then paint the weights in weight paint mode.
First add a vertex group and in edit mode make sure to remove every weight from your vertices.

Then add a solidify modifier to your mesh, set the factor to something > 0 so there is at least a bit of displacement with a weight 0.

Then go into vertex weight paint, with the ALT key pressed left-click on the bottom of your object, then drag your cursor up to the top and release the mouse button. You will see a gradient on your mesh :

Play with the solidify and the vertex group factor. Tweak a bit the mesh and use a negative thickness to get something approaching your image. Final result :


Is there a way to control Emission values using an empty's movement?

To animate emission with an empty movement you can use driver. To create it, click with right mouse button on numeric field of Strength property of the shader, choose Add Driver>Manually Create Later (Single). Then open Graph Editor, change mode from F-Curve to Drivers, click on one of frames on the curve you'll see, go to properties panel on the right (press N if closed), go to Driver, choose Scripted Expression as Type, in Expr window type var,for Object choose Empty, and for Type and Space choose X Location (or Y or Z, doesn't matter), World Space and done. Check gif below to see the process.


How to switch to Inverse Kinematic for Make Human model in blender 2.78?

You need to check "Override Exported Data" when importing the mhx2 file, and add a rig:

The rig controls are under the "MHX2 Runtime" tab (Layers and "FK/IK Switch") in the tools panel. The MakeWalk addon is not needed for this, only the MakeHuman import-runtime.


bpy.data.textures.new(...) error to create new textures

You have to select manually or by script object on which this texture will be applied. If the model is selected it should be highlighted or press 'R' the model should be able to rotate.


"track to" object under "parent" constraint

As I understand your problem here the my solution.

Try to do this setup from different way.

Add a "rotation" bone, witch will control hole system in z rotation.

next setup "camera direction" bone, lock its moving in x axis and parent it to the "rotation" bone. I use IK in both cases.

When you just need to setup your bones with correct lengths and axis locks. On last bone make IK constraint to the "camera direction" bone with rotation option enabled


Use a Grid Fill option. Select the edge loop around the hole, then press Spacebar and type Grid Fill. Play with its settings in a Tool Shelf's operator panel (T).


How to add shape keys to dimension of an object

Dimensions is just consequence of outside vertices rotated and scaled in object space. It could be modified only manually or by a script.


Tips for anime style swift movement and teleportion effects for blender 2.9

You can try to use KeyMesh which is an addon that will create frame to frame animation (model your speed lines, duplicate, deform, etc..)
Or you can try another 2D approach using grease pencil by following this tutorial>>
which basically shows you how to apply grease pencil over a specific layer. You'd create your character's "smeared" colors and then animate as the video shows.


Animation exported to Unity is always Default Take

When you import the model into Unity, a "Default Take" is included in the .FBX. It shouldn't matter if you're directly importing the .blend or .FBX, the default take is created. The default take would include all of the keyframes.

Basically, in Unity you then create additional animations clips (walk, melee), all of these are created based on this Default Take.
When you create additional animation clips in Unity, the source take is usually always the "Default Take", because this is the master source for all animations.

You should end up seeing something like this for the clips:

CLIP           RANGE       SOURCE TAKE
Default Take   0 to 100    Default Take (master take)
Walk           27 to 50    Default Take
MeleeHit       -1 to 26    Default Take


Possible to make the bones visible when the mouse is hovering over a rigged model?

As far as I know there's currently no way to do it without coding a custom solution that will hide bones and only show them on mouse hover. This would actually be very cool if we had something like this as default on blender (with maybe a slider to customize mouse distance-to-bone activation, etc) but as of today we dont.

The best similar solution that I can think of is an addon that is called Skin Selection, unfortunately, it's paid.

https://www.blendernation.com/2017/09/18/add-skin-selection/

This is a video of it working:

https://www.youtube.com/watch?v=x8AOj-nDn2o

It allows you to select a bone by selecting the surface of the mesh as if it was the bone... and allows for multiple controllers to be assigned to similar regions of the mesh. So nothing gets in the way, every bone is hidden.

I have not bought it to experiment and say how hard it is to configure, or how automated it is, but I'd advise you to check it out, its not that expensive.


Image Texture completely washed out in Render, but not in Viewport Shading

There is object "Plane" in a Collection "FloorPlan" which is hidden in viewport ("closed eye" symbol) but it's still rendered. So it overlaps the floor and causes the glitch in the final render.
In Blender 2.8x, the nasty thing is that objects in a collapsed collection, are still rendered. You need explicitly disabled them (or the collection) for render ("camera" icon). The toggle is not shown by default. You need to activate it in the filter settings of the outliner.

In Blender 2.9x, the checkbox of the collection collapses and inactivates the collection. Then everything inside of the collection is automatically hidden, in viewport and render.


how to add frame numbers over footage in blender video editor

In the scene preferences turn ON metadata. Select the information that you would like to see in the frame. You can choose to see the scene properties but not the strip properties unfortunately*.

Here is the overlay in the render view, only available when a new frame is rendered.

Sorry it does not seem to be available in the VSE live view. You could keep a little UV Image editor window open and hit f12 occasionally.

*According to this code entry for the Metadata function https://developer.blender.org/D1592 you cannot access Sequence Strip information.


Given the fact that there are more than seven billion people out there, it approaches certainty that many might share a similar view, even among the Blender community right now.

Personally I never saw this as a two way street until you brought it up. I have never seen the word used in that particular manner outside 3D. Turn B into A's parent would be more obvious, I agree.

It all comes down to definitions and associations. You try to give the verb a universally applicable meaning. And Blender's use of the verb collides a  bit with previous uses of the word.

In Blender, parenting A to B should always mean: B is the parent, A is the child.

Just substitute 'parenting' with 'glueing'. Glue A to B. It's at least tempting to assume that B is somehow bigger, even if it's a bit biased.


Is there a way to lock a bone axis? rigging

You have two options, while in pose mode you will find a Transform Locks panel in the bone properties, these are also available in the 3D viewports properties region N. This can prevent a user transforming specific axes.

A more rigid approach is to use constraints, There are several limit transform constraints that will prevent bones being moved or rotated outside of your settings. Here you can also set limits, so you can allow a bone to rotate 30 degrees on one axis.

The transform locks only apply to the viewport, an fcurve or driver can move a bone with these locks enabled. Constraints are applied after fcurves so can prevent an extrapolated fcurve from going outside your settings.

