text:
3D slicing using Dynamic Paint leaves holes where there shouldnt be any
I am using dynamic paint to take slices as an image sequence through a prexisting mesh (also created in blender). For this I create a plane and set that as a canvas which passes through my mesh object outputting a cross section every frame. I have played around with the parameters (dissolve time = 1 etc) and the output is clearly doing something right but leaves me with holes within my mesh. Hopefully the images below will explain this better.
These images are for the first slice (easiest to get images for). Ive circled an example of the issue.
UPDATE: Blend file now included.

Here is the code which assigns dynamic paint parameters Xmax, Ymax and Zmax, specify the location of the canvas.
context = bpy.context
active = context.active_object

print('Setting Up Ballast Brushes')

bpy.ops.object.modifier_add(type='DYNAMIC_PAINT')
bpy.context.object.modifiers["Dynamic Paint"].ui_type = 'BRUSH'
bpy.ops.dpaint.type_toggle(type='BRUSH')

print('Setting Up Plane')

bpy.ops.mesh.primitive_plane_add(enter_editmode=False, align='WORLD', location=(0, 0, 0))
bpy.data.objects["Plane"].scale[0]=Xmax/2
bpy.data.objects["Plane"].scale[1]=Zmax/2
bpy.data.objects["Plane"].scale[2]=1
bpy.data.objects["Plane"].location[0]=Xmax/2
bpy.data.objects["Plane"].location[1]=0
bpy.data.objects["Plane"].location[2]=(Zmax/2)
bpy.data.objects["Plane"].rotation_euler[0] = 1.5708

print('Setting Canvas Parameters')

bpy.ops.object.modifier_add(type='DYNAMIC_PAINT')
bpy.data.objects['Plane'].modifiers["Dynamic Paint"].ui_type='CANVAS'
bpy.ops.dpaint.type_toggle(type='CANVAS')
bpy.context.object.modifiers["Dynamic Paint"].canvas_settings.canvas_surfaces["Surface"].surface_format = 'IMAGE'
bpy.context.object.modifiers["Dynamic Paint"].canvas_settings.canvas_surfaces["Surface"].image_resolution = 1000
bpy.context.object.modifiers["Dynamic Paint"].canvas_settings.canvas_surfaces["Surface"].use_antialiasing = False
bpy.context.object.modifiers["Dynamic Paint"].canvas_settings.canvas_surfaces["Surface"].frame_end = endframe2
bpy.context.object.modifiers["Dynamic Paint"].canvas_settings.canvas_surfaces["Surface"].use_dissolve = True
bpy.context.object.modifiers["Dynamic Paint"].canvas_settings.canvas_surfaces["Surface"].dissolve_speed = 1
#bpy.context.object.modifiers["Dynamic Paint"].canvas_settings.canvas_surfaces["Surface"].use_dissolve_log = False
#bpy.context.object.modifiers["Dynamic Paint"].canvas_settings.canvas_surfaces["Surface"].dry_speed = 1
bpy.context.object.modifiers["Dynamic Paint"].canvas_settings.canvas_surfaces["Surface"].image_output_path = str(path)
bpy.ops.object.editmode_toggle()
bpy.ops.uv.smart_project() #the actual unwrapping operation
bpy.ops.object.editmode_toggle() #exiting edit mode
bpy.context.object.modifiers["Dynamic Paint"].canvas_settings.canvas_surfaces["Surface"].uv_layer = "UVMap"

File is not attached ... use https://blend-exchange.comand given code copy&paste into you Q.

Hi apologies, I was trying to add it, but the file is too large I think, Ive added the python code as a placeholder until I can get the blend file on here

Apologies for the delay @vklidu blend file now uploaded

You could simplified file to make it smaller ... just a Plane and one problematic stone, like that you could notice it works. So why it is not working in group? I would say for its overlapping geometry.
I can imagine that hole in place of crossing stones , but it happens just it is crossed somewhere. If you move stone behind it is fine.
You can try Remesh Modifier > Voxel > 0.001 m, before DP, but it would be very intensive calculation, but it worked ...

Or Separate stones by Loose parts set them Rigid Body (create a collision box) and let simulate for a few frames just to solve overlapping. Than merge them back into one object for DP.

Thanks, looks like this is a more serious issue with my grouped stones, im wondering if its because Im using group on many stones

The only one issue I can see is overlapping geometry, that you would have to solve. I edit answer if it will inspire you for some solution.

Thanks, I see what you mean about the remesh to voxel being intensive, im trying this now and it works, just takes a while. Ill try the rigid body option if I think this is taking too long

I tried also Remesh > Sharp > 7 > 0.99, but it generated some small things too. I would go by RB, because not only Remesh operation take a time, but also rendering is enormous long. Also I saw some faces (normals) are flipped.


text:
Weird normals(I already Recalculate Normals,Remove doubles)
So I am having a problem with my mesh I am not positive if it is normals I am a bit of a noob to blender probably been using it for 2 months  and I don't know something you may know
any help will be appreciated this is how it looks like
https://i.gyazo.com/21b0692adb4aafb5e089992e9361a344.mp4
ask any questions
and as I said
I already remove doubles and recalculated normals
Here is the file

Fixed

It's a bit hard to tell from the clip, any chance you could upload your .blend file? You can do it here - https://blend-exchange.giantcowfilms.com/

Yes give me one second

I have added the blend file

Hey. I think you uploaded your .blend1 instead of your .blend. Do you mind re-uploading? The file cannot be opened otherwise.

Sorry one second

Okay I done it it should work now

Ok, there are a couple of problems here.
The first and foremost is that you have many edges marked "sharp".

To fix this, simply enter edit mode, select the whole mesh (A), right-click and select "clear sharp"

However, as you can see, the mesh is still affected because of "ugly" topology. Blender favors the use of Quad based topology, and though sometimes tri's or n-gons are unavoidable, they are best kept on flat (non curved) surfaces. To reduce the chance of shading based artifacts, always try to keep your mesh as quad-based as possible.

To fix this for your project, you can either re-topologize it manually, or an easier approach would be to use a Remesh Modifier, either in it's own, or in conjunction with manual adjustments.

Once this is done, if you want your mesh "smooth" again, you could add a Subdivision Surface Modifier, and shade smooth. (NOTE - the smooth shading did not work properly for me until I applied the Remesh Modifier. I am currently using 2.9, so I'm not sure if it's unique to this version, but if it isn't shading smooth for you, try applying the modifier first)

Aw man thank you so much this been a problem for the longest I'm pretty sure a bunch of other people will use this post in the future will use this as well!

Hey, no problem. The remesh modifier might not give the exact topology you want, but it should at least make it easier to adjust manually if necessary.

I had strange-looking shapes that went back to typical appearance after I enter Edit Mode, select shapes and go to the menu Mesh > Normals > Reset Vectors

source: Stack Exchange

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

sort: votes


text:
Struggling to Understand Vertices Behaviour
Blender Guru Anvil Tutorial Part 2
In the above link, the tutorial has a step at the end in which he completes an extrusion with a clipping mirror modifier. At this point, the vertices at the ends of the semi-circle on the bottom of the anvil become locked to their actual vertex locations, instead of being near them due to the shade smooth and subsurf mod. I am unsure why this is occurring.

could you be more specific with the time? not gonna look it up through the video

Sorry meant to mention it's right at the end

Hello and welcome :). It's not really clear what you problem is. Does clipping not work for you? If that's the case, please, add a screenshot so we know what you're talking about.

Unfortunately I don't have access to the file with my issue. However, if I'm not able to get my issue across I shall wait until I can upload a screenshot and hope that helps.

A time stamp would also help. I'm a little unclear from looking "right at the end of the video" which of Andrew's operations you have in mind. Are you confused/asking about how he is using "proximity edge loops", as he calls them, to force sharp edges despite the subsurf modifier?

It's when he adds clipping to the mirror modifier in the GIF above. The points at either end of the semi circle then jut out sharply to exactly where the vertex point is whereas every other vertex does as seen in the GIF.

That gif is very helpful. What it is showing is how Clipping works: it stops vertices from moving across the plane across which the active Mirror modifier is occurring. As a result, if you drag a bunch of vertices along the y-axis towards the x-z plane, for a Mirror modifier that currently is mirroring over that plane, then the vertices get "stuck" at the plane -- and, if they had nonuniform y locations, they will all agree on y-locations if you push them far enough into the x-z (or other Mirroring) plane.

I have now added an image of my issue

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


text:
custom properties via bpy.types.Scene not showing in UI
In a new blender file with v2.93.0 on arch linux, I go to the "Scripting" workspace and I run this in the console: bpy.types.Scene.x = bpy.props.IntProperty(name="Something"). That used to render the property as a widget in the "Scene Properties" panel but now it doesn't anymore. Any idea why this could be happening?
I'm not entirely sure which version still worked, but I think it was in 2.8x.
UPDATE: It also doesn't work with 2.83.15. How could I make this widget show up?

I think the property is there, the UI just hasn't been updated to display it.
You added a custom property globally to all objects that happen to be of type bpy.types.Scene. You can make the current scene aware of it by simply setting the current scene custom prop to itself.
import bpy

bpy.types.Scene.x = bpy.props.IntProperty(name="Something")

bpy.context.scene.x = bpy.context.scene.x

Note this will fire the update, set and get callbacks for this property.
It will then appear in the Custom Properties panel when you next hover your mouse over it. If you want the UI to update immediately, you can force a redraw, but it is advised against in the documentation.
bpy.ops.wm.redraw_timer(type='DRAW_WIN_SWAP', iterations=1)

Thank you for that answer! Unfortunately, I can't get it to work, the UI isn't showing any new custom property for the scene. However, following your steps, I can save and load the .blend file and then the UI DOES show the "x" property. I can also access bpy.context.scene['x'] (but not bpy.context.scene.x) but bpy.types.Scene.x raises exceptions. So it seems the modified "Scene type" isn't persisted. My (actual) property also defines a update callback, like bpy.props.IntProperty(name="Something", update=myFunction). Is there a smarter way to do this?


text:
Did I destroy my 12 hour render trying to save it?
I got up this morning and I went to save my overnight render, I turned on the screen and saw it for a moment, then I went over to Image to save it and at this point I think my mouse accidentally clicked on the "Open Cache Render" button and the whole image turned transparent/black, I didn't close the scene yet but I did move to another layer and did a quick 1 sample test render to confirm that doing this causes the same issue, the entire render is now just a flat transparent nothing.
Is there a way to get my render back?
PS: It's not the end of the world if it's gone, just wondering if there is a way to come back from loading up the "Cache Render", In the future I'm going to try and find a way to save the Render as soon as it's complete like for an Animation so I don't have to worry, although this is the first time I did this after countless renders so I guess it's just a freak accident.

