How to create light beam effect? (Alone in the Dark opening)

You could try with a cube encompassing your scene, and you plug a Volume Scatter node into its Volume Output to create a mist. I'm personally struggling with this solution so here is a solution with compositing that comes not too far.

It must be much easier with Eevee and the Principled Volume, but your question is for Cycles and I can't make Eevee work on my computer.

I guess it can be improved:

Create your title. Give it a black Diffuse node, put in front of your camera. Duplicate the title, put it behind the black version and on another layer, in Edit mode extrude a bit and scale it a bit with Shrink/Fatten, give it a white Emission node, with a Strength of 2.

In the Render panel > Film, enable Transparent so that you layers are transparent. In the Node Editor / Compositing, organize your nodes: Basically you need to mix (Alpha Over) the render layer with the black title with the render layer with the white title. I put some blur here and there, but the important things are to put a Sun Beams effect after the white title and a Glare effect just before the Output. The Sun Beam will create the beams behind, the Glare will fake a bit of glow in front of the black title. And you can move the Sun Beam X and Y value as if the spot was moving behind.

Here is what it gives:


when i try to uv unwrap my mesh , blender hangs and become unresponsive, why?

Potential Solution: Smart UV Project

Although I've never tested this method on a UV Unwrap task that has crashed Blender, I've found that using the 'Smart UV Project' option is much faster using the normal 'Unwrap' function.

I found this when unwrapping the mesh of an ANT Landscape body, where it would take several unresponsive seconds before Blender processed the unwrap using the regular unwrap function.
However, when I unwrapped again using the 'Smart UV Project' option (with the default parameters), it was almost almost instantaneous.

I know this is a pretty old post but I'll leave this here just in case anyone finds it and gets help from this answer. (Hope I haven't broken any community forums by 're-opening' an 'archived' thread.)


How do I invert this timer in BGE to make it count-down?

You could simply negate the time property (-1800 seconds) and parameter of datetime.fromtimestamp(-textObject["time"]):

import bge
from datetime import datetime

textObject = bge.logic.getCurrentController().owner
if textObject["time"] < 0:
    time = datetime.fromtimestamp(-textObject["time"])
    textObject.text = '{:%M:%S}'.format(time)


Automatic superposition of similar objects?

Selecting objects by mesh similarity isn't a feature that Blender currently offers. Theoretically this could be implemented through an add-on.

In edit mode there are option to select similar areas on the current mesh. This is not shape recognition though.


Baked and applied normals reflect light at an angle

Found it. I had to add a normal map between the wood displacement EXR and the normals.
Simply because I didn't know this was the way to allow blender to interpret image to normals as described here

Actually, the person who deleted his answer to my question deserves all the credit. So thanks :)


How can I disable only being able to extrude along the blue axis of a face?

Extrude Tool works along the face normal, by default (that's what the blue axis shows).
You can change the orientation and direction through the pop-up menu.


How do I get some objects to be rendered with perspective, some rendered as orthographic in the game engine?

You can set a camera to render orthographic if you render the 3D and 2D objects separately.  Although, for a game, wouldn't you just make the buttons separate anyways?


Laying (linked) pentagonal tiles - trouble snapping

You can get there using vertex snapping and some manual rotation.

Make your base tile a single face pentagon. Remove double vertices (there are some).
Don't use object instances yet, you'll convert them all in the end. Just copy new tiles now.
The main angle is 71°. Type the equations directly into the rotation field.
Enable Vertex Snapping > Median. Origin points will now snap to vertices.
Put your origin to different vertices if needed.

Convert tiles into instances

Select all objects and go Object > Set Origin > Origin to Geometry. This will keep them in place.
Select all tiles and turn them into instances Object > Make Links > Object Data

The main face angle is 71°

Type equations into the Z rotation field.

Use Vertex Snapping > Median to snap origin point to vertices. Move the origin point if needed.

Make all tiles into instances of one. But make their origin points centered first.


Mirror-Modifier applied, but still mirroring

You need to disable symmetry lock. It only happens in sculpt mode, the option to turn it off or on can be found under tools  >  symmetry lock.

Click the shaded option to disable, x by default.

Don't worry, you did nothing wrong


Why does my procedural texture look different after cell fracture?

When you use procedural textures the texture coordinates are based on the object's position, rotation and size. When you shatter the object it will turn into many objects with different position. It can be solved by using the Texture Coordinate node's Object output using a common object as reference. This will however not solve the problem once you move the parts away. The texture will "slide".
You will need to create UV coordinates and bake down your procedural texture to an image and have this applied as a new material.


You can see a property as "game object variable". This means it is part of the game object. (A variable is an separate object within a specific context e.g. a function).

Accessing a property the same like dictionary access.

Without check for existence:

propertyValue = gameObject[propertyName]

This fits in most situations. If the property does not exist you get a KeyError.

With pre-check:

if propertyName in gameObject:
    propertyValue = gameObject[propertyName]

This is a good situation when you can't guaranty the property is set, but you do not call this code very often.

With error handling:

try:
    propertyValue = gameObject[propertyName]
except KeyError:
    print("Warning: '{}' in {} does not exist.".format(propertyName, gameObject.name))

This is good when you expect the property might not be set and this situation is no reason to stop and this code is called very often (faster than pre-check).

With default value:

propertyValue = gameObject.get(propertyName, defaultValue)

This is good when you do not want to stop if the property is not set. In this case the default value will be given. Attention: The property will still not be set!

If you skip the default value, the default value is None. Be aware the default value is always evaluated, regardless if the property exists or not. Therefore the default value should be fast to get e.g. already exist or it is a primitive type such as numbers or strings.

Adding/updateing:

gameObject[propertyName] = newValue


How can I export baked fluid simulations that work in Xcode?

It appears that the Alembic files originally thought to be moving in Xcode weren’t using the mesh stream as thought before. I don’t have a Mac, so I couldn’t actually see the result. My partner saw the object translating in Xcode and thought it was working, but the mesh stream I was seeing in Blender was not actually running in Xcode.

This means that we have no working example files of a mesh stream playing from an Alembic file in Xcode.

We’re going to move away from Alembic and give OBJ streaming a shot.


I think your low poly mesh does not have smooth shading enabled. You can enable it again by selecting your low-poly mesh, then pressing W -> Shade Smooth or going to Object -> Shade Smooth.


Sort out a complex UV map for a complex mesh

Select all the UVs in UV/Image Editor, from the UVs menu select UVs From Islands.

Then in Object Data tab create a new UV Map and unwrap the model. While all the UVs are selected, create an image in the new UV Map where the new texture will be baked and keep this UVMap selected.

Then make sure you have a material and the original texture is applied there using original UVMap.

Click on Render tab and in bake menu select textures and click Bake button.

In the same way as described, it is possible to bake multiple materials that are using same or different UV Maps, to a new single or multiple UV Maps, each with separate texture.

The described above steps are aplicable for Blender Render internal engine. Workflow for Cycles is a bit more tricky though is well depicted here:
Possible to bake texture to new UV map?


Assuming you are working with Windows...
With the Windows Explorer visit the directory of Blender 2.8.
Find the Blender.exe (or how it is called under Windows...I am Linux guy...;)
Select that file
Click with the right mouse button it and select "Create shortcut here".
Move the newly created shortcut onto your desktop.
Do the same for the other version of blender.
If you will get an filename conflict, rename Blender.exe to Blender279.exe / Blender280.exe beforhand.


The Big issue is Change the Engine type

From Blender Render to Cycles Render
Grass is to small
In the Particles -> Render -> increase Size.
Then render. Hope you get cool grass.


Better topology would be like this (I believe this is what you are looking for) with the knife tool:


Why are the unwrapped UV faces different sizes and proportions to my model's faces?

You can try to use a front orthographic view, select some faces and choose U - project from view. Then change the view and go on with other faces, until you unwrap the whole model.

The classic UV algorithm gets confused by your convex Ngons, a clear topology, with only not convex quads, would avoid the problems.


The Normalmap is not Normalized. Normalize your Normalmap to get correct results.


I had the same problem and I think it's a threading issue.
(AFAIK the render engines are written in C++, so it's not surprising considering threading and memory management in C++ are a PITA).

You should keep your CPU levels to below around 50% for the blender-app.exe process.
In my case, if I bring down the threads to a max of 4, the scripts run without problems (still using all cores).
Slows it down somewhat, but at least it keeps running...

Something like this in a script file:

cd C:\Program Files\Blender Foundation\Blender
blender -b "your_blender_file.blend" -t 4 -a
pause

Hope it works for you.


The reason for this is not resumable data. Click on the button near the cache . Hope that helps!


How to fix Boolean modifier shading issues on a convex surface?

You can add Weighted Normal modifier and if you didn't enable Auto Smooth, add Edge Split modifier or enable it and change the value until you have a good result. You can also remesh and sculpt it.


How do I create 2 Edge Loops adjacent to selected Edge Loop?

'Beveling' should achieve what you want. Select the edges you want to add other edges around and press Ctrl+B to bevel:

Increase the 'bevel segments' by either scrolling the mouse wheel up while bevelling or change it in the toolbar (T) after beveling to keep the original edge.

As to how you would do this programmatically you might start with this:

bpy.ops.mesh.bevel(offset=0.5, segments=2, vertex_only=False)

(Though it might be better to try and find an alternative to bpy.ops.., see this)


You need to drag the Specular Intensity in the Material tab all the way down to zero. And enable Intensity under the Specular in the Influence tab of the texture, as seen below.


Is there a way to make a given value relative to another piece of value?

You can do that easily with drivers. Drivers can be hard to understand, but are very powerful.

RMB  click on the Offset field in the Follow Path constraint that you want to be linked to the other constraint's value (I will call this object 1).
Chose Add driver
Open up the Graph Editor and switch it to Drivers, click on the Offset Factor (Follow Path) in the list of drivers on the left.
Press N to open up the Properties panel to edit the driver.
Change the var type to Single Property, point the Prop: to the object that has the other Follow Path constraint.
Select the object that has the other Follow Path constraint (in my example it is Suzanne).
RMB  click on the Offset field in the Follow Path constraint chose Copy Data Path
Select object 1, go back to the Graph Editor, and paste in the value for the Path:, should be this constraints["Follow Path"].offset_factor.
Change the Expr: to be var + 10.


how to render semi-transparent objects with transparent background as a png with cycles

You can use a Holdout shader:

The holdout shader will render as actual image alpha, as opposed to giving the color of the environment on the other side of the object.