Update for 2.8x

From 2.80 the transform locks have been moved into the same panel as the transform values. They also don't visually stand out as buttons.


Is there a way to clamp transform values to a set number?

Ah! Nevermind, I figured it out. The little checkbox on the constraint, "For Transforms". How did I miss this.


How to have a displacement modifier vary it's shape within an array

Displacement Modifier:

Edit:

As @Duarte Farrajota Ramos pointed out - for Array Modifier it's sufficient to just have Displace under Array without changing Texture Coordinates. Change is needed only for manually duplicated meshes.

This one is very simple (taken that you are using Texture Type other than Image Texture).

Just select Texture Coordinates as Global in Displace Modifier.

  Note: I've forgot to add Array Modifier in this example, remember to
  add Displace Modifier AFTER Array Modifier.

For this example I've used Texture Type > Distorted Noise.

Micropolygon Displacement (experimental):

You can read how to use it here: https://wiki.blender.org/index.php/User:Maiself/Micropolygon_Displacement or just search for tutorials on the internet, there are a lot of them.


That should work for any node.. But another way is to hold ⎈ Ctrl and drag  LMB, "cutting" the node link(s) (aka noodles):


Hot element's glare in a colored lamp in rotational animation?

How to Create a Glow Effect in Cycles

Okay so although you suggested that you'd prefer this not to be a compositing-based solution, as mentioned in the comments I'll put this together regardless as it is a very useful and adaptable effect.

Here's the end result of what we'll be creating:

The bulb itself is fairly simple, with a coloured-glass, domed bulb and an inner filament object. The materials are also fairly simple. The glass bulb simply uses the Principled BSDF shader with the following settings:

It is also important to set the Pass Index to 1 in the Settings dropdown of the Material tab in the Properties panel, as this will create an ID mask of the bulb object visible to the camera, which we will use in the compositing step. The final part of this process is to adjust the render and scene settings. Rendering glass with a thickness is always a bit process-intensive and can cause fireflies and noise, so I used the Branched Path Tracing method with the following settings to help reduce it:

Now, once that is rendered out, on to the compositor! The first step is adding a Glare node and adjusting the threshold and size. This step will require tweaking on a per-scene basis, but it will add a centralised glow at the heart of the bulb, wherever the filament is visible.

Next, the outer-glow effect can be developed. Remember that material Pass Index that we set earlier? We'll access that with an ID Mask node, giving us a b/w mask of only the bulb.

Using this mask, we'll now add a Blur node and set it to Fast Gaussian. This node will act as the 'spread', or light falloff control, of our lamp; the greater the blur, the larger the width of the glow.

The penultimate step of the compositing process is adding a Color Ramp to act as our light intensity controller. The left side of the ramp should be set to pure black, however the right side should have a dark-grey value. How dark this right side is, defines how intense, or bright, the final glow will be, and should be adjusted accordingly.

Finally, this edited mask can be used as the Fac input of an Add node to mix between the original image and a glow colour. This glow colour should technically be the colour of the bulb's glass shader, however you can be artistic with it!

And there we go, a compositing node setup that adds a realistic yet entirely customisable glow to the render! Here's the final node setup in its entirety, and I've also added my .blend file to you to play about with as well.

Hope this is of some help to you, and don't forget to upvote/mark as the right answer if it is! :)


Armature with Spline IK Constraint animation problem

If the track is made from pieces parented to bones:

Select all track pieces
Object > Animation > Bake Action
Check all the boxes and hit OK
Now the animation is baked and should export without problems.

If the track is single piece deformed by Armature modifier:

You will have to bake the animation of bones (same as above but bake to Pose)
Or convert it into Shapekey animation with this script. This will also export fine.


What you can do is just delete the python folder from the Blender directory (or move it to have a backup) and Blender will look for python preinstalled on the system. Note that the version must match (current Blender python version is 3.5.0, it works with 3.5.1 though) and environment variables need to be set (at least under Windows).

Info from here.


Use the Non-Linear Animation Editor.  First make an action of the character resting, standing or whatever you want him doing, then, having that strip set to 'Hold Forward' make another strip for the walk cycle.


Is it possible to turn off grid in orthographic view?

Assuming you have 'Grid Floor' turned off as moonboots shows, there's a quick trick .. when in one of the standard Orthographic Views, tap 46 on your Numpad..(rotating your view by + and - 15 degrees). This converts your standard Orthographic View to a User Orthographic View, from exactly the same angle, and the ortho background grid disappears


How do you move a face without creating another faces?

There are multiple vertices on top op each other. Go into edit mode, select all (press a), and then open the tools panel on the left by pressing t. There's an option called "Remove doubles". Press that and you should be fine.


Cell shading, Can EEVEE do well with NPR like BI?

Yeah, I've tried a bit and it really doesn't support the basic cel shading I do. You might contact SageLightBWK on BlenderNPR. He's been in contact with Ton about an NPR engine and is looking for coders.


If anyone stuck in the same dilemma; Here's a solution.

And @Firewall's comment showing the shader script can also be implemented.


If you save from illustrator (or Inkspace) into SVG format, then you can import your elements to blender using the built in SVG importer:

Just make sure that all of your elements have been coverted to pahts.

Please read this post:Why can't I import a SVG file from Adobe Illustrator or Inkscape?


Any good Python reference book for Blender 2.8?

I recommend that you use the official docs, everything else will be out-dated and therefore not very helpful.


Inset faces not working as it had been a few moments ago

Your topology is not good, you have overlapping faces and vertices, if you move your face up and move some vertices you can see that it's not a quad but an ngon, you can inset an ngon but in your case it quickly creates overlapping.

Oh and as pointed out by Csarb3d, you need to apply your scale, it will fix the second point.


Particle system puts everything on a circle around object ? Tried with Geometry nodes too, the same

Your hair object is far from its origin on the X axis, that will shift the hair away from the emitting faces on their Y axis (I still don't know why hair's X axis becomes Y on the emitter though). If you move the hair object in Edit mode towards its origin it will shift back:


For best results you can either combine curve circles in 2D mode, then keep it as a curve object and extrude/bevel as needed OR you can create a mesh plate circle and a group of mesh cylinders and use the boolean modifier. You won't get subsurf on the inner holes this way but it's better if the plate has to be a mesh.