If you didn't specify a place for it to be saved blender automatically places it in a folder on your C drive called tmp. C:\tmp\ you might find it there.

It's not there and I'm confident that my Render is gone now which is fine, but I did a test render just to make sure and my Blender definitely doesn't automatically save my Image unless I'm rendering an Animation, if I just press F12 to render a still I have to manually save it, I do have a file destination set but as said it only seems to do anything for rendering animations. Is there an optional setting to enable automatic saving once finished? That'd be useful.


text:
Assign a different material to objects within dupli_group instances
Say you have a cube and a sphere grouped as 'Group'. You instanciate that group and link it to the scene. Now when you click on the instance, there is no material panel.
See the two pictures below for a better understanding of what I'm trying to do.

Is it possible to access the duplicated objects in the dupli instance in order to give them new materials ?
The only thing I succeeded in doing is to assign a material to an object instance but not to objects within a group instance.
Python answers are welcome.
As requested, here's the code to create a dupli_group instance:
layers = [True] + 19*[False]

# Could replace this with bmesh method
object1 = bpy.ops.surface.primitive_nurbs_surface_sphere_add(radius=1, location=(0, 0, 0), layers=layers)
object1 = bpy.context.active_object

object2 = bpy.ops.mesh.primitive_cube_add(radius=1, location=(4, 0, 0), layers=layers)
object2 = bpy.context.active_object

group = bpy.data.groups.new('some_group_name')
group.objects.link(object1)
group.objects.link(object2)

group_instance = bpy.data.objects.new('some_group_name_instance1', None)
group_instance.dupli_type = 'GROUP'
group_instance.dupli_group = group

bpy.context.scene.objects.link(group_instance)

Then I would expect to have a way to target object1 and object2 within group_instance and to set new materials that won't affect other instances.

Can you outline the exact steps taken to "instantiate that group" ?

@MrZak I'm sorry, this doesn't answer my question.

Unfortunately, I think it is not possible to do exactly what you want to do.
One of the advantages of using an Empty with dupli_group is that you don't have the overhead of storing much in the way of differences (location, rotation, scale).
If you want to alter the group, you will probably have to instantate objects by copying the data from the group.  There's actually a keyboard shortcut to Make Duplicates Real (Ctrl Shift A) that would work for interactive use.  Since you were using python in your original project here is a small python script I wrote that might accomplish your mission:
import bpy

def mission1(group, scn):

    parent = bpy.data.objects.new("parent", None)
    scn.objects.link(parent)

    for obj in group.objects:
        o2 = obj.copy()
        o2.parent = parent
        for i in range(len(o2.material_slots)):
            ms = o2.material_slots[i]
            ms.link = 'OBJECT'
            ms.material = o2.data.materials[i]
        scn.objects.link(o2)

    return parent
#
#

anchor = mission1(bpy.data.groups["Group"], bpy.context.scene)
anchor.location = [2,0,2]

The parent object is not strictly necessary, but it gives you the ability to manipulate the location and orientation of the group very much like the dupli_group empty you were using before.
An important drawback is that once you have instantiated these copies modifications to the group (adding, removing, relocating objects) will not be propagated.

Thank you for clarifying this. I'm not sure I understand correctly, do you keep the mesh in memory or do you copy it entirely ? Since I have several thousand instances of my objects, I want to keep the mesh data shared across the instances.

The object.copy() creates a new instance of the object datablock, but the mesh datablock is shared by the original and the copy.  If the mesh were not shared, then it would not be necessary to use per-object materials.

Ok that's what I thought, I used groups because of the dupli_group property but then it lead me to this lack of control. I was using parenting and grouping to simplify selection of instances in the viewport but this came at a certain cost. Thanks !

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


text:
Delete unused Empty
in my scene I had an object with a mirror-modifier attached. I made several copies of it. Now I discovered that it also copied the empty I used as the mirror object. I want all new objects using the same empty as mirror object. So I changed (most of) them to point to the original emtpy. Now I want to delete the unused copies of the empty. Is there a way to figure out which empties I can delete and which I have to keep because some are still used for mirroring.

If you want to delete all empties in the current scene, which are not used as mirror object by a mirror modifier, you can use the following script:
import bpy

scene = bpy.context.scene
obs = set()

for ob in scene.objects:
    for mod in ob.modifiers:
        if mod.type == 'MIRROR':
            obs.add(mod.mirror_object)

for ob in scene.objects:
    if ob.type == 'EMPTY' and ob not in obs:
        #scene.objects.unlink(ob) # version < 2.8
        bpy.data.objects.remove(ob) # do unlink is default

Note that it will remove empties even if they are used by other modifiers for instance. There is no direct way to figure out all dependencies to tell what users a certain object has.

This method works for me:

Export as .fbx, unselect "empty" from object types
Import .fbx in to a new Blender project

et, voila

Exporting and importing is rarely a correct solution for anything. Gone are any materials, modifiers, and properties your objects had

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


text:
Access to object location from previous frame in cycles
Is there a way to access an objects location data from the previous frame in cycles? I want to make a shader that colors the object accordingly to the distance the object traveled between the current frame and the last one.
My goal is an animation with moving cubes colored by the "speed" they have.
Also, I guess thats information that is not available in osl?

Isn't this what you want to do: http://blender.stackexchange.com/a/29184/7777 ?

See the docs about drivers, they're comprehensive.
Also see TextEditor -> Templates -> Python -> Driver Functions
Add a Driver
If your object is key-framed, you can evaluate the F-Curve using a frame number like fcurve[index].evaluate(frame-1)

Add a Driver to a custom property of your object.

Make a python expression text block with something like the code below, and Run the code so the expression is added to the driver_namespace
import bpy
from mathutils import Vector

def driver_delta_to_RED(frame):
    # triggered by a frame change, any code inside here gets run.

    p = bpy.data.objects['Plane']
    current_xyz = p.location
    fcurve = p.animation_data.action.fcurves

    x = fcurve[0].evaluate(frame-1)
    y = fcurve[1].evaluate(frame-1)
    z = fcurve[2].evaluate(frame-1)

    # may want to find the top speed first, and normalize
    # this value using that information
    delta = (current_xyz - Vector((x, y, z))).length

    nodes = bpy.data.materials[0].node_tree.nodes
    nodes[1].inputs[0].default_value = (delta, 0, 0, 1.0)

    # the return value is of no relevance and can be static.
    return 0.0

bpy.app.driver_namespace['driver_delta_to_RED'] = driver_delta_to_RED

Add the function call to the Driver

if it's a frame behind or ahead of what you want, then instead of the Driver, it might make sense to add an application_handler specifically the frame_change_pre or frame_change_post handlers.
The code for Drivers and frame_change handlers is slightly different, but the app handler docs will describe how to get the current frame from inside the handler function.

You can simply use the animation nodes addon from Jacques Lucke Blender Artists Post (for further informations you can search on youtube)
To accomplish you objective you need to use a frame input and a cycles material output.
Node Setup:

You need to turn on the "Frame" Input and
you need to turn off the "Use Current Transforms" under the Advanced Node Settings
to access the location from the previous frame.
Result:


text:
How to find the rotation components between two similar trirectangular tetrahedrons?
I have two trirectangular tetrahedrons like on the following screenshot. My goal is to find the roll pitch yaw rotation components between the two.

One of them has its 3 orthogonal edges along X, Y and Z as you see on the picture. The second one has it's top vertex on the origin like the first one, but it has been rotated around all 3 axis.
An idea I tried is using the snap tool, to rotate the object and to snap it to the other one, but I couldn't find how to do that.
-- EDIT --
How can I rotate the first one so that it gets exactly superimposed with the second one ?
After that I'll be able to directly read the 3 rotation values in the right menu, which I'm interested in.
As an approximation of the result I want, I can rotate it manually and get approximative values by eye (see screenshot below with values in the red circle), but is there a way to get exact values ?

Thanks !

Sounds like a test more than a question... Just delete the second shape. Then select the first one and duplicate it. BOOM... done.

@Dontwalk But that won't give me the rotation values around XYZ ? I want to find those 3 values so that when applied on the first object, it rotates it exactly as the second one. Do you see what I mean ?


text:
How to get the color of a vertex group with python?
Is it possible to get the color of a vertex group that is coloured with dynamic paint? I have a mesh of tree which was created from particle instance and then applied. Then I joined all of that to create a single mesh. Then dynamic paint was used to draw a color on that.
The complex part is that I need to get the color of the vertex group which was named leaf-1.
I proceeded with dynamic paint for coloring the mesh and that is a brilliant tool. Now I need to export the color values of that vertex. I thought the dynamic paint values are stored in the dp_paintmap vertex color. But that values are full of (1.0,1.0,1.0,1.0). I have been searching for this and found a similar question. blender.stackexchange.com/questions/123261/getting-color-values-produced-by-dynamic-paint
Please help me. Where is this data stored?