Or you could use a Transparent shader, which will allow other objects to be visible through the transparent object:

Note that transparent in Render settings > Film must be enabled, otherwise the holdout shader will appear black and the transparent shader will show the environment behind it. You did mention that you already did this, so you should be good.


Why does my rendered object appear too big compared to object taken with real camera?

I just realized my error. I was setting the scale of my cube instead of the dimensions and since the default dimension is 2m^3 the cube was double the size it should have been.


Welcome to Blender Stack Exchange!

It looks the automatic weighting failed when you tried to parent the mesh to the rig. This is unfortunately a common occurrence in Blender. It seems to happen when you use somewhat dense meshes like you have.

There is a really easy fix though. Select both the mesh and the rig and scale them up a lot. I tested your file and it worked when I scaled them up 100 times. All this does is space things out a bit (a lot) more and the automatic weighting seems to like that better. Then apply the scale on both objects with Ctrl+A. Then parent, scale down (by .01 instead of 100 this time) and apply the scale again.


How can I export the motion tracking markers to csv?

The script on this github page can export the data of each motion tracking marker.


How do you specify the name of a primitive created via the Python API?

After some  more searching I found the solution here Adding Named Objects in Blender with Python API

The following example creates five cubes with names 'LittleCube000', 'LittleCube001', 'LittleCube002', 'LittleCube003' and 'LittleCube004'

for i in range(5):
   add_cube(location = (i*2, 0, 0))
   bpy.context.active_object.name = 'LittleCube{:03}'.format(i)

You can also find an object named 'OldName', and updated to 'NewName':

object = bpy.data.objects.get('OldName')
if object:
    object.name = 'NewName'

However, if 'NewName' is already in use, then a numerical suffix will be automatically added to it.


In this case you could use the absolute bounding box. Setting the dimensions of your right object to the dimensions of the left one should give pretty good results:

Note You'll probably have to watch out for the y value. Make sure to use the same ratio as for x and z to prevent the object from stretching.


Array modifier is scaling objects for seemingly no reason

The array modifier's object offset offsets each copy by the location, rotation and scale difference the object and the target, the empty in this case, have. You object has an uneven scale that is less than one, and since the empty has larger scale than the object, the object is scaled up for each copy.
Hit CtrlA -> apply scale to set the object's scale to 1 on all axes and the scale won't change. Also for doing circle arrays, there should not be difference in location, else each copy of the object will also move by some offset. You can apply the location of the object as well to move the object's origin to the scene center.


As Akados mentioned, there is a problem with your normals.
What are normals?
Every face has a normal. It's the direction the face is pointing at. One side of every triangle is considered the "outer" side and the other is the "inner" side.
Why is shrink/fatten confused?
When you use shrink/fatten, it moves the faces in the direction of the normals.
Fatten = move towards the "outer" side.
Shrink = move towards the "inner" side.
It makes sense when you think about it.
Since the "3" in your example has the correct normals, it works fine for that part of the mesh. But the "D" part seems to have flipped normals, so the shrink/fatten actually moves faces in the opposite direction.
How to fix it?
Blender knows how to automatically get the normals right. You have to select everything in the mesh and Make normals consistent, using the shortcut ControlN.


capturing user view movements as a camera?

This script should fulfill your needs. Basically it uses a modal operator (runs parallel to Blender), takes the current position and view and stores those in an array (records at the currently selected framerate of the selected scene). When you click with Left-Mouse a new camera is created that has your movement assigned to it. Right-Mouse or Esc will cancel the command. You can find it by pressing Space in the 3D-Viewport and searching for "Record View Movement". When you leave the viewport the script pauses recording until you reenter.

Just copy and paste the script into a texteditor and run it once (Alt+P) or write a full plugin (in this case give some credits to stackexchange). Anyway, here is the script:

import bpy, time, bgl, blf
from mathutils import Vector, Quaternion

def bgl_draw_fx(self, context):
    """A drawing routine that we show while our operator is active"""
    font_id = 0  # XXX, need to find out how best to get this.
    bgl.glColor4f(1, 0.3, 0.3, 1)
    blf.position(font_id, 15, 30, 0)
    blf.size(font_id, 12, 72)
    blf.draw(font_id, 'Recording...')
    # restore OpenGL to default
    bgl.glDisable(bgl.GL_BLEND)
    bgl.glColor4f(0.0, 0.0, 0.0, 1.0)

class RecordOperator(bpy.types.Operator):
    """Translate the view using mouse events"""
    bl_idname = "view3d.record_movement"
    bl_label = "Record View Movement"
    def __init__(self):
        self.fps = 1
        self.timer = None
        self.lasttime = 0
        self.recorded_movement = []

    def registerModal(self, context, event):
        args = (self, context,)
        self._handle = bpy.types.SpaceView3D.draw_handler_add(bgl_draw_fx, args, 'WINDOW', 'POST_PIXEL')
        self.timer = context.window_manager.event_timer_add(1.0/self.fps, context.window)
        context.window_manager.modal_handler_add(self)

    def unregisterModal(self, context):
        bpy.types.SpaceView3D.draw_handler_remove(self._handle, 'WINDOW')
        context.window_manager.event_timer_remove(self.timer)

    def execute(self, context):
        """Gets called by us"""
        action = bpy.data.actions.new('RecordingCamera') # create action
        curveLocX = action.fcurves.new(data_path="location", index=0) # create curves
        curveLocY = action.fcurves.new(data_path="location", index=1)
        curveLocZ = action.fcurves.new(data_path="location", index=2)
        curveRotX = action.fcurves.new(data_path="rotation_quaternion", index=0)
        curveRotY = action.fcurves.new(data_path="rotation_quaternion", index=1)
        curveRotZ = action.fcurves.new(data_path="rotation_quaternion", index=2)
        curveRotW = action.fcurves.new(data_path="rotation_quaternion", index=3)
        frames_c = len(self.recorded_movement) # get frame-range
        curveLocX.keyframe_points.add(frames_c) # add frames
        curveLocY.keyframe_points.add(frames_c)
        curveLocZ.keyframe_points.add(frames_c)
        curveRotX.keyframe_points.add(frames_c)
        curveRotY.keyframe_points.add(frames_c)
        curveRotZ.keyframe_points.add(frames_c)
        curveRotW.keyframe_points.add(frames_c)
        for frame, (loc, quat) in enumerate(self.recorded_movement):
            curveLocX.keyframe_points[frame].co = frame + 1, loc[0] # set keyframes
            curveLocY.keyframe_points[frame].co = frame + 1, loc[1]
            curveLocZ.keyframe_points[frame].co = frame + 1, loc[2]
            curveRotX.keyframe_points[frame].co = frame + 1, quat[0]
            curveRotY.keyframe_points[frame].co = frame + 1, quat[1]
            curveRotZ.keyframe_points[frame].co = frame + 1, quat[2]
            curveRotW.keyframe_points[frame].co = frame + 1, quat[3]
        # apply created data
        cam = bpy.data.cameras.new('RecordingPlayback')
        camObj = bpy.data.objects.new('RecordingPlayback', cam)
        camObj.rotation_mode = 'QUATERNION'
        anm = camObj.animation_data_create()
        anm.action = action
        context.scene.objects.link(camObj) # link to scene
        context.scene.update()

    def modal(self, context, event):
        if event.type == 'LEFTMOUSE':
            # apply movement
            self.execute(context)
            self.unregisterModal(context)
            return {'FINISHED'}
        elif event.type in {'RIGHTMOUSE', 'ESC'}:
            self.unregisterModal(context)
            return {'CANCELLED'}
        v3d = context.space_data
        if v3d.type != 'VIEW_3D':
            return {'RUNNING_MODAL'}
        ctime = time.clock()
        if (ctime - self.lasttime) > (1.0/self.fps):
            rv3d = v3d.region_3d
            # record movement
            current_rot = Quaternion(rv3d.view_rotation)
            if rv3d.view_perspective == 'PERSP':
                current_pos = rv3d.view_rotation.to_matrix().col[2].to_3d()
                current_pos *= rv3d.view_distance
                current_pos += rv3d.view_location
            elif rv3d.view_perspective == 'CAMERA':
                current_pos = Vector(context.scene.camera.location)
            else:
                print('BUG, unknown perspective:', rv3d.view_perspective)
            self.recorded_movement.append((current_pos, current_rot))
            self.lasttime = ctime
        # don't block input
        return {'PASS_THROUGH'}

    def invoke(self, context, event):
        self.fps = context.scene.render.fps
        self.registerModal(context, event)
        return {'RUNNING_MODAL'}

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

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

if __name__ == "__main__":
    register()

Note: You can combine this with any technique that manipulates the current view (for example flight-mode Shift+F to record the movement and play it back. This is imo one of the best features of this script. Just trigger recording and go into flight mode. Keep in mind that you have to press Left Mouse to keep the recorded animation.


2.80 grease pencil - highlighted points in edit mode

Under Edit Mode on a Grease Pencil object go to the Overlays menu in the 3D View header and enable Edit Lines.

Bellow increase the opacity value as desired. Stroke edges will now appear in a very faint gray color, and selection in orange.


Follow path offset field can't be keyframed, generates error

I downloaded your .blend file and found that if you uncheck the "Fixed Position" box, you can keyframe the "offset" value and it works fine.

Hope this helps!


Nevermind...I solved it...
There wasn't anything wrong with the smoke, but the light was going through a transparent shader mixed with a diffuse shader which was blue, projecting the blue tint on the surface of the Earth


Morph a ball into another (Terminator T1000 style)?

You can do this effect with Meta objects.

Shift+A > Metaball

They work like this:


Applying Array Modifier - Still instance?

No.
They are never instanced, even before the modifier is applied.

The array modifier makes a new copy of the mesh for each repetition, storing the same geometry over and over. This allows other modifiers to make modifications to the mesh as a whole.
Unless you separate them after applying the modifier, they are all one object and part of the same mesh.