Option 1 - Joined Curves in 2D Mode

Create the small holes as bezier curves as well as the large plate circle. Make sure all are in 2D mode, and then select all, including the large cirlce and press CTRL J to combine them all into one Curve object. Because you are in 2D mode the inner circles will cut out the the outer plate circle. Then you can extrude the curve and add a bevel. Keeping it in Curve mode will give you the best smoothness on the inside of the hole cutouts. If you convert back to mesh, you won't have the same level of smoothness, and adding subsurf will introduce shading errors.

Option 2 - Cylinder Group with Boolean Modifier

Create a Mesh Circle for the plate. You can extrude/bevel/subsurf it to get it looking right.
Then take your group of bezier circles, join them together into one object (we'll call it "Tubes").
Reduce the curve resolution (Preview and Render) to the lowest possible while still maintaining a circular shape (2 or 3 usually works, we need lowest geometry possible and will regain our smooth curve with subsurf later on)
Make sure the Tubes curve object is in 3D mode (this is to avoid creating caps in the mesh cylinders) and then convert the Tubes object to mesh with ALTC
In Edit Mode extrude the circles vertically so that they will be greater than the thickness of your plate mesh.
Add a Boolean modifier to the Plate mesh and select the Tubes object as the target object. Select Difference as the mode. Then set viewport and render visiblitiy of  the Tubes object to off in the Outline. You'll see perfectly cut holes in your plate object. (Note: you control the smoothness of the holes with subsurf on the Tubes object)
In order to hide some viewport surface errors, select the Plate object, go to Object Data toolset, in the Normals panel, check the Autosmooth options, and change the Angle to 30 degrees.  You should now have perfectly smooth surface with smooth holes cut through.


I'm guessing you're adding vertices by Ctrl-clicking.

This button, or CtrlSpacebar toggles the visibility of the manipulator.

Using one of the shortcuts - (G,R,S) for translation, rotation, or scale, dismisses the manipulator, even if it was visible.

In an orthogonal view, using E to extrude, (rather than place,) new vertices, allows you to move them about in screen space, without having to go to a separate operation.


How to move freestyle line sets to another layer?

Sadly this is not possible by default, however here is an effective workaround

Under the Render Layers tab there is a checkbox that enables/disables it for that layer. And no, this does not render the Freestly pass if you just set it by itself on a new render layer.

Using this we will be able to (with come complex compositing) get just the Freestyle pass.

Start by adding a new Render Layer and unchecking the Freestyle checkbox. When you render now, you should get two images, one with freestyle and one without. This is exactly what we need for the next step, which will be done in the compositor.

In the compositor, add another Render Layer node by selecting the already present one and pressing Shift+D. Change the dropdown on the bottom of it to the second render layer. Now add a Color Mix node and set it to Subtract and connect it as shown.

Now we have a basic image we can work with:

Now replicate this node setup to take this image and make it useable:

(Basic Math node set to Multiply with a value of 10, and a color mix node set to black and white with the math node input driving the factor.)

Now we have our image to use as the factor to mix the rendered image with a black (or any other) color. Add another color mix node, connect the output of the nodes we just added to the factor input, change the top color to black, and connect the plain render layer image output to the bottom color input. You should now have a node setup like this:

(I added the blur node to make the Freestlye lines less sharp, but it is completely optional)

Your render should now be complete, you can now access just the freestlye render:

And can use that to customize how it is used in your final image.


Checker Patterns appearing on the Render

It seems to be caused by the "use mist" in each material. I don't know why it works like that but disabling the "use mist" makes the objects solid.

Also that file isn't exactly great with scene and model work. You'd probably be better off creating your own sets. Forget about Blender Internal as the next big release won't even have it. Go with Cycles.


How to create screw thread with a circular profile

The main problem is from known limitations for Boolean - non-manifold geometry.

If you select non-manifold geometry by Ctrl+Alt+Shift+M you'll see these boundaries selected :

So to apply Boolean without problems in this case fill the boundaries of the screwed circle.

You can do that by pressing F while they're still selected. Then add Boolean to the cylinder and choose Union.


Where can I change the background color of the notification in the Info header?

To my knowledge it cannot be changed, it is defined by the Box group in the User Interface tab. The only bits of it I could change were the border color and the gradient. The text color is changed globally it seems.

One workaround you could use is to tick the shaded check box and set both values to 100, this gives a bright white which might help against a darker color.

Default

Brighter


Create the bi-pyramid's base.

If the base is going to be a regular polygon, just do: Add > Circle, then look for this menu to change the number of vertices. The menu is obtained using F6 in Blender <2.79, or you can just find it in the bottom-left of the Viewport in Blender2.8+

Jump into Edit Mode (Tab). Select all the vertices (A), then Extrude upwards in the Z direction (E then Z). If you hold Ctrl after starting the extrusion, you can do it by snapping to fixed increments.

Deselect the top vertices, select the bottom vertices (I used the B Box Select tool), and Extrude them downwards

For both the top and bottom ends: select them, then scale to zero: S, 0, Enter

To finish, select all the vertices (A), then do Remove Double Vertices from the right mouse button menu (Blender 2.8+) or from the W button menu (<2.79)

The mesh is already done after step 4, but step 5 gets rid of redundant geometry and open surfaces (which is a requirement for many operations, including boolean, subsurface, 3D printing).


Why is my donut so grainy (cycles rendering)?

The noise or grain, in the image, is a can be decreased by two means.
First: increasing the samples
The "Render and Viewport value" is in fact the number of samples that Cycles are going to perform. The viewport refers to how many samples are done in the viewport rendering, and render refers to how many samples are done when actually rendering the final image.It could be that you increase the viewport samples and didn't increase the render.
In general the more samples the better, but you also have diminishing returns, for example, the difference between 10 and 100 samples is a lot, but between 100 and 200 not that much by comparison. also the more samples the longer the render is going to be.
Second: Denoising
In this method, you do a moderate amount of samples and add a denoiser after the render. There a couple of ways you can do this in Blender.

the first way can read more here
and here you can check another way
to denoise

the second way of denoising requires compositing in Blender, so if you are just beginning it may seem to complicate, so you may want to use the first denoising method.
as for the question "Is this the best I can expect with my GPU?" you are not technically limited to a certain quality by hardware, it just means you are going to have to wait for more for the same quality, but if you have the time you can do it. a GTX 1650 is pretty good.
hope this helps, good luck with blender :)


my material or shader Node on the top right bar is gone how do i get it back?

The tabs in the properties window depend on the selected object, to see the materials tab you need to select some object that can have materials applied to it.


