text:
Transparent mesh in Edit mode
I am working on large project (256x256 meters) and I use metric scale.
Suddently, in Edit mode ( either in Solid or textured)  all my mesh are transparent . By running a search about the issue I found it can be related at this one
1: Shadows along edges of mesh in 3D View and this one
I tried to change the clip Start at 1mm End at 10M but nothing changes. I tried to change these values in many ways but nothing change.
I am sorry to post it as a new question , but my "reputation" does not allows me to post comments.
TYVM in advance
Note : It is NOT the "Limit selection to visible" button ;-)

Welcome to Blender.SE! Could you post a pic of your screen including the 3D view in edit mode, the outliner and the modifier tab? It would be helpful to see something in order to understand why the proposed solutions in other question don't work in your case.

Grrr...when i try to upload other pictures , it says my ruputation does not allows me to post links and does not accept pictures. Anyway...no modifiers. let me think how i can show outliner

https://gyazo.com/5ae1cb23315b5abb15d1fb653f5d2b1c (the outliner)

Disable Hidden Wires
You may accidentally enabled the Hidden Wires Option in the Shading section of the the Property bar.

Because the mesh is composed by a single N-gon, there are no other wires to display than the boundary edges.
The option is available since 2.69 version and is usually helpful while retopologizing. You can find more info in the release notes.


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How to Loop cut multiple selected edges at once
I am coming from Modo. And in Modo I could select multiple edges and cut loop of them at ones. What I mean, for example, is if I have a cylinder with 32 faces and I need to add an edge loop to every face,  I select top edge loop, press ⌥ Alt + C and it cuts every single edge of that loop.
But in Blender when I chose edge loop and press ⌃ Ctrl + R it only cuts which edge my cursor is on. So, do I need manually add edge loop to every edge one by one?
I found only one tip for that problem, select face loop, insert it but it works on simple geometry but for complex shape it doesn't work perfect.

@Duarte:  in my opinion questions which were asked for newer version of blender (which looks totally different for beginners (and me) should not be closed with answers of older blender versions....

Actually that already answered thing is not an actual answer for that question :D Not even relevant. Dont know how to delete that thing. It will mislead people

You should be looking at the subdivide operation.

Here, in edge mode, I've selected two edge rings (ctrl alt RMB on edge, then shift ctrl alt RMB on edge, at least for me; interfaces may vary depending on startup interface choices) on the left, and then used a subdivide operation.  I accessed the subdivide via the context menu ('w' key for me) followed by selecting subdivision ('s').
We can see that it made a loop cut through both of the edge rings that I selected.

Oh, Wow. It is 99.9 percent what I want. It even enables some fancy posibilities. ))
So, first thing first, for this to work, I need to select all edge loops where I want new loop cut will go. But with like you said, via edge ring and select->edge Loops->edgeLoop menu, this will work.
With Ctrl+E and subdivide Edge-Ring function, it even makes smooth loops and keeps curvatures with blend surface interpolation choice. For some reason it doesnt work pecfect with subdivide :/
The only problem, I cant slide new loop same as loop cut tool. But technically, I can with extra steps

source: Stack Exchange

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

sort: votes


text:
How to change properties panel layout
I've watched information of new 2.9 changes and noticed that UI is more friendly. I've downloaded version 2.9 and I still can't get what I saw.
I Googled but didn't find anything. I have added an image of what I want to change.

Are you sure about running 2.9?

Hello :). You still have 2.8* opened, not 2.90. Notice the small arrows to reorder modifiers, they were dropped in fhe latest release.

The right layout I saw in "whats new in 2.9" on Blender site when They write about "unsubdivide and rebuild". The left layout is from 2.90. I thought that there is something wrong with my 2.90 if its different that what is shown on blender website. I didnt noticed that 2.83.2 had it the same as on "whats new". It's quite confusing.

These changes in modifiers UI indeed can make older versions' UI seem more friendly

Mystery solved.
New features are shown on blender.org on older version. It confused me.

I feel so stupid. Sorry for taking Your time.

Thanks for responses
Best Regards

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


text:
Why the duplicated cloth object does not fall?
I duplicated the two cloth objects from the cloth object that I've already adjust the physics and played it back in the timeline. When I do this, the original object falls, but the two duplicated objects stay around the pivot point position and curl up into a ball on the spot. Please give me advise to solve this problem if you know what is causing this.

