text:
How can I write the vertices of a 2d polygon to a text file?
I'm trying to figure out how to save the vertices of a 2D polygon to a text file.

e.g. i have drawn two flat squares on the X-Y plane, which i have named "Square 1" and "Square 2", locations of their vertices are:
Square 1: (1,1) (1,0) (0,0) (0,1)
Square 2: (4.2,4.2) (4.2,3.2) (3.2,3.2) (3.2,4.2)

I would like to save these vertices to a simple text file in this format:
Square 1: 1 1, 1 0, 0 0, 0 1
Square 2: 4.2 4.2, 4.2 3.2, 3.2 3.2, 3.2 4.2

Any help is welcome, Thanks!
after some more googling i'm finally getting somewhere!
import bpy

current_obj = bpy.context.active_object

    print("="*40) # printing marker
    for face in current_obj.data.polygons:
        verts_in_face = face.vertices[:]
        for vert in verts_in_face:
            local_point = current_obj.data.vertices[vert].co
            world_point = current_obj.matrix_world * local_point
            print('%.2f %.2f, ' % (world_point.x, world_point.y), end='', flush=True )
    print("")

this outputs to the console in the format i want, however printing to a file in the for loop doesn't work.

To keep it similar to what you have already scripted.
import bpy

current_obj = bpy.context.active_object
f = open("d:\\test.txt", 'w')  # use 'a' to append
for face in current_obj.data.polygons:
    for vert in face.vertices[:]:
        local_point = current_obj.data.vertices[vert].co
        world_point = current_obj.matrix_world * local_point
        f.write('x: %.2f\t y: %.2f\n' % (world_point.x, world_point.y))
f.close()

face.vertices[:] creates a full copy of the list of vertices. Why is that necessary?
Also, you can use f.write('x: %.2f y: %.2f\n' % (world_point.x, world_point.y)) instead of the manual rounding and string conversion.

@dr.Sybren Thank you Dr. Sybren. updated & removed some trailing white spaces.

Awesome, cheers! I'll see how that goes tomorrow! Thanks

Thanks to your script i figured out where i was going wrong when writing to a file, i would use "d:\test.txt" not a double backslash.
Now i just have a permission error :-) but that's ok.

The double backslash is necessary  because a single backslash is a special escape character. See the Python documentation for more info.

You can export your planes as FBX. In the export dialog, tick Selected Objects and switch the version to FBX 6.1 ASCII.
Now you have a simple text file, although with much overhead. In there you will find a line similiar to this:
Vertices: -1.000000,-1.000000,0.000000,2.000000,-2.000000,0.000000,-1.000000,1.000000,0.000000,1.000000,1.000000,0.000000
I got this result from exporting a simple standard plane where I moved one edge. The vertices are all in the order x,y,z. With search and replace in your text editor, you could delete all 0.000000, which are the z-values. They are all 0 and thus easily to distinguish from x- and y-values, since all your planes are on the x-y-plane.

Thanks for your suggestion, while this does get the data i need into a text file, the overhead and the inclusion of the Z values would wreak havoc on my subsequent programs that require the polygons, and adding another script to clean it up the FBX seems like a doubling of work for no gain.
I would much rather have a single python script that outputs the vertices into a text file.


text:
Constraint the camera to look at an object
In my scene I have a camera sitting at the origin. I would like to contraint it so that it always looks at the center of a given object. But the camera should not change its position.
I found some answers using a "TrackTo" or "LockedTrack" constraint but could not manage to make it work.
Could I probably use a Driver for this and if yes, how can I adjust it?
Thanks in advance!

source: Stack Exchange

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

sort: votes


text:
Curve Editor — Move 2 Handles the same time
I am quite new to blender and started out to do some animation with shape keys. That is working quite fine so far and now I would like to make that whole thing a bit more vivid.
Therefore I would like to tweak the Interpolation curves in the Curve Editor, what is in principle working as expected, there is only one thing that bugs me. Please see the image below:

Marked in red are two curves which are somehow identical in shape, but each of them is for a different property, what is just as wanted.
I would like to edit both curves, so that they stay identical. I can select both anchor points and drag them around, but I cannot select two handles at the same time.
Is there any way to do this? If not, how can I copy the setting of one point (anchor and control points) from one to another?
Thanks in Ahead!
[UPDATE]
After some hours of trying and searching the web I just came over drivers, as mentioned in the comments. That lead me to what I am after and gave me ever more flexibility.

Exactly what a driver does, choose one property that you are going to keyframe, and drive the other(s) with it.

I might have missed something, so is it not possible to edit these two curves at once, so that they stay equal in shape?

Added as a comment as it doesn't answer the question re handles which I'm not sure about, rather suggests another approach.

which? Let me know please…

Have you tried selecting them with box [B] or circle [C] select?  You can't select the handles this way but you can select the keyframes and use [S] and [R] to move the handles.

[B] did not work for handles, but for the anchors

It worked for what I was trying to do, which it was adjusting the fade of several curves at the same time. I think you just forgot to mention that you had to use the circle selection tool (shortcut C) in order to use middle mouse button to deselect. I just thought this hint would help other people. Thanks for the gif!

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

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

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

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

Thanks for that answer, it works as described. Unfortunately it could deliver the result I was after…

Posting for posterity, but mass, deselecting can be done more easily (at least now).  First, drag a box in the graph editor to select the keyframe points you want.  Then Ctrl-drag a box to deselect the points and handles that you don't want to move.

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

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


text:
Boolean Modifier Red Won't Work or Behaves Strange
I'm using Blender 2.73 on MacOS.
I've been happily blending away for months since the last time I had a prob with modifiers. But not much issue lately. Suddenly I had a crash (I was subsurface-modifying and it went into a perpetual spin that wouldn't finish.)
I lost some work, but picked up from my last save again and kept going.  As I came to the steps where I need a few boolean difference operation, I couldn't use it anymore - it's shaded red (see pic) and it failed to apply.
I added a cube and tried with that, and it failed to apply also.
I created a new empty file (below), and it also shows boolean as red, and when I try to apply, it does strange things. Intersect instead of difference etc.

Here's a copy of the file for download - just two cubes. Can you see some setting that's precluding me from using the boolean modifier or making it behave weirdly?
Question then is what does the red shading indicate? I searched the docs for "boolean modifier" and "red" and can't find any explanations. Googled wildly without any success.

can you share the specific geometry that refuses to boolean?

Yes - here's the link https://www.sendspace.com/file/64z8na   Verified again that it's a closed object. I was trying to punch the two smaller blocks out of the large flat one.

It's red because there's no object selected to Boolean with. When I picked the other Cube it worked fine.

The "Cannot Execute Boolean" is because of this beauty:

In this case the geometry was obviously a bit untidy. But it can happen that this similar situation happens at much smaller scales, which are less easy to see without zooming in. In this case the manifold check in the 3d printing tools doesn't pick it up either.

Aha!  I didn't inspect the geometry close enough for weirdnesses.  Result of over-doing my bevel.  Thanks for sleuthing that out for me.  :)  Prob worth updating my version too, as recommended.

If you aren't updating Blender every 2 or 3 weeks you are doing yourself a disservice :)

Red color.  The Boolean modifier needs you to specify the other cube for [OBJECT] in the panel.  The red means you have not satisfied the requirements of the panel for it to execute. User Error. If you want A intersects B. You must specify B in the panel.  Simple problem now that someone else looks at the image.
For the other first failure. Make sure that both objects are closed objects.  Start with simple closed objects and then progress to more complex objects.

It's possible I never noticed the red colour to the modifier until I started having a problem - so that's poss a red-herring (:/) Wish that info were in the docs.   Regarding the failures though, the object is closed ( I do a 'select non manifold' and can verify that it's a closed object to be certain. I also checked all normals which are fine.

@RossGK consider video tutorials on a video website as part of the total COMMUNITY documentation.  Every person here has wisely seen or created video tutorials.  Blender.org written documentation is not going to receive any awards.  Its unlikely that a software writer will provide high quality documentation.  I digress.  Perhaps you and I can create an organization to give documentation awards to Blender.org.  You probably would want to learn the basics of hammering by watching someone hammer first.  The fine points can be discussed here at Blender Stack Exchange.


text:
How to make a material with thickness dependant transparency
I want to recreate the material of the icing on these donuts; transparent at thinner areas and opaque at thicker areas. I fiddled around with transmission, alpha, and volume absorption, but couldn't recreate it. Any ideas?

Have you done any reserch? https://blender.stackexchange.com/questions/72495/create-a-gradient-effect-like-for-coffee/ https://blender.stackexchange.com/questions/36183/get-object-width-in-cycles-as-value/ https://blender.stackexchange.com/questions/35726/fluid-in-a-glass https://blender.stackexchange.com/questions/76081/honey-shader-in-cycles https://blender.stackexchange.com/questions/77215/suspended-particles-inside-a-material-procedural

are you using Cycles or Eevee?

Im using cycles

I could get the effect i want via principled volume, but i was unable to output a white color via that node. Bumping up the volume bounces under 'Render Properties'> 'Light bounces' > 'Volume' fixed the color issue as far as i can tell

Does the transparency actually have to match the depth, or are you just going for the appearance of it? If you just want the look, you can simulate the depth (bumps and valleys) of the icing using a Noise Texture as the basis for a Bump (Normal) map, and then use that same Noise texture as the basis for the "translucency mix". That way, the simulated "low (thin) areas" have a higher degree of transparency, making the icing appear thinner in those areas, and vice-versa:

The transparancy has to match the depth, im looking for an effect similar to if not the one volume absorptions produces, problem is that node butchers my colours, and idk how to get the same effect on the donut.

Omar, if you use this option, you can still match the depth! Just add a displace modifier to the icing mesh, create a new texture, go to texture settings, and add a noise texture from the internet. Then, in Chris' answer's node setup, use the EXACT same noise texture as a image node instead of his Noise Texture. This way, the noise texture will match the thickness/displacement!