Blender Video Editor: Clip stays attached to cursor after releasing left click during drag

With the clip selected, you can hit 'g' to move (just like the 3D view, the Graph Editor, the Node editor, etc) and use your mouse to reposition the sequence. When you are finished, left-click to accept, or right-click to undo.

I think you will find that this is very easy to use, and, even better (because it is exactly like the rest of blender) it is also easy to remember.


Well, I ended up putting an extra edge loop around outside the bevel. While that didn't ELIMINATE the shading, it minimized it enough so as to be no longer visible.


Turret Tracking with Polygon-Aligned sets of Objects in Animation Nodes 2.1

I am going to discuss a pure Animation Nodes approach instead of of using constraints, because, as you said, it is simpler and more flexible.

Base

The base is simple, we instance the base object, position it based on the polygons centers, and orient it based on the polygons normals as follows:

Turret

For the turret, the same will apply, but we are going to use the vector directed from the turret to the target empty as the guide for the Direction To Rotation node. We can compute that vector by subtracting the centers from the target location as follows:

The output rotation matrix is something we will use later, so make sure to expose it as an output.

Barrel

The barrel have the same orientation as the turret but it can rotate around its local Y axis, to rotate the barrel around the local Y axis, we multiply the rotation matrix we computed before by a Y rotation matrix. The location is also the same except it is shifted along the normal slightly, to do this shifting, we simply add a scalar multiple of the normal to the location as follows:

Now the only thing left to do is to compute the angle at which we are going to rotate each barrel along the local Y axis. To compute that angle, we are going to compute the angle between the the vector along the length of the barrel and the vector directed from the barrel's location to the orthogonal projection of the target empty on the plane of barrel, this angle:

Does that make sense? We will implement that as follows:

There is something slightly wrong with this implementation, the angle is not directed, it is, in fact, the smallest angle between both vectors. To get the signed angle (Directed angle) we can either use the Quaternion Output or investigate the cross product, we will be using the cross product method here as it is simpler. We compute the cross product between the two vectors, normalize the output, subtract it from the normal of the plane, return the sign -1 if its length is close to zero and 1 if not, then multiply the signs to the angle as follows:

One last thing to do is clamp the rotation so that the barrel doesn't go through the base, and maybe expose the limits as parameters. So the final result is:

Blend file:


Transfer uv maps operation error or Mesh not identical?

a work around is to snap every vert from mesh A to mesh B via vert index and use data transfer by close proxy.
please see this post on how to snap it via vert index: snap objects of same topology together by vertex index
special thanks to @lemon for comment here and provide solution in above post.


If you say the knife does not work for you, as it only cuts the surface, then you may want to use the option Z to Cut Through, for a snapping on angles to ensure a clean cut, you can also use C, so a cut from the front or any orthogonal view can be made in a straight line.

Here the optional functions of the knife tool:

A cut through cube:

Another option would be to use bisect, where you can also find some optional functionality mentioned while the tool is active.

Here a bisect example, bisect has the advantage that you can select the fill option and it will generate a surface that closes the cut:

I believe bisect might be a good idea as you can adjust not only the direction but also the position interactively.

Happy Blending.


There is no built-in functionality for that. However, You can setup a custom camera view matrix using a bit of Python.

import bge
scene = bge.logic.getCurrentScene()
cam = scene.active_camera
# get projection matrix
camatrix = cam.projection_matrix
#modifying the camera projection matrix by modifying the x and y terms of the 3rd row to obtain a shift of the rendered area
camatrix[2][0] = 2*shiftx
camatrix[2][1] = 2*shitfy
cam.projection_matrix = camatrix

See this for detail.


I have no option to export my model as an FBX

The FBX format for export is actually available as an addon in the Preferences , You should go to EDIT>PREFERENCES and go to ADDONS to search FBX like this -


Export 3D model along with UV map: how to convert UV image into a material before exporting it?

Credits to denis for resolving issues in exporting 3D model with UV map. At first, when I tried exporting the 3D model and preview it to Unity via import the 3D model leaves it completely white at all. I put the UV map I've made in Blender and exported as .PNG file; attached onto the material in Unity and leaves a mess. Now, I took his advice and added the texture file in the textures tab under materials of the 3D model and saved. I checked at the material viewport and the UV texture appeared as part of the material.

Now, when I tried exporting the 3D model and import it onto the Unity project, the 3D model is still blank. A few seconds later after researching about this issue, I found this answer (marked in green) from the Unity Q&A section. All I have to do is to import the UV texture map (in .PNG file, exported from Blender) and attached the texture onto the material and...bam! The 3D model finally shown with the textures on it and displayed it correctly. It displayed it correctly because the 3D file is now contained with an info on UV map to display the textures accordingly.

I assumed the reason why it worked is because once you add the texture in the textures tab via Blender before saving and exporting it, it generates a UV map code and it is included in the 3D model file itself.

Here's the sample pic below. In the middle, my 3D model exported in .DAE format. Mirrored but leaves only half. No texture attached onto the material, completely blank or white. At the far left is my 3D model exported in .FBX, mirrored, 100%. This is where I took the first two attempts in exporting 3D model with a UV map displayed. It leaves black since I simply attached the UV map onto the material directly via Unity. On the right, my exported 3D model also in .FBX format. This time, the UV map displayed correctly using with Denis' simple proposed solution on UV map display and solution on about exporting with textures. The reason why there's an error on rendering the textures from that 3D model (color black) is because I forgot to add the UV mapped texture at the texture tab in Blender. I was new here on studying texture display in Blender but I'm learning it quicker. Making a 3D model has a learning curve but it is easy once I got a grasp on observing how it works.

UPDATE:
Recap on how to export UV texture mapped 3D model:

Make a UV map via UV map editor and select specific mesh part.
Next, once you're satisfied, save the UV by (Image > Save a Copy) and edit for colors and details in Photoshop.
Save the new UV image map in .PNG format, attach the new image file (Image > Open Image or Alt + O) at the UV editor, and refresh it.
Next, at the materials under a 3D object, attach the image file at the textures tab. At the mapping under textures tab, check the Coordinates if it set to UV. Check the material if a texture appears. Preview the UV mapped texture by setting the viewport to material.
Save the 3D model and export it in .FBX.
At Unity, add the 3D model file and the texture file. The materials folder will automatically generated.
At the materials folder, attach the texture to the material. Add the 3D model to the scene by click and drag it. Preview it and all done!