PS - The third attempt somehow worked. In the end, I do not know the cause of this problem. I'll add a screenshot here.

can u provide blend file?

sorry, I can not provide the file. But if anyone have any idea where the cause might be,  I will share the information and screenshots of the area. So please let me know.

I just tried the third copy. This time, it fell just like the original object. I still don't know why the first two didn't work, but I can move on for now.


text:
Parts Of Object Hidden, Cannot Be Sculpted
When I enter Sculpting mode, I found some vertices cannot not be sculpted.

I switch to edit mode and I found these vertices are hidden (?not sure).
I can press Alt +H to unhide these vertices. But when I switch back to sculpting mode, these vertices still cannot be sculpted.

Switch back to edit mode and this part is still hidden. (like fig.3)
How can I make these vertices available for sculpting?
What kind of function make this situation?

This recently happened to me and I believe this is a glitch. When I switch to tab mode I tried to reveal hidden Alt+H  the vertices. When I switch back to sculpting mode, I can't sculpt it.
Again, I believe this is a glitch. I tried to copy the mesh to 2.83 version, unhide the vertices, and copy it back to 2.9 version and it worked.
Edit: after that, whenever I add a mask the it will be invisible. I think it's a bug

Thanks a lot! It work I use 2.83 to fix mesh!


text:
How do I interpolate two Bézier Curves and create instances in between?
I am trying to create realistic book pages. I've created two Bézier curves for the top and bottom pages, and now I'm trying to "interpolate" them and create instances between the two curves. I think this might work by determining the position, size, and rotation of the vertex and averaging in the geometry nodes or by adding some modifier I don't know of.
The two orange curves are the top and bottom of the book. The yellow curve is the one I want to calculate. In addition, I want to control the set of curves in between with a slider.

I hope I could explain the problem understandable and there is a solution :D

Don't know if it's worth a shout, but does anyone know of a surefire way to import vector paths from Adobe Illustrator as Bézier curves in Blender? Because interpolating (Blending, as it's called) between two paths like this is totally possible in Illustrator so if it can be done there then imported, this could be a solution. Disregard this if a better solution exists (especially one that is done entirely within Blender)

@Onyx if you can export them as svg, you will be able to import them into Blender

Assuming both curves have the same number of control points, this is how you can interpolate between them :

Transfer the attribute form one curve to the other by control point index, then mix both positions and use the factor for interpolation. Then use a Set Position node to change the CP positions.
If you're using a Bezier Curve, it's a little bit more complicated since you need to also interpolate the control points handles positions.
Relevant docs:
curve handle position node
set handle position node

Here's another solution that will work with curves that don't have the same number of control points. Unfortunately, I couldn't get the resampled curves to keep the handle positions so it needs a higher number of control points.

Oh, green marked nodes! ...I like green marked nodes! ...and I like this beautiful solution too! ;-) +1

@quellenform hehe yeah this ans CTRL H to keep only relevant sockets makes life much easier in bigger node trees :)

At a little risk of distortion.. no need for the incoming curves to have an equal number of control-points. You could resample them so they do.

@RobinBetts fair point ! I'll add it to the answer. :)

Nice answer! I just put these together, so I'll share in case anyone wants to check them out. Here's the basic version and the resampled version.

@Mentalist this is so good! I am trying to add two more curves to your resampled version and drive all of them with the onr factor but cant get it to work. could you make an example with four curves? any help would be much appreciated.


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How to render by material in Blender
I wanna ask how to render an object per material, So i.e I want to render only an object with the same material(pink) and then in the other layer it will be another object also in the same material(Blue). So it will be 2 different render image output, pink object and blue object.
How do I do that. Please help
Thanks!

Please clarify what you mean by: "So it will be 2 different render image output, pink object and blue object"

Please clarify your specific problem or provide additional details to highlight exactly what you need. As it's currently written, it's hard to tell exactly what you're asking.

What you ask sounds pretty close to Cryptomatte in the Compositor. First go into the Layer panel and under Cryptomatte activate Material:

In the Render panel > Film > enable Transparent:

Do a render, open the Compositor, enable the Nodes and Background options (you should see your render as background, press V and AltV to zoom in and out), create an Output > Viewer node, create 2 Matte > Cryptomatte nodes, mix the 2 Cryptomatte with a Color > Alpha Over, click on the "+" button of the Cryptomatte node in order to pick up one object, click on the "+" button of the other Cryptomatte node in order to pick up the other object, you can assign a different effect to each layer:

You can visualize the mask of each Cryptomatte with the Matte output:


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How to quickly clean up unneccesary edges?