So they are never instanced, because they are never actually separate objects.

To instance objects with an array modifier, you could try using the technique in my answer here.


How to unwrap a model in 3d viewport (not UV unwrap)

I may be mistaken but I think you've gone a complicated way. It is less trivial to make a plane follow a curve than the opposite.

I propose you start with a plane instead.

Create a plane Scale it on X axis by 10
Enter edit mode (tab) and select the top and bottom edges
Subdivide by 40 (spacebar then search for Subdivide)
Enable proportional edit mode (see screenshot) and select two vertices
Move the upwards and while moving, use your mouse wheel to increase the proportional editing falloff
Exit edit mode and rotate the plane by 90° on X axis
Create a circle (shift+a, curves > circle) and scale it by 400% (that's just an example)
Make sure the circle is at coordinates 0, 0, 0
Select the plane and add a modifier called Curve
In the modifier, select the circle You should now see the plane wrapping around the circle
Adjust the scale of the plane to do a full revolution (here scale at 12.56)

And with this you're done. You can then apply the Skin modifier to the plane to give some depth. You can duplicate the plane the circle and make a smaller inner tube. There are many possibilities this way.

UV texturing is pretty easy too.


The error you are receiving is due to the fact your trying to change the object mode when no objects exist, because you've deleted them all.


Objects are "containers" for data. Mesh objects contain mesh data, curve objects contain curve data, etc. When you deleted the curve, you deleted the container, not the data that it contained. So, in your code your operating on the first curve in the curve data block, which would be the original curve.

Some options you have to resolve this are:

a. Delete the curve from the curve data block
 b. Find the curve that the curve object contains, and operate on it.

I would do the later:

curve = bpy.data.objects["curve object's name"].data
spline = curve.splines[0]


How the Fresnel effect works and how to construct Physically-Based shaders in Blender?

[Pseudo explanation.]

The normal gives us the normal surface orientation for each surface point. The incoming output gives us the direction of incoming camera ray. In the "middle" of a sphere the normal will be pointing directly towards the camera, hence at that point (only) the incoming and normal vector will be equal.

We are especially interested in the small incoming angle, where the glossyness will be stronger. If we sample a surface area on the "side" of the sphere (from camera view) the incoming and reflected rays have a small angle.

The more rough the surface gets, the more rays will be reflected in the direction of incoming.

With the roughness converging towards 1, the ratio of incoming reflected to normal reflected direction will also converge towards 1. The ratio is represented by the slider, switching from normal glossy reflection to (fake) incoming normal reflection.


Apply -1 x scale (mirror) to object mesh and keep custom normals with python

Alright, I found the solution with some help of the answer of batFINGER here.
There's surprisingly little information on the internet about manipulating face normals at the vertex positions, confusingly called 'split normals' or 'loop normals'.
To work with split normals with python you first need to use the method calc_normals_split() on the mesh or else you won't get accurate vector values for the split normals or loop normals.
It took me hours finding that out.
In stead of setting x scale to -1 and applying transforms at the object level, you should edit the vertices, face normals and split normals at the mesh level.
code:

import bpy

## get active object and mesh
ob = bpy.context.object
me = ob.data
## Very important to include line below for working with custom normals!
me.calc_normals_split()
me.use_auto_smooth = True
## go through each polygon, reverse second to last loop,
## multiply x vector of loops with -1, store mirrored vector in
## mirror_split_normals for later use.
mirror_split_normals = []
for iter_poly in me.polygons:
    reverse_normals_indices = [iter_poly.loop_indices[0]] + [i for i in reversed(iter_poly.loop_indices[1:])]
    for i in reverse_normals_indices:
        mirror_split_normals.append((me.loops[i].normal[0] * -1, me.loops[i].normal[1], me.loops[i].normal[2]))

## mirror vertices in x by multiplying x by -1
for v in me.vertices:
    v.co = v.co[0] * -1, v.co[1], v.co[2]

## flip face normals and apply mirrored split normals
me.flip_normals()
#me.update()
me.normals_split_custom_set(mirror_split_normals)

Original mesh:

Mirrored mesh:


Material won't apply to mesh with UV map

You don't see the texture is because you are in solid view in the viewport shading.

Switch to material or rendered view.

Bounding Box.

Only shows rectangular boxes that outline an object’s size and shape.

Wireframe

Objects appear as a mesh of lines representing the edges of faces and surfaces.

Solid

The default drawing mode using solid colored surfaces and simple lighting.

Textured

Shows meshes with an image applied using the mesh’s active UV Map. For Cycles materials, the image is the last one selected in the Node Editor. For other render engines, the UV Map’s applied face texture will be shown.

Material

A fast approximation of the applied material.

Rendered

An accurate representation using the selected Render Engine and lit with the visible scene lights.

For more info please refer to the blender manual:

https://docs.blender.org/manual/en/dev/editors/3dview/properties/shading.html


You can use UV>Cylinder Projection with your surface faces selected. Just make sure you don't select the bulging parts on top and bottom. They have to be mapped seperately, as well as the top and bottom caps. (Don't use Live Unwrap to avoid your UVs getting messed up)

BTW: If you don't want to deform your can later on, you can save a lot of geometry in your model (and even then, you can always add more geometry later, while it's more time consuming to remove unwanted geometry).
You don't need any of the edge rings between the two shape defining ones at the top and bottom. It's always good to keep the polycount low, be it for vfx or games.


How can I edit a shape-key mid-range without drivers?

Shape keys can be used to change a mesh shape with a certain amount of vertices into an other shape with more (or less) vertices. But for the sake of (my) argument lets assume it is the same amount of vertices for the start and end shape. The same way i think you are using shape keys.
In that case i believe a shape key can be seen as a recording of two location coordinates for every vertex in the mesh. (a recording like an animation keyframe). One for the start shape and one for the end shape.
I think (when the shapekey Value is changed from 0 to 1) an individual vertex moves from its starting position to its end position traveling the shortest possible distance. In other words, it moves in a straight line.
If i understand (or imagine your problem) correctly, you are essentially asking if a vertex (part of a single shapekey) can have a third coordinate location (like an animation keyframe) along the way. A third location it would be at if the Value is somewhere between 0 and 1, and that is not somewhere on the strait line between the start and end location. I'm pretty sure at the moment it can't.
Probably there is some other solution to your problem, but i think you would have to approach your problem (and possibly phrase your (new) question) differently.
Hope that gives some insight : )


TexturePaint; where are all the options?

Click on the little wrench and screwdriver icon on the right side. Above the render settings in the Properties panel.


Before anything, thanks to Cegaton for sharing a related post about my problem

the solution was to use an environment texture and not an image texture, since the world sky is not a mesh you can deform or uv unwrap it needs a different kind of texture


Real Translucency (NOT Transparency or SSS) in Principled Material Setup

I'm not sure why there is no Translucency option on the Principled shader. Perhaps there is a way to get translucent behavior from the Principled shader, but not that I know of. Here's a possible way to combine the two shaders, which should take thickness into account.
There's an answer here that goes over a way to find the approximate thickness of an object and use it in a shader by using the Ambient Occlusion node with Inside enabled.
While I'm not sure of your exact situation, I think it could be a reasonable way to mix the main shader with the translucency. I'd start by seeing what the Ambient Occlusion node outputs. It might be good enough as is. You'll probably need to adjust the distance though. I'd set it a bit higher than the thickest point on your mesh that you want to be translucent.
In some quick tests I did, I found the output might not be perfect on it's own. However, it's a pretty good start. You may want to mix in the Pointiness output of the Geometry node to isolate any raised sections (bumps, veins, etc.) that shouldn't be translucent. Mixing the two outputs using a Math node set to Maximum seemed to work well.
A quick hand painted texture could be used to "mask" the general areas that you want translucent. Add a Math node set to Multiply to add in the texture. This would just ensure that nothing is translucent that shouldn't be.
Here's a really quick test I did as a proof of concept. Far from perfect, but I think the idea is there. The dark spot is a Suzanne that I placed just underneath as a test. The mesh is just a subdivided cube with a thin section in the center and a couple sculpted "veins".

And the node setup:

As you can see there is a few spots on the outer edge that ended up translucent. With some tweaking of the ColorRamps it might get a bit better, but manually masking might be the way to go.


not clear glass how do I fix is it hacked?

By default the Material Preview mode will use a default HDRI (world image) and that's what is reflected on your object. To change that you can go into the Viewport Shading panel and check Scene World for example:


Blender randomly loses environment texture

I run into this issue all the time, mostly when using scenes that have DDS files as textures.  No idea what the issue is, but I use a workaround to avoid it.

If you run it from the command line with a limited number of frames per run, you can do the whole run without worrying about getting the pink textures.  For example, the following series of commands will render frames 640 through 669, in 3 batches of 10 frames each.  By using the #### format in the render output, it will automatically put the frame number into the filename.  That way you can get a nice image sequences without running into the texture issue.

blender --background intro_scene.blend --engine CYCLES --render-output //tmp/HM-####.png  -s 640 -e 649 -a
blender --background intro_scene.blend --engine CYCLES --render-output //tmp/HM-####.png  -s 650 -e 659 -a
blender --background intro_scene.blend --engine CYCLES --render-output //tmp/HM-####.png  -s 660 -e 669 -a

No idea why it does this in the first place.  It's really frustrating.  Here's the full error for anyone who wants to dig into it a bit more:

Failed loading CUDA kernel C:\Program Files\Blender Foundation\Blender\2.79\scripts\addons\cycles\lib/filter_sm_52.cubin.
Error: CUDA error at cuModuleLoad: File not found


Can modifiers be computed and applied from the command line?

You'd have to use bpy.ops.object.modifier_apply, e.g.

import bpy

for obj in bpy.context.scene.objects:
    bpy.context.scene.objects.active = obj
    count = 1
    length = len(obj.modifiers)
    while obj.modifiers:
        name = obj.modifiers[0].name
        print("%s: Applying %s (%d/%d)" % (obj, name, count, length))
        bpy.ops.object.modifier_apply(modifier=name)
        count += 1
print("All done.")

For info on how to to run the above, see here.


How to convert Damped Track and Follow Path of camera into Frames?