In Cycles you can plug a Principled Volume into the Volume input of the Output, set its Density to the good value, also mix a Transparent node with a Glossy. You can also add a bit of fake noise on the surface with a Bump plugged into the Glossy:

Density nodes consistently ruin the color. the object becomes grey instead of white

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


text:
UV Islands should be identical but are different when unwrapped
I've unwrapped a model and 2 islands that should look the same don't. I want to straighten the left side out to look like right side island. Any tips on how I may go about this?
I have UV Tool kit and UV Packmaster 2 add ons if thats any help.
Thanks.

Hello :). The first island has some stretching visible, you probably didn't mark all the same seams before unwrapping.

Thanks I'll take a look :)


text:
Show seams only
Is it possible to hide the model but still show the seams? I have a complex model that I am trying to UV map but am struggling making both sides symmetrical. So it would be useful to see only the seams to check its symmetry.
Thanks

I've fixed this by selecting the lines of a model I want to mark as a seam and then shift - h to hide everything but the selected lines. I can then easily check to see if I missed anything.
To select check seams once they are done, select a seam and chose select similar>seam from the select menu then shift - h to hide all but the selected seams.
Its ironic that after struggling with this for days I discover a workaround after posting.

So often the way... :D


text:
Animation doesn't show up in render. Issue with image sequencer
I broke a glass in blender and initially I got the renderer animation in image sequence, later i did few changes in animation and now the renderer is not giving the animation in image sequence. Only the 1st frame is getting repeated. Kindly help solving the issue immediately.

Do you have any animation clips in the video editor? If you do, remove them, and try rendering again.

show us your blend file


text:
How can i get this drag and drop mode/operator?
i have add addon that imports objects, it needs to add the object based on normal direction like the asset browser.
i have tried using:
bpy.ops.object.transform_to_mouse(name="building 222", matrix=((0, 0, 1, 0), (1, 0, 0, 0), (0, 1, 0, 0), (17.3634, 11.8099, 20.2586, 1)), drop_x=708, drop_y=410)

but it seems the matrix is from the drag and drop operator, the above line just prints {'FINISHED'}
thanks

From my tests it seems the object needs to be selected for the operator to work (and context override doesn't work).

how did you get it to work, when the object is selected

A default cube, named "building 222" moves when selected and your code is pasted to console, so I understand it as working.

when you use the asset browser and drop any asset into the viewport, you enter a mode that shows a grid that snaps and reorients its self to face normals, i want to get that mode


text:
Need help adding a button in the node editor using gpu or bgl
what i have sofa just lets me draw a rectangle in the viewport,
need a button in node editor thanks
import gpu
from gpu_extras.batch import batch_for_shader

vertices = (
    (100, 100), (300, 100),
    (100, 200), (300, 200))

indices = (
    (0, 1, 2), (2, 1, 3))

shader = gpu.shader.from_builtin('2D_UNIFORM_COLOR')
batch = batch_for_shader(shader, 'TRIS', {"pos": vertices}, indices=indices)

def draw():
    shader.bind()
    shader.uniform_float("color", (0, 0.5, 0.5, 1.0))
    batch.draw(shader)

bpy.types.SpaceView3D.draw_handler_add(draw, (), 'WINDOW', 'POST_PIXEL')```

Editor windows are composed of several region and how you add a button depends on which region you want to add it to.  For instance, if you want it in the header you would add a menu entry; if you wanted it in the sidebar; you would add a panel to the side bar and place the button in the panel; et cetera.  But you don't use gpu or bgl for buttons.  Which part of the editor do you want the button in and what do you want it for?

i need buttons that are always visible in the node editor without first pressing N key, it seems the onlyway to do that is using GPU module

You can stick them in the header; the bar across the top or bottom that has the menus. Will that serve your purpose?


text:
Becoming desperate over Boolean with complex objects - Research Heart Surgery
Since I'm still learning, I tend to figure out most by myself. For days now I'm failing at performing some boolean operations that I need for my research in pediatric heart surgery:
I've attached a file for you where you'll find:

A model of the blood-filled structures of a heart.
The surrounding shape of the heart muscle

What I'm trying to achieve is to carve Model 1 out of Model 2, then to join Model 1 + 2 and then to thicken the walls of Model 1 where it's not touching Model 2 by 1mm to create the wall of the blood vessels. And finally to print the model.
At the end the now closed ends of the vessels should be cut open to enter the interior with surgical instruments.
I've tried all imaginable possibilities by now but end up always with a huge mess. Meshmixer doesn't help much as well.
Anyone out there that doesn't mind explaining me how to do that properly?
Thanks a lot!
https://pasteall.org/blend/b39ff13400874d408795da0dc9afe454

Duplicate the blood vessel object and then hide it by pressing H (This will used later). Select the unhidden blood vessel object and go into Edit Mode. Select all vertices by pressing A, press Alt+S to Shrink/Fatten (This is different to normal scaling) and press 1 to fatten by 1m. (This is actually fattening by 1m in this case because the unit scale is off my 1000x, so 1m is actually 1mm).

Add a Boolean modifier on the blood vessel, set it to Union, select the muscle object. Set Solver to fast.

Unhide the extra blood vessel object. Select it and go into edit mode. Select the vertices near the ends of the blood vessels where you want the holes to be and pull them through the fattened mesh. Repeat for all places you need holes.

Select the fattened mesh with the Boolean modifier on it. Add another Boolean set to Difference. Select Fast as the Solver. Select the smaller blood vessel object as Object. The object with the modifier stack can now be exported and sliced for printing. Make sure when exporting, you have only this object selected and have the Selection Only and Apply Modifiers options selected in the export menu.

very nice animation benus!

That's actually down to the ChituBox slicer, if anyone was wondering.

what you need to do is start by remeshing both objects with the smooth and smooth shading option on.
Then do the boolean difference.
then take the object you want to make hollow and put the solidify modifier on it.
now delete the faces which u dont want like the blood vessels that are covered.
add a glass shader
here u go
https://pasteall.org/media/8/a/8ad4c7264c55ac5784d421a42541f44f.blend
hopefully i understood u correctly. if you need more help write me an email. zenbauhaus@gmail.com


text:
Transparent motion blur in Cycles
I'm rendering an animation with motion blur (Shutter: 0.7) of a flyover of a bridge with moving cars on it.
The problem is that the cars get transparent as seen in the image. Can this really be the correct behavior or is something wrong with the motion blur implementation? And if that is the cause, any idea on how to fix it?
The train is also moving but is shown correctly. The cars are made from a particle system, that renders a group of cars, while the train is an actual model.

Second render without Motion blur:

Edit:
I did some further testing and here's the result: motion blur is broken together with curve-guide.
I've created an emitter emitting one particle shown as a box (with the group option). There's a curve-guide guiding the particle. To the right, there's a box, animated by hand with keyframes to follow the motion of the particle. They have almost the same speed. Clearly it messes up.

Now I would like to know if there is a another way to make my cars follow the road. I could try a lattice which doesn't have the rendering issue, but it's not as precise. As suggested by gandalf3, I could use the keyed particle system, but I can find no way to get a uniform speed along the way.
Lastly, should this edit be in another question? I'm not that familiar with the Stack Exchange norms.

I doubt that the motion blur would be the cause. Have you rendered with motion blur turned off? Are you compositing the final image? If your willing to share the blend file it may help someone find the issue.

It could be the motion blur: In case the particles disappear (dead or unborn) in the motion blurs sample frame-range, you could get a slight transparence.

The motion blur is definatly part of the problem; here's a render without:
https://www.dropbox.com/s/asrxlwkv3h5eico/frame270.png
Also, the particles are not disappearing for more than 100 frames after the rendering shown, so that can't be the issue either.  I am compositing, but the problem is in the raw render. unfortunately, I'm not able to share the file.

And before the current scene?

And the vehicles in the still image have a totally different position. Is it possible that the movement of the particles is too fast?

The particles are created also long before the shown frames. The two pictures are ~50 frames apart, so that's why the cars have moved. Besides that, the cars are moving at approximately at the same speed as the train and the camera, so not insanely fast.

Does the problem still occur if you set Shutter to 0? What if you gradually increase it?

@KåreWedelJacobsen Is it at least possible for you to share the material node setup for the cars? Or maybe screenshot of your compositing setup? As it is, there are many things it could be. Right now we can't do much more than speculate.

I'll post some screenshots tomorrow, when I'm back at my work-pc, but I think I have narrowed down where the problem is, see my comment to user320's answer.

@Wedel Adding info about why the issue happened is fine. It is better to keep each post as one question, so you would be better off with a new question of How can I animate cars moving along the bridge?

It seems I have found a solution now.
In the Particles-tab there's a Cache option. If the particles are Baked they render properly even though there is a curve-guide affecting them.

To expand on user320's answer,
It seems that if you animate your emitter object, the particles will be motion blurred with the Emitter motion.
Presumably, this will be fixed with the addition of Deformation motion blur.
Possible solutions depend on the requirements of the car motion, but basically a method that does not require moving the emitter should work. (Perhaps a boids or keyed system)

I didn't know about the keyed system, so I'll give it a try.


text:
How can I make my cloth sim show tight folds?
I'm trying to achieve visuals like the following:

Unfortunately, this is the best I've got so far...