This is the result of converting a couple of metaballs into a mesh. I feel like extra edges on faces are gonna be a real pain while sculpting, so I was wondering if there's some way to make the process of cleaning up quicker.

You could use select edge loops or simply the Remesh tool (it will completely change the topology but as you are talking about sculpting...)

You could also use the decimate modifier, then a subdivision surface.

As far as I can see, we are not talking about "cleanup" here, but "remeshing".
You can of course do this (manually) in Blender, but if you want to do it automatically, Blender unfortunately has only limited tools to give you an acceptable result.
One possibility is to reduce the mesh or something similar. But it does not look good.
An algorithm can unfortunately never decide for you what is important to you. So you need a mechanism where you decide yourself what details are crucial for your object.
So the answer is: either remesh manually, or live with the artifacts of automated processing.
An alternative, if you consider a workaround via an external program as a solution and don't want to use ZBrush or similar, is Instant Meshes.
With this small tool you can quickly reshape your mesh and then edit it again in Blender.

thank you a lot! i'll try this


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Vertices/edges dissapear when zooming in in Edit mode

Two pics of what I see when I try to zoom in and I don't understand what happened and why did it start acting up like this.
I opened the file with a cat head, then added a cube, moved it to the side, and deleted it in edit mode to start working with the tool "Polybuild". In the process I remember clicking on "merging vertices" and turning on the magnet to the vertices. Then deleted the whatever I made with Polybuild and then came back to look at the cat head and now it was acting weird as per picture. What happened? How do I make vertices/edges look/act normal again?

It looks like there is more than one cat head in the scene, and depending on zoom Blender shows the one you're editing or the other in front. Probably it is something similar like the problem in the following question, check the answer there: Can't select or edit certain parts of my mesh during retopo.


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fix model compatibility between version 2.70 and 3.1.2
I downloaded a model from the internet for personal use but when I opened in Blender 3.1.2 some textures are missing and I can't fix it... This model was made in 2014 with blender 2.70. Please help I tried everything I spent so many days to find something but nothing.
Blender 3.1.2 https://i.sstatic.net/FB1E2.png
Blender 2.70 https://i.sstatic.net/STxKY.png

Hi :). It looks like the 2.7 version is using Blender Render. That's an old engine, no longer supported. You may need to recreate the materials from scratch (should be easy tho)

Unfortunately thats not my model and I don't want to modify it without permission...
But there is nothing to patch these bugs?

You must have some tutorials on how to convert materials from Blender Render to Cycles: https://www.youtube.com/watch?v=FiZ4rBF-7yE

Hi :). This is not a bug. The old Blender Render is a completely different render engine. Either use older Blender versions, or update the materials.


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Strange 'Stretch Marks' after rendering
Object in the viewport, Solid shading:

Object rendered:

Here you can see before and after rendering. There are some distortions and irregularities visible on the front face of the mesh between the circles which are supposed to be the eyes.
How can i fix/prevent this?

The geometry around the eyes is deformed and bad topology makes it obvious.
Select the outer edge ring around both the eyes.

Scale them to 0 along the Y axis (in your case). In my image it is the X axis. To do this, this: S Y 0 enter.

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


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How to select only a border of selected area?
I selected some area and I need to get selected only border of this area. Does anyone know any function to achieve that? Or a script?

Select Boundary Loop
You can find the function in the Select Menu.
It will select only the boundaries edges of the provided face selection.
As said in the manual's page:

...based on all regions currently selected, it selects only the edges at the border(contour) of these islands.

Here's an example of usage:

Thank you! Just what I was looking for.

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


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Transform manipulator is no longer in center of selection
I am new to Blender and i have a very frustrating issue. I find it difficult to get used to all the shortcuts so i may have pressed something i didn't mean to :

XYZ axis should be in the center of the object / face / vert (like in the first picture), not in the center of the 3D cursor (like mine is in the 2nd picture).
How can i achieve that ? And how can I return it back ?