Finally the answer is found.
https://developer.blender.org/T82451
Thanks to Phillip
You need to read this from the evaluated object, see

import bpy

ob = bpy.context.object

depsgraph = bpy.context.evaluated_depsgraph_get()
object_eval = ob.evaluated_get(depsgraph)

#vertex colors are in fact stored per loop-vertex -> MeshLoopColorLayer
if ob.type == 'MESH':

    #how many loops do we have ?
    loops = len(object_eval.data.loops)
    verts = len(object_eval.data.vertices)
    print("--------------------------------------------")
    #go through each vertex color layer
    for vcol in object_eval.data.vertex_colors:
        # look into each loop's vertex ? (need to filter out double entries)
        visit = verts * [False]
        colors = {}

        for l in range(loops):
            v = object_eval.data.loops[l].vertex_index
            c = vcol.data[l].color
            print("Vertex {0} has Color {1}".format(v, (vcol.data[l].color[0],vcol.data[l].color[1],vcol.data[l].color[2])))
            if not visit[v]:
                colors[v] = c
                visit[v] = True

        sorted(colors)
        print("Vertex-Colors of Layer:", vcol.name)
        #print(colors)
#        for v, c in colors.items():
#            print("Vertex {0} has Color {1}".format(v, (c.r, c.g, c.b)))
#
        print("")

The magic of depsgraph


text:
Quick smoke animation by python invisible - Working by GUI
Opening Blender > General > Object > Add> Quick Smoke results in an animation displaying the moving smoke. As expected.
Doing the same in python, displays the the smoke in frame 1, yet it disappears after hitting SPACE (start animation)
import bpy
from bpy import data as D
from bpy import context as C
from mathutils import *
from math import *

cube = bpy.data.objects["Cube"]
bpy.ops.object.modifier_add(type='FLUID')
bpy.ops.object.material_slot_add()
bpy.ops.object.quick_smoke()
bpy.context.object.modifiers["Fluid"].domain_settings.cache_type = 'ALL'
# bpy.context.object.modifiers["Fluid"].domain_settings.cache_directory = '/tmp/blender_leBmMS/cache_foo'
bpy.ops.fluid.bake_all()

Your script works when invoked from the Python console in 2.93.5.  What error messages show up in the terminal or info window?

It works fine when I run it as a script as well.  Perhaps share your blend file? (How to add a blend file)  The only time it fails in anyway it's when I run the script twice. The second time fails because there's already a fluid simulation modifier on the cube.

Ah, I think I might have it.  Your script will fail the way yo describe, if the cube is not the active object, because quick_smoke needs an active object.

As per @MartyFouts, after you assign the object "Cube" to the variable cube, add the statement cube.select_set(True)

TL;DNR You appear to have hit several errors in a row in your testing, because you're not resetting the scene between tests.
As written, there are (at least) three ways your script can fail.

There is no cube in the scene or at least none named Cube.  But that gives a different error than you described.  In the terminal window you'll see error messages that look like this at the end

Traceback (most recent call last):
  File "C:\Users\stupi\Downloads\foo.blend\Text", line 3, in <module>
KeyError: 'bpy_prop_collection[key]: key "Cube" not found'
Error: Python script failed, check the message in the system console

The cube already has a fluid modifier.  But in this case, the simulation will run.  The only error indication will be the message below.  But in this case you'll have two smoke domains in your outliner view.

Warning: Only one modifier of this type is allowed

The cube exists, is named Cube, does not already have a fluid modifier but is not the active object.  This too gives a message and doesn't create the domain.

Traceback (most recent call last):
  File "C:\Users\stupi\Downloads\foo.blend\Text", line 6, in <module>
  File "C:\Program Files\Blender Foundation\Blender 2.93\2.93\scripts\modules\bpy\ops.py", line 132, in __call__
    ret = _op_call(self.idname_py(), None, kw)
RuntimeError: Error: Select at least one mesh object

Error: Python script failed, check the message in the system console

If you want a simpler script that doesn't do error handling you can replace your script with
import bpy
bpy.ops.object.quick_smoke()
bpy.context.object.modifiers["Fluid"].domain_settings.cache_type = 'ALL'
bpy.ops.fluid.bake_all()

Or you can write a script that checks for the named error conditions:
import bpy

def smoke_setup():
    object = bpy.context.object
    if not object:
        # There is no active object
        # you may want error handling or messaging here
        return

    if object.type != "MESH":
        # The active object is not a mesh
        # you may want error handling or messaging here
        return

    if object.modifiers.get('Fluid'):
        # The active object already has a Fluid modifier
        # You may want error handling or messaging here
        return

    object.quick_smoke()
    object.modifiers["Fluid"].domain_settings.cache_type = 'ALL'
    # object.modifiers["Fluid"].domain_settings.cache_directory = '/tmp/blender_leBmMS/cache_foo'
    bpy.ops.fluid.bake_all()

smoke_setup()


text:
I cant find denoising but I have blender 2.90.1
So I made a roblox gfx and it has denoising, but I made a new one, and it doesnt. I have no idea why- and the difference is very clear. You can also see that the second one is kinda transparent. And they are both cycles
Also, I have blender 2.90.1 so its like...
Thanks!!

You have set your render engine to EEVEE rather than Cycles.  EEVEE doesn't have denoising.  If you switch back to Cycles then the render pass for denoising, as well the render options for render time denoising will reappear:

Note that if you did switch from Cycles to EEVEE you may have to modify your compositor nodes when you switch back.

awhhh thank you so much for your answer!! it is very appreciated although, they are both cycles.
:(


text:
GIS blender add on error: No imaging library avilable, how to solve it?
I would like to use a blender add on called BlenderGIS. When I try to use it, I get the error message No imaging library available, ImageIO module was not correctly installed. I tried the solution proposed here but it is not working for me.
~S. Pouria Doris(PCG)

That's a third-party addon but there are quite a few links for that error if you search Google. There seem to be detailed instructions here.

i've already seen this site and i didn't get that at all, if u know the soulation, i'd be great if u explain it with pics or a tutorial

The solution to your problem is here

As I said, the addon is not part of Blender so we can't help you directly, but the link @Marty Fouts has given you points directly to the explanation and solution in the FAQ section of the Wiki for the addon.

thx i myself saw that but i'm kinda busy rn so i need to try that later, but thx to u guys, thank u so much, i hope that link will help meh ;)


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I cannot paint in the "Texture Paint" mode
I'm trying for hours to use the "Texture Paint" mode in the right side.
But unfortunatelyI can't paint, I checked the slots, but with no successed.
The left side, works ok!
Can you help me please?
Blender Project


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All animations are not exporting in .glb format?
I tried creating a ps1 style character in blender by following a tutorial. I created 7 animations in there as you can see below.

But when I reimport the .glb file inside blender, it only shows basic_attack1, basic_attack2, basic_attack3, basic_attack4
I need to export it as .glb file. I am using blender 2.91.0.
Below is my export settings for animation.

heres the file,

The Blender documentation has a section on how to ensure that your scene can export to glTF. It looks like only some of your actions are marked as NLA tracks, which is probably why not all are exported. See:
https://docs.blender.org/manual/en/latest/addons/import_export/scene_gltf2.html


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More number of spheres increasing glTF file size
I am new to blender, I'm trying to build a block which has 100s of spheres(you can say molecules of metal block) and continously vibrating. Currently I am using around 100 molecules for just 1/4th of metal block and the exported(.glb) file size is few MBs if I add more spheres to cover the entire block file size will be even more.
Is there any better way to optimize the spheres keeping their size and animation same.

i have never tried it but Blender has Linked duplicates that do not create complete copies but just links https://docs.blender.org/manual/en/dev/editors/3dview/object/editing/duplication.html#linked-duplicates

Linked Duplicates are optimized by Blender better in recent versions (see glTF-Blender-IO#950), and should avoid duplicating vertex data in these cases.
If you find that Blender (or other software, for that matter) is still duplicating data in your glTF file for some reason, there are a few optimization tools that can clean up the glTF file after export as well.

gltfpack CLI tool overhauls a glTF file, simplifying and optimizing lots of things. Probably the most comprehensive optimization tool here.
gltf-transform CLI or JavaScript tool provides a dedup command to detect and fix duplicated data. An additional instance command applies the glTF EXT_mesh_gpu_instancing extension, which can further optimize the rendering of these types of models, but not all glTF viewers support the extension.


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Cycles render for Facebook without color
I am writing to you because I have a problem with files to use for 3D posts on Facebook.
I had done a lot of tests all using BLENDER RENDER: file had the color and the characteristics that I had set by the nodes, everything was ok but did not have the shine of the Glossy BSDF.
Then I changed the rendering engine in CYCLES RENDER, and checking from the rendered mode it has the shine I needed, I again exported my work in .glb for posts on Facebook, but so I see it all as gray as in the picture .
A) Can you explain to me why and how to solve?
B) Can someone tell me how to set a colored background?
Link to post (.glb) with Blender Render:
https://www.facebook.com/paginaprovaSynptc2018/posts/2189922261052625
Link to post (.glb) with Cycles Render:
https://www.facebook.com/paginaprovaSynptc2018/posts/2191151167596401
Thank you all

You have to consider that materials in cycles get translated. As the  glTF 2.0 Exporter documentation says:

Blender supports two material settings: One for Blender Render and one for Cycles Render. Fortunately, the glTF 2.0 Materials can be simulated using the Cycles Render by implementing a custom node tree

You can't just write materials in cycles and then translate them, this will just not work. You have to use the ones provided by the repo.
This is really well explained in the documentation (I'm assuming you're using this exporter):
https://github.com/KhronosGroup/glTF-Blender-Exporter/blob/master/docs/user.md

OK, Thank you a lot.
Unfortunately I do not know how to integrate and I can not use those provided by KronosGroup

@GianlucaCorsini blender cycles uses a node based system that works inside blender: it will just not export to another renderer (in this case three.js)
You have two options: use the nodes provided by the  glTF 2.0 Exporter repository, or try using the blender internal render (the custom one) that should export in most renderes

Another option would be to use a Principled BSDF material with the new (currently experimental) importer/exporter: https://github.com/KhronosGroup/glTF-Blender-IO. Some features of Principled BSDF do not yet exist in glTF, and would be ignored. But you should be able to safely use these textures: base color, emissive, roughness, metalness, AO/occlusion, normal.

Ok, Rage and Don McRudy.
Thank you,  I'll try this weekend and i'll give you a feedback.

So, i use this importer/exporter: https://github.com/KhronosGroup/glTF-Blender-Exporter


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Problem with the Specular Glossiness node and Metallic Roughness
Goodmorning everyone
I write because I have a problem with the Specular Glossiness node: I do not know how to connect it to Metallic Roughnes.
I'm creating a 3D file, to be exported to glTB 2.0 (glb) to create a 3D post on Facebook.
I downloaded Importer / exporter from KronosGroup, then I imported the Metallic Roughnes node onto my project on Cycles Render and later I imported also Specular Glossiness.
I was able to give a metallic look to my 3D element, but I would also like to give the effect of the reflection so that the Synapticweb logo that you see in my first pic, is reflected in the element that is below it.

But I do not know how to do this.
Although I link the Specular Glossiness output to Metallic Roughnes, there is no Glossy effect.
Here is an example of my post: https://www.facebook.com/paginaprovaSynptc2018/posts/2225106837534167

Can someone help me?
Thank you very much

I guess that facebook's 3d viewer does not support real time reflections. Cycles uses raytracing to calculate the reflections while most online viewers use rasterization like game engines. In order to get reflections in these engines you would have to create reflection probes or screen space reflections (which does not seem to be supported by facebook yet).