I'm using the 'pinning with hooks' method seen halfway down this page - I'd let the cloth drape itself naturally over the figure (which looks pretty close to my target!), but I want to have the objects below the membrane to rotate and move. Hence the pinning.
If there's anybody out there with experience on tight cloth folds, I'd really appreciate some notes.


text:
High-poly normal map wrapping unevenly onto low-poly mesh
I am having a problem wrapping my high-poly normal map onto my low-poly mesh. It seems that the coordinates of my normal map are not correct or distorted. I baked them exactly on top of each other, set UV as my mapping coordinates, and did all the necessary procedures for baking a high to low-poly normal map. On the left is my high-poly mesh and on the right is my low-poly mesh. What is causing this problem?

try to recalculate normals : in edit mode, select all and Ctrl+N

it could just be that you have the normal map set to 'Color' in the node editor.  Once it's baked, you should change the node to 'Non-Color Data'.  If that does not fix this, you can try uploading the model to PasteAll.org and paste the URL here.


text:
I am trying to render two renderlayers, but the second layer black background is on top of the first layer
So, I followed some tutorials and modeled planet Earth and an asteroid. Because it's two different compositions I separated each one in a different render layer. But only the asteroid layer is rendering properly, and the planet is not showing. I don't know what I am doing wrong, so I think is easier if you guys check it out if you can.
Here's the .blend
Any help is appreciated, thanks :)
Blend with packed textures

@poor The link is working now

@ifsando Your .blend seems to be working fine for me.. Note that your compositing tree doesn't combine the renderlayers, but aside from that I don't see anything amiss (there are some missing textures, but I imagine that's just because they weren't packed with the .blend)..

@ifsando the same here as gandalf3

Oh right.. Didn't think about it. Here I think this should work:           https://mega.co.nz/#!QpRziQ5Q!UyYsjiN4h7ZVF9IPDNIPnXKFWS5S5TVAKYc6k766nQE                         The asteroid layer has a black background that is rendering on top of the earth layer after composition. In this file I tried to fix that by putting an alpha over node. But it didn't work

The lens distortion node is making all the pixels in the asteroid layer opaque so that the alpha over covers up the earth layer.
The solution is to do the lens distortion after combining the layers:

The lens distortion should be done after combining layers anyway, as with a real lens everything in the image is distorted.


text:
Can I manually edit the points along a path or curve in the blender UI?
I create a curve or a path in Blender and can clearly see that it is defined by a set of points. What I want to do is manually edit the position of one of these points, instead of dragging it. That way I can ensure my curve / path is 100% accurate in terms of direction and length.
I am new to Blender and this community, so forgive me if this question is stupid. I have searched google, this site, and the blender manuals and have found nothing.
How can I do this in the Blender UI?
My properties menu looks like this:


text:
Smooth Mesh Modeling
What is the best method in Blender to model the area in the red circle below?  I have tried a number of methods (deleting faces, using F to join edges, etc) but am not completely happy with the results.  The meshes need to remain clean and relatively low-poly.  Any advice would be appreciated...
Thanks,
Jeff

Here you can see what I'm experimenting with, attempting to join a cylinder smoothly to a cube.  I've taken some edges from the cube, and attached them to the cylinder.  However, when I add the Subdivision Surface, the faces "buckle in" somewhat (Bottom Image)

Which particular part of the process causes you trouble/you are not happy with?

Hi Ray, thanks for your response...
Well, I'm not happy with the result...the mesh looks a little awkward and not perfectly smooth in the end.  The joining edges part works out very easily, but when I apply the Subdivison Surface, I'm not happy with the look.  Is the above method the best way to create this sort of shape, or is there a better way?
Thanks,
Jeff

I suggest adding pictures of what you have so far by using the [edit] link under your question so people might be able to diagnose why adding a Subsurf to your model might not be working so well.

Hi Ray, are you saying that my method above is the best way to achieve this?  Just want to make sure I'm not overlooking something obvious! :)

I'm not currently saying anything about the method, I just think you need to show in your question what you've got so people will be able to help you better, whether that's improving your current method or suggesting a new one.

Hi Ray, I added some images for reference...

I would also try joining some basic shapes with booleans, to get a general shape, then either adding bevels to and/or retopologize the result

In that example I worked only with the cylinder and extended it out and squared it off to look like a cube edge .. But if you want to attach the cylinder to a separate cube and want it to join it properly, you have to match vertices.
Remove the faces off the top of the cube and then add or remove vertices to the cube along the edge so both the cylinder and the cube have the same number where they meet. Then you fill in the faces, bridging the gap .. I have an example. The cylinder has 32 vertices along the edge and the cube began with 4. I connected the corners to the cylinder using edges, that's 4. THen I added 7 vertices on each side of the cube. That gave the cube 32 as well (7x4 +4). Then I began filling the gap.
If you look at bolts in the add-on 'bolts' you'll see they are made the same way basically where the screw part meets the head .. the cylinder is extended along the flat to the edge and the hexagonal edge vertices have to match the cylinder (ie top of the screw).
Also I have a quick example of attaching two shapes very roughly similar to your die cast example. I attached them  (this involves some editting where they meet) and THEN I worry about extending the flat area which I started to do. Hope it helps.
Oh ya, I saw the comment about retopo ... that's a good method too .. In essence it's joining various shapes and then laying over it a mesh you construct. You have know about how to lay meshes you build on top of objects which is what retopo is .. anyway .. good luck

Thank you for this very detailed description as well as examples!

Cylinder to cube .. well, the thing is I would maintain the cylinder geometry as it flattens out .. so would scale out one end a bit before I worry about defining the cube part .. Here's an example. See how the cylinder where it flattens out is still radiating circles .. then I square it off at the cube edges.

And ah .. I would take the same attitude to your other example.. model the shapes separately, radiate they out where they flatten so their geometry is not compromised, and then join them to each other manually.

I will give this a try, thanks for the advice!

How did you get your cube to match the geometry of the cylinder?

Would love to know how you're doing your "squaring off", that actually seems like a better way to go!

There's a trick for aligning vertices in a row. You can align vertices along any axis. To do it so they form a straight line along say the Y axis  .. select vertices, then hit S (for scale)  then 0 (zero) then X. All vertices selected will then have their X=0.

authors: Александр Косович


text:
Animation problem on rigged object after export
I am making custom models for mod in a game and am having a problem I can't figure out.
I rigged and made an animation it works good in blender, but after I export it and test in game the armature doesn't move the mesh.
Here's the blend file I saved. And don't mind the bad weighting, wanted to test it out first before finishing it.
Its for crusader kings 2. You are able to view models and animations using jorodox tool in google chrome. It only reads .dae files.

oh yes sorry, its for crusader kings 2. I checked and didn't see any tages. and you are able to view models and animations using jorodox tool in google chrome.  It only reads .dae files. https://chrome.google.com/webstore/detail/jorodox-tools/pmhbboeiannanamjandkhiakpaaoecoo?utm_source=chrome-app-launcher-info-dialog

Nvm, I figured it out. The model would only show the animation after i converted it to a .mesh format. But now I have another problem, my animations are only half a second no what i do.


text:
Compositing/render question
Im working on an project in which i modeled a stargate and a jumper (spaceship from stargate). I also have some video footage in which i want to place my models. The tracking and camera resolving is done.
Now i have on the one side the problem, that i want some tears/scratches on the ground where the stargate is grounded in (i tried a uv map on the ground (background layer) and created there one with some scratches but in the result there is nothing rendered) - so i tried it with a plane in the foreground cause i thought if the uv map is transparent except of the scratches.. doesnt worked as well. so how i realise this?
the other problem is, that the spaceship should come out of the stargate - so it is animated but should "appear" (like that https://youtu.be/tNSiS9wN-GI ) the problem is, that i dont know if i can use this that easy cause he uses dynamic paint and a node to check greater or lower 1. may you guys have an other idea.
i use cycles renderer, so a lot of solutions i found doesnt work :/

You should keep to one question at a time. The ground scratches are a different problem to the emerging puddle jumper.

To animate the puddle jumper coming through the stargate you could use a boolean modifier to hide it behind the event horizon.

Create a cylinder big enough to enclose the puddle jumper and place it behind the stargate.
Add a boolean modifier to the puddle jumper and select the previous cylinder as the object and set the operation to difference.

Disable the renderability of the cylinder so that it isn't seen when rendering, or you could give it a transparent texture.

Edit:
The easy way doesn't always work. As the boolean modifier doesn't always give a good result with some meshes, it can be better to do it in compositing. By giving the hideout mesh an object index you can use it to create a mask in the compositor. This answer explains using an object ID to composite multiple objects together.
First you want the background to be transparent, by enabling transparent in the film settings (part of the render settings).

Enable Object Index in the render layers.

Then give the object an index number.

Now in the compositor you can add an ID Mask node and connect that to the IndexOB and set the index number to match the number you set for the hideout object. The little box in the mix node will combine the alpha from the render and the mask.

thanks so far. your solution seems quite easy. but i still have some trouble. http://blend-exchange.giantcowfilms.com/b/2018/ in this file i have my jumper and the hideout object. the jumper is hidden at the start but when it starts to apear the whole jumper is apearing.

Seems the boolean doesn't like your model, there is a variation to the boolean modifier in 2.78 that is better but it is still glitchy. compositing will be the way to go, thought someone else would have answered with that by now.

wow just wrote an comment, that i downloaded 2.78 and tried it. and it doesnt work. and now i see your edit - thanks a lot!! i try it tomorrow cause today i have no time. but rly thanks

used your solution. works great so far - just one (little) issue. i have a bachground layer in which shadow should be casted. and now i get the shadow. https://i.sstatic.net/W5VVk.jpg i tryed to disable the shadow of the hideout object but it still renders the whole shadow of the jumper https://i.sstatic.net/vVZ0A.jpg . one other strange thing is that sometimes i get as result something like that https://i.sstatic.net/NxBkp.jpg - hope you can help me out. if u want i can add the blend file

Also use the mask when you mix the shadow - I think the hideout would need to be bigger so that it masks the shadow behind the gate and don't enable the box next to mix type. Probably easier than trying to control the casting of the shadow.

i tryed to use the mask with the shadow - but it doesnt work that well (more like it doesnt work - no change) maybe i mixed it at the wrong place. i also think that i get trouble with the shadow of the stargate? will it also be masked out? i have added an image of the node editor: https://i.sstatic.net/XvbY6.jpg

Your masking the shadow too early, I expect the extra shadow is the AO behind the gate. After you mix the shadow and AO use the mask to cut that part out behind the gate before you multiply it onto the background.

sorry that i have to ask you to explain/show it a bit more detailed. i tryed it with mixing nearly everywere but i didnt got my expected result. more or less i think it isnt rly possible cause my layer contains at the beginning bothj shadows and i think i cant treat them separately?! I ask only reluctantly but could i try to do it in the blend file: https://drive.google.com/file/d/0B42TgHX-y392a0szVWU1c0YtWUk/view?usp=sharing  (blend exchange didnt liked this file..)

https://i.sstatic.net/xJ3K5.jpg

authors: Артер Вакилов


text:
How to make a 90s Cel animated look in blender

I'm trying to created the Cel animated look in blender but with 2D animation beside, mimicking the style from the 80s and 90s I feel like theirs some nuance to it that I need to set up nodes for. Theirs also something about the inking that just a regular black line doesn't capture like the colors painted behind it have some influence how could i recreate that?
Im also trying to add a super faint drop shadow to the main character against the background which I think could help, but I also don't know how to do that.