How to create a buisness card with an embossed effect?

There are many ways to do this.

The low poly approach:

Using an image as texture to control the displacement you can connect the texture to the Hieght socket of a Vector>Bump node, and plug that to the Normal socket of the shader you are using for the card.

This will create a bump map, faking some relief and shading the object using the existing lights in the scene.
Alternatively, you can use the texture and plug it to the displacement socket of the Material output. Fine tuning amount of displacement can be done with a Converter>Math node.

Note that with both of these node setups you will be creating the illusion of displacement without adding any geometry. But if you look at the card from a side it will look like the flat plane it is.

High poly approach

To get real 3D displacement, set the displacement for the material to True or Both.

For version 2.79 enable the experimental Feature Set.

Then subdivide the original mesh so that you have denser geometry.

Another alternative is to use a displace modifier that uses the texture to displace the geometry of the card.

Note that the last two techniques require more geometry, to get a smooth result requires the object to have more vertices.


How do I only render what I see, excluding what I have hidden?

You need to select the filter in your scene view window, and make sure that the camera is enabled. This allows you to make certain objects not render in the viewport.
Bonus Tip:
If you have many different objects to turn off final render visibility on, select all objects you don't want to be rendered. Set the active object (yellow highlighted) in the scene viewer to be turned off in renders. Then once the camera icon is turned off for the active object, right click the icon and around the bottom of the pop up window, select copy to selected. This will set all other selected objects to have the same value as whatever you right clicked on. This also works for things like modifier settings, loc/rot/scale values, and much more.


Cutting a speed-adjusted clip distorts audio/video alignment in Video Editor

looks like blender can only speed control video, but no audio.

but you can change the speed of the sound by pitch:


Particles not responding to size changes

Set Render As to Object and link it to a new created object (looks like you need a sphere). Path (Hair) and Halo (Emission) do not contain any geometry data so you can't scale them.


I realized that somewhere in the modeling process, the skin and eye meshes had become very, very slightly rotated. This meant that my mirroring was also rotated.


The domain simulation of doing bake can't be resumed, it always starts from 0. Offset is for holding or use the cached animation later.


Unable to view fire simulation in rendered view

It seems "Quick Smoke" does not add any material to the Smoke Domain. Here is an example for Cycles.


The 2 main things that'll take up video mem are gonna be:
how big are your textures, and how many vertices are in your scene.

Use the decimate modifier on your models effectively.
Try out scene simplify.  I'm certain you can look those up for more info.


Starting a render from a callback gives error “Missing 'window' in context”?

Create an override dictionary.

Pass the context dictionary

bpy.ops.render.render(od, "INVOKE_DEFAULT")
Made a complete copy of context.  This is somewhat dangerous since an object reference to a removed object may be accessed which will core dump blender.  I have a feeling the context members required to override hinges on the render display mode selected. with new window scene.render.display_mode = 'WINDOW' mode, it appears only the context.window is needed.

Have put in a count to stop after 5 renders to test.

Test run, code slightly altered (highlighted) to render frames 50, 40, 30, 20 and 10. In image editor display mode, renders to the image editor (if no open images) or opens one in the largest area

import time, bpy, functools

count = 5
def render(od):
    global count
    count -= 1
    timestr = time.strftime("%Y%m%d-%H%M%S")
    print(timestr)
    # I get no error in the line below
    bpy.ops.render.render(od, "INVOKE_DEFAULT")

    return 2 if count else None

def loop(c):
    print("LOOP", count)

    # override
    c["scene"].frame_set(10 * count)
    return render(c)

if __name__ == '__main__':
    f = functools.partial(loop, bpy.context.copy())

    bpy.app.timers.register(f, first_interval=5.0)


Alternate tiling around a cone/curve (Rocket hull)

It depends what you mean by non-destructive, but you could try it this way:
Create the pattern:

Array it on the X and Z axis:

Bend it 36° with the Simple Deform modifier (Bend mode):

Give it its final rocket shape with a Mesh Deform or a Lattice cage:


How to quickly render 2D/3D Mathematical curve animations without the shadow details

You can use Eevee rendering (Blender 2.8) with the following base setting. Eevee is physically less accurate than Cycles but much faster.

The setting is very basic:

Material: just use colors as you don't want shadows/shaders (bottom of the image above)
Wireframe: use a wireframe modifier (on the right in the image)


Why won't text Boolean correctly after the second Boolean operation?

You need to 'Remove doubles' for you text objects (merge vertices on top of each other):

Enter edit mode for the converted text object.
Select everything.
W> Remove Doubles.
Repeat for each text object.

By default, when text objects are converted to a mesh they are left as separate parts, like the front of the text and  the sides. This creates a messy boolean operation (or more messy  than usual). Here, I applied the first boolean and you can see that it creates disconnected faces (the selected ones) meaning the second boolean doesn't work as expected:

Cleaning the text objects with 'Remove Doubles' will create a cleaner mesh, ready for the second boolean.


How to know if the toolshelf/properties/header is ON/OFF with python?

there's no official way to know, you can just know, i just found a trick with the interface region width

import bpy

bpy.context.area.ui_type = 'VIEW_3D'
area = bpy.context.area

for region in area.regions:
    if region.type == 'TOOLS':
        if region.width == 1:
            print("toolshelf closed")
        else:
            print("toolshelf open")
    elif region.type =='UI':
        if region.width == 1:
            print("properties closed")
        else:
            print("properties open")
    elif region.type =='HEADER':
        if region.width == 1:
            print("header closed")
        else:
            print("header open")


I was really stumped when I switched operating systems, reinstalled Blender and suddenly my animations would no longer render. Turns out my Output path wasn't writeable in the new operating system. Perhaps it's unlikely your issue ends up being so simple, but since I stumped me for a bit, I thought I'd post my solution here and hope it helps someone else.


This usally happens when normals are facing the wrong side of the mesh

Using the backface culling  in the N panel will make the concerned faces transparent (see-through as in your UE4 game engine)

You can check your faces normals with this option in the N panel. This will show you the normals in the viewport.

To make the normals consistent go in Edit Mode with Tab, select all with A (only the bad faces could be enough), and use Ctrl+N (recalculate), or  Shift+Ctrl+N (recalculate the other direction), or select the faces and click Flip directions


In wireframe mode, the object is actually supposed to be see-through. You also set it to transparency mode so that is why the lines aren't visible. On the top section, you will see the square behind a square like here :

and click on the square where I have pointed, your problem should be fixed.
cheerios,
Aster17


How to keep initial orientation when adding copy transforms constraint?