Most likely you pressed . (period) button; this changes the Pivot Point to 3D Cursor. See http://blender.stackexchange.com/questions/24140/manipulator-widget-appearing-where-the-3d-cursor-is, http://blender.stackexchange.com/questions/8604/transforms-moving-around-the-3d-cursor

Ah yes, an easy fix.
To fix this problem click the small button on the bottom of the screen, in your case it should look like this:
Click on the button and click the default, "Median point"
Your manipulator should be fixed then.


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How can i connect the body to the hand?
Im pretty new in Blender and this is one of my first modeled characters.I'm trying to figure out how to Connect body to hand, but I don´t know how.
The body and hand are both joined (and they have Mirror modifier added) but every time a try to connect them with Bridge Edge Loops it makes something horrible... see picture 2.

Like Duane Dibbley is saying you are having the hand on the wrong side.
Try to attach the hand on the other side or enable 'Adjust Edit Cage' in the Mirror modifier:

I would say it's better to actually turn off Mirror modifier in Edit mode in order to see where real geometry is. Then it should be easy to move parts of mesh as needed.

What I do in this situations is:

Join the two meshes -> Select the two meshes and type CtrlJ
Go to Edit Mode
Select each vertex and merge them with AltM
Select the merge you like

authors: Алексей Ватагин


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How do I make the ends of a pole less square?
I have a pole-like shape (octagonal prism) with a bevel added on both its ends and branched into two. The faces are triangulated and the triangles are converted to quads. I applied a subdivision surfaces modifier. The edges of the ends are not perfectly circle, though; there's difference between the bevel thickness with subdivision surfaces.

screenshots album
How can I fix this and make the ends look less like squares and more like circles?

To make subdivided edges look as expected make the corner loops follow the curvature of the desired shape (i.e. circle).
In this case, dissolve quad face in the middle (select edges, press X > Dissolve Edges), inset resulting Ngon twice (press I with face selected), select inner edge loop and merge it at center (Alt+M > At Center).

Note that you might want to dissolve also 4 edges in the resulting cap to get rid of tris.

I would delete the four edges that make up the "square" in the middle in Edit Mode. Then select the vertices around the opening that was created. Then press Shift + Alt + S and drag your mouse to create a circle shape.
With that circle opening still selected press E to extrude and S to scale the extrusion down. Then press E again and Right Mouse Click.
Then press ALT + M and select Collapse from the drop down menu to close it.


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2.80 Addon zip file installation
Will 2.80 support zip file installation of addons? What are the requirements for the zip structure and its contents? I have tried multiple directory structures (as noted in this related question), all of which fail to import in 2.80 (my addon is a python package/directory, containing an __init__.py etc).
EDIT: It seems like I should be using the "Install Add-on from file" button in the user preferences to perform the install, not dropping the zip in the blender addons folder. That also gives an error message, see the bottom of this post for that.
Working/runnable: Contents of the actual package, NOT IN ZIP FORMAT (normal py package/dir), verified to run/import in 2.80 (git.351f537fa83):

Broken: Addon as a zip file, structure 1 (__init__ and all files directly inside top level of zip file).

Also broken: structure 2 (named package folder containing __init__ and all files directly inside top level of zip file)

The error message is the same in both cases:

Install via button, also broken: "Install Add-on from file" button in the user preferences, using a zip file in "structure 1" format above.

I would go for structure 2.  User can either install from file (using zip as the file) or drag the folder from the zip into addons folder.

Good point. I'm hoping the import from file will be fixed sometime soon so that I can verify it with the install button, maybe I'll submit a bug report...

make sure your add-on is specifically written for 2.8, Blenders API had been drastically changed and most add-ons if not all are behind re written to be compatible. it seems your add-on is using a function that had been replaced or merged. correct me if I'm wrong.


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blender videoediting Use Python batch save mp4，Save all the cut small videos in batch
A long video, divided into multiple small videos (soft cut using the K hot key).
Save all the cut small videos in batch
Save separately
use Python
For example, a 10-minute video, divided into two 5-minute. I need to click 'Animation' twice to output two videos. I want to use Python in accordance with the custom 'shift + K', fast bulk rendering output two videos.

For example, a 10-minute video, divided into two 5-minute.
I need to click 'Animation' twice to output two videos.
I want to use Python in accordance with the custom 'shift + K', fast bulk rendering output two videos.

If the strips in question could be selected before executing the strip, this task becomes fairly easy, since we can use the final_frame_end and final_frame_start attributes of each strip.