When you Bake Action, be sure to enable the Visual Keying checkbox. This ensures that the 'final' state of the object is captured, after all transforms, constraints, etc. have been applied.


How to achieve more physically accurate motion in the game engine?

All of the answers here so far do not quite fix your problem. it is actually quite easy to fix. Radish Has the right idea (using linear velocity set to Add). This answer also expands (and says more clearly) what StealthyRobot said in his answer. (Although the numbers which he gave there do not work as expected)

First you need to use linear velocity with the settings local and add enabled.  (I assume you already have this)

Now we can fix the overshoot problem. to do this increase the damping on the Translation for your character.

If you are using Torque to steer, also set Rotation dampening.

It also might be useful to view this question

Realistic Jet Flight

You can see it working here

If you had trouble following that, (hopefully you did not) or if you just want to see it working, feel free to take apart/play with the blend file.


Hair physics and/or particle edit with particles rendered as objects

Figured it out, I've just got to bake the simulation before I change the render type to object.


Keyframe the ocean modifier time property

Use keyframe_insert

Two things here,

Add modifiers with Object.modifiers.new(...) returns a reference to
the modifier
Add keyframes with keyframe_insert(datapath) method.  Set the value, insert the keyframe.

Test script

import bpy
context = bpy.context
bpy.ops.mesh.primitive_plane_add(size=2, location=(0, 0, 0))
ob = context.object
om = ob.modifiers.new(name="Ocean", type='OCEAN')
# (frame, time) pairs
data = ((1, 1.0),
        (10, 3.0),
        (100, 33.0),
        )
for f, t in data:
    om.time = t
    om.keyframe_insert("time", frame=f)


Why does editing leaves behind the previous mesh?

There is a active Mirror Modifier on your Object. However the mirrored Object is not a half Object but a full Object already. You can see this also by the mirrored vertex transformations on the other leg. So either cut your mesh in half and still use the mirror modifier, or delete the mirror modifier


SOLVED
I was able to solve this issue by creating a new edge using the knife tool to intercept the weirdly interpreted anchor points.


How do you scroll the amount of loopcuts/bevel segments in edit mode without having to change the middle button to scroll?

After pressing Ctrl+R, you can use PgUp to increase and PgDn to reduce the number of loop cuts. Using this you can adjust the amount to fit your needs dynamically, while entering a number can be faster if the amount of cuts needed is known.
Updated:
The Num + and Num - as @moonboots mentioned and the above mentioned PgUp and PgDn work for me in Blender version 2.83.3, which should be the version* used if you do not work with the experimental ones.

*version used currently as it's the stable and also LTS version at the time of this post.


You may want to watch the first 8 minutes to know how the action editor and the NLA work.
In general the clips you are not seeing, are in "replace" mode or have not been stored correctly on the Action Editor with it´s corresponding user (but as a fake user), are not present on the graph editor and are not taken in account.


How do I create a material that is only visible under one specific light?

As sambler pointed out in his comment, Rich Sedman's answer to how to vary a material's response to shadow rays, depending on the light to which they are cast, is very complete. This suggestion  takes the same basic approach, but instead of using drivers to feed the location of a lamp into a node tree, looks ahead down a shadow ray using OSL, to figure out which lamp is casting the shadow.

The setup for this example has cubes which are going to receive shadows, and shadow-casting circular planes just above them. The spotlight we're interested in has a plane just behind it, and parented to it, as a target for the forward-probing ray. Everything in the scene has the default Pass Index of 0, except the target plane, which has an index of 20.

(The target plane is there, because I couldn't manage to hit the spotlight with the forward ray.. perhaps someone can explain why?)

There's a little OSL script which casts a ray forward from a shading point continuing in the same direction as it arrived, and returns the index of the next object encountered.

#include "stdosl.h"
shader NextObj(
  output float nextObjIdx  = 0.0
)
{
  if (trace(P,-I,"mindist",0.0001)){
    getmessage("trace", "object:index", nextObjIdx);
  }
}

It's used in this tree: If a ray is a shadow ray and the next object encountered has a Pass Index greater than 15, the multiply returns 1, else 0.

The material is applied to the circles, which are blue-transparent to any light associated with index greater than 15, but fully transparent to all other lights.

this is the sort of result:

For lots of reasons I think the geometric approach is better than this one, but maybe someone can improve it? Or come up with a way of manipulating surfaces more directly?


I always get rendered and old version, I cannot save the new version neither

When you duplicated your bottles, you also duplicated their animation data. After you reposition your duplicates, you also need to overwrite the location and rotation keyframes, or they will jump back to the original position as soon as you hit render or change the frame.


Using Anaconda Python 3 in Blender Winx64

I succeeded using the following solution:

Install anaconda2 x64(I use python 2.7 usually, so I installed it.).
Install Blender 2.77a x64.
Create py35 environment for blender by command conda create --name py35 python=3.5 anaconda.
Rename C:\Program Files\Blender Foundation\Blender\2.77\python to _python.
(a) Copy & Paste the folder from C:\Anaconda2\envs\py35 to C:\Program Files\Blender Foundation\Blender\2.77\python.
(b) Or, alternatively, create a link to the anaconda installation. This way any updates will automatically be available: You need to run cmd as administrator (use right click on the item)

D:\Blender Foundation\Blender\2.77>mv python python_old
D:\Blender Foundation\Blender\2.77>mklink /j python d:\Anaconda2\envs\py3
Junction created for python <<===>> d:\Anaconda2\envs\py3

Try import bpy, import pandas, import numpy, import scipy, import sklearn, ...etc. on Blender python console.

Console, Text Editor both worked fine for me.


Does gltf only support the export of one strip per NLA track?

The exporter can only use a single strip per NLA track — the limitation is tracked in github.com/KhronosGroup/glTF-Blender-IO/issues/763.


Change clamp indirect to 0.  You have it set to .01, which feels like it should only affect it in a small way but in truth the smaller the value for clamp the more of an affect it will have.  0 = off.


I think a pretty efficient way to solve this would be to have a more distributed (softer) weight paint on the armature rig. This way, the bones will not bend so sharply.

Hope this helps!


Method for drooping mesh vertices over rounded objects

Just from the looks of it, I'd say that the object you want to shrink has a way too low vertex count to fit the model. Try to add some loop cuts and then try the shrink wrap modifier again.

Depending on what you want the end result look like, it's also possible to copy a part of your mesh, convert that part into a new object (hit P) and go from there.

There is also the possibility of using physics but I never tried it with solid objects.


How to set keyframe handles to be interpolated via script on the fly (low-level variant: keyframe_points.add(int) + keyframe_points[i].co=..)?

When using keyframe_insert() the default interpolation set in preferences is applied to each keyframe as it is added, this doesn't happen when using fcurves.new(), which always leaves it at bezier. If you don't want to use bezier interpolation then you will need to set the interpolation for each point as you create them.

fcu_x.keyframe_points[i].interpolation = 'LINEAR'

Then you will want to call fcurve.update().

  update()
  Ensure keyframes are sorted in chronological order and handles are set correctly


How To Make An Object Fade As Another Intersects With It?

Finding a falloff that drives the transparency depending on the camera proximity.

The node setup:

Take the coordinates of the camera as "object" in "texture coordinates" node.
Get its length to the mesh "vector math" using "length"
Add a little value so that we won't reach 0 in next node
Negative power so that the value is bigger as the length decreases
Tweak the curve using "vector curve" on X: small values are 1 and bigger values have a falloff to 0 rapidly
Get the X component tweaked above
Multiply the result with the value that already drives the cloud transparency, so that transparency is due to both the texture and the result of the proximity

You may have to tune values and curve depending on your cloud/plane configuration and size.


How to use the render result from one scene as a texture in another scene

Neither Cycles not Blender-Internal support this, You just have to render out the files to an image or a movie, then load them in as an image texture afterwards.


Need help with modeling the cross-guard of a sword

I've tried something, tell me if this is what you want:


How do I extract texture from an obj file?

Obj files don't contain textures. You have probably forgotten to download an additional file with your download, or the model doesn't include textures.


As mentioned by eromod, you can lock the transformations in the (n) properties shelf.

Another (Less good) idea: You can set the Translation Damping under Rigid Body Dynamics to 1, but this still allows the object move a little bit.


Particle system only shows one particle?

From the comments:

It will eventually add all of them, but you have it set to add them from frame 1 to frame 200. I think you would get the effect that you want if you set the end to frame 1.

Turn off physics by setting it to No, set the start and end to the same value, and then give them a really long lifetime...you have it set to the default of 50.


Fastest way to achieve such effect is to animate the object and use the tools Blender is already providing.

First of all your objects need to have some kind of animation in your scene, even if you are rendering a still. Motion blur/Sampled motion blur need to acquire the pixel's velocity vector from the scene and sample from there the blur effect.

In the provided example, Suzanne's Y rotation has been keyframed.

Pick a frame where the object is in motion (e.g not frame zero, where Suzanne is still, but something like the fifth).

The things you'll have to enable change their names a bit between the two built-in render engines:

Cycles:

Enable Motion Blur checkbox

Blender Internal:

Enable Sampled Motion Blur checkbox  and set an approriate value for the number of samples you would like to render (more samples cause longer render times but increase the effect quality)

In both cases you should set an appropriate Shutter frequency value(low values make stronger blur).

There is also a Compositor node if you prefer to add the effect during post-production. It can be found in the Filters menu. You should in this case enable the Speed/Vector pass, connect the relative sockets and tweak the parameters to your taste.


In Node Editor, why is the RGB Curve Node different?

The first image is from the material nodes.

The second is from the compositor nodes.

The curve editor in the Compositor works differently, it has additional controls to determine the ranges for the curve.
From the Blender Manual:

Black Level
Defines the input color that is (linear) mapped to black.
White Level
Defines the input color that is (linear) mapped to white


Given a rectangle (4 vertices), how to make ONLY ONE of the corner rounded

Use a bevel modifier defined by a vertex group with only one vert selected.


I am sorry, but the question is still very unclear... You don't have to share your project, but at least give us more informations. For now I'll try to interpret your question as best as I can, and I'll edit it later if you explain yourself better.