You need to keep your rig clean when you build it. This means transforms should be zeroed out before working on them, especially with constraints. You can clear transforms by pressing AltG, AltR, and AltS to clear translation, rotation and scale, respectively.

(1) After your transforms are clean, you can add constraints. I always recommend using local space for copying transforms, unless you have a very specific reason for using any other space.

(2) Alternatively, you can also use a combination of copy location, rotation and scale constraints to achieve the same effect. This also allows more minute control over the constrained object. Again, I suggest using local space for each transform space to keep it predictable.

(3) Yet another option is to use the child-of constraint, which essentially makes the constrained bone behave as a child. This constraint offers you the option to set an offset like you're asking about (set inverse). With this constraint, I recommend creating the two bones exactly on top of each other, meaning they originate from the same point. They will have the same pivot points, so scaling and rotation behave predictably.

(4) Copy transforms constraint is good to use if you have bones right on top of each other (ie a bone chain with a duplicate chain controlling it). This is just because it's a very simplified constraint. The transformation constraint is a decent replacement for drivers, in such a case where python execution is disabled. Child-of is a good way to get parent-like hierarchy behavior while keeping bone hierarchies separate.

(5) Make some simple bone chains and play with each type of constraint to see which fits your needs. If you absolutely need to keep transforms on the bone in question, then use the combination of constraints in (3) and enable the offset option. This takes the bone's transforms into account at constraint creation.


Kind of "apply" for a clamp to constraint?

You can just apply the Visual Transform. (read about this some more on the wiki)

Bring up the Apply menu with Ctrl + A and choose Apply Visual Transform, or alternatively, select the object, press Space and type Apply Visual Transform and select the option.

You can then safely delete the constraint.


Too add custom buttons to the UI here in 3D view / Toolpanel you could something like this:

import bpy

class DissolvePanel(bpy.types.Panel):
    bl_label = "Dissolve Panel"
    bl_idname = "OBJECT_PT_hello"
    bl_space_type = 'VIEW_3D'
    bl_region_type = 'TOOLS'

    def draw(self, context):
        layout = self.layout
        col = layout.column(align=True)
        row = col.row(align=True)
        row.operator("mesh.dissolve_edges", text = "Dissolve Edges")
        row.operator("mesh.dissolve_verts", text = "Dissolve Verts")
        # invoke custom operator
        # row.operator("object.simple_operator" , text = "All")

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

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

if __name__ == "__main__":
    register()

To run dissolve edges followed by dissolve vertices you would need to define your own operator, to enable the All button uncomment this line in the above script:

# row.operator("object.simple_operator" , text = "All"):

Custom operator (from editor's templates)

import bpy

def main(context):
    bpy.ops.mesh.dissolve_edges()
    bpy.ops.mesh.dissolve_verts()

class SimpleOperator(bpy.types.Operator):
    """Tooltip"""
    bl_idname = "object.simple_operator"
    bl_label = "Simple Object Operator"

    @classmethod
    def poll(cls, context):
        return context.active_object is not None

    def execute(self, context):
        main(context)
        return {'FINISHED'}

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

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

if __name__ == "__main__":
    register()
    # test call
    bpy.ops.object.simple_operator()


How to render a wireframe & glow lines effect on a house?

One way to do it is by adding a wireframe modifier to your building, for those shots where you want the wireframe.

instant success:

But don't apply it, else it will modify and change all the geometry of the object. You can disable it from modifying the object by pressing the little eye symbol.

The glow effect could be achieved using composition and a slight influence of the blur node. Or read similar QA threads on this site for suggestions: Glow with depth in Blender?


Blender Cycles: baked texture is completely black

It turned out that I tried to render Diffuse, but the Principled shader does not render diffuse. Rendering Glossy worked.


Can I un-hide everything without selecting everything?

Yep.To hide and view anything on view port,you could just toggle the small eye like icon on the outliner. This is especially helpful when there are a lot of objects on the scene. see I have plane as well but I've toggled it off,so you cant see.You can toggle any number of items on or off to hide or view.Hope this was helpful


is there a way to make blender look for textures in the current directory?

You can store paths relative.

Save your file first. When importing an image, make sure the checkbox Relative Path is checked. (Lower left of the open image dialog.)

Examining the image in the image editor will reveal, that it's path starts with two slahes  //.

  When relative paths are supported, the File Browser provides a Relative Path checkbox, when entering the path into a text field, use a double slash prefix (//) to make it so.

  Relative paths are the default but this can be changed in the File tab of the User Preferences Editor.

So make sure, that relative paths are used by default by checking the box.

Now all paths relativ. Moving the .blend file and all image (etc) files, preserving their relativ location in the file structure, will not break the link in the .blend file.

However, if the relativ path changed (e.g. you renamed the images folder to textures), the links will be broken. You can restore them by searching for missing files. Go to File > External Data > Find Missing Files. Choose the directory containing the missing files and Blender will try to reconnect them.

Also next to this menu entry is the useful "Make all paths relative".


Dynamic proportional edit connected to an object?

Two possibilities (at least) : hook modifier and vertex weight proximity + shrinkwrap.
And an edit using dynamic paint (following the comments).

Hook modifier :

The setting is the following :

The hook modifier is defined for the plane, and an empty is use as a hook. You can tune the falloff and the proximity. You must define a vertex group (assign the wanted vertices to it).

Vertex weight proximity and shrink wrap :

This can be a more dynamic solution.

First add a vertex weight proximity modifier. That will assign to the vertex group a value depending on the distance to the empty.
Then add a skrinkwrap (targeting to another plane) and using this vertex group.

You need to define another plane to skrinkwrap to (this plane is placed near to the surface... not visible here as it is in wire display mode).

A third solution using dynamic paint :

The object is in wireframe here to allow to see the moving object (here spheres replace that was empties previously).

The principle is the same, as before but the weights of the vertex group are given using dynamic paint.

Configuration for the spheres used as brushes : here 'proximity' is used (other options available) and you have also some option for the falloff.

Configuration for the grid : we are painting on 'weights' on the vertex group.