Ok, But maybe it's possible by Blender 2.80 Beta ?

You can export Principled BSDF materials to glTF in the Blender 2.8 beta, although only certain nodes are supported. Documentation is still in progress, here: https://developer.blender.org/D4082. Facebook does support metal/rough PBR materials and realtime rendering.


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How to bridge small gaps between objects like welding with less faces
I am trying to bridge two tubes together like welding.So I applied union to the two tubes and used Remesh modifier with Voxel size of 0.001m. It turns out that there are 5 million faces. It is hard for me to decimate them, which freeze my computer. Am I using Remesh correctly? Or is there a better way to bridge objects other than Remesh? I want a clean object to export for Salome to edit mesh for FEM analysis. Thanks.

Perhaps you're looking for a boolean modifier, on Union mode?

I forgot to mention that I have applied union first before remesh. Union helps to connect the mesh of the two tubes. I want to make the bridging area obvious...like a domain so that I can set material for it.

Why do you remesh the tubes after you use union? Just use bevel if you need it to look smooth.

@ZargulTheWizard You kind of remind me. I may not need to use remesh after union. I am looking at welder add-on and shrinkwrap modifier something like that. But still not satisfied yet.

Shrink wrap? This is getting weird…

I agree that shrink wrap is not what I want...I am open to other solutions...


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Automatically Create regular bridge between cylinders
I want to create bridge automatically between two long objects like cylinders. Does anyone know how to create bridge as the screenshot shows easily(Figure 1)? I know by union and remesh, it can create something similar, but the mesh will be irregular(Figure 3).
Any hint will be appreciated. Thank you.
Here is my files:
https://www.dropbox.com/sh/ele0gddjpxgnyy6/AACs0OizY_RklNubc7yT7rT4a?dl=0

it's hard to figure out what your trying to do, from that one screenshot.
try adding more screenshots of different perspective and modes or just try to share the blend file.
it would be easy for others to understand your issue

@Nand27 Yes, I have updated the question. Thanks.

https://www.youtube.com/watch?v=Ci1jBOm_5NY Adding holes in curved surfaces.

https://www.youtube.com/watch?v=M4F6Q6h2-ao Bridging edge loops.

I don't think using a union by adding a third cylinder would make it irregular.
also you can remesh it with a lower value like .05 if your not satisfied with the geometry.
Since this question seems to be answered I can't demonstrate it here.
I hope you got you answers.

@RonJensen Thank you for the links. However, these are manual operations.  I wish there will be something automatic. I need to work on more cylinders like these...


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Cylinder cross-sections become inconsistent when using curve modifier
I drew a bezier curve and tried to applied curve modifier to a long cylinder with this bezier curve. I noticed that the generated cylinder has self-penetration on its cross sections. How to avoid this? And how to align the cylinder with the curve? The curve has an origin outside the curve. I don't think it is hard to edit the origin point of the curve. Any hints are appreciated. Thank you.

the curve and the cylinder should have their origin at the exact same position, is it the case?

You probably have reversed handles on control points.
Select the Bezier Curve and enable Curve Edit Mode normals in the Overlays drop down:

set the length to something large and edit the curve.
If the curve handles aren't backwards, it will look like this more or less

But if they're backwards, then it will look like this

If they are reversed, then your cylinder will have kinks in the same places

To fix the curve, select the control point that has the reversed normals and rotate the handle until they point the right way.
You'll have to do this for every screwed up control handle.  It looks like you have two.

I have opened up the bezier curve (see above). It may contain reversed normals. I generated the bezier curve by linking points. Is it a better way to control the normals instead of rotating the handle(which should be the points, right)?

Typical to extrude new control points from one end or the other


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Looking for an alternative to Holdout, that doesn't require background to be transparent
I want the white bands of the cone to completely fuse with the white of the background. As it now, because fo the shadow effects, that's not the case
I was thinking about using the holdout shader for the white bands, but that only works when you set the Background to transparent. So won't have the desired effect.
I know, I could render the animation with the holdout shader and the background set to transparent, and then composite the video on a white background with my video editing software, with all the hassle and loss of quality and flexibility that entails.
Surely, there must be a solution inside Blender for this. Anyone?
I have tried completely erasing the shadows on the white bands, but unsuccessful.
Merry Xmas everybody!

Couldn't you just do the compositing in Blender?

Just make your cones band emit pure white and remove the non linear color lookup in the color transforms.

@Leander setting the color to "emission" It is a serious (mental) work-around, but it does the job, if you combine it with setting 'roughness" to maximum. Thanks.


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Giving thickness to a line
In 2D-space I have this simple line consisting of three vertices connected by two edges.
How can I give thickness to this line? The thickness should only be in 2D. So in orthogonal bottom, top, left or right view the line should be invisible. Also, the corner in the line should be hard, not smooth.
extra question: how can I shape the ends of the line (rounded, squared etc.)?

Try a dedicated "Vector Software" like Illustrator or Inkscape ,they have options like line thickness and end types built into them.

https://blender.stackexchange.com/questions/87253/can-i-extrude-a-path-in-x-y/87254 https://blender.stackexchange.com/questions/72423/how-to-import-svg-file-with-same-thickness/72430

@starzar The long segment should be able to rotate with the middle vertex as pivot point. That is hard to do if the whole thing is a fixed inkscape drawing. I could construct the line with two very narrow rectangles, overlapping at the pivot point. But then I don't need Inkscape for that, and the pivot point would look wrong anyways.

Hello :). You can select the edges, and extrude them along the Z axis to get a 2D thickness. Not the most elegant solution, but it works. And the middle corner will stay sharp.


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How to make an object parent to a vertex of another object
Suppose you have three cube objects. Is it possible to make one vertex of the first cube child to the second cube, and another vertex child to the third cube?
This would mean that if you move the second and/or third cube, the first cube is being deformed.
So the general question is: you can make a vertex parent to an object, but can you also make an object parent to a vertex?

Look for a "Hook" modifier.

That did the job. Thx.


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How to keep video and audio together in the Video Sequence Editor
When I import video footage in the Video Sequence Editor, it separates into a video strip and an audio strip. Fine.
But it's also possible, even accidentally, to afterward move these strips separately from each other. I don't want that to happen. I can't even think of a reason why the voice of the person speaking in the video should ever be out of sync with the person talking.
So, how can I block the video strip and audio strip of moving separately from one another?

Its actually very useful and common to edit the two separately. Often editors will remove pauses, ums, uhhs, etc from a recording but don't want jump cuts in the video so they will cut up the audio and play b-roll or use a shot where the speakers face isn't seen. Its also important for timing as viewers tend to have very short attention spans these days.
Dedicated programs Like Ardour for the audio are often better than VSE (With exceptions). I don't actually use VSE much but my suggestion would be to select your two tracks and try to parent them. Or check the tool/property panels .

One way would be to combine the sound and video into a "Meta-strip" (GTL-G)
The Meta-strip can be cut and moved about as you would a strip of movie film with sound locked to it. Remaining sections can be selected and restored as two again if necessary, i think with ALT-G.  (I'll have to go check)  To add smoother/softer transitions between sections or to fill in gaps you can copy and mix in some ambient sound from the same sound strip

To keep video and audio in sync, use the parenting function in the VSEQF add-on:
https://github.com/snuq/VSEQF

You can select them both and group them into a meta strip (CRTL+G or right click and select "Make meta strip").
They become a single strip.
If you then want to edit stuff inside the meta strip, just select it and press Tab.


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How to print a graphic on a glass window
I have a glass window (a plane object) on which I want to print a graphic.
However, the glass turns black. below is a screenshot of the shader set-up I used. What did I do wrong?

Related: https://blender.stackexchange.com/questions/164277/add-two-principled-bsdf-with-aplha/164279?noredirect=1#comment277527_164279

Consider using the shrinkwrap mod with a text image.

You can use the shrinkwrap modifier and add a small offset from the surface to avoid Z-fighting @cegaton

To make a proper glass pane:

Use a BW image instead of a transparent one
Use the Mix Shader node
Add some thickness to your glass pane, so it bends light like in reality

Additional notes

It's better to use Principled BSDF if you're going for realism
I used two materials so it looks better. Glass with white stripes for front face, and pure glass for the rest.

Hi! Just a quick sidenote: Adding manual line breaks to your post, probably breaks the layout of the website for a few devices. I didn't test it but I guess the website is created without such exception in mind. Cheers!


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F12 (render image) keeps repeating
After I press F12, Blender (as expected) renders the current frame. But as soon as it has finished, it discards the product (without any opportunity for me to save it) and starts all over again, and again, and again ...
What's going on?

Sorry, no, 2.81. I have delete blender-render

I have not installed any other add-ons than those that came with Blender 2.81

I inadvertently created 2 view layers. So it was not "again, and again", but only 2 repeats. I have deleted the layers, which solved the problem.

Congrats on solving this by yourself :). Don't forget to mark your answer as accepted later, so others can easily find it.


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Particle system to one mesh - and keep materials?
I have created a particle system with an emitter emitting Lego pieces and filled a big box with these Lego pieces. Object Info > Randomize on the colors of the Lego pieces with 5 colors on Ramp.
When emitted I convert the particle system to mesh and join all the meshes (all the Lego pieces), but all the Lego pieces turns into one color only.
Is this because of the 16 material limit? Any way to get this conversion done and keep all the different colors of the pieces?

Object Info > Random works with different objects. So when you join all objects, It becomes one object and Randomize will give only single value for that.
If you do not join objects into one then Object > Random will work.
If you want to join all objects, What you can use here is Geometry node's Random per Island input. Keep in mind Random per Island is Cycles only, see
https://docs.blender.org/manual/en/latest/render/shader_nodes/input/geometry.html


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How can I UV map this texture onto this model?
[
I have a texture that is 2048x2048 pixels and 1 material assigned to my mesh. How can I arrange the UV map so that every "floor" looks different; with properly scaled texture?

You can't make any of the UV faces larger than the texture quadrant, if that makes sense. So you can make each UV face fill up the whole corner, like this:

And then you can stack all the faces on top of each other:

But you can't make any faces larger than the UV layout because of the way your texture is created.
If you need to scale the textures smaller, you need to subdivide into more faces.
Otherwise you need to separate into 4 textures, because a single texture can repeat, like this:

With 4 textures in one, you can't do that.