I'm new to blender and don't really know how to work the nodes super well so any help would be really appreciated.

Learn the nodes!  docs.blender.org -> Render Engines -> Materials. Also, this question has been asked a lot of different ways before now. Check out the MP-Lab addon on GitHub as their anime characters implement this fairly well.

I mean professional anime artists in Japan already have a hard time making good looking 3D anime, I doubt you'll achieve anything like that with 3D modelling Blender. Cinema 4D has a bit more toon shading options, but realistically, learning 2D animation IS the way to go. You can then use Grease Pencil in Blender to draw 2D characters.

I came across this video last night and this question today. If you haven't found or created a solution, hopefully this helps:
https://www.youtube.com/watch?v=ZsvZsVPhTVs

Please include relevant details in your answer. Link-only answers are less then ideal, because the content could become unavailable or change to when the answer was posted.


text:
Image planes greyed out when opening blender file
Im working on an animation and ive imported the background and props as plane pngs with transperancy but when i reopened my file everything was greyed out. I keyed the movement of everything and I really don't want to have to reimport and re-key everything. How do I fix this?

This looks like the Viewport Shading Mode in the top right corner is set to solid:

When you reopen a blend file the Viewport Shading Mode is always set to solid and nearly everything is displayed as grey mesh.
Change it to Material Preview or Rendered Mode (the both right buttons of the screenshot). Then you should see the textures again.


text:
Red Line at bottom of video sequencer gone in new update

Hey guys their used to be this red line at the bottom of the video sequencer that isnt there anymore in the most recent blender update, do you guys know how to get it back? it was super useful for just scrubbing through and making the animation render quickly.

You switch the drawing on in the View menu(Check: Show Cache and Final Images):

You select, what you want it to show here:

And if you want it to prefetch, you check that here:

Wow thank you so much!!! is their anyway to have it so it automatically has the cache final images on all the time, when i open a new file i have to go and manually do it again

If you set it up the way you want it you can go to: File Defaults Save Startup Settings. And it'll have the settings you want each time you start a new project.

@ValentinoValentine If your question has been answered, please mark the answer accordingly.


text:
Selective ray visibility
In the Object Properties tab I can choose the ray visibility of that object.
In other words I can choose if that object is visible on camera, if it casts shadows on diffuse shaders, on glossy shaders, and so on.
Is there a way to choose on which objects it will have ray visibility?
Maybe a trick using layers?
What I want is an environment HDRI that is visible reflected on a glossy object A, but not on another object B.
EDIT: I saw the question was marked as a possible Duplicate, but maybe I need to explain my question in a better way.
I don't need to remove the environment reflections from the glossy objects.
Both the object A and B have a glossy component in the node tree but I need:

the object A to reflect/refract the environment map with all its material components (glossy, diffuse, glass, etc...);
the object B to NOT reflect the environment map with any of its shaders.

I can choose which kind of shaders an object casts (in the Ray Visibility panel) but not on which objects it casts it (and that's what I need).

Possible duplicate of Cycles: How do I exclude the Environment Texture from reflections?

I edited my question to explain the difference.

Cycles being a physically based rendered is not adequate for these types of intricate relations

Possibly this could be done in the compositor... but that depends on how it should work with reflections of those objects... for example, if object B (which reflects the environment) is visible in the reflection off of A then should the environment be visible in that reflection of the reflection? If not then I think I have a compositor solution. If the environment should be reflected in that reflection of the reflection then I don’t think this is possible in Cycles (same goes for the opposite - A visible in reflection of B not showing environment).

Ok! Interesting... Actually I don't mind about the reflection in the reflection, so... could you tell me your compositor workaround? I'm looking forward to try it! :-)

One possibly solution to to render the image twice - once with the Envionment and the other without the environment - and then use the compositor to combine the images, using the render without the environment for the chosen object.
To demonstrate, consider the following scene :

The cube is set to emissive (to reflect in the surfaces of the other objects), Suzanne is reflective, as are the two spheres. The left-hand sphere will be the one that doesn't reflect the environment; to indicate this, its object Pass Index has been set to '1' - the other sphere (and all other objects) have been left with Pass Index set to '0'. The environment has been set to an HDR image.
In order to render the scene twice, we can add an additional render layer :

One render layer should have Use Environment enabled and the other should have Use Environment disabled. Ensure to enable the Object Index pass - this will give us access to the object Pass Index in the compositor.
Setup the Compositor nodes as follows :

The IndexOB is used to generate a mask to pick out the object set to Pass Index of 1 (the left-hand sphere). The two rendered (one with and one without the environment) are mixed together based on this mask so that the 'without environment' image shows where one sphere is and the 'with environment' shows for the rest of the render. The Dilate/Erode node allow you to control the blending at the edges of the transition to remove any harse artifacts.
This produces the following result with the left-hand sphere showing all reflections except the environment :

Right! That's exactly what I needed! Thank yout very much! :-)


text:
Is there a way to exclude an axis from the solidify effect?
Lets say I have this object:

and I want to solidify it to 3d print it.
I would like to have a constant thickness on the XY plane.
I mean: I want that every 3d printed level has the same thickness.
If I use a Solidify modifier wiht a certain thickness (let's say 2.5mm) It works with the normal of every face, so it works also on z axis and the thickness is not always 2.5mm if measured on XY plane:

If I go to edit mode and extrude the faces I can't find a way to get what I want.
Is there a way to do it?
I don't need it to be with Solidify. It can be done with Displacement, Animation Nodes, Python or anything else. I just need to do it in a smart and quite fast way.
Thank you all in advance!

If I'm understanding your question right, then this option doesn't exist because excluding a specific axis could result in a non-manifold mesh or overlapping geometry.

That can be extruding along X/Y only? Or some meshes are too complex?

The problem is to keep the same identical (and I want a specific value) thickness on all the mesh.

so extrude first, but don't move, then push/pull the distance you want (with no z)

You can do it in two steps:

Extrude, but don't move E then RMB
Then push/pull using shiftZ to avoid z displacements

"Push/pull" is available in the tool bar (alternate from shrink/flatten) or via menu "mesh/transform/push pull".
Though, you'll have to tune the distance with the mouse as the operator panel does not allow to choose the concerned axis.

It isn't what I need. I need a constant thickness along all the object and I want control on that number (the thickness).

This doesn't work for me at all.  Perhaps it's a Blender 3 thing.  If I hit E and then RMB, nothing has happened.  RMB cancels the extrude.  No additional set of linked faces has been created and I can use push/pull on.


text:
Why are modifiers not applied to child objects?
If an object has one or more children or other descendants, you would expect that when you apply a modifier to that object, it would apply to the descendants as well. At least for the Array and Mirror modifiers, this would be extremely useful.
However, this does not happen. Empty objects are recommended for grouping objects together, but they cannot even have modifiers -- there would be no point, unless they could be applied to the children, but this doesn't work even for normal parent objects.
I tried to report this deficiency as a bug, but it was immediately closed as "Invalid", by somebody who apparently didn't bother to read it.
https://developer.blender.org/T44150
That bug report has some examples attached, of a situation where this ability is in fact rather necessary -- empty parents are being used to apply coordinate transforms, rather than grouping objects, but this then prevents the Array modifier from being used in the necessary way.
Is there any rational reason why at least the Array and Mirror modifiers cannot be applied to child objects, at least as an option?
Other people are asking the same question:
Applying array modifier to multiple items
It's been suggested that my question is a duplicate of the one above. They are certainly related to the same issue (which is why I included the reference in the first place). However, the question that person actually asks is "What am I thinking wrong?" -- as if he's misunderstood the situation. I don't think I have misunderstood the situation, and the question I'm asking is why at least the Array and Mirror modifiers don't work in the way a lot of people would expect.

as have been said before the modifiers work on the geometry level (they effect mesh which is only a part of the object ) there is no hierarchy (parent child ) on this level ,so you should try linking the modifiers or use drivers

There's obviously a distinction between the part of the mesh which came from the children, and the part that came from the parent, or the modifiers wouldn't stop there. What's needed is for this distinction to go away, and for the modifier to be applied to all of the mesh, regardless of whether it came from the parent object or its children.

possible duplicate of Applying array modifier to multiple items

Your bug report was closed because the modifiers are acting as expected, so there was no bug. Of course, you and others might want this feature and not understand why this feature doesn't exist, but the bug tracker would not be the place for that. Unfortunately, I cannot give a solid answer as to why it hasn't been implemented.

@RayMairlot should we close this if the duplicate doesn't have an answer ?

@Chebhou I have retracted my vote. Marking as duplicate should mean the target question already has a suitable question, which in this case, it doesn't.

Apparently modifiers AREN'T working as a lot of people would expect, in relation to child objects, because there are a lot of questions here asking how to accomplish something like this. Mine is just the first to explicitly ask why the Array modifier can't be used for this purpose. For many projects, if something works in a counterintuitive way, and is less functional than it obviously could be, then that issue is made the subject of a bug report. If that's not so for Blender, then what is the appropriate venue to point this out?

Where does one formally submit a feature request?