The way I understood it is that you want your light to shine through the top face of your object, but not through the bottom faces. I assume you want your top face to be a solid material, and I assume you want to keep it all as one single object. I'll also assume the spotlight direction is always above the object and that you don't want to have extra objects (e.g. shadow catchers). As you can see a lot of assumptions here.

In this case you can do it with 2 different materials applied to the cube. On the bottom faces you have your normal material, while on the top face you have this material:

The principled shader is your material, the other nodes are just there to allow the light to go through the face itself


Why is vertex drawing ignoring grid snap settings?

If I want to draw some vertices on the ground plane, I seem to have to
  place the first vertex with Ctrl-RMB (not Ctrl-LMB as the manual
  states...

That's probably because Blender used RMB for selection by default prior to 2.8. WWas it on the 2.8 manual or the 2.79?

For your issue you have to extrude, cancel the moving of the extrude by using right clic mouse button, then move it with G (dont deselect anything by error) to get the snapping effect.


How to render a cycles scene in luxrender?

Luxrender in version 1.6 (latest iteration) offers a basic material converter. Check out the release notes on the Luxrender Site here (scroll down to the last entry): http://www.luxrender.net/wiki/New_in_1-6

The button to convert all materials is in the render tab:

to convert elements individually, do a space bar search in the 3D viewport. Hit Space and enter 'convert' gives you these functions:

Disclaimer: If this makes your renderings FASTER I'm not sure. It depends on the scene and the aim. But it gives you a quicker starting point.


Armature bug: keyframes are "ineffective"

On the timeline panel try setting active keying set to "Whole Character Selected bones only".
See if that fixes the problem.
Also .blend would be nice to see if there's anything else I'm missing from the pictures.


Blender Game Asset Creator Tutorial: 5.5 - Unwrapping The Cone

You receive this error because you don't have an active face (quad) selected.

Select one face from your mesh to make it an active face. It must be a quad (four vertices).
Select all faces by hitting A. You will notice the active face looks a bit different than other selected faces (it's lighter).
You can now unwrap with Follow Active Quads option.

This is how an active face looks like:


Spinning existing vertices around a point

In these illustrations, the track to be deformed is lying in the XY plane, Y up, X across.

You can use the spin tool to generate new geometry: extend your object around an arc of a circle, by selecting the top row of existing vertices, and AltR spinning them. In the Tool region, set the Axis to (0,0,1), the Angle to 90 degrees, and the Center to the center of the circle from which the arc is taken. (The empty in this illustration is just to show roughly where the center is)

But it's hard to adjust the center without constructing guidelines, and destructive. It's probably easier to use Simple Deform > Bend, with these settings, and an empty oriented and placed as shown:

That example uses the 'Limit' setting to restrict the deformation to the halfway point in the track's X, in the empty's space. You may need to slide that up and down, depending on the extent of your track in the empty's X.

Or...

.. you can restrict the deformation to a vertex group. (The angle setting becomes a bit counter-intuitive)


How to set backround image in Blender 2.8

You need to add a Texture Coordinate node and connect it to your Image Texture node, otherwise blender won't be able to map the texture properly. You can then move, rotate and scale the texture using a Mapping node.

For comparison, without Texture Coordinate node:

And with:

EDIT: After seeing your screenshot, I see the issue: you are editing a MATERIAL node, when you should be editing the WORLD node. Simply select "World" from the dropdown list on the upper left corner:


The Blender Game Engine and the Blender's simulation system use two different pysics solvers. To see the game physics settings you have to set the Blender engine to 'Blender Game':

But the softbody settings of the game engine do not offer any settings for plastic deformation:

So why is there a difference?
The solver used in the animation system is more powerfull and accurate, but as you may have noticed it is much too slow for a game.
The solver in the Game Engine on the other hand uses a very fast position-based softbody simulation called Shape Matching (see the paper for more information). While the paper also describes the implementation of plastic deformations, this is either not implemented or not activated in Blender.


Change UV Map Image Without UV Map Scaling

First select the UVs in the UV/Image editor, make sure the X and Y cursor location is 0, switch Pivot point to 2D Cursor and scale the UVs using S button, hit X to limit the scale on X axis, input 0.5 and hit Enter


Should you ALWAYS use Blender's subsurface modifier?

No.  Whether you should depends mainly on the intended use of the model and its geometry.

A model that only appears in the background may not need the benefit of the modifier and render time will be reduced if it is not present.

Not all models require the benefit. If all of the surfaces of a model are flat, like the boards in a picket fence, then the subsurf is not necessary and the rounding that gives realism to edges can be provided by a bevel modifier.

Not all that do require edge loops. Often a judicious application of the bevel modifier will produce good results, with the advantage that the bevel modifier is non destructive. This can provide advantages when creating or changing models.


How do I run a script on multiple .blend files from the command line?

There is nothing wrong with either script. The problem was the use of an ampersand (&) in the file path. Don't use special characters in your folder/file names. Newbie mistake on my part.


Writing my first blender Addon and I am confused on these string keywords

The example "strings" that you show belong to two different categories, frame_start and frame_end are property names while render.render is an operator name. The properties will display as a number that you can edit while the operator will show as a button that will perform an action when clicked.

The strings that you use need to match an existing property or operator for them to work, an operator is identified by it's bl_idname property. You can specify a property or operator name and have a different string shown by passing a text paramater.

row.prop(scene, 'frame_start', text='adjust this here')
row.operator('render.render', text='This is my render button')

To create extra properties that are only used by your addon, you can use custom properties, which you should create in your addons register() function.

class MyPanel(bpy.types.Panel):
    ...
    def draw(self, context):
        row = self.layout.row()
        row.prop(context.scene, 'my_prop')

def register():
    bpy.types.Scene.my_prop = bpy.props.IntProperty()
    bpy.utils.register_class(MyPanel)

For operators, you can make your own and then use the bl_idname that you set in your operator class to show a button for it. If no text paramater is passed, an operators bl_label property is shown on the button.


Try to disable the Snap option (magnet icon button on the bottom horizontal menu bar of the 3D View)


Good question. You've picked up what looks like an anomaly, unless someone comes along to correct us.

In all the cases in the main square below, the right two faces are selected before 'Inset' is called.

In the top row, 'Individual' is not checked. The two faces are considered a region. The inset is made on all edges at the boundary of the selection, ignoring edges at the internal boundaries between faces.

In the top left case, 'boundary' is checked, permitting the inset at the boundaries between the region and the outside world. In the right case it is not, and the external boundaries are not inset.

In the second row, 'Individual' is checked. An inset is made at all internal boundaries as well as external, when 'Boundary' is checked, on the left.

However when 'Boundary' is not checked, I would expect the inset to be made at internal, but not external boundaries, producing a result like the last in the bottom row. But it doesn't.

The only way I could get the expected result on the far right was to select each face in turn, with 'Individual' not checked, treating each face as a 1-face region, and inset each region individually, with 'Boundary' unchecked.

In short: the  'Individual' setting does not respect the distinction between internal and external boundaries made in the 'Boundary' setting.


Joining mirrored object causes half of it to disappear

If you are using the mirror-modifier, make sure to 'Apply' the modifier in the 'Modifiers' tab under 'Properties' in 'Object Mode'.

If you have multiple Meshes that are mirrored via the mirror-modifier, first 'Apply' the mirror-modifiers on each, then continue joining the meshes via Ctrl+J.


There are two register and unregistered functions. When running the script both are registered as the __name__ == "__main__" evaluates to True and use the version of those functions that are defined upon that time

When running as an add-on the full module is loaded and blender will handle the calls to register and unregister functions. After loading the module only the latest version of the register and unregister functions are known. Hence only the custom draw function is registered.

This can be fixed my merging the two register functions and the two unregister functions.

bl_info = {
    "name": "HTML Render Combo",
    "author": "Virgil Sisoe",
    "version": (1, 0),
    "blender": (2, 79, 0),
    "location": "Properties > Render",
    "description": "Quick panel to export Documen HTML",
    "warning": "",
    "wiki_url": "",
    "category": "Render",
}

import bpy
#DEFINE CUSTOM OPERATOR FOR HTML EXPORT
def main(context):
    """for ob in context.scene.objects:
        print(ob)"""
    bpy.ops.render.render()
    bpy.ops.scene.export_documen_html()

#CREATING CLASS
class SimpleOperator(bpy.types.Operator):
    """Export HTML"""
    bl_idname = "object.simple_operator"
    bl_label = "Simple Object Operator"
#CHECK
    @classmethod
    def poll(cls, context):
        return context.active_object is not None

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

#DEFINE CUSTOM PANEL FOR EXPORT
def draw(self, context):
    layout = self.layout

    # write the layout code below here
    row = layout.row()
    col = row.column(align = True)
    col.scale_y = 3
    #row.operator("render.render", text="Render", icon='RENDER_STILL')
    row.operator("object.simple_operator", text="Render + HTML", icon='RENDER_STILL')
    row.operator("scene.export_documen_html", text="HTML", icon='FILE')

    scene = context.scene
    box = layout.box()
    row = box.row()
    row.prop(scene, "documen_folderpath", text="Export Path")
    row.prop(scene, "buttons.directory_browse")

#render panel path
def register():
    bpy.utils.register_class(SimpleOperator)
    bpy.types.RENDER_PT_render.append(draw)

def unregister():
    bpy.types.RENDER_PT_render.remove(draw)
    bpy.utils.unregister_class(SimpleOperator)

if __name__ == "__main__":
    register()

There are other stuff missing from the file like the "scene.export_documen_html" operator.


Make constraints to fit cylinder into centre of icosahedra joint

You can get there in three steps:

Select inner faces of the joint
Co Mesh > Snap > Cursor to selected (3D cursor is the center for new objects)
Add a cylinder with six sides - it will be precisely in the middle


what parameters to imagemagick will convert from EXR to PNG that matches how blender interprets the RGB values?

The short answer is that EXR holds data. In the case of visual data, it is a convention that the visual RGB data is stored in a linearised format.

When encoded as a linearised format, there is no idea of what transfer function is embedded into the data. This means that the imager has to apply the proper transfer function that covers the proper range of data within the EXR.