How can I use multiple textures onto 1 mesh with 1 material?  (in this case)

I think you need 4 materials.  Is there a reason you can only have 1 material?


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Blender 2.93: the Python dependencies (Scipy, geomdll and more) and Sverchok addon don't work in my Windows pc
I had Sverchok and all of its dependencies working fine on Blender 2.92. Now I installed Blender 2.93 but it recognize only the pip and cython dependencies. Some hint?

Have yo utried installing the latest versions ? There has been some changes in the API in 2.93

After a clean install I had success with some other dependencies. But I saw that Blender now has the Python 3.9 while Freecad, open3d and some other have Python 3.8 or lower. So Blender doesn't accept them.


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How do I set default material properties in Blender?
I have a large collection of models that I import into Blender.  When I import it, for each material zone, I have to do the following:

Select 'Normal Map' for normals
Select 'Image Texture' for normals color
Open and select the normals map
Select 'Image Texture' for base color
Open and select the diffuse map
Set specular to 0

This gets beyond tedious.  Is there a way to set steps 1,2,4,and 6 above to be the default whenever I add a new material slot?

Create a material that has all of the nodes you want.  Call it something like "baseline" or "default material".  Select the "fake user" shield, so that Blender won't delete it.
Now, for each model, select the default material, and click the button to make a copy.  Rename the copy appropriately. Select each image texture in turn and change the image by clicking on the folder icon and using the file browser.

Fantastic.  You have saved me tons of tedious work.  Thank you!

You're welcome.


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How to get LED light appearance right
I’m trying to create an instructional video about one of our boards and wanted to show the name (and later on the diagnostic patterns) of the LEDs on the board. I have three colours, red, green, blue, and despite the materials have an overall similar structure (except for the colour), the result of the emission and the compositing is completely different one from the other.
Where am I lost? What am I doing wrong? These are the images of the LEDs:

The most satisfactory one is the green, and the least satisfactory the blue which seems to have no bloom whatsoever.
The three LEDs have a different model but the issue does not depend on the model, as I have applied the blue material to the green LED without ay improvement.
Here are the Nodes I used in the shader:

And the compositor nodes:

The super odd thing (to my eyes, at least) is that I had to use a threshold of 2 as despite the blue material has a much higher emission value in comparison to the green and red (50 vs 15), the glare effect disappears if I set the threshold higher than 4.9 (say, 5).
Thanks to everyone who can help me shed some light on this doubt.
Edit: just to clarify, this it the real appearance of the device:

so practically, the opposite of my render. However, I'm not after photorealism but at least I'd like to have a more evident glow around the blue lights. I'm open to any solution (compositing, render layers, etc.)

can u provide blend file?

I can't find it at the moment, but there once was a question here where someone else also was wondering why his glowing colored lights looked different. In short, I explained that for example a white light where you have RGB (1/1/1) is of course brighter than a completely red light with RGB (1/0/0) since the green and blue channels are not emitting any light. Another thing is that different colors are perceived with different brightness for the eyes or even optical instruments, I don't know how much this is relevant in the render engine though.

using Eevee, you can use bloom instead of the compositor.

@OmarFilippini What is your Base Color ... from your screen it doesn't look like the same ... green is green, but Red and Blue are what? If I set it appears as brighter color when black its intensive color, but never black (or. dark grey) like in your screen.

@gordon, actually being that (just by chance) the colours of the LEDs are R, G and B, for each led there's one of those colours having the emission close to 1

@OmarFilippini My last sentence was: "Another thing is that different colors are perceived with different brightness for the eyes or even optical instruments, I don't know how much this is relevant in the render engine though." If you look at vklidu's answer, there he posts a greyscale gradient of color intensity. This is sort of what I meant.

I'm not sure if there is too much to say ... blue is just visually darker color ... so less prominent for blooming. Here all colors intensity of 10.

Options for compensations are several ... it depends on circumstances ... here just Emission Strength Red 20 / Green 10 / Blue 40 + brighter blue color R0/G0.2/B1

Notes: Base color is set white here. Used default Bloom setup (Render Properties).
Also helps to use not strongest color like Red 1/0/0 but brighter 1/0.1/0.1. Here with few adjustments in Color Management > Filmic > Very High Contrast, Exposure 1.8, Gamma 0.3 ... but can be enhanced also in compositor.

Result of Compositor > Glare > Fog Glow is the same ... there you can duplicate this node few times to even make the effect stronger ... and the same can be achieved by Bloom > Intensity and Radius too.
Speaking to Treshold - it is based on color intensity ... so it make a sense if bloom is cropped in order blue-red-green.

Your file can be fixed in the same way provided in this answer ... just keep in mind - you can't see a light without darkness :)

This is what I meant by simplified file share via https://blend-exchange.com

Related - RGB to BW

@Chris thank you for your comment. The blend file can be discharged here: https://drive.google.com/file/d/1rpaBf4aI2COY1i9fuu6_3U4xUFykutb6/view?usp=sharing

thank you. I'm not using the bloom effect as it gave me a bloom effect (sort of an halo) also around other component, but I now found out that the problem was due to the threshold set at 0.8. However, there's no improvement in using bloom vs the compositor

Yes ... that is right - Bloom in Eevee is the same as your Glare>Fog Glow in compositor ... and I'm not saying you to use it .. it was just a note what I used ... I guess Lemon suggested to you, because it is just more straight forward solution to see result realtime in 3D view. I tried to explain why it is less blooming and what should help.

Thanks for the file ... just to let you know - the proper way is to use https://blend-exchange.comm to upload file and copy-paste given code into your question via edit. Also like now people has to ask you for access and be owner of google account Thank you keeping site organised.

Thanks @vklidu, your suggestions proved to be very useful!


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Noob in BGE Just have anything work with python script
Folks I have spent many hours trying to get out of the starting gate, there are many nice tutorials which step through using python scripting in the game engine (three I have tried - which claim to be starters(. As yet I have not gotten anything to respond. Ok not completely true on a windows machine I was able to get a print out (not in the python console window but in a console which was generated on running the game engine) - I work on either linux or windows machines and yet the tutorials never seem to get even the most basic response (move a block with a key) using python. This has not been a problem with the logic blocks. I save the named script which I try to create to test, I set up an always block which is wired to the python script which is in turn seen and selected in a control block - I am in "pulse mode" (continual looping sort of correct?) but still nothing ever moves or responds.... As an aside In linux under the window tab there is no toggle system console option and no second console log pops up upon running the game engine, and the system terminal does not seem to be the place and the python console window option does not seem to be tied to bge ....It feels like something very simple is missing but darn if I can tell what it is.... Thanks
Addition Below is one screen shot to address a comment and provide perspective the sphere is just for reference and not used. The console in this case gives a syntax error - The same error occurs when I change the name of the control object from own to Cube to as shown Player...... THANKS !

When you use windows,what error pops in "Windows-->Toggle system console" ?

"Toggle system console" works fine / is present in the windows version, however on another recent tutorial there is still no motion. This tutorial was posted for 2.7 - I am using 2.7.1

Upload your blend file here: http://www.pasteall.org/blend/ and edit your original question with it. You are not giving us any error report so far. Like what are you trying to do with the script?

I think what you mean by "pulse" is True level triggering.

Yes true level triggering - I will create a file to upload

you need a colon: after the if statement if    something    :

GREAT _ I really appreciate the help from folks - The extra [ was eventually the problem the : mentioned also was not correct in the posted code - (previously I had the : in there but took it out amongst several other corrections!) anyhow thanks very very much. Things now work and the world is my oyster!

The show console menu is only available on windows, on other systems you start blender from a terminal window to see the same output as the windows console.
Programming languages are very strict when it comes to interpreting the code you give them. As Chebhou pointed out, you are missing a : at the end of the if statement, you also have an extra [ before the keyboard.events. Any small error like this will prevent the script from working.
The error you got says there is an error on line 11, many times it is a line or two before that that has the mistake that needs to be fixed. In this case it says the player.applyMovement() is incorrect because it doesn't fit in what it accepts next, it wants either a : to end the if statement or a boolean operator like and to join the function result with the previous test condition.


text:
UV unwrap triangles/flatten curved surface
Some time ago I made a piece of a prism turned towards the sky and now I want to make it in metal, so it had occurred to me to make a UV unwrap on the sides so that I had them flat, then vectorized them and sent them to a laser cutting machine for later mount them.
Prior to this, I was trying to do it with sheets of paper and I'm seeing that the sides don't fit. Reading through the forums I have seen that for an unwrap to be a faithful flattening I have to do the step of "follow active quads" but this object that I made is made of triangles and when I perform the action of "tris to quads" it does not transform all of the triangles.

For what you're describing, you don't want a follow active quads unwrap; you want the unwrap you're showing.  Except you have to be aware that each piece won't work as a flat piece of metal.  They need to be scored at all edges so that they can bend along those lines and along no other lines.

Hi Nathan,
First of all thank you for your reply.
In the unwrap that I attached it shows that, right?
The sides are perfectly separated by the edges that join them. However when joining these planes back on metal, paper or any material they do not conform to each other :(

No, there are more edges than that.  Every face is a triangle, with three edges.


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How to easily build concentric curved tubes to make layered tubes?
I have built tubes by Bezier Curve, converting to mesh, and adding solidify modifier. I want concentric tubes now. I could not directly scale the duplicated tube, which will cause it to be not concentric (as shown on the left in the Figure 1).
I have been able to duplicate the Bezier Curve and go through the process and add thicker layer (on the right of Figure 1) to make concentric tubes. But there seems to be a little gaps between the outer tube and the inner one. However, this process will not work for dynamic tubes, especially when they change locations.
Figure 2, I tried using curve modifier, but only can move or rotate it or a little shrinkage. I think I need subdivisions on the cylinders, right?
Figure 3(left), Later, I tried more subdivisions, which works good for one cylinder, but not for concentric cylinders joined together. Even I also set subdivisions for the inner cylinder.
Figure 3(right) using array modifier to elongate the cylinders and join them, add curve modifier, and separate them by loose parts. Make sure the origins of the cylinders and the curves at the same spot.

A simple idea may be to make the inner tube slightly larger (overlapping the outer) and then subtract the outer tube to get a perfect fitting inner tube.