And as before the grid has a shrinkwrap using the same vertex group :

Updated blend file :


To elaborate on Noidea's comment, Vertex Groups probably are the most simple option. Here's what you can do to create a Vertex Group:

Select the vertices that you will want to be able to easily select later.
Go to the Properties panel > Object Data tab > Vertex Groups dropdown.
Add a new Vertex Group with the plus button.

Double click on Group to rename it and name it something that will signify which vertices you are grouping. I named mine End Cap.

Make sure that the Weight: value is set to 1 and click Assign.

Now, anytime that you want to select those vertices, click Select. You can add as many Vertex Groups as you want. In a demo I built, I used Vertex Groups End Cap and Loop Cut (for the loop cut on top of the end cap, useful if adding subsurf, for example). Watch how I can easily integrate those two Vertex Groups into my workflow of nothingness.


Blender 2.8 - texture does not appear on extruded circle

You need to UV Map the extruded cylinder. The reason why textures appear on a cylinder (and cube) created from the Add menu is because those are basic shapes that are used a lot, so they are already set up (which means UV mapped) for using textures, but since you extruded your cylinder from a circle, it doesn't have a UV map yet. I suggest looking up tutorials on the internet on how to learn to UV map models, because it is a very important thing to know.

UV mapping a cylinder is trivial, any basic tutorial will do.


You can find the source code here:
https://github.com/blender/blender/blob/master/source/blender/nodes/shader/nodes/node_shader_mixRgb.c


You can use an addon called Animall to animate the texture.

CYCLES

Activate an AnimAll add-on (File--> User Preferences--> Addons--> AnimAll). It'll be displayed in the tools menu in the 'Animation' section.

Setup the image texture in the Node Editor. Enter the "Edit Mode"and unwrap the mesh (press U in 3d window) using the Project from view.

In UV/Image Editor place the UV island on the desired part of the image texture (note that you have to make perfect spaces between images in graphics program. In this case the images have 200 px of space between them).

Check the 'UVs' box and insert the first keyframe (clicking 'Insert').

Go to the next frame (right arrow), place the UV island on the next part of the image texture (in this case i go 200 units along x axis) and inesert the keyframe again. Repeat this process moving right.

Place the UV island in the lower row (in this case I move the uv island -600 units along x axis and -200 units along y axis)

Continue the proces and position the UV island on the last image part (of course the moving patern could be different). Go to the 'Object Mode' and play the animation (alt+A).

8.- Select all keyframes on the dopesheet (or Graph editor) and set them to Constant

You can also prepare the texture like this, so it will be easier to jump between images. Remember about doing perfect spacing between them.

Go to NLA Editor, change the action name (CTRL+LMB) and click the 'double arrow' icon.

Now you have your 'blink animation' in one block and you can place it wherever you like on the timeline.

Hope I helped.

--------------------------------------------------------------------------------------------

BLENDER INTERNAL RENDER

I'm adding an update, since Warianos wants to know how to do the same thing in Blender Internal. So here it goes:

Select the mesh you want to have an animated texture on it, and in Shading panel change the Material Mode from Multitexture to GLSL. Add a lamp (a sun lamp for example), so you'll be able to see the texture when you apply it.

With the object selected in Object Mode go to the Materials Panel. Add the material. Set the Diffuse and Specular values if you want.

Go to the Textures Panel, set the texture type to Image or Movie, then click the Open button in Image panel and load your image.

In Mapping panel set the Coordinates to UV.

In 3d window set the Viewport Shading to Texture

Load an image in Uv/Image Editor window. Unwrap the mesh using Project from View option. Enable an AnimAll addon and check the Uvs box.

Now the process looks like in my previous answer. You press Insert in AnimAll panel and add a keyframe. Then you go to other frame, change the Uv island's position and press Insert again.

Being in Object Mode, with the Viewport Shading set to Texture you can now play an animation to check out how it looks like. If you don't want the smooth transition between images you may set the Curve Interpolation type to Constant, by pressing T in graph editor window (as Cegaton suggested in his answer).

Hope it is what you wanted to know.


How to Hide light sources in mirror Blender Eevee

Go to Light Properties - Specular Value = 0, Radius = 0
That's fix's my Problem.


" When is it useful to use mirror? "

If you can imagine placing a mirror along one half of an object, and the object appears correct, use a mirror.
Even when the geometry on both sides is mostly mirrored and differs slightly, you can edit each side individually after applying the mirror (breaking the symmetry).

For anything with symmetry:
you can mirror x,y , try it! place the origin at the center and tick both x,y axis for the mirror.

an Array Modifier can be useful when the repetition goes beyond straight x,y mirroring. Use an empty as the object offset and rotate the empty on (for example) the z-axis by 60 degrees, to get a radial array like this example:

Note: object offset is generally referred to as the pivot point when talking about radial arrays.
And then there is the Screw Modifier, which can be considered a Lathe modifier, which lets you draw a profile and rotate it around to form the shape. This is very common practice. I prefer the screw modifier instead of the Spin tool, because you can keep editing the profile without having to 're-spin'

You can combine these geometry modifiers, for example you can mirror a section then radial array the result. Here's a crude example


Constraint the camera to look at an object

Set the camera with a Track To constraint.

Select the "Target" object.
In the "To" section select -Z and in the "Up" section set it to Y
Use World Space

The camera will then point at the target object's origin.

To understand those settings you have to think of the LOCAL AXES for the camera: X is Horizontal, Y vertical and Z is depth. Negative Z is what is in front of the camera.

To maintain the object's Z axis aligned at all times enable Target Z.


Tree branches pointing downwards Sapling Addon

Try adjusting the settings in the fifth box of the Branch Growth tab (third row, first column) and the last box.


Object Transform Origin to Geometry Floor

Enable the align tools Add-On.

In the 3D Viewport select your objects, open the Sidebar (N)
Go to the Item tab.
In  Align Tools > Advanced Align Operations, click on the Advanced button.
On the bottom left of the viewport window the Align operators control will open.
Set the Operator to Pivot mode.
Enable Active too, Self and Min
Then  set the Axis you are aligning, in this case it should be $Z$

Then your objects origins are at the bottom.
For older versions of Blender the interface looks like this:


Can an object ever "own" an AN node tree or are the trees always independent?

I'm very new to AN so this might not be accurate.

I think the answer is no, you can't associate an animation nodes graph with an object; it's part of the scene. I think this is very much by design however, as you can have one node graph control many objects, even selecting an entire collection of objects at once.