If you are using the "Default" rendering view, which is the sRGB EOTF, you can identify the different transfer functions and have ImageMagick convert appropriately with something like:

convert myexr.exr -colorspace RGB -colorspace sRGB mynonlineartiff.tiff

If you are using any transfer function other than the sRGB EOTF, the process would require further effort, and in most cases, ImageMagick would be an unacceptable tool to harness. OpenImageIO and OpenColorIO would be more suitable.


2.8 box selection does not select everything, tiny objects not selected?

When I use "Origins (All)" - selection works ....

^ I try to find an example, because I'can't supply this (customer) data ...


How to set start and end frame for hair animation

Thank you to @FFeller for his comment, it really answers everything, but since he didn't write an actual answer, I will answer my own question for future viewers.

In order to disable a hair animation for part of a render to speed up BVH creation, as FFeller said in his comment, one would insert keyframes on either side of the period where the hair is present in pairs, with the enabled pair on the inside and the disabled pair on the outside (probably with one frame difference between enabled and disabled keyframes, otherwise results can be rather strange). This would be done by navigating to the correct frame, setting the camera icon to either enabled or disabled (depending on which is needed) and then pressing "I" over the icon to insert a keyframe. The icon should now be highlighted in yellow and there should be a keyframe on the corresponding frame.

keyframe which is set to enabled

keyframe which is set to disabled


Engraving a text string in Blender Internal Render

Create your lingot first. Add a text object and give it some thickness extruding it in the properties geometry tab.

Place the text where you need it and convert it to a mesh: Alt C and select Mesh from Curve/Meta/Surf/Text

Select the Lingot,  add a Boolean Modifier and select the Text as object and use difference as operation.

You can now move the text to another layer that is not part of your rendered layers.

If you have different text objects you can change them by selecting them in boolean modifier.


How to convert images from logarithmic space to linear?

If you intend to transform a log encoded image to scene referred linear, you need to be certain of the following characteristics:

The log encoding format of your source footage. There are many different log encoding formats, and to achieve a proper transform, the exact log encoding, with variables, must be known.
The source footage colour primaries. The source is encoded with specific colour primaries that must be known.
The destination colour primaries. These must be known to transform to your reference correctly. Blender's default configuration reference space assumes BT.709 primaries, for example.
The destination transfer characteristics. In the case of default Blender, the reference space in the compositor is scene referred linear.

Once you know these details, the proper transforms can be added to the OpenColorIO configuration, and your data can be transformed correctly.


How to increase performance in the View Port?

If your cubes have more than 8 verts then I suggest using a decimate modifier. But not applying it. It will reduce the polycount and you can just undo it for a final render by deleting the modifier.


Array modifier questions from a beginner

19:30 He basically duplicate the set of windows with CtrlD and then proceeded to deleting the array modifier that was copied during the duplicate fuction.

18:30 Ctrl L - It's basically a quick method to select a mesh and all it's joined elements. This is extremely useful if you have multiple sub-meshes joined together to form the main object. Sometimes you may want to select that one sub-mesh to apply a material or hide it temporarily.

Applying a modifier makes it permanent and irreversible. However you can undo it if it's still within the undo range. Usually you will want to apply modifier at the end of the modeling process.

Extra Note

Personally, I usually just hit L, this works in UV editor mode too when you want to select a UV island.


How do you make a character navigate along a grid in the BGE?

Your request is pretty simple.

Limit any movement to:

90 degree turns
steps of 1 BU size
do not use the physics engine

This assumes you want to move in discrete steps (in frame t the object is at A and in frame t+1 the object is at B without any intermediate steps).


I was struggling days to find out what caused the problem with baking normal maps and think I found a nice solution. I could have used much easier way to bake normal maps for my mesh.
To bake normal map for my mesh, I needed to do the following:

Have only one mesh for baking normal map
Use multires modifier on that object
Raise the levels of subdivisions as high as I need to have nice details
Once I've created details in sculpt mode, go to Cycles Render Engine
Go to "Render" tab and open "Bake" option
Make sure that "Selected to Active" is disabled (becaused baking normal maps with this option is based on other method)
Change "Bake Type" to "Normal"
Hit the "Bake" button and be happy to have good normal map.

This way of baking normal maps for mesh is usually used when your mesh has fine topology (the mesh consists of square-shaped faces and not triangles), because multires modifier will subdivide all faces and mesh that consists of triangles, will deform the mesh alot. However, it's easier to subdivide squares and it doesn't cause any problems this way.


Node - Need to reopen texture so it is visible in render mode

When you have opened a texture into a material, then want to modify it by painting on it while it is wrapped around the object, the changes aren't really permanent. In order for the changes to be saved permanently, and this is what I have done, is go into the UV editor, find the texture if it isn't displayed immediately, make sure the changes are visible there, then click on the menu entry Image and either Save As Image if you want it as an external resource, or Pack Image if you want these changes to follow this particular Blend project only.

Hope this was helpful.


You probably think of using Proportional Editing with Random Editing Falloff.


How to place a 3D model in the same posion in a photo for rendering?

This video mentions a software that will probably help you with aligning things up with the scene background, he starts mentioning it at about 1:38. Also, are you using hdri images and putting them as the world background?

youtube.com/watch?v=nb6rSMAooDs

Hope this helps!


In object mode, you can just select the UV sphere, right click and choose "Shade smooth".


Quick smoke in blender 2.8 goes the wrong direction

You have a wind force in the scene. If you want that to make the smoke go up, scale the domain, and rotate it parallel to the Z axis. Then bake the smoke at whatever your settings are for it, and your problem should be fixed. This problem was caused because the wind blew the smoke across the top of the domain, not up.


Add new expressions to existing scripted expressions in driver?

I managed to solve this myself. The problem was that Blender overwrites the value of the expression each time the driver is created when calling driver_add(). Instead I get the old value from the driver in animation_data before creating the new driver and save that as a string. Then I split the string by "+", check each string if it ends with the pose bone name, and if it does, I replace the value rather than adding it again. Finally I set the expression to the new string (after adding the pieces of strings back together).


Particle system doesn't affect part of mesh?

Make sure use modifier stack is checked under the emission rollout of the particle settings.


I assume that would be the "Windows" or "Apple" or "Super" key. Its name varies depending on your OS (Windows, Mac or Linux). It's the one between Ctrl and Alt on most keyboards.
I've never heard it be called "OS" key though, so I might be wrong. If so, I'm curious to know what it is.


How to save a render image as JPEG with white background instead of default black background at alpha transparent areas?

No, but it's quite simple to do with nodes..

In the compositor (press ⎈ Ctrl← Left arrow), enable Use Nodes in the header and add an alpha over node (⇧ ShiftA> Color):

The color in the top slot is the color which will be used instead of transparency.

Now transparency will be automatically filled in with white (or whatever is in the top socket) when the scene is rendered.


You could try saving your model at various points that you'd like to show, and then import/link them all into one file, and keyframe their visibilities in that file.

Get all your objects into one file.  Import them if you don't think you'll need revisions.
Select the object you'd like to show first.  Get to frame 1.
Hit the "Eye" icon in the outliner to make the object invisible.  Keyframe that object's visibility.  (Hit "I" on the eye icon in Outliner).
Advance to frame 2, make the object visible again, and keyframe it again.
Advance however many frames you'd like this object to be visible.  Let's say 24 frames.  On frame 24, keyframe the visibility again.  Then on frame 25, turn the visibility off, and keyframe it.
Open up a NLA window, select that object, and press the 'down' arrow to push the action onto the stack.  That just enables the NLA to manipulate actions.
Load up your other objects, and load them into the NLA editor.  Just keyframe your un-keyed objects to get them to show up.
Select another object's track, and from the NLA menu select Add >> Action.  Select the action from the first object you keyed.
Repeat step 8 with the other objects.

Hopefully that makes sense to you.  To see a rough idea of this setup, check this out: http://pasteall.org/blend/40878


Mesh with with color on the front side, and black in back side

Well by default all faces have only one normal. A normal indicates the direction that a face is pointing in. In general 3D it is usually not possible to have the same face show different colors. For more on normal's read https://www.blender.org/manual/modeling/meshes/editing/normals.html

Even if you have cloth you have a back face and a front face of cloth it may be paper thin but it still possesses thickness. A butterfly wing has some thickness too and the front and back should usually be modeled as separate faces this is important if you are going to use the model in another engine or you want it to work anywhere.

But certain render engines provide that feature where the reverse side to the faces normal can be a different color.

Blender cycles provides that feature but it is part of the materials.Blender internal also provides that feature but its implementation is different.

I guess you can use this feature if your model is limited to cycles otherwise create another face for the butterfly wing.

You can test the above node setup by  Just adding a plane and adding a cycles material to it and using the above node setup (rotate the plane and and you'll get the idea).


How to create fire materials using the new Principled Volume node that visually look the same as the "old method" of fire materials?

Here is my final result.

The result using the first node setup:

And the result using final principled setup:

Let me start of by saying that smoke simulation and rendering is not something I am very familiar with, so despite being able to replicate the material fairly well, I don't necessarily understand everything behind why it works the way it does. But I'll explain what I can.

A quick summary of what I did:

Left the default color as white, and used the colorramp as the input for the Emission Color.
Increased Emission Strength to the value you had, but then dialed it back some as it was too strong. I noticed that the two images aren't exaclty the same, and further reducing the Emission Strength could probably fix that.
Increased the Density to half of the value you used in the first setup, as this looked closest.
Left everything else as the default. I tried changing the color and temperature attributes, as well as the Blackbody settings, but they seemed to have no effect with this setup.

So, from what I understand at the end of this, the Principled Volume Shader is basically setup to replicate the original node setup you have, and it does it well. There does appear to be some differences in how the shader works compared to the old method, namely in how the density works. I noticed that (before emission was added, which made the details hard to see) the Principled smoke looked more dense than the manual smoke, but if I decreased the density it would get to the point of areas being nearly transparent before the main density looked similar. More details were visible in the principled smoke, and since in this setup the smoke was colliding with the domain, the principled setup had more defined boundaries, whereas the manual setup was much less defined. Perhaps with some experimentation, or a better understanding of how the shader works, as my knowledge is limited, a more similar result could be achieved.

The good news in all of this is that smoke is now much easier to setup, as the final setup I arrived at was just this:

Hope that helps!