@Real Do you mean using the same bezier curve to create two tubes first?And bend them together, and then substrate?

Yes, make a larger and a smaller and subtract the larger from smaller. See here

@Real You're right about that. I have been able to build two cylinders and add the same curve modifier to it. Thank you!

I say you try this as a solution:
Add a cylinder. Delete the top and bottom faces of it. Give it a solidify modifier. Duplicate it and scale it down by locking the Z axis until it's boundaries fit in the inner boundaries of the biger cylinder.
Once you are happy with the thickness and scale apply the solidify modifier. And then hit Ctrl+A to apply scale on both the objects. Then select both of them and hit Ctrl+J to join. Then rotate them along the X axis by 90 degrees. Then go to Object>Set Origin>Origin to Geometry. Then apply the rotation. Then add in an array modifier. Set the X and Z offset to 0 and the Y offset to 1. The count on the Array Modifier will change the lenght of your object. Then add in a path.
Rotate the curve on the Z axis by -270 degrees. Then add in a curve modifier on your object and select that path. Then scale that path to be as long as your object. Now if you go into edit mode on your path you can play with the verticies of your path and your mesh will be deformed.

Chaudhry, thank you so much for your time in figuring this out. It seems a good method. But I still have some questions. Why do you apply array modifier? I tried your method, but not works well, as updated in the question area. By joining the cylinders, they become one, which may prevent setting two different materials, right?

@tryphena I apply the solidify modifier not the array. And I joined both the cylinders so I don't have to add the modifiers on both the objects. You can always edit the cylinders in edit mode. And for setting new materials you can just go to edit mode, and assign a new material to a specific part of a mesh.

Okay. You mentioned: "Then add in an array modifier. Set the X and Z offset to 0 and the Y offset to 1. The count on the Array Modifier will change the lenght of your object." So this is not necessary?

@tryphena this is necessary if you want a long cylinder. Or you can just go into edit mode and elongate both the cylinders.

@tryphena I'll try again and check if I forgot to add something in the answer. But if one thing is done wrong the same thing will happen as you have shown in your question. I think you did the last part of my method wrong.

@tryphena I see now what is wrong. make sure to rotate the curve on the Z axis by -180 degrees after rotating it 90 degrees. It works. In simple words make sure that your curve has a rotaation of -270 degrees.

Yousurf, I see your point in using array modifier(similar to this tutorial https://www.youtube.com/watch?v=_3NFtRBDCV0), which gives more flexibility to the long cylinder to bend. The rotation can be implemented by changing the deform axis in curve modifier. I have some more updated in the question area.


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How to avoid tube overlap in rigid body simulation
I created two tubes by Bezier curves and add sodify modifier to them with a small thickness. And add rigid body and collision to the tubes. I check the normals, upscale the steps per second and iteration number, set sensitivity margin to 0, but they still overlap. And when they hit each other, they rotate together.
I hope someone may give me some advice. Thank you.

Hi Vklidu, yes, I have changed the type to be convex hull, and set margin as small as possible but larger than 0. It seems work. When I have more objects, however, the objects on top will be floating not touching the bottom objects...

I am using microscale. I am not sure if that causes the problem. Please check the file in the link. Thank you. https://blend-exchange.com/b/7Xk4kxSY

Specifically in your case just delete all innert geometry and use Solidify modifier. Also there is not a need to use Collision modifier that is aimed to be for Cloth a nd Particles sims.

Don't set Margin to zero, use as much as you can (to result with good looking sim). To simulate thick objects is always problem. Low margin value increase possibility of objects penetration (like that you see with your setup - they hook each other and rotate as crazy).

Anyway ... Margin didn't solve the issue here. Result was hysteric as in your case.

I had to start with defaults.
In this example - add Curve object, set Depth, Convert to Mesh, add Rigid Body / Active / Shape>Mesh / Margine 0.01, add Solidify modifier (Thickness 0.02) ... copy object few times and run sim.
What definitely helped here ... use tubes thickness as modifier not as real geometry.
Solidify modifier > Thickness 0.02

Note: Margin 0.01 is from some angle view visible so you can use also 0.001, but sim can became jumpy.
General rules for successful sim - Apply Scale, Origin to Geometry (it is not your case).

So the issue is caused by inner faces of a tube (when real geometry). That is weird for me since margin is low so there is not even a possibility collision margin crossing from inside tube through to outside (to create effect like switched Normal direction). So I don't have an explanation for that.
Increasing Solidify modifier Thickness to 0.06 and Apply Modifiers make the sim possible.
Solidify modifier > Thickness 0.06 ... Apply modifier (make real geometry)

Note: In a middle of anim it exploded because of collision penetration so I enabled Margin for floor object 0.04 that make it stabilised.

Hi Vklidu, thank you very much for your hard work to figure my problem out. However, I still could not reproduce your result. The file you uploaded have some setting missing. I add collisions to the tubes and the plane, and set substeps for frame as 120 and iteration number as 60, and the tubes fall without penetration. I have been able to remake a tube in your file and fall as expected.

And I have found that I shall not click the "apply" in the solidify modifier. In your file, if I click "apply" in the solidify modifier, the tubes will penetrate each other..But in my another computer, I start the same process to build the tubes, they just hit and fly away..I have tried add rigid body/collision before solidify and add solidify before rigid body/collision. no luck

Don't use comments for "chatting". Please delete comments and try to summarise your actual thoughts into one simple comment ... or even better "edit" your OP (original post) if you have more info about the issue. Thank you ... BTW I used 2.93 and worked in 2.92 as well for me. If answer solved your issue consider mark as accepted https://blender.stackexchange.com/tour Thank you keep site useful :)

very nice to have your instructions and help. Thank you!


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Is it possible to get the Compositor File Output image sequence to match the Rendered video?
I've done some basic Compositing starting with a sequence of EXR files. All I put was a Glare Node, Composite output, and File Output. In the Compositor I set the file output to PNG and specified a folder. The Composite Node uses the main Blender Output Properties rendering an MKV file which is saved in a different folder so we keeps things separate. After Ctrl+F12 I get both the PNG sequence and the video file but only the video file has the Compositing applied. The PNG sequence looks just like the original EXR sequence. What am I missing?
Edit: A screenshot of my Compositor Nodes

can you provide blend file?

Make sure the glare node is connected to the file output node.

I added a screenshot. @brockmann Node connections where the first thing I checked. I've been trying different things, videos, and web searches all seem to indicate that I'm doing it right. This is Blender 2.9 if that matters.

You're rendering PNG files, so semi-transparent glare doesn't show up over transparent background. Check these questions: Fire over transparent background 1, Fire over transparent background 2 and this one Glare over transparent background

@GordonBrinkmann Thank you. That pointed me in the right direction. I appreciate your time and expertise. I've been struggling with this for a few days before asking so I'm glad to be on the path to a solution finally.


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Problem with importing model. Points
After importing obj file I get just unlinked points.
I have nice model in one hand

And after importing .obj file in blender getting just a cloud of unlinked points

The solution was to import the object not with "Wavefront(.obj)", but with "Wavefront(.obj) (legacy)"


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Materials fail to export to babylon.js
After baking my textures (the left window is in material view, not render) I attempted to export to babylon.js (built on top of three.js):

I did not use any kind of checker pattern in my material--rather, I applied a different material to the dark and light squares and a third one to the grout:

So, it can't be a UV issue since there was no actual checker textures to begin with. I think the checker pattern on the right may be some default texture for babylon.js, but I'm not sure.
Has anyone got this process to work?
EDIT
Here's the javascript that loads the .babylon file into the scene:
BABYLON.SceneLoader.Append("", "babylon\\checkerboard2.79.babylon", scene, function (scene) {});

It may be worth trying to file a bug on BabylonJS if the exporter is not working as expected. Alternatively, you could export to glTF — BabylonJS can import it natively, it supports PBR, and Blender 2.8 has an exporter built in. Then at least you can test the model in other viewers and determine if the bug is in the export process or the library.

Minor: ThreeJS and BabylonJS are separate libraries, so I'm removing the three.js tag here.


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How can I export a model with its textures applied?
I have a blender model that is 7Mb, a laptop with 4 image textures applied to it. I am trying to export it to use in Google Poly.
When I follow this tutorial to export as a .fbx, the resulting .fbx file is 28Kb and doesn't display textures once I upload it to Poly.
I tried using the gITF 2.0 export, but again, the resulting file was 16Kb.
As a last resort, I exported as .obj (the last format Blender can export to that Poly accepts), but the resulting .obj and /mtl files were 1Kb and 5Kb.
The other questions or tutorials I found did not apply to my situation, since I am using UV photographic textures in Cycles.
Is there a way to export a model and its UV textures to .obj, .gITF, .glb or .fbx from Blender?

Maybe this tool might solve yur problem
https://blendermarket.com/products/glb-texture-tools

The most likely explanations for why your textures are not exporting would be that (a) the textures are not in an image format supported by the export format, or (b) the material is not configured in a way that the export format's addon understands.
In the case of glTF 2.0 (I can't comment on FBX or OBJ), images must be in PNG or JPG format to be exported. The material should typically use the Principled BSDF material — arbitrary material node graphs cannot be exported from Blender to any format.
For full details on how to configure your materials for correct export from Blender, see the documentation of the Blender glTF exporter. In particular, this is a standard material setup with a base color texture:


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Problem with Viewport shading not displaying my models
Today Ive gotten a problem with my viewport shading.
If I work in "Display in solid mode" the models are showing corectlly. https://i.sstatic.net/tOTVL.jpg
But if I change to "Material preview mode" or " Rendered" my models go "grey as the background" invisible.
No textures and no colors showing.(attached photos).
https://i.sstatic.net/uKAn9.jpg https://i.sstatic.net/t1HGV.jpg https://i.sstatic.net/3d7OQ.jpg

I had used Blender a lot on my system previously and never had this problem, also when I copy the same files to a different computer the viewport shading is showing the models correctly.
I had searched litteraly all day if anybody had a similiar problem with no luck.
Also I had reinstall my drivers, tried different versions of Blender, tried different project files, tried Blender demo files, also I have tried to reset Blender config to default and to install blender to another disk. Nothing worked.
It is also the same if I use eevee or cyclees. (Only difference is that it somehow renders in Cycles normally).
Am I missing something obvious? I really cant get viewport to be showing my models normal again.
I appreciate all the help.
FIXED: It was a Radeon graphic card driver problem. I downgraded to 20.9.2 and it works now like a charm.

https://blender.stackexchange.com/questions/204044/viewports-broken-on-rx-580 https://blender.stackexchange.com/questions/204897/how-come-all-of-my-objects-are-just-outlines https://blender.stackexchange.com/questions/204687/eevee-rendering-materials-dont-work

Do you happen have to an AMD gpu? They are having alot of issues lately it seems.