I'm voting to close this question as off-topic because it is a featur request

This is just not how modifiers are intended to work.
Perhaps it's just me, but I never thought of modifiers being applied to child objects. Indeed, this would seem rather strange to me.
But why?
Modifiers are another kind of datablock which can be added to objects, much like materials or constraints.
Yet neither materials or constraints are applied to child objects, as this would be quite limiting. Imagine if child objects always had the same materials and constraints as the parent!
If this was how it worked, parenting objects would be pretty much equivalent to joining them with ⎈ CtrlJ.
I think the same reasoning holds true for modifiers.
And for the record, I'm not convinced that your assertion that "modifiers don't work in the way a lot of people would expect" is correct. At least in the question you linked, I don't see anything that suggests to me that the OP was expecting modifiers to affect child objects..

To answer your question about arraying an empty, I think parenting is not the tool you are looking for. Group instances sound more like the kind of "compound object" you want, however it isn't possible to add modifiers to them. This is because modifiers operate on mesh data and not objects, and empties don't have any mesh data (group instances are empties with dupligroup enabled).
Instead you could use a particle system or dupli objects to place objects along an arrayed face, e.g. like this.
Or of course you could copy the modifiers to all the child objects.

If you want to have light parented to an object that have mirror, it is impossible?

@softyodayoann Not sure what you mean? If you have a new question, it's best to start a new post (and link to this one if it helps provide context).

I found a solution by asking at the discord. Because light can't have modifier, you must add a location constraint to act like a mirror.


text:
How can I achieve a Kuwahara painted effect in Blender?
An example of this effect in action, and code for Unity can be seen here.
I'm somewhat new to shader coding and converting such work to Blender - I don't suppose anybody has any suggestions on how to accomplish the effect, or even where best to get started?
Thanks in advance!

Not a shader, reminded me I Bookmarked this https://github.com/MeteHanC/Python-Median-Filter  to make really noisy cycles renders oil painting-ish.

@batFINGER - Heyy, that's pretty interesting. I wonder how I could incorporate that with Blender. I'm a decent Unity C# programmer, but this is going a little beyond my knowledge. Thanks, though!

This has been added:
Summary:
The filter is used to reduce noise while preserving edges. It can be used to create a cartoon effect from photorealistic images.
The idea is to offer two modes:
Classic aka isotropic kuwahara filter: simple and faster computation. Algorithm splits an area around a single pixel in four parts and computes the mean of the region with the lowest standard deviation
Anisotropic Kuwahara filter: improve the classical approach by considering the direction of structures of regions
https://projects.blender.org/blender/blender/pulls/107015

This filter is still experimental and you have to enable it, but in Blender 3.6 there is no “Full Frame Compositor" as described here: https://devtalk.blender.org/t/compositor-new-node-kuwahara-filter/29205


text:
How can I write a Python script to turn all normals on a curve to face outward…!
I’ve completed a few professional projects in C#/Unity, have worked through 90% of Microsoft’s Beginners Guide to Python, just started Python the Hard Way and have done a bunch of beginner Blender Python tutorials. I’m kinda starting to become familiar with Blender’s api.
I’m currently trying to build a network of interchanging, overlapping roads similar to the image below, which is then wrapped into ball of twine (but roads).

I’ve got one road working, as seen in this tutorial, then wrapped it into a ball with this answer.
The following is my current effort (file link here ):

You can also see this attempt as the blue ball in centre right of the following image (the other images are examples of my ultimate goal):

Here it is in 3D! =D

    Junction Test01014
    by reverendspeed
    on Sketchfab

My problem is I can’t seem to get the roads to all face outwards - the beziers are being bent somewhat randomly. I’ve been pointed in the direction of this control , but unfortunately I’d need to apply all my modifiers and then change the direction of the bezier control points independently - which obviously slows iteration to a crawl.
I’ve been trying to think of what kind of code I need to get all the normals oriented correctly - presumably:
I import Math and Mathutils
select all the curve points (bpy.ops.curve. select_all ( action=‘TOGGLE’ ))
and get a Vector3 list of the curve points
Going through each point, I’d get a Vector3 from the centre of the bounding box to the current point
Then set the bounding box quaternion to face the Vector3 direction…
…But I’m not sure how I’d do that. Or where I’d get the bounding box centre of a Curve - or if I can get that box after the curve has been twisted up by the modifiers.
If I try to apply the rotation, will this happen to the modified object or the underlying data? Would it be possible to undo this change when I want to unroll the sphere and edit the underlying bezier?
…
I’m really confused, folks. I think I’ve talked myself into a corner here, and I’m not sure where to start with the code. I’d really appreciate any suggestions you could make.


text:
How do i prevent a transparant image from repeating while exporting?
I am trying to export this 3D-laptop as a gltf-file. The model contains a png-image, see below:

I applied these nodes to make the png-image transparant on the laptops surface:

This are my export settings:

However, when I export the model, it comes out like this:

As you can see, none of the nodes are applied while exporting as a glb-file. The png-image is not transparant anymore and it is repeated. I don't know why this is the case. May you please help me?

This sounds like https://github.com/KhronosGroup/glTF-Blender-IO/issues/1113, which was fixed in Blender 2.90. Are you using a recent version of Blender? If so, and it's still not working, you may need to file a new issue there with the .blend file.

Thanks for your comment @DonMcCurdy. I'm using the most recent version of blender. I'll look into it and eventually make the issue. Thanks for your time and help! :)


text:
Problem with appending model after previous linking
Just starting to add external models to my scenes. I first tried linking a model but found that it wasn't really suitable for what I wanted since I couldn't apply changes or edit the model. I deleted the object from my scene and appended instead but still couldn't apply or edit. I tried with an older version of my scene by appending and I am able to apply and edit with no issue so it seems that somehow linking first has left something lying around that is causing me problems. I tried making everything local and that didn't help. Is there any way to see or "cleanup" these items that might be causing me trouble? (Or is it perhaps something else?)

Well, putting it into words helped me look for the answer. In the outliner, there's a drop down which lists orphaned data. I cleaned that out and then I was good to go. There's also a clean up->purge option in the file menu but I never got to try that.


text:
How to make search folder script in add-on preference?
How to make search folder script in add-on preference? I want to make a button to search a folder in add-on preference that can search resource files like the Extreme PBR add-on.

Hi and Welcome! Consider that the bare minimum here is to show some effort towards your goal. I'd recommend always add the current state of your code to your question, makes it way easier to give an answer. Please read: https://blender.stackexchange.com/help/how-to-ask, cheers.

The example given is just a regular StringProperty added to the AddonPreferences. Notice that the subtype of the StringProperty is set to DIR_PATH:

import bpy
from bpy.types import Operator, AddonPreferences
from bpy.props import StringProperty, IntProperty

class ExampleAddonPreferences(AddonPreferences):
    bl_idname = __name__

    filepath: StringProperty(
        name="Example File Path",
        subtype='DIR_PATH')

    number: IntProperty(
        name="Example Number",
        default=4)

    def draw(self, context):
        self.layout.label(text="This is a preferences view for our add-on")
        self.layout.prop(self, "filepath")
        self.layout.prop(self, "number")

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

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

if __name__ == "__main__":
    register()

Further reading

AddonPreferences in the Docs
How to create a Folder Dialog?
How to create a custom UI?


text:
why does adaptive subdivision misses its target dicing scale?
I've been using it for years, but I'm still confused. Here I have a 1 million poly scene, with a render dicing scale at 12 pixels.
So it should barely subdivide like 2-3 times, but rendering a crop image with a wireframe shader override, I see that some pieces are subdivided way more than what they should with 12px dicing scale, they seem to even have several subdiv per pixel...

So it took 6 minutes to compute the subdivs, 40 Gb of Ram, and filled my 24 Gb of Vram.
The strangest is that some objects are way more subdiv than others, althought subdivs shouls be in kinda pixel space, not object space.
Thanks for any hint on understanding how to keep these subdivs under control.

The strange thing is also than in viewport it does work nicely, subdivs are quite right as the meshes gets closer to the camera, but it works like this only if the viewport subdivs are set to Zero in the modifier, as otherwise it just brute force carpets adds whatever viewport subdiv you input instead of zero.
One reason it takes this much ram (40Gb) on this simple scene is probably that my objects are multi-users, so the adaptive subdiv turns them into single users, but most of the geometry is also just collection instances, and these are said to remain as instances in the documentation.

I just tried a dicing rate of 512px, that should prevent any subdiv, and I get the exact same result, 40Gb or geometry divided smaller than a pixel.

Doing more tests, on another scene a high dicing rate value does seem to prevent subdiv, so it might be a bug, but the minimum amount of subdiv is not 0, but 1, so all objects will be subdivided once at the minimum, even if they're super high poly and far away from the camera.
That might be why some objects are overly subdivided, they are already having faces smaller than a pixels, but the adaptive subdiv brute forces a minimum of 1 subdiv, no matter the pixel size of the object's faces.


text:
Cannot truly separate parts
There must be an easy answer to this. I'm in 2.82 and I made 10 dupliverts of a mesh on a plane with 12 points. I made them all real in object mode, selected all in edit mode, did P - separate by loose parts. I thought all was well as I could move each mesh independently and they each had their own origin. No trouble moving them independently etc. However when I go into edit mode for any of the 'independent' meshes, all the other ex-dupliverts are selected too! I cannot make them individual mesh-wise, even though they appear to be independent objects and are listed as such. I cannot even colour them independently. Any ideas?
Edit: here is the file.

Did you duplicate them with SHIFT-d or with ALT-d? In the second case they are the same mesh in different objects. Could you provide the file?

Hi mugnozzo, I did neither. I just parented the mesh to the plane and in the instancing tab changed from None to Verts or Faces. How do I provide the file?

You can from here: https://blend-exchange.giantcowfilms.com/

Ok! I gave an answer below and I edited your Question linking the file directly there, so all will be clearer to those who will see the question in the future.

The objects in the file you provided in the comments of your question are linked copies.

Select them all together;
press F3 (or spacebar, if in blender 2,79 or earlier);
type "make single user" to find the "Make Single User" command and click it;
in the popup that appears check "Object Data" (see img) and press OK.