Need advices on the topology of this mesh

If your render is OK you can keep it as it is, there must be simpler topologies like this one:


This topology is so messed up (current Sculpt Mode will do that), it might need a retopology.

Either use a Shrinkwrap Modifier to get a clean result with a new mesh and far less verts (after the rough adjustments, you can enable the modifier to be active during Edit Mode which glues your verts to the surface) or use use the Bsurfaces addon. With it, you can convert Grease Pencil strokes into topology. You need to set the grease pencil to Surface or otherwise the strokes won't connect to the underlying mesh.


2 related(?) questions: How to scale or extrude multiple selections together?

In Blender, you can change the behavior of these operations like extrude and scale to suite your needs by setting the Pivot Point. The select menu is located in the bottom bar in 3D view.

In your case, you need to extrude or scale selected loops / faces individualy, so you need to select the Pivot Point to Individual Origins:

You can also use the shortcut Ctrl. for that.
For switching back to Bounding Box Center, use ,

The result - scale:

Extrude


Shadow Catcher, Shadow Rendering Behind Tracked Camera Scene

Well, I'd like to be more explicit in how I fixed it but basically, I went around and figured out that I had objects on the wrong layers.  After I switched from Blender Render to Cycles I was still having issues, even though Shadow Catcher was a much simpler option.  Even though the composite was working in Blender, it wasn't until I moved things to the proper layers that the shadow would show up. Now everything looks right and I'm on to my next challenge!


Parenting with automatic weights generates empty vertex groups

Hey I just got the same problem with the ManuelBastioniLAB Addon and what seems to work for me is the following:

So do you remember that you have to check your mesh, that had to be only close mesh with no additional objects like the eye balls and teeth... well after i spitted and isolated the body I deleted the double vertex by getting to edit mode, select all the vertices, press W+Remove double vertex BUT changing the "merge distance" to 0.0400 or any slightly higher value instead of the default one, for some reason double vertices used for the edge split to fix edges normals on a smooth surface are not as close as they have for the default "delete double vertex" function to do the job.

Hope that works for you! It took me a long time to find out!


Using argparse in script yeilds memory error

I had the same issue, so I use try and except to fix this problem in python 3.3 in blender 2.69.

Solution

try:
    args = parser.parse_args(argv)
    do_something(args)
except SystemExit as e:
    print(repr(e))
# END OF FILE

Results

When we run blender like this:

blender --background --python argparse_blender.py -- -h

(Or like this blender --b --P argparse_blender.py -- -h)

We get the desired output:

usage: blender [-h]

Run blender in background mode with this script: blender --background --python argparse_blender.py -- [options]

optional arguments:
    -h, --help  show this help message and exit
SystemExit(0,)

found bundled python: [...]/blender/2.69/python

Blender quit

Suggestion

I would write the whole argparse_blender.py like this:

import do_something
import argparse
import sys

argv = sys.argv
if "--" not in argv:
    argv = []
else:
   argv = argv[argv.index("--") + 1:]

## set the prog name to match real usage
parser = argparse.ArgumentParser(
    description = 'Run blender in background mode',
    prog = "blender -b -P "+__file__+" --",
)
try:
    args = parser.parse_args(argv)
    do_something(args)
except SystemExit as e:
    print(repr(e))
# END OF FILE

Because it gives nicer output:

usage: blender -b -P argparse_blender.py -- [-h]

Run blender in background mode

optional arguments:
    -h, --help  show this help message and exit
SystemExit(0,)

found bundled python: [...]/blender/2.69/python

Blender quit


Set parenting with automatic weight causes my mesh to deform in the abdominal and pelvic area

After a quick search I solved it. I had to CTRL+A in Pose Mode and Apply Pose as Rest Pose before I set the automatic weight.


Adding/removing items to CollectionProperty in PropertyGroup and UNDO

Your operator should define bl_options = {"UNDO"}:

class MyOperator(bpy.types.Operator):
    bl_options = {"UNDO"}
    ...

See https://docs.blender.org/api/2.79/bpy.types.Operator.html?highlight=bl_options#bpy.types.Operator.bl_options


Using more RAM for render doesn't give any speed up for render. Blender uses as much memory as it needs.


Personally, I don't trust the knife tool unless it's to do something very specific. It can make lots of irregular faces if used as a freehand tool. I'd rather stick to loopcuts and not worry about the extra faces.

Judging from your second screenshot, seems like you're trying to make some kind of piece/emblem from your current mesh (which is starting to look pretty weird). I'd recommend to make that part as a different object and then join or parent to your first object.


The symmetry operation will happen on the armature's local X axis, but you probably rotated it 90° on its Z axis in Object mode, so the local X axis is not aligned with the global orientation any more. So cancel the symmetry, apply the rotation (CtrlA) and symmetrize again.


Transform Effect

Transform strip effect is the way to manipulate input strips around the "canvas". As stated by the Blender Manual page:

  Transform is a swiss-army knife of image manipulation. It scales, shifts, and rotates the images within a strip.

Select the given video strip and add several Tranform effect strips to it (the must all be referred to the input, the one in blue, so always pick it before adding each effect).

You'll not need to duplicate the strip several times, as the effect strip is already a copy of the input video itself, but with custom parameters.

Make sure to assign a Over drop blending mode to each tranform strip and mute the input one.

If you are planning to use multiple views (as shown in this video), just assing a transform strip to each input video:

The 4 input videos were made by rendering the same animation from 4 different cameras:

You can find several templates for Blender at: DIY hologram using a 4-sided pyramid


Found a solution in compositing based on this BlenderArtists thread.

To pixelate a render layer or image, you simply need to use the distort scale node to scale it down, use the pixelate filter node, then scale it back up.

The amount of scaling up and down control the amount of pixelation.

EDITED: If you really want to reproduce the effect from the original image, with the pixelated outline as well, you need a slightly more complicated node setup:

Download blend file here.

Original vs. pixelated+outline side by side:


Particle System Dupli Object's Children Not Rendered

Group all the objects and under the particles render tab set the render to Group and check whole_group.


Animation is rendered in Eevee instead of cycles

This happened to me, here is how I fixed it.

I rendered an animation in EEVEE to see what it was like and then created a video using the video sequencer.

Next day, I decided to do a Cycles render, but regardless of settings it always seemed to render an EEVEE render for both single image and animation.

Then I realised, I still had the EEVEE png files referenced in the Video Sequencer.

I deleted the strip, and then Hey Presto, I got Cycles rendering back!


Use Region.tag_redraw on the corresponding region. The region type of the T-Panel is 'TOOLS' and the type of the N-Panel is 'UI'.

I.e.

for region in context.area.regions:
    if region.type == "UI":
        region.tag_redraw()


Blender can track backwards and forward accurately with no problem. I've done it many times.
So there is your answer.
Most likely the issue is with the compression used on the video. Intraframe compression or image sequences works great. Video with long GOP does not and might lead to errors retrieving frames going backwards.


Rounded corners - but not as you know them - messing up the mesh for sub-division surface (Piano key)

In my opinion you can keep ngons and tris as long as it doesn't create any bad pinching or artifacts, but if you want to keep quads only, given that a triangle can be cut this way:

you can end up with this topology, which seems to work fine:


Why can't I see the Cycles Rendering button in Node Editor?

There is no cycles render button on the node editor.

To switch render engines the button is in the info window.

then select your render engine

If that is not the button you are looking for please add an image on the original question that shows what buttons you expect to see.


Torus object stretched in array curve modifier

The curve modifier distorts the objects, that is the intended behavior. If you want an undeformed array use either Duplifaces or a particle system instead.

Add your Array+Curve modifier stack to a simple plane mesh instead.

Create a new plane mesh, parent one single chain link to it and activate Duplifaces on the plane's object properties.

Then add the array modifier, use an empty object rotated $90º$ to introduce rotation to each link. Activate the Object Offset option and pick the empty.

Adjust spacing and settings as desired, and then add the curve modifier exclusively to the plane object alone.

Alternatively use a particle system instead of Dupligroups feature with one particle per face if you wish to hide the original link independently. Manually adjust particle count to match the number of arrayed links.


Is it possible to use the 'Split' tool in Python?

This can be done using the bmesh api.
The operator you are looking for is bmesh.ops.split.

However, the functionality you want to create is already in blender, with CtrlE> Edge split, or bpy.ops.mesh.edge_split

Note that you could also create and apply an Edge split modifier, however it's probably easier to use the edge_split operator.

As for selecting the "next face", you can select a face by setting its select value to True:

bpy.context.object > data > polygons > select

E.g. bpy.context.object.data.polygons[0].select = True will select the face with an index of 0 in the active object.

Note that you have to be in object mode for this to work:

  The mesh data is accessed in object mode and intended for compact storage, for more flexible mesh editing from python see bmesh.

You can set the mode with the mode_set operator, e.g. bpy.ops.object.mode_set(mode='OBJECT')

How you define the "next face" is up to you, as AFAIK there is no absolute definition of which face should be the "next" one.


A Black Material Problem on imported DAZ Obj materials

I had a closer look at your images, and it seems like in your new material, the node group's shader output is not connected to the material output node.

Connecting these up should fix things.


How to model one object's edge to match another object's curved edge

Try using a combination of snapping. For your purposes you will probably want to consider the vertex, face, and edge snapping options. How well it works will probably depend on your topology and stuff, but it's the only method I know could work for sure. There are modifiers that might work too, but I don't have a lot of experience with most modifiers, and they seem a little touchy sometimes.
snapping options http://images.akamai.steamusercontent.com/ugc/171536664510008542/B850D16F4CE2FDE3175B3335D995E9232771F92A/

The horseshoe icon turns snapping on or off. You can also hold ctrl to toggle it on after grabbing the vertex or object you are going to move. With the ctrl hotkey it will only be on while you are holding the hotkey.

If having the engravings clip into the ring doesn't matter, then you can probably do it all with vertex snapping. Position an engraving so the back vertices are all inside the ring where the engraving will be sitting.

Then toggle your vertex snapping on and grab the front vertices and start snapping them to the appropriate vertices on the outer edge of the ring. MAKE SURE that while doing this, you lock your transform to the right axis. Hitting "g" then the "x", "y", or "z" key will lock your transform to the corresponding axis. In your case you will probably be using the "x" or "y" lock.