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How do I make these PBR roof tiles not flat?
I'm trying to model my house using Blender.  I'm stuck with trying to get a realistic tiled roof.  When I follow a tutorial online, I think I'm doing all the correct steps in the Shading area, but it still looks flat in the the Cycles render.
This is the texture I'm trying to use https://texturehaven.com/tex/?t=roof_09
(although I will need to find a better one for my final design!).
But it looks totally flat:

What might I be doing wrong?
Here is my .blend file:  http://files.staging.x-rm.com/nick/house5b.zip

First off, change the color space of all your image textures (except for basecolor) from sRGB to  Non-Color

Done... Looks "different" but still very flat.

If you want true displacement, you'll have to (heavily) subdivide your mesh. I tried on your file by using a Subdivision surface modifier, but the results were "uneven". I think you need to UV unwrap again.

It's a large file, difficult for me to be very helpful.. but 1 thing.. you need at least a Subdivision Surface modifier set to 'Simple' and 'Adaptive' to have displacement work at all.. at the moment, it has no geometry to displace. I'm not sure the bump is mapped correctly.

There are 2 different things:

For your normal setup, you need to switch the Image Texture to Non-Color as Christopher says, and the Normal Map to the default Tangent Space (I don't know what's Object Space though):

For your Displacement node. Again switch to Non-Color. Also, you've plugged this node into the Displacement socket of the Output, and you've chosen Surface > Displacement > Displacement & Bump in the material Settings, which means that you want the bump effect but you also want a real displacement effect. The displacement itself acts on real geometry, it can only affect an object that is subidivided enough, otherwise nothing happens. Your roof is just made of one face, so it can't be displaced for real. Therefore for the moment only the bump effect happens (which cumulates with the normal effect, which is ok if this is what you want but it may be redundant. And it will also be redundant with the real displacement):

As you can see here is what it gives if I subdivise enough a plane and give it your setup (I had to decrease the Displacement strength though), not sure the height map is good though, giving the result:

non-color doesn't mean black and white, it means that the data will not go through any kind of color transforms (or color management).

sure, thanks for the edit  ;)

Thanks!  I have switched to a commercial texture and made the changes above but it's still not working for me.  However currently I have other issues with rendering: https://blender.stackexchange.com/questions/206702/render-suddently-coming-out-black-in-blender-2-91

what do you mean when you say that it doesn't work? It seems to work fine. Of course this won't be real displacement as this is not the option you've chosen in the material settings, plus each side of your roof is only made of one face so you can't get any real displacement with only one face. Also, are you sure you need both the normals and the height? It's not a problem but as they seem to do both the same thing I guess only one is necessary


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How to go about modelling this roof shape in Blender?
How to go about modelling this roof shape in Blender?  I started off doing it in Tinkercad and then importing the STL file but that seems to have side effects and doesn't result in a model which is easy to work with. I've been advised to model directly in Blender but having followed some "roof tutorials" I'm struggling to replicate this roof shape (and create the overhangs):

I guess what I'm trying to do is raise up the vertex A (see below) to create the ridge, but then somehow pull up the vertex B (see below) proportionally so that it creates a planar face?   Or am I simply going about it the wrong way?

Here is my .blend file:

Thanks!

I guess you need to switch to another way of modeling in Blender (compared to some other 3D softwares), you could start from the shape you show but maybe the best is to start from scratch.
Create a cube, subdivide, pull the top edge:

Create an additional edge loop on the left:

Extrude the side walls:

Cut an horizontal edge:

Pull the vertex:

Rework a bit (the knife tool is useful, K to activate, W to cut through, C to cut perpendicularly, also bevel for the top, CtrlB):

Since latest versions you have the Extrude Manifold tool (AltE) that allows to work a bit like Sketchup or others, but you often need to give some corrections afterwards to keep a good topology (good doesn't meaning a lot, it all depends on your needs of course):

Thanks! I'll give that a try now

Thanks so much for your help! I got it modelled in the way you described in only a few minutes.

Now I just need to texture it and it's pretty much done :)
https://blender.stackexchange.com/questions/206509/how-do-i-make-these-pbr-roof-tiles-not-flat


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How to extract certain keyframe from current scene to another file with just the selected keyframe as first and only keyframe?
I have a animation of several objects falling one after another. My baked sequence last up to ~13500 frames. It is a simulation of the constructive process of a breakwater.
I want to extract my final result of the baked animation, this is, the last keyframe of my scene as a single scene on another .blend file. In which my last keyframe is the first keyframe of the new file.
I don't know which is the proper approach to achieve this, I've been looking out and trying diffent things (delete all keyframes and save as new file, append scene from target file...) but I can't achieve exactly what I want.
I hope you can help me,
thanks!

BEFORE you try my solution, make a backup!

go to your last frame, select all objects

in the timeline press "I", select "all channels"

This creates a keyframe for every object+property which already has keyframes so that we later can move this keyframe to the start

now select just the last keyframe

press CTRL-I to invert selection

Now all keyframes for all objects except for the last frame should be selected

press X -> delete keyframes

Now you should only keyframes on your last frame

select all keyframes again

move them to your first frame

save this file under a new name

Ready

Thanks for your submission, I think I have an issue I didn't point out. As I ended and saved, all keyframes still on cache and animation replays, Is there any way to delete current state apart from cache saved? But If I delete all cache memory, what I obtain is the starting situation, where objects are ready and waiting to fall at its target keyframe.

you can just hit "delete bake" in scene properties -> rigid body world -> cache. But of course, if an object has rigid body - you cannot expect that there is no animation if you clear your cache. Of course it will fall down. If you don't want that, you have to delete the rigid body from the objects.


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My hair particles move when in particle edit mode
I'm new to particles and may have missed something but but i'm sure its some bug:
When I switch to particle edit from object mode, the hair particles project towards my screen (pictures below). Also im using vertex groups here but its the same problem if I cover the whole surface

As soon as I click particle edit, this is what I see. Note that the hair now leaves towards the right side of the viewport. Even if I rotate my view, they remain in the same place:

please provide your blend file

Updated with file

I can't reproduce the problem with your file.

Thanks for having a look. I think its my system, windows 7 with no graphics card


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Now to adjust the line thickness of the gizmo without changing other thicknesses?
I would like to increase the thickness of the lines in the gizmo, since on some pc/monitor/mouse is really hard click on the 1 pixel lines to do something.
I know that there is the property for the size of gizmo but it doesn't change the thickness of lines, only how big are the circles and arrows.
Can this be done making a new gizmo with python?
I found this addon https://blendermarket.com/products/gizmo-pro-addon-blender-2
that make me wonder if is something doable.
I have seen the templates for gizmo but with only that I am really not able to go further, do you have any gizmo tutorial?
Thanks for your time.

See this posting from a year ago.

Hi man , thanks for reply ,
yes setting can be set to thick to have the lines, like 2 pixels thick XD
and also we can set the " resolution scale " but that setting change the whole blender to unusable size...
with some settings is really hard to click on the lines and i usually mistake clicking on Trackball style rotation...
if you have any more trick let me know
Thank you very much for your time


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What is the difference between UV Unwrapping and UV Mapping?
I am totally new to Blender.  It seems that UV mapping and UV unwrapping are the same.
Can anyone please clarify the difference.

Please don't write in all caps, it is the online equivalent of shouting,
is harder to read
and is considered rude.

https://blender.stackexchange.com/questions/57420/confused-about-unwrap-vs-modifier-unwrap

It's not the same. Although there are explanations for UVs and modifiers at the provided link, they are not explaining a difference between Unwrapping and Mapping. Unwrapping, like the word says, is first of all like stripping the faces off as if you're peeling a fruit, you get the skin laid out in 2D in a big or smaller islands or whatever. Unwrapping usually creates a UV map automatically - however, this map is not carved in stone. While keeping the "skin's" parts, you can scale, rotate and move them in the UV Editor to map the UVs according to e.g. the textures they cover as needed.

A UV map is the flat representation of the surface of a 3D model used to easily wrap textures. The process of creating a UV map is called UV unwrapping.

and the process of using a UV Map in a material is called UV mapping.


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bone axis-orientation is unexpected changed when modify bone.tail by python
I want straighten editbone, but using python
bone.tail = bone.head + bone.parent.y_axis*bone.length
will unexpected change axis-orientation.
How should I fix it?

I had a similar problem. Try using Blender 3.0 if you aren't already, it may be fixed.

@scurest  Is it ? i download blender 3.0.zip , it still is wrong.


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Making only the grid lines of a grid object visible in the the Render Viewport
I would like to use a grid object as an orientation tool, for properly arranging objects against my HDRI background scene. This requires that the grid lines (and only the grid lines) of the grid object are visible in the Render Viewport.
However, in the Render Viewport, the grid object shows up as a solid rectangular plane, without grid lines. The only viewport in which the grid lines are visible is the Wireframe Viewport.
How can the grid lines (and only the grid lines, so you keep seeing the HDRI background) be made to show in the Render Viewport?

Delete > Only Faces leaves you with just the vertices and edges of your grid. Does that show up enough against your background in Material Preview mode?

Of course it does. Sorry, had a moment of overload and could no longer see the wood through the trees.


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Imported video is in slow-motion
I imported a video file (an interview with a person, mp4) of 60 fps into the Video Sequence Editor. The idea is to superimpose a Blender animation that has 24 fps. Unfortunately but not surprisingly, the video (not its audio) plays in slow motion.
Too much work has gone into the animation to convert it to 60 fps. Can Blender convert the video file from 60 fps to 24 fps? Or any other solution?

You can use HandBreak to transcode your footage into the needed framerate, or you could render your animation alone and edit it together in a dedicated video editor like Premier, Kdenlive, etc. Blender can be used to transcode but its not the most convenient way.