Make sure, the desired strips are selected.
Then execute the script. (Note, that there will be no feedback except for the console, so you will have a hard time tracking the progress of the render, except for checking on the filesize of the created files. Blender UI will freeze untill the completion of all renders intiated by the script.)
import bpy

seqs = bpy.context.selected_sequences
scn = bpy.context.scene

# store the filepath and original start and end
filepath = scn.render.filepath
start, end = scn.frame_start, scn.frame_end

# loop through all selected sequences
for s in seqs:

    # set the rendersettings start and end to the
    # current strips start and end
    scn.frame_start = s.frame_final_start
    scn.frame_end = s.frame_final_end - 1

    # add the strip name to the rendered movie name
    scn.render.filepath = filepath + s.name

    # start the animation render operation
    bpy.ops.render.render(animation=True)

    # write something to the console so we know
    # that a clip finished
    print("Rendered", s.name)

# REstore the filepath and original start and end
scn.frame_start = start
scn.frame_end = end
scn.render.filepath = filepath

The best way to do this is probably to render an uncompressed video and convert it to shorter after, it is usually better to do it like that because it is more flexible.
I do have a personal rule of only render in lossless file format so I don't get compression artifacts that get worse from adjusting the image.
If you want to get a video I would recommend AVI raw and convert it to mp4 later so you don't have to re-render the whole thing to get rid of artifacts.


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change and update Spot Size when camera lens change?
How can I get set spotlight size to update when I change the camera lens angle?
The goal is to preview wich camera can see in scene and configure them trought custom panel. Need update in viewport

With driver: driver is not updated automatically, and I need to update manually
By Script: How can I call a function when camera angle value change?
I try tu use custom prop with update function but I don't know how to make it work

This simple script:
#bpy.data.lamps['Spot'].spot_size = bpy.data.cameras['Camera'].angle

import bpy

# Define property.
class MyLensProp(bpy.types.PropertyGroup):
bpy.types.Object.Lens_ValueL = bpy.props.FloatProperty(name = "FOV     angle", default = 0.5, min = 0, max = 360,update= Update_Lampe_Ange)

def Update_Lampe_Ange(self, context):
    C= bpy.data.cameras['Camera'].angle
    bpy.data.lamps['Spot'].Lens_ValueL =  C

    PL= bpy.data.lamps['Spot'].Lens_ValueL
    bpy.data.lamps['Spot'].spot_size = PL

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

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

if __name__ == "__main__":
register()

In https://blender.stackexchange.com/a/90723/29586 the driven value is only automatically updated on change of frame. Does animating the active camera trigger the update of the driver on frame change?

Frame change, update the Spot size but not change the preview lighting cone.

Here's a solution that certainly works for me on Blender 2.76b.
I believe your problem is that the driver values aren't propagating through correctly. I have had problems with certain drivers types in the past - for example, with drivers on values within materials. However, I have always had consistent results with drivers on Object Custom Properties and this forms the basis of this solution.
Start by creating your spotlight and add constraints to Copy Location and Copy Rotation to the camera. This will ensure the lamp always resides at the point of the camera.

Select the camera and go to its Object properties. Create a new Custom Property to drive the camera attributes. By using a property to drive the value (rather than manipulating the camera attribute itself) we can ensure we hook in to trigger our drivers whenever the property is changed.

Note : Ensure to include the decimal part of the property if you want it to remain a floating-point number when setting the property initial value - ie, '35.00' rather than '35' - otherwise you will lose the ability to set it to fractional values.
If there are multiple camera attributes that you would want to adjust that would each affect the camera viewing angle then add multiple properties - one for each attribute. In my example I am only adjusting Focal Length, hence only one property 'focallength'.
Right-click the camera attribute (in my case Focal Length) and Add Driver.

Swap to a Graph Editor window and set up the driver so that it has a variable of type Single Property with Prop set to the object Camera and Path set to ["name_of_property"] - ie, in my case '["focallength"]. Set the Driver Type to 'Scripted Expression' and the Expression to 'var'.