Aha...many thanks, you are my hero. I had just assumed that the separation by loose parts did all that, obviously not. Cheers!

Glad to help you!

@mugnozzo Also available in Object mode under Header menu > Object > Relations

Right! I have the habit of using the search menu and I often don't remember where the commands are. :-) Thanks!


text:
Smoke too far from emitter
I am doing a simple animation with smoke emitting from a circle on top of the chimney, but it is not behaving like it should.
I have initial velocity off.
The tank is going from right to left(forward)

Could you be more specific? Are you telling that the chimney moves from right to left and the smoke do the same, instead of going up and remaining in his X and Y position?
Are there constraints/parenting anything else that could move the smoke domain?
Is there wind or other phisic simulation (except for smoke)?

Sorry for unspecific question. The smoke has copy location constraint with the hull. There are no other forces. The smoke behaves funny, because it generates on spot, which it hasn't reached yet for first half of animation, and than no smoke is generated for the rest of the animation.

Ok! Thanks for the details... I'm trying to figure out how can it happen but at the moment I don't find a possible cause of it. Would it be possible for you to share the file or (if you can't) to share a similar file that replicates the problem?

Allright, so i fixed it. Instead of adding constraint to the emmiter itself, i made it a child of another object with the location constraint. Works just fine

Good! Glad to hear it.


text:
How do I make text come out out of an impossible space?
I'm looking to recreate the text being generated by two horizontal bars in the Marvel logo https://youtu.be/fqxIrmdtLEk?t=25s (@00.25 secs)
I've already generated the text, just looking for a way to achieve the animation part of it.

What do you mean by impossible space?

I mean the horizontal bars generating the text, like in the above video.

Ok. UNderstood. Just give a look to my answer. Is it clear?

Basically you need a text and two couple of cubes.
First couple of cubes: you can simply create a single cube, mirror it (with a modifier, on z axis. Don't apply the modifier) and move it up (Z axis) in edit mode to see it's twin. In edit mode hook the whole geometry to an empty object.
Second couple of cubes: duplicate the first (they will be hooked to the same hook) and in edit mode scale them bigger to cover all the writing.
Convert the text into a mesh (ALT+C) and add a boolean modifier to it (difference with the second couple of cubes).
Now if you move the hook you'll get this:


text:
How to give specific color in specific area?
As shown below, the yellow color appears only on both edges, I have tried vertex color for the yellow, but I can't give another color in node editor.
Is it possible to give specific color on specific area?

Did you try to use a texture?

In the reference image, all the colours are blended with each other so I think that you will need to texture paint your model.

You can assign any one material to a face at a time. However, you can apply a uv image to the object. This will allow you to paint freely on the object in as much detail as you wish.

To assign colors you want to see in the rendering you should add them to the material.
You can assign different materials to different faces (but I would not recommend it in this case, cause you'd need to many faces), or use UV-mapping as shown below:

If you have an image with the map of the colors you want to apply to the object you can load it in the UV Image Editor, if not you should create it.
Then you need to unwrap (search on YouTube for tutorials about it; you'll find a lot of tips to do it) the faces.
Position/rotate/scale the unwrapped faces in the UV Image Editor (you'll see them if you are in edit mode and have all the geometry selected.
Use nodes to apply the (UV map as a texture for the object's material).

Look at this tutorial if you need help with unwrapping/texturing.

Maybe someone coming here years later will actually find use to this answer as no one actually answered this question in a way for a new person to blender can understand.

In object mode select the object you want to color.
Click on 'Material Properties' in your tab menu.
Click plus sign to add new material (this is just a base material don't add color.
Click the New button to add the material to the list of materials for this object.
---click assign
Click tab to go into edit mode.
Select the faces you want to specifically color.
Under material properties click the plus sign again
Click the new button again
Pick whatever color you want to add to the object under base color.
---click assign

If you think of a new user who doesn't know about using different materials, then I doubt this is helpful. Let's assume that someone creates a UV Sphere. The sphere comes with a default material in the first material slot. Now if he follows your instructions, he starts by adding a second material to it in Object Mode, then he selects some faces in Edit Mode and creates a third material where he changes the color to let's say blue and that's it... now he has a white sphere (default material) with two extra  materials white and blue on it which are not in use...

I see you edited your answer after my comment... but now you first tell to 'click assign' after adding a material in Object Mode, but that's not possible because the Assign button only shows up in Edit Mode. It is also unnecessary to say "this is just a base material don't add color" because a base material can of course be colored, too - why should it be white? I can see no value in your answer, one could only learn how to add two materials and maybe add a color to some faces. I would rather suggest to watch a beginner tutorial on materials and then it's minimum basics you can learn.


text:
Vertex Paint For Multiple Objects in Blender 2.8
How can I set my favorite color to all of the selected objects?
I can't attach my objects not at all.
The number of objects is high and I can not adjust their color vertex one by one.
Sorry for my bad english.
Thanks

The answer from Seyed changes the vertex color of all scene objects. This script changes only the selected objects:
import bpy
import random
import time

# start in object mode
bpy.ops.object.mode_set(mode='OBJECT')

# get selected objects
objects = bpy.context.selected_objects
for obj in objects:

    mesh = obj.data

    if not mesh.vertex_colors:
        mesh.vertex_colors.new()

    color_layer = mesh.vertex_colors["Col"]

    # or you could avoid using the color_layer name
    # color_layer = mesh.vertex_colors.active

    i = 0
    for poly in mesh.polygons:
        for idx in poly.loop_indices:
            color_layer.data[i].color = (1, 0, 1, 1)
            i += 1

    # set to vertex paint mode to see the result
    bpy.ops.object.mode_set(mode='VERTEX_PAINT')

this answer is for vertex color of single object

I converted it to multiple objects:
import bpy
import random
import time
# start in object mode
objects = bpy.context.scene.objects
for obj in objects:

    mesh = obj.data

    if not mesh.vertex_colors:
        mesh.vertex_colors.new()

    color_layer = mesh.vertex_colors["Col"]

    # or you could avoid using the color_layer name
    # color_layer = mesh.vertex_colors.active

    i = 0
    for poly in mesh.polygons:
        for idx in poly.loop_indices:
            color_layer.data[i].color = (0, 1, 0, 1)
            i += 1
    # set to vertex paint mode to see the result
    bpy.ops.object.mode_set(mode='VERTEX_PAINT')

Hello Seyed, I'm trying to use your script and keep getting this error with not much happening-
Traceback (most recent call last):
File "M:\3D\Jen_n_Tim\ShatteredMoon\ShatteredMoon_V2.Bake.blend\Text", line 10, in
AttributeError: 'NoneType' object has no attribute 'vertex_colors'
Error: Python script failed, check the message in the system console
Any ideas, or does it not work in Blender 2.92?
I tried with both mesh.vertex_colors.new() and mesh.vertex_colors.active
same result.


text:
More than 32 colours for gradients in Cycles?
I'm trying to use UVW generated mapping of a lot of splines and each spline has a lot of points. I want to add gradients of colors to the meshes and I hit a limit in Cycles ColorRamp. I can't add more than 32 colours for one gradient or I get an error.
Using python and any automated way, how is it possible to have a gradient with more than 32 colours that I can map on uvw coordinates ?
I already thought of breaking curves into many polylines but I'm trying to find a clean solution on the mapping side.
Follow-up, May 2015
This question arose from a previous one answered here How to colour vertices of a beveled curve mesh without converting to mesh?
I have curves with sometimes more than 32 points and I would like to color these points without converting to mesh I insist so UVW texturing is a good way to do it. However, the gradient node only accepts up to 32 colours.
So far, I solved the problem by writing an OSL shader that parses XML data.
The shader takes a value as input, let's say a voltage, and outputs a colour for it, based on a colour map. For scientific visualisation, it often happens you want to map some values to colours. So this answers your question gandalf3, the colours are representation of values of a certain unit and I don't think we can work on a pattern here.
What's important here is that a voltage at a given point is mapped to a colour, regardless of interpolation and all. Each and every voltage point will have its colour, which can then be interpolated with the following voltage point.
A voltage point can be anywhere along the curve so what matters is the ratio. 0.0 is the start of the branch, 1.0 is the end of it. Points can be somewhere within that ratio.
When we simulate voltages, the values change over time so the colours will reflect the state of each time step.
So here's the node setup:

The example below takes this XML data – produced on the fly while reading voltage values – and converts the voltage points to colours.
<report min="0" max="100" unit="mV">
    <compartment id="0" start="0.0" end="0.2" value="12.0" />
    <compartment id="1" start="0.2" end="0.4" value="25" />
    <compartment id="2" start="0.4" end="0.6" value="10.5" />
    <compartment id="3" start="0.6" end="0.8" value="38.5" />
    <compartment id="4" start="0.8" end="1.0" value="76.6" />
</report>

And the OSL sample code (took me a while to figure out this works!):
#include <stdosl.h>

shader xml_color_mapper(float Value=0.0, string Xml="test.xml", output color Color=(0.0))
{
    // The second parameter is an XPath string
    // Example string xpath = concat("//color[@name='",Name,"']/text()");
    int report = dict_find(Xml, "//report");

    string smin = "";
    dict_value(report, "min", smin);
    float min_value = stof(smin);

    string smax = "";
    dict_value(report, "max", smax);
    float max_value = stof(smax);

    color value_color = color(0);
    for (int comp = dict_find(Xml, "//compartment"); comp;  comp = dict_next(comp))
    {
        string sid = "";
        dict_value(comp, "id", sid);
        int id = stoi(sid);

        string sstart = "";
        dict_value(comp, "start", sstart);
        float segment_start = stof(sstart);

        string send = "";
        dict_value(comp, "end", send);
        float segment_end = stof(send);

        string svalue = "";
        dict_value(comp, "value", svalue);
        float value = stof(svalue);

        if (Value > segment_start && Value < segment_end)
        {
            float ratio = (value - min_value) / (max_value - min_value);
            value_color = color(ratio*ratio, 0.1, 0.1);
        }
    }
    Color = value_color;
}

The only drawback to this method is that I need OSL and thus CPU mode. OSL isn't supported yet in Blender (2.74) in GPU mode simply because it takes time to implement it.
Now that I have written the OSL shader, there may be a way to do the same with Cycles (math) nodes.

if you find a way to mix two Color Ramp nodes based on the geometry then you will have 64 colors available.  Figure this out for the first one and you should be able to add as many as you want.