So you will position the engraving, turn vertex (or maybe edge snapping) snapping on, grab a vertex from the front face of the engraving, lock it to the x or y axis, then move it until it snaps to the closest outside edge vertex of the ring. Then repeat until the engraving is following the curve of the ring.

If you don't want the back vertices of the engravings clipping through the ring, do the same as above, only instead of vertex snapping use face snapping and snap the back vertices to the faces of the ring.


How to keep shape of geometry when adjusting mesh?

Whenever you have an object you want to smooth by adding geometry you should always try to work solely with quads (which you are doing right). However, vertexes which have more than 4 edges connected will result in an uneven smooth.

Topology like the image below is better but still not perfect. It really depends on what your end use is.
You, can add more or less sharpness by inserting 'edge loops' closer or further from the borders (which only works with good topology).

A better way going about modeling this would be something like the following image: (not perfect but should help you get on the right path)


How to align local coordinate with global axis?

Press CtrlA to bring up the Apply object Transformation menu and select Rotation.

From the blender manual:

  This will make Blender consider the current rotation to be equivalent to 0 degrees in each plane i.e. the selection will not rotated, the current rotation will be considered to be the “default rotation”


Bryce "Zoom to Selection" Function in Blender?

If the idea is to move your camera towards the rectangle selection,
you can lock the camera to view (in "N" panel) and use Shift+B
if you want to really "Zoom" perfectly in your rectangle, you can use this addon I made : https://caetano-veyssieres.com/blender/, using the "Crop" button and multiplying the resolution to your needs. You can't re-iterate the process at the moment but I hope to make it possible.


WireFrame Mode is missing when hitting ctrl + tab

Use "shift + Z" to jump between solid mode and wireframe mode. "Z" to change between wireframe, solid, material preview, and rendered modes.
Hope it helped.


Is there a way to sense all collisions except the one selected?

That is super easy to do logically.

You want the controller (in this case it is an and controller) to send a positive pulse to the actuator(s) when the the cube collides with anything Except for the objects with the property Water.

The first collision sensor is always true as long as the cube is not colliding with Water. True level triggering is enabled, so every logic tick the and controller gets a positive pulse. however, for the actuator to receive the pulse, all sensors must be true, at the same time.

The second collision sensor detects a collision with anything.

With this setup, a collision with water obviously will not work because the first collision sensor will not be true when colliding with water. When the cube is falling or hovering, (not colliding with anything) the first collision sensor will be true, because the cube is not colliding with water, but the second will not be true.


You can subdivide the angles and smooth them, even in sculpt mode.


Round of a half cut cylinder with subsurf

Add a cylinder;
Apply E and S to the bases and delete created faces. Remove doubles;
Join the edges with Bridge Edge Loops to make inner faces. The result should look as below;

In face selection mode select, with B, and delete half of the cylinder created thus;
Make faces where the crossection was made (see the image below);

Done.

If you want you may make more quads with Ctrl+R


Blender 2.80 Objects have sound attached to them?

Add a speaker object to your scene.

The speaker object has just the functionality you are after.

  Speaker

  The speaker object is used to give sound in the 3D View. After adding the object, the various settings can be changed in the
  Properties editor.

Add a speaker to the scene Add > Object > Speaker

Add sound and fill in the properties accordingly.

Image from 2.83

The speaker object can be animated as other objects.


CUDA error at cuCtxCreate : unknown error

I had this issue before when rendering an animation.
The solution is to simply decrease the tile size under performance.


How do I make my vertices fill correctly with mirror

You've enabled the Adjust Edit Cage To Modifier Result option of the modifier (fourth button), so you're confusing the real mesh and its mirrored image, and you've created the new vertices in the mirrored space. Deactivate this button and it will appear clearly. Also, activate the Clipping option so that the vertices stick to the axes and don't trespass.


Yes, there is. In the properties panel ( to the right ) hit the button in the top bar next to the render setting (next to the camera) which looks like two pages. This is called the Scene settings. Under layer, you can choose which layer to render. Hope that helps :).

Edit: There is one more thing you can try. In the top right where it shows the different objects in the scene, you can’t hit the camera so they won’t be visible in the render. I’m not sure if this will preserve lighting though.


Indirected Bounces in closed rooms are heavy in general. But simplifying your Material could help a bit.

When your goal is to simplify the shader and to do the hole material with one Principled Shader you have to pool all the shader channels and bake masks separately (emission, roughness, color, etc.)
Add-On Node Wrangler and its "Viewer Node" does help a lot (Ctrl + Shift Click to Get a Emission Output of the clicked node) You want to always bake via emission channel to not get shadows in your bake. (Maby im wrong on that part and it would be easier to just bake the passes via the bake menue instead of pooling them in the shader editor, have to test it tomorrow)

as an example I put all the emissions as absolute white to get a mask that produces 100% emission at the needed areas.
Create a Image Texture Node in your material. Doesn’t have to be connected, but has to be selected! Because of your procedural textures you have to use a huge resolution to get the details. The example pic has only 1k texture for reasons of baking speed..
Cycles Render Panel > Bake > emmission pass: uncheck selected to active, set margin low or 0, hit bake with image texture node in node editor selected.
Image Editor > Save Image! Otherwise you will loose the data.

For your other channels (color, roughness etc.) just pool them together and route them to the viewer node.
After Baking all the Maps plug then In your principled shader and you should save the calculation time for the 4d procedural noise textures.


Is it possible to animate 2 folds on the same sheet?

Assign only the needed vertices (tips) for each bone as follows:

And then you should fold it beautifully.


How do I thicken my procedural dot texture?

What kind of dots are you making? If a "swiss cheese" effect would suit you, a Voronoi texture works quite well. If you like, you can use a Power (math) node to control the size of the dots.


texture sky doesnt work in blender 2.8 (Eevee render)

I just checked and it is not supported in EEVEE (yet?) according to the official documentation. https://docs.blender.org/manual/en/dev/render/eevee/materials/nodes_support.html


What would be the best way to UV unwrap this kind of mesh?

UV maps are like present wrapping in reverse. Use Mark Seam to Mark places on the mesh to “cut,” then UV -> Unwrap to create a UV map.
Think of how you would create this mesh if you were making it out of cloth, and then Mark Seam where the seams would be. Then, select all, and Unwrap.


Hotkey to Frame all Objects into viewport?

To frame all objects in one viewport do: Home or Ctrl + Home Both with the origin as the camera focal point
Or Shift + c
This will also bring the 3D cursor back to the origin.
Numpad . will frame the currently selected object or objects.
Numpad / will frame the currently selected object or objects and hide everything else, until you press it again.
You can change them here (to F):

This however will affect only the (single) viewport under the mouse cursor.
I imagine affecting multiple viewport at once will require a script, but i'm not sure.
EDIT:
If you want to experiment with a different hotkey layout you can always click Add Key-config Preset (the little "+" icon), to make a new preset and try some things without messing up you current key setup.


Well exporting textures is going to be an issue but I'll assume here you will only require exporting UV coordinates.

This would be trivial to accomplish using any type of automated texture coordinates like Generated or Object, however, to be able to export texture coordinates you will most likely be required to unwrap your mesh and create a UV map, unwrapping doesn't translate well into scene referred units, since unwrapping will more often than not introduce distortions.

The way I see it you have two options, both involving third party addons.

Either use World Scale UV or Magic UV addon.

What they both do is try to unwrap your mesh in such way that it approximates texture size to a defined scene dimention.


Why is my asset appearing as non-transparent?

Looking at the material, nothing is connected to the alpha input of the shader. Connect this, and then make sure in the material settings that alpha mode is set to “hashed” and not “opaque”.


UV-unwrap cylinder (lightsaber) with extrusions / insets

You might be looking for Follow Active Quads. This is a method of unwrapping (available by default as a menu option after hitting U to unwrap). This will unwrap the mesh based on the last selected quad (4 point polygon).  The effect is to create a totally flat UV map based on that last selected polygon. Usually you use it to (for example) unwrap a sphere to a totally uniform square of polygons.

Otherwise, I would just mark a seam down the entire cylinder (top to bottom) and do a normal unwrap.


Render is duplicating random frames when loaded into 3D tracker

Most likely the video is recorded using a LongGOP format and not an intraframe codec.
http://tiliam.com/Blog/2015/07/06/effective-use-long-gop-video-codecs/
What that means is that every frame does not contain the full information for the picture, but only records the changes from a reference (I) frame. Blender has a hard time dealing with that format.
Try exporting the video as an image sequence or a video format with intraframe encoding, so that every frame is available to blender for tracking.
Another common error is using video files recorded on some phones and screen recording software that encode using a variable frame rate. Blender cannot deal with such files correctly, they need to be converted to a stable frame rate (or an image sequence) in an external app, before importing into blender.


Volumetric light rendering a hard cut-off in the scatter rays

The problem was the camera clipping distance was less than the size of the volume.
By reducing the size of the volume so that the far side of the volume is within camera clipping distance the artifact (mostly disappeared)

A second problem I then had was the top of the volume I had given a surface shader (and a separate material) which caused lesser artifacts on top of any objects. Removing the surface shader fixed this.


The trick here is using the same technique as described in this answer, but tick the option Scale for Duplifaces.

Just create one plane mesh, make sure it is 1x1 units in size. Make sure you apply its scale if you scale it in Object Mode.
Create you sphere, at the same scene coordinate as your plane. Also scale it so it is 1x1x1 units in size. Make sure you apply its scale if you scale it in Object Mode.
Create your Bezier curve object, adjust shape as desired but make sure it stays at the same scene coordinate as your plane and sphere.
Create one Empty object type and scale it to 95% scale (or adjust as desired). Once again make sure it stays at the same scene coordinate as your plane, and sphere.

Add an Array modifier to the plane, set the Empty as Object Offset and adjust the relative spacing so it matches the scale factor of the empty. In my case for 95% scale the Relative Offset should be 0.975.

Now just parent the sphere to the plane, activate Duplifaces and tick the option Scale so duplis are sized according to face area.
Adjust the Array as necessary.