Now, varying the value of the Property 'focallength' should automatically adjust the camera's focal length.
Note : Cycles provides different sets of Custom Properties for different aspects of each object - for example, in the Camera properties there is also a Custom Properties tab. It's very tempting to use these properties rather than the main 'Object' properties - since when adjusting the camera attributes they'll be closer to hand. However, I have found that those properties do not play as nicely with drivers as the Object properties so they are generally best avoided. By all means give it a try - your version of Blender may well handle it better - but bear in mind that if the driver values are not propagating properly that that could be a cause.
Now for the lamp. Select the lamp, got to its Lamp properties and Add Driver to its Size.

Swap to the Graph Editor again and find the driver. Again, in the Variables section we need to add our Camera Property as a Single Property set to '["focallength"]'. This will ensure that the driver is triggered on change of that property.
However, in the Scripted Expression expression, instead of using the variable (var), set the expression to take the camera angle directly from the camera. This will set the lamp Size to the same angle as the camera whenever the 'focallength' property changes.

Note : If you want to be able to alter multiple camera attributes - eg, Focal Length, Sensor Size, etc. - then simply add multiple Custom Properties, one for each. When setting up the driver on the lamp add multiple Variables  - one for each property. This way, whenever any camera attribute is amended (via the property) it will also trigger the driver on the lamp to capture the camera angle.
Now adjusting the camera (via its custom properties, not the driven camera attributes - note the property at the bottom-right of the following image) should propagate the angle to the associated lamp (note how the lamp in the top-left window always matches the camera width).

Note : My particular version of Blender only supports circular lamps - the same principle applies to non-circular spot lamps.
Blend file included

Hi Rich, Thanks a lot, I'll try your blend and solution tomorow, It seems working as I want, I'have tested this solution but the difference I see, that you're  using complete pathdata to custom propertie instead of "var" ...

I wonder if there’s an issue with the order that the two drivers are being applied - if the ‘angle’ driver is perhaps being evaluated before the focallength one. I don’t believe there is any way to indicate the order that drivers are applied - other than the order you create them, perhaps. If tr problem is specific to 2.79 then I’m afraid there’s not much else I can do as my system won’t run that version at the moment.

Hi, I have test it, I'm using the last 2.79, it seem not stable, switch internal, then it work only in cycle in render mode ...strange ... Is there a stable solution using animation node? or scripting?  I don't understand well! I would like compare several method to choice the easiest, and robust one, perhaps it could be interesting for other ...Thanks for your help,...my dysfunction come perhaps from my custom ui I create...

Note : This answer relates to the interpretation of changing camera angle as being to change the actual camera, rather than the properties of the camera - which was not the actual intention of the question. I have left this answer in place since it may be of use to someone searching for related issues and it does describe an apparent issue in the OpenGL render.
After running some tests, it seems that there is a problem in the behaviour but I don't quite get the same results. Most notably, my render preview mode does correctly update and the actual render also appears to work correctly - the only issue I did find is in using OpenGL render where the light cone was not updated.
Here's my setup :

I've created two cameras and added markers to the timeline - one at frame 1 and another at frame 20. These markers are bound to the relevant camera so that the view starts at the first camera and changes to the other on frame 20.
I've set the Pass Index on Camera #1 to 1 and Camera #2 to 2 and the driver on the spot lamp size is set to 'bpy.context.scene.camera.pass_index /2' - since it's in radians this will be 0.5 radians (28.6 degrees) for the first camera and 1.0 radians (57.3 degrees) for the second camera.
If I render the animation I get this up to and including frame 19 :

And this on frame 20 and beyond :

Manually skipping through frames produces similar results in the 3d Editor window, whether in Render Preview mode, Solid or Wireframe :

Where I do get strange results is if I do an OpenGL Render - in which case the lamp size wasn't being updated (note the lamp cone lines not changing their spread) :

However, if I moved the timeline frame to be after frame 19 then the OpenGL animation did work correctly! (note the change in spread of the light cone - only change is the 'current' frame in the timeline at the time the render is triggered) :

So, in summary, there does appear to be a problem - and a problem that is dependent on the start frame in the timeline at the point the OpenGL render is actioned. I don't know if the same issue could potentially occur in 'full render' - perhaps I just didn't hit the same situation. More extensive testing required.
Note that my tests were all performed on Linux using Blender 2.76b.

EDIT I repeated the test using 'full' render and the lamp size in the final render did correctly change - so this looks like the issue is restricted to OpenGL render (at least, in my case). It would be interesting if you could repeat the tests. I'll upload my Blend file so you can test with that if desired.