(I know this is old, but if you still would like an answer) Are all 32 colors different? Or is there a recurring pattern (e.g. green blue green blue etc.)?

These are some node groups to accomplish colorRamps mixing based on the UV coordinates and certain scale ( in this example it's 8 ), which give as a total of 256 color,  this is the final setup :

and these are the node groups needed :
"Equal to" node group : compare two numbers and output one if they are equal else a Zero

"Mapper" node group : remap the input ( by scaling) and output an integer number ( 0, 1, 2...) for controlling the color switches

"ColorRamps" node group : a group of colorRamps sharing the same factor input

"Decoder" node group: switch only one of the outputs to one if the input is equal to it's order

"ColorMix" node group: switch between colors based on the input if input = 5 the output will be the color-5

this will allow you to combine multiple color ramps as follow :
for this example ( scale = 8 ): colorRamp zero will be used for U coordinates from 0.0 to 0.125 ,and colorRamp one from 0.125 to 0.250 and so on. You can try any scale equal to or less than 8 .
Note : since color ramps are separate there will be no transition between them but you can fake this by repeating the last color of the previous node as the first color of the next one.
test render :

Thank you Chebhou ! I will take time this week to test this and to translate this to Python.

@nantille the 32 color limit is in the source code can't be changed from python unless you rebuild,  also tried pynodes but sadly they don't get updated in cycles, just a question you said the color is based on the voltage, is this voltage changing over time and how are you feeding the voltage value into the material ?

I see, I want to avoid rebuilding as much as possible. I'll edit the description to make it clear about the voltage.


text:
Unwrap mesh with spherical projection in python
I would like to have the same result with python as in the UI when I do unwrap > sphere projection on a mesh.
I know it's possible to use the operator bpy.ops.uv.sphere_project() – as mentioned in this answer – but I'd rather use the low-level (bmesh?) alternative, if any.

Related: http://blender.stackexchange.com/a/10444/15861

Yeah I saw this one too but that doesn't help much here. I suppose there is no answer to this question until a python blender guru looks at it. This is a shame that features in the UI cannot be replicated without using it in bare python...

The low-level alternative here is to calculate the map yourself, which, in all likelihood, will be slower than simply using the operator. Doing things via low level commands is usually a good idea, but not always :)

It's a wee bit strange to speak about "low-level" in a high level language. I don't want to do low-level stuff, I merely wish to call the function that the operator in the UI uses to do the same, without anything on the scene. I use curves to mesh some objects and at no point in time I need to link to scene, which tremendously helps when you have thousands of objects.

Of course I link to scene when meshing is done. And the uv unwrapping is one of the last steps that may be automated.

In Blender 2.9 the Python for calling this is
bpy.ops.uv.sphere_project()


text:
How to colour vertices of a beveled curve mesh without converting to mesh?
For scientific visualisation, I'm using a lot of splines which are bevelled with an object (i.e. a hexagon). I control the level of details depending on the context.
Without losing the benefits of curves, I want to assign colours to the curve points so that the generated mesh will show these colours (with interpolation).
Here's an image of what I would like to achieve. The image below is an example of the object I want to map colours to. Some splines have hundreds of points. Each point has a colour so the mesh has to show the "exact" colour at the proper location.
I browsed stack exchange for an answer and I also did try to answer my own question before posting it here, see below.
1. the naive way
I tried looping over the curve points but there's no colour property. Meh.
2. curve mesh data
So, this is about looping over generated mesh vertices and then calculating how close they are to a point in order to assign the proper vertex colour.
When I have a meshed curve in my viewport, I do a loop
for mesh in bpy.data.meshes:
    print(mesh)

And I get 0 as a result. But my mesh is there, I can see it in Blender.
3. weights to colours with Cycles
So far what I did was assigning the colour value to the weight property of curve points, like this simplified code:
    polyline.points.add(len(points) - 1)
    for i in range(len(points)):
        vertex = points[i]
        # x, y, z and weight
        polyline.points[i].co = (x, y, z, w)
        # radius of the point (only meaningful if a tube-like volume is drawn around it)
        polyline.points[i].radius = r

I thought there would be a way to then transfer the weight to vertex colouring of the curve mesh but I found none since I can't access the mesh data.
So I randomly tried to find a way to use weights with Cycles, maybe there is something that I can plug to the colour input of a standard material ? Didn't find any.
4. using BMesh ?
Bmesh doesn't support curves so it's a dead end here as well.
5. uvw mapping
As Chebhou wrote, I could use UVW mapping but I would like to see this in python. However, I'm asking for a way to match colours at every curve point. It seems that uvw mapping is non linear so how do I know to what coordinate in space (on the mesh) a color will be ?
UPDATE : there is a limit to how many gradient elements you can have in a color ramp, 32 colours max. I have splines with way more points than that. I need to find an alternative way of using UVW mapping.

Check use UV for mapping in the curve tab (this act as unwrapping the curve mesh ):

use the U input from the texture coordinates node to control the color using ColorRamp node along the curve :

render result

UPDATE
It seems that the UV space is divided equally between the bezier points , and using this info we can use the ColorRamp to assign a color to each point using knowing its order in the spline :

the number of elements in the color ramp should be the same as the number of bezier points
distribute the color ramp elements evenly
the color of each bezier point is the color of its corresponding element in the color ramp

this is a curve with 3 splines each spline has each own material :

using the previous idea gives the following result( color-ramp interpolation is set to constant to show thee relation between elements and bezier points ) :

Scripting : the following code has been used to create the last image materials
assuming you have

a dictionary of points' colors
material slot for each spline
-each material has a ramp node ( the material should be as the previously used one ^)

import bpy

curve = bpy.context.object

colors = {  0 : [(0,0,1,1), (0,1,1,1), (1,0,0,1), (1,0,1,1), (1,1,0,1), (1,0,1,1), (1,1,0,1)],
            1 : [(0,1,0.3,1), (0,0,1,1), (1,0,0,1), (1,0,1,1), (1,1,0,1), (1,0,1,1), (1,1,0,1)],
            2 : [(1,0.4,1,1), (0.8,0,1,1), (0.5,0.5,0,1), (0.6,0,0.2,1), (1,1,0,1), (1,0,1,1), (1,1,0,1)]
         }

if curve.type == 'CURVE' :
    i = 0
    if len(curve.data.splines) <= len(colors) :
        for spline in curve.data.splines :
            spline.material_index = i
            color_ramp = curve.material_slots[spline.material_index].material.node_tree.nodes['ColorRamp'].color_ramp
            l = len(spline.bezier_points) -1

            for e in range(1,l) :   # if i>0  create new color elements
                color_ramp.elements.new(e/l)
                print(e/l)
                color_ramp.elements[e].color = colors[i][e]

            color_ramp.elements[0].color = colors[i][0]
            color_ramp.elements[-1].color = colors[i][0]

            i+=1

Thanks for the reply but I need more than that. Maybe the method is right for a start. In my scene I have splines with dozens, sometimes hundreds of points. I have colour values for the points, not for the uvw map. So how do I exactly map colour values at the curve points ? I'm interested in the python approach here since I need this to be automated.

@nantille do you have the distance between the points ( not straight , the length of the segment  ) ?

I have a list of points so I can easily calculate the straight distance between p1-p2, then p2-p3, and so on. That would roughly give me the length of the curve. If we need to have the real curve length, then there must be a method somewhere that calculates this. I use bspline interpolation, sometimes poly which is some linear interp. I know that for bezier curves you can use mathutils.geometry.interpolate_bezier(). I would like to avoid using mesh duplicates (http://blenderscripting.blogspot.ch/2012/08/determine-length-of-curve-in-blender.html) for this since it can be solved with math.

Ah ! Then it's easy, I can split the ramp in as many color points as there are on the curve, separating them by equal distance. UVW mapping will take care of the rest. But there's still a little issue. I mentioned b-spline curves, not bezier curves. Does this also work for nurbs ? If not, do you know a method so that I can give my points list and I get a list of bezier points from that ? The handles would need to be computed automatically.

replace bezier_points  with  points and see if it get the same results

I tested the constant thing and it works for bezier and nurbs alike ! Thanks Chebhou ! I'm on the right track with this. This is much appreciated.

I was struggling for a while on how to show on a curve some data (i.e some defined color at each vertex of the curve).
I finally found a solution. IIt's not complicated but require some scripting.
Instead of starting from a curve. Starts with a line :
me = bpy.data.meshes.new('mycurve_mesh')
verts = [x1, x2, x3...]
edges = []
for i in range(len(verts)-1) :
    edge.append([i,i-1]);
me.from_pydata(verts, edges,[])
ob = bpy.data.objects.new(me, 'mycurve')

Then put your vertex data in a vertex group (Be aware that vertex group store a float but only between 0 and 1 so you need to store the min max of the data). Note also that you need to have the piece of data for each vertex.
vg = ob.vertex_groups.get("data")
mini = min(data);
maxi = max(data);
for i,d  in enumerate(data):
    v = (q-mini+1e-20)/(maxi-mini+1e-20)
    vg.add([i], v, 'REPLACE');

Then you need to add two modifiers a skin modifier and a subdivision surface and you will end up with a tube. Note that you can control the radius of the tube by changing the mean radius X, Y.
Then you need to convert the vertex group to a vertex color layer :
vcol = ob.vertex_colors.new();
vcol.name = "data";
for poly in ob.data.polygons:
    for loop in poly.loop_indices:
        vertindex=ob.data.loops[loop].vertex_index;
        weight=vgroup.weight(vertindex);
        vcol.data[loop].color = (weight, 0, 0);

Now you can access the vertex color using a attribute node (and an separate rbg node).