This doesn't mean you can't have the features you want! Because AN is open source, you can always visit the project on GitHub, and under the "Issues" tab either request new features, or ask for further explanation about the design of the project.


How to make this animation look more like a satellite orbiting a binary star?

There are three things I'd recommend.

One is making your background black. Any other color will artificially reduce the contrast, making the stars (and Suzanne) seem less bright than they are.

Another is improving Suzanne's material. It should be a correct, Fresnel diffuse (if diffuse is what you're going for), and it should be a lighter color, something closer to white. It looks dark green at the moment. Dark colors don't reflect as much light as light colors (that's why they're dark ;-) ), so the light source has to be brighter. Colored materials react to colored lights in funny ways. In particular, your green material is going to be preferential to the white light, over the red light, making the red light look dimmer, even if it's the same intensity.

For a (mostly) correct Fresnel diffuse shader, just mix a diffuse shader with a glossy shader, plugging a fresnel input node into the factor slot on the mix shader. Fresnel in factor, diffuse in top slot, glossy in bottom slot, mix piped to surface. This will make her reflect light a bit more reasonably.

Lastly, if you need a sun lamp to "see what you're doing" then something is wrong. It's necessarily going to mask/diminish/hide the effect of the two stars. It won't LOOK like Suzanne is being lit by the pulsar because her dark side isn't DARK... it's being lit by the sun lamp. If you want to make the depth more obvious, decrease your focal length, and re-position the camera.

Hope that helps!


Why does the leg bone move the whole body?

You are using vertex groups to bind armature to mesh : so you'll have to

Delete the duplicated vertex groups
Fix/reassign the needed ones ( Head, Body, Arm_L, Arm_R, Leg_R and Leg_L )
Use only one Armature modifier ( delete the others )


The Compositing and Material Editor are two node-based Editor Types that are very different. Beginners can get these mixed up.
The Compositing Workspace is to edit your final renders and do things like color correction, effects, and things like that.
The Material Editor is the actual Editor you want. This will actually let you change how the material is defined through tweaking nodes, and you can simply access it by changing the Editor to "Shader Editor", and selecting a sprinkle. If you want to change the colors, just go to the colorramp (the thing with a colorful bar) and change the colors by selecting flags.


Can I use array modifiers to create staggered rows of blocks in a dome?

There is an addon called Building Objects available in blenders addon contrib collection that may come close to what you want. With it enabled you get Add->Mesh->Building Objects->Wall factory to create a wall made of bricks.

While the radial and curve options will give you an igloo like brickwork it doesn't offer any adjustment for the curvature, so this may be a starting point.

If you don't want to install git to get the addons, you can get a snapshot of the contrib repo from here.


How do I stop the cloth modifier from treating a joined mesh as separate meshes?

Yes, there is a way to make it act as a single mesh. The way to do it is to add appropriate vertices to vertical and horizontal bars in edit mode and join them.


How do I rename all object as same as their material name?

Name objects after active material
May or may not work as you expect.  All objects could share one material and hence renaming would end up with objects named "Material", "Material.001", ... following the blender naming convention for unique object names.
An object can have many materials.
Test script have renamed every object in scene after the name of its active material if it has one.
import bpy
from bpy import context
from bpy import data

# all objects
all_objects = data.objects
# scene objects
scene_objects = context.scene.objects
# selected objects
selected_objects = context.selected_objects

for ob in scene_objects:
    if ob.active_material:
        ob.name = ob.active_material.name

for all objects in blend edit and use
for ob in all_objects:
    ....

similarly for selected_objects


Make modifiers update in the game engine

What I've done for similar situations:

Parent the water (object plane watter?) to the boat collision mesh.

Add the rest of the water outside the two.

Make a surf animation in the water enclosing the boat so that it roils up in front, but only when the boat moves.

Now when the boat moves, the hole moves with it. Brilliant huh?


How can I replace a material from Python?

Ok from the above I noticed there are possibly 2 approaches to the same problem.

1) is iterate through the list of available materials linked as data and replace the material. This will not work if materials are linked by Object.

Sample code below:

import bpy

def replace_material(object,old_material,new_material):
    """
    replace a material in blender.
    params:
        object - object for which we are replacing the material
        old_material - The old material name as a string
        new_material - The new material name as a string
    """
    ob = object
    om = bpy.data.materials[old_material]
    nm = bpy.data.materials[new_material]
    materialnum = len(ob.data.materials)

    for i in range(0,materialnum):
        # test if the old material is in the list of used materials and replace it
        print ("running ", i)
        if ob.data.materials[i] == om:
            print ("match found", ob.data.materials[i])
            ob.data.materials[i] = nm

2) Iterate over material slots and replace the material in the slot of the object. This as batFINGER pointed out is a solution wherein whether the material is linked to the Object or Data is irrelevant and hence probably a better solution.

import bpy

def replace_material(object,old_material,new_material):
    """
    replace a material in blender.
    params:
        object - object for which we are replacing the material
        old_material - The old material name as a string
        new_material - The new material name as a string
    """
    ob = object
    om = bpy.data.materials[old_material]
    nm = bpy.data.materials[new_material]
    # Iterate over the material slots and replace the material
    for s in ob.material_slots:
        if s.material.name == old_material:
            s.material = nm

Notes:

1) The above samples do not do any error handling the script will just fail if the materials do not already exists. I wanted this kind of behavior.

2) For brevity sake I have posted only definition of the functions themselves this function can be used for a single object or along with looping to work with several objects. An example of such is shown in the main() function in the question.

Usage:
Suppose you have an object named "Bottle" 2 materials "Red paint" "Blue rubber"
and you want to replace the material "Red Paint" with "Blue rubber"

then you would use:

obj = bpy.data.objects["Bottle"]
replace_material(obj,"Red paint","Blue rubber")


Blender Nodes in Editor doesn't show preview Image

You need to render the scene before anything shows on the compositor. HitF12 or press Render.

To have the Viewer Node's image as background behind the node tree you need to enable the backdrop button:

If you press N on the Node Editor's window  you'll see Controls for size and placement of the backdrop:

Or you can zoom in and out by pressing V or ALTV

You can also choose to see the Composite Node or Viewer Node in a UV/Image Editor window.
Selecting Render Result will display the Composite Node


How to put green screen video on a plane in Cycles

Using only the material nodes you could use the image texture's color components. With a good clean key background, just send the green value (alter contrast to taste) to a mix node and mix to transparent.

Here it is in action, with a very poor key background ;-)