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How to child a control point of a Bezier curve to an object
The straight line is a 2D Bezier curve, with two control points. The bevel function gave it some thickness. The circle is a separate 2D object.
Now, when the circle moves, the idea is that that end of the Bezier curve should move with the circle, staying at the circle's center. The other end should remain where it is.
So, somehow that end of the Bezier curve should be "attached" to the center of the circle. I thought using the Hook modifier. But that requires a vertex group to attach to the object. Bezier curves apparently can't have vertex groups (couldn't find it in the property view), so can't use the modifier. Then I considered using the parent function, but apparently a vertex can indeed parent an object, but an object cannot parent a vertex (at least, I couldn't find a way). And anyway, again, Bezier curves don't have vertices. So wouldn't have worked either.
Anyone?

Perhaps this also?  https://blender.stackexchange.com/questions/117061/how-to-draw-distance-lines-to-a-central-object/117236#117236

I found the solution in a YouTube video:
Suppose you want to make Object A the parent of a control point in a Bezier curve (Object B).

select Object A, then shift-select Object B (so both objects are selected)
click edit mode. Object B will open edit mode.
select the control point you want to "attach" to Object A. click ctrl+H.
choose "selected object"

When you now move Object A, the control point will move accordingly, while the other control points of Object B won't, hence deforming the Bezier curve.
PS: you can also use this method when Object B is a simple mesh object (i.e. vertices instead of control points).


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Background insertion does not work
I want to insert an image in the background of my scene. The classic method to do that is with this compositing node set-up:

However, the image node (left of screen) doesn't seem to pick up the background JPG file I assigned to it. I can tell because otherwise, that JPG picture would be showing in that node. And indeed, when I press F12, the picture is not in the background. I know, the Render Layers node isn't showing the scene either, but at least it did its job; the object of my scene appears with an alpha background.
Interestingly, when I start a completely new file (with the Cube), and try the same set-up (with the same JPG file), it does work; the Cube is set against the background of the picture. And yes, the picture shows up in the image node as well. Here's the screen shot:

How come the node picks up the same JPG picture in one Blender file, and doesn't in another?

This happens when you don't check ✓ Use Nodes in the Compositor.
In such case, only the Render Layer will be composited, as you described.

Thx! Sometimes, I wonder if things like this are put in Blender with the sole purpose of testing your wit and resolve :(

It definitely seems like it. That bloody checkmark is a nightmare :).


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Missing isosphere when importing to Unity
To build my tank for a Unity game, I am using Blender. Currently, I am making a turret consisting of an isosphere with half of the faces removed (I needed the bottom to be "flat") with some minor visual edits, two cylinders (one is the hatch, the other the antenna), and a cube to act as a hinge:

The inside is hollow. When I imported it to Unity (drag and drop from File Explorer straight to Unity Assets folder), the entire isosphere was missing as you can see from the preview:

I have tried to correct the normals with CTRL-N as mentioned in other Blender forum pages but it still doesn't work. How exactly do I make my isosphere appear in Unity? Also, after some testing, the shapes don't affect the isosphere (it won't load even by itself), the scale is positive, and the normals are all facing outside.

@MrZak Actually, they are are all positive (+1)

Is it possible for you to share the file? I didn't really use drag-and-drop to Unity import feature, did you try exporting fbx and importing it there? If the object isn't imported at all then it's likely not a Blender problem but import/export mismatch

@MrZak Oh thanks! Exporting to .fbx first worked

As I see the object won't really be rendered in Blender at all because it's Duplication in Object tab in Properties editor is set to empty Group. Try setting that to None and exporting again. Working with fbx probably means that was something with .blend import into Unity


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How to Create/Bake Maps for a Mesh that are Darker at the Bottom and Lighter at the Top
Anyone know of a way to bake a map for an object that is dark at the bottom and becomes gradually lighter to the top, which is perfectly white? This would differ from a displacement map in that it would work on objects that fold over themselves, such as a tree, or a cave, or a bridge.
Thanks partner.

Related https://blender.stackexchange.com/questions/46748/create-a-displacement-map-from-high-res-terrain-to-use-on-low-poly-terrain/46756#46756

Yea, bu... "This would differ from a displacement map in that it would work on concave objects."

How does a displacement map fail for concave objects? Could you show an example? Please edit your question and provide some screenshots of what you are doing and why a displacement map doesn't work for you

You're right. What I really mean is objects that fold back over themselves, and wouldn't be able to be represented by a displacement map. Thanks for correcting me.

So basically you want an unequivocal way to represent an infinitely complex 3D object with a 2D representation method. That sounds impossible, if I understand correctly. If someone were to crack that one up it would be a huge breakthrough for data interpretation and storage technologies.

It can be mapped like ambient occlusion map, if that makes it any easier.


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Blender 2.8 Selection issue in Edit mode
Problem with selecting multiple vertices/edges in edit mode. When i want to select vertices one by one or using box select/ lasso select etc. blender behaves like in wireframe or x-ray mode. It grabs vertices from backside of the mesh. This issue i have since 2.8 beta and it still here in 2.81 alpha. The same problem in stable version. May be here is some feature that could turn off this or this is a strange behavior of 2.8?

in the future please use the [edit] link below your question to add more info, instead of the comments.

I see that you tried to add it in the question. Yah, SE strips out all script elements like that. Best thing to do is use the built it image upload tools.

@David thanks for explaining. I could not use the built in feature because of size, so i tried to do in another way.


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dark and light areas on car panels
I've just started to use blender to make car models using blueprints, I've run into this problem where i have dark and light areas on the panels for example the top half of the front wing is supposed to be all light and the bottom half is supposed to be all dark. I've already flipped the normals, can someone help me?

You are referring to the lighting artifacts? (Some faces are lit more than others that should be equally lit)

does that mean that there's something wrong with the mesh?

It could be a topology issue. Post a close up wire frame screen shot or upload the file.

Yeah, this is an issue with your mesh, I'm 95% sure about that. Upload your .blend file and I'll take a look at it unless you want to see if you can correct this yourself

I'll upload it and get some helpful advice from you guys, but i don't know how to upload the file :\

Go to this link; http://blend-exchange.giantcowfilms.com/ and upload your .blend file there. Then copy your link into your question (Press the edit button below your question). This makes it easy to download your file and it will never expire, to help future people searching for your issue.

Thanks, I noticed that the bottom of the wing has a curve on it, could that be straightened up?

Just go to edit mode and fix that to your liking. To do this, turn on proportional editing, that way you'll fix the curves in a jiffy

A simple subdivision surface fixes this:

This is caused due to some faces being bigger than others, and as such Blender reflects the light differently. This happens when smooth shading is enabled, and the angle/size of two or more faces right next to each other differ greatly.
If using a subdivision surface modifier is not suitable to you (This should work with Blender Game engine as well), modifying the faces may be your best bet.
Hope this helps.

You're welcome. Regarding the rounded edges that occur upon subdividing, that's easy to fix in edit mode. And if you found my answer useful, please consider marking it as the answer.


text:
I would like to apply an emission shader to specific parts of a texture

I would like to add the emission shader to the green parts of this texture. How would I do that?
Edit: How do I make a mask from this texture

You should create a mask texture that is all black except for the emitting parts which should be white

Your going to want something lie this: http://imgur.com/a/8fcEJ I did this in photoshop, just select the colour range of green and then converted all of the green parts to white and put it over a black background.

May the dragon consume you! ;) Any reason the green areas do not have their own material? My first guess is that you have a geometry limit.

First of all you'll need a map that will define the areas where light is being emitted from, like this:
Then to mask it over the diffuse map you'll need to create a simple node setup where you use the new texture to control the way two shaders mix, the white areas will use one shader, the dark ones the other one:

(You don't have to use a diffuse node, I just used it for the example) Your final result should be something like this:
Obviously yours will be on the actual model. Hope this helps.


text:
Render suddently coming out black in Blender 2.91
I have been working with a blender file for a few hours with no issues. Then all of a sudden, I noticed the the lighting had changed in the Modelling view.   I went to check how it came out in a Render and the render is completely black, with some tiny white dots which seeem randomly placed like stars.
The scene looks like there is a load of ambient lighting still there when I disable the sun effect in the World tab.  Yet despite the extra ambient light (which I don't want) AND the sun clearly shining away in all of the edit views, the render is black and I can't work out why.
I will post a screenshot and my Blend file below:

Here is my .blend file:
http://files.staging.x-rm.com/nick/house6.zip

Check your Scene settings, you've chosen your house as Camera, select your camera instead. Selecting another object than a camera may be useful sometimes to see what an object is pointing towards (for example select a light and press Ctrl0):

As for the light, it's your world that lights up your object, open a Shader Editor, switch to World and see, you have a Sky Texture plugged into the Output.

If you don't want the world to light up the scene you can unplug its nodes or play with its Ray Visibility settings:

Edit: Additional edge loop in order to sharpen your roof (but Subdivision Surface modifier doesn't seem necessary here, it is supposed to round the shape with virtual subdivisions):

To get a proper displacement for the material called Pantiles you need to unable Material > Settings > Surface > Displacement > Displacement Only. But as your topology is not very good the Subdivision Surface modifier subdivision won't be very good either, you'd better rework the topology a bit so that it is made of regular square faces:

Thanks! That fixed rendering.  Any idea where the extra ambient light is coming from?  And how can I send you a tip / beer money?  :)

ithe world is lighting up your scene, see my edit  ;)   don't worry for the beer

Fixed! Looked like the sun was OK but I'd set the "strength" of the actual image too high.

Do you know what's causing this "sail" at the junction of the walls? Have I missed setting a crease somehow?  https://imgur.com/a/0Jf4gQj

actually you don't have any light for the moment, you must be talking about the world background strength, and if you decrease it it will darken. For the curve, it's because you've given your roof a Subdivision Surf, I don't why as for the moment it doesn't seem to be necessary. You've created creases in order to sharp the edges, I'm not too familiar with these kind of tools, I prefer to have a clean mesh with additional edge loops if I want to sharp edges, but again here you don't need Subdivision Surface or creases. If you want to keep them for some reason, then add an edge loop (see edit)

I added the subdivision surface mod because theoretically I'm using a 3D displacement mapped roof tile, however that doesn't seem to be working properly as per my previous question you commented on:  https://blender.stackexchange.com/questions/206509/how-do-i-make-these-pbr-roof-tiles-not-flat

You need to unable Material > Settings > Surface > Displacement > Displacement Only (see my edit)