The question stipulates without converting to mesh, which appears to be the first step in your answer.

yes you are right..sorry my bad... I supposed that you want to bevel the curve with an object and that's why you don't want to loose the benefit of the curve....


text:
How to get a random number only once per instance, in stead of for each vertex, in geometry nodes
I've built this rather complex way to create a box with tape on it in geometry nodes. This is because I need to create many different boxes according to specific size profiles.
The setup works but I have to put in a different seed manually for each box which is plugged into the ID input of the Random node. Otherwise a new random value will be picked for each vertex resulting in a crumpled box.
I want to get rid of the Seed input so a new random box will be created each time. I've tried putting this in a node group and adding a random node to the Seed input but that didn't work either. So how do I get only one random value per box? I'm sure this is easy, and probably a duplicate when you know the answer, but I'm stuck.
This turned out to be a duplicate as I expected. For a different but also elegant solution see this thread:
questions/319805/how-do-you-randomly-translate-vertex-groups-for-individual-instances-for-instanc
This is the part with the random values:

This is the entire node tree but is illegible so the entire belend file is linked at the bottom.

The "crumpled box"

Link to the Blend file:
https://www.dropbox.com/scl/fi/8hgvdpb7xbhn97pczy0kn/Pakket01.blend?rlkey=b57ww3luox1p7mj4ikzhoywpw&st=2u777ist&dl=0
Using Blender 4.1

just use store named attribute on domain "instance" after your instance on points node and plugin any random value you need.

Hi Chris, I'm not sure how to connect that up. Should I instance (on ponts) the entire object, or  crate a node group out of this first? and Where does the named attribute go, and what "Name" should I use?

if u provide your blend file, i can update it.

Thanks Chris, There is a dropbox link in the bottom of the question, please let me know if this doesn't work.

Judging by the title alone, here's an example of how to do it: How Do You Randomly Translate Vertex Groups for Individual Instances for Instances on Points?

Thanks Markus, that is also a very elegant solution. Especially the island index is very nice. It avoids the Capture attribute that always baffles me. I never know what to use as input. This makes it a duplicate as I already expected.

i hope, that this is what you want?

So i just made a nodegroup out of your package GN setup and used it in a repeat zone, to position each individual package on a grid.
There was no instance on points node in your setup - so i was not sure what you wanted...hope it helps.


text:
How to save cut video as a video file in Blender 2.92.0
As the title says. This is similar to this answered question, but before marking it as a duplicate please note there's a problem with that post: it is outdated.
Basically, all existing answers that I found on various sites refer to pressing some Animate button as a way of triggering the process of saving to a file, and the button has disappeared. On the current interface the most similar one I found is Render → Render Animation at the top menu, but all it does is creating a new window with a playback, which has no obvious way of finally triggering the save to a file (and I also found a Sequence Render Animation menu elsewhere, which seems to do the same thing).
I've been searching for about two hours already, and I'm kind of becoming desperate at this point. I find amusing that Blender even has a documentation about setting up a video output, but it lacks the most crucial step: how to make those properties result in an actual video file.
For reference, below is a screenshot of the current interface.

At the top-right half of the window you can see a panel with video output settings: a codec, a quality, and most importantly there's an output directory. But whatever I do in the program, the output directory is always empty.

I found it! Turns out, it is the menu Render → Render Animation: it makes a window pop up, and after that window finishes playing, a video file appears.
But as I mentioned, I tried that menu and it didn't work, right? So why wasn't I finding it? Well, turns out when you set up the output directory for a file, you must end it with a slash. Otherwise the last /-separated chunk of the text would be interpreted as part of a resulting filename. Which means that if I wrote a path /tmp/foo (expecting the file to end up in the /tmp/foo directory that I created), then it saves to a file like /tmp/foo-SOME-POSTFIX.mkv, and I had too much stuff in my /tmp directory, so I simply missed it.


text:
How can I avoid this camera tracking error? "Some data failed to reconstruct (see console for details)"
I'm currently following Sebastien Konig's Match Track Blend DVD and have encountered a problem where despite matching camera type, lens type and trying to solve for distortion, I'm getting the following console messages when I try to Solve Camera Motion:
bpy.ops.clip.solve_camera()
Some data failed to reconstruct (see console for details)

And I'm getting an average Solve Error of 0.9561, where I'm used to getting .4 and below. So what's going on?
The related files can be found here.
This may be related to another question I've asked on the site - Why can I not select camera trackers in the graph view of the Movie Clip Editor?
I figured that the issues were different enough that I should give them different questions.
Many thanks to everyone who built and everyone who visits this site. StackExchange/Answers style-sites are very useful to me and I appreciate any time spent trying to answer the questions people ask here. (Thus ends that digression!)

What does it say in the console when this occurs?

I have been able to reproduce this, but I haven't found any consistent reasons for this happening.. The only thing that happens every time is problematic tracks will not display any average error. I can get rid of this by cleaning bad trackers and making sure there are a good number of good trackers, but I don't know what actually causes this.

Simple:
Here are a few measures to fix this issue:
Take good footage that isn't to shaky or blurred.
Double check that all of your tracks are accurate.
Add more accurate tracks.
Delete a track, then solve camera motion if it didn't help, chose a different track and then and repeat.
make sure that not all your tracks are on one single plane in space (eg. on a wall)
If all fails, then your shot is simply to difficult to solve.


text:
How to cut exactly a plane with a particle system so the particles dont leave the limit area?
I want to find a way to dont let my particles system outside a delimitation area in that way the grass dont leave the square area, as u can see some are going out of the object
How can i limit the particles to stop at exactly the edge of the square ?

Why are they going out? Maybe check the origin position of the particle?

Tried, the origins position are ok. The only thing i could think of is if i down size the particles planes, but in that way i have another problem, that is the particles plane doesn't match the object under him so looks pretty weird

Hello please share your file

Here is the file https://drive.google.com/file/d/1iLP8B3KcYSmSU4TTYqM2epG-GlZK89bJ/view?usp=sharing

It goes out because of the Radius value you've set for the Children, which probably means how far (in units) they can go from their parent:


text:
How can i make this text follow this circle path?
The point where im trying to get is making the text orbit the sphere, i already tried to use the follow path but guess im doing something wrong, because the animation cames pretty broken once i start playing.
here you can see what I want to do and what is happening in the video below:
https://youtu.be/AYrB4X8kDXU

I would just use the Curve Deform to get the text bent around the curve and then add keyframes to rotate the curve itself. Rather than messing with the offset or whatever, that seems like a big headache between a Curve Deform, Follow Path constrain all rolled into one.
Curve Deform:

Then just set the curve rotation to 0 on frame 1 and 360 on one frame past the last frame and it will loop perfectly.


text:
How to mirror actions from a object to another in real time?
im having some trouble with trying to mirror my actions into another object. So basically imagine Cube 1 and Cube 2 side by side, what i want to do is to when i change any form our scale of the Cube 1 the  Cube 2 take this actions as well. Sorry for the newbie question, im new at blender !
Here is a print of the problem im facing.

Thanks in advance !

Hello :). You can use linked duplicates for this: Blender Manual - Duplicate Linked

Thanks man !!!! thats exactly what i wanted

No problem, welcome to Blender :)


text:
importing a rdc file into Blender gets an error
I am wondering if anyone here can help with an issue relating to plug-ins. I have successfully added these plug-ins, and I understand that they work as there are several people on YouTube who are using them without any problems.
My question is; I get an error when I try to import a RenderDoc file (rdc) Blender is telling me that the captured file is an ‘Invalid RDC render file’. I have tried Blender 2.83, and have tried the latest version. I have also downloaded the latest version for both RenderDoc, MapModelslmporter v3.70, and MSFSToolkit v0.40 still no joy.
What I am trying to achieve is to import 3d files from google maps, then take the converted snap-shot pictures, which are saved as a .rdc then import them into Blender.
Has anyone attempted this, or has anyone done something similar? Any help would be appreciated.

BlenderGIS can import earth maps live from blender, which may be more effective.

Yes, I have tried that, the only thing is I can not get the 3d textures from the screen grab.


text:
What is non-sub modelling?
What is non-sub modeling? For what purpose and where is it used?I have some knowledge on the subject, but I'm asking because I don't fully understand and I'm not sure. Thank you in advance for your answers.

I don't know if that's a standardized term, but I assume it means modelling without the use of a subdivision surface modifier.  Subdivision surface naturally curves and smooths edges, but at the cost of extra geometry. I assume "non-sub" would be trying to achieve the same curved, smooth effect, but without the modifier or the extra geometry that comes with it (low poly modelling, essentially).

What's the context in which you heard it used?

@ChristopherBennett I answered before I saw your comment.  If you'd like to turn your comment into an answer, I'll remove mine.

@Marty Fouts - Its all good - all I planned to do was leave the comment anyways. Go for it.

https://blender.stackexchange.com/questions/112221/when-and-when-not-to-use-subdivsion-surfaces/ https://blender.stackexchange.com/questions/99412/what-exactly-is-hard-surface-modelling

For example, in some videos I watched, neither boolean nor subd were used in accessories such as environmental design. This made me suspicious. This leaves us with the choice. We can model both methods without using subd and boolean. I can model using both methods, but this dilemma confuses me. Thanks for your answers.

non-sub, usually non-sub D, is a term used to describe a range of Blender modeling techniques that do not use the subdivision surface modifier.
Modeling techniques based entirely on sculpting fall into this category, as do techniques that use non-destructive boolean workflow for creating Hard Surface models.
A common difference between hard surface techniques that use subd and those that don't:  subd techniques use loop cut and similar tools to control the sharpness of corners, where non-subd techniques tend to use bevels for the same purpose.
There are several arguments for avoiding subd, the most common being that subd creates a great deal of unnecessary geometry.  That makes non-sub popular with low poly count modelers, especially those creating assets that are meant for export to game engines.