Thanks Rich for your tests and research ..., but it doesn't seem to do what I' searching , your set up seems to not update ... I thouhgt it can be a simple thing but ... its looks like harder than i was thinking...

That's weird. If I load it (need to ensure auto-running of scripts is abled - it should prompt at the top-right of the window, or enable it in User Preferences - to enable the driver (otherwise you end up with a 1 degree spot lamp)), move the mouse over the 3d View and press Shift+Z to go into render preview mode, and then press right-cursor twice to skip forward two frames (from 18 to 20), my preview is updated fine (to the image included above). I suppose the next consideration is what version of Blender are you using - could that be a difference?

Rich, no version blender problem, it work (great) as you say ... but Your solution need to configure lens camera and then with conversion passIndex (I can't add driver definitly to passIndex), so in fact for me it's like configure lens cam then angle size spotlight? I'm wrong?

Hi @Ellt. Looking at your edit I realise I didn’t fully understand your issue. I’ll try and setup your situation and try and replicate it.

Thanks, I think perhaps trought custom properties and update fonction it could be done, but I m new with coding ...sorry if I wasn't clear with my need. The idea is to see quickly in "real time" what, each camera could see in a scene ...


text:
Rounding building faces
I am very new to blender and have started making a building (image below). It is made of an extruded bezier curve converted to a mesh. However, I would like to round some edges (marked in red below) and don't know how to approach it. I have tried proportional editing, different modifiers, but nothing is working. I have included a picture of how I'd like it to look when seen from above. How could I do it?

Any help is appreciated
Marius

Could you sketch out the edgeflow you are expecting on your mesh? From there we'll be able to suggest a tool, bu you should decide the kind of approach to topology based on your project needs. From the point you are presenting, I would probably give a try to booleans, but I can't tell if it's appropriate...one more thing: why you tagged cycles?

You may need to add more geometry... hard to tell. If you edit a screen grab of your existing geometry it would help. You could also edit into you question your .blend using http://blend-exchange.giantcowfilms.com/

Also, I think it would be easier to make the shape you sketched first and then raise the height of the building using proportional Editing.


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Particles (hair) size and random size in blender 2.79a not available in advanced
After many years on C4D, I started to learn Blender and follow the beginner tutorial series of Andrew Price.
On part 7 about particles, he changes the size and the random size of the particles group that needed to create sprinkles on a donut.
He uses this menu, as shown in the doc blender doc
But for me, in Blender 2.79a the size / random size is available in the "render" tab while Advanced is unchecked. When Advanced is checked it disappears from the render tab and I can't find it anymore.
So if I want to tweak and randomize my particles, I have to check/uncheck.
Is it normal or am I missing a thing on 2.79 ?

edit : confirmed that in Advanced those settings are available in Blender 2.79.

It is normal and documented here:
https://lists.blender.org/pipermail/bf-blender-cvs/2018-January/103452.html


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Why do bones further down the chain get stretched when a bone is rotated?
I have 10 bones inside a cylinder so the cylinder can bend, like an elephant nose or octopus leg. However, when I rotate a higher bone, eg bone 5, the children bones stretch or get longer. How do I turn this off, so bones keep the same length when higher bones are rotated?
Edit: adding screenshots:
Here is a screenshot. It is a cylinder, I used extrude so it would have several sections of vertices, and it has 7 bones in it (the cylinder has the Armature as parent.) I added a cube to show the stretching, it also has the armature as parent with Automatic Weights.
After rotating bone 4, the cube is stretched, and it looks like the bones after bone 4 are stretched too.

What I'd like to do is have the rotation applied, the further down children bones keep their length and not stretch, and for the cube to point in the direction of rotation as it does now, but not stretch the cube.
I've uploaded my blender file, named as "bendAndScale.blend". I'm sure it's some constraint, I tried to add one but couldn't figure it out. Thanks in advance for the help.

Welcome! This sounds like you have some scaling issues on some of your objects, but to be sure, it would help us if you provided an example blend file demonstrating the problem. You can upload a blend for your question here: http://blend-exchange.giantcowfilms.com/

Thank you for the welcome. I've uploaded my blender file, and added a screenshot to show what is happening.

The Problem
As I suspected, this is a scaling problem. The bones distort because you have non-uniform scaling on your armature object. Select your armature object (not a bone in pose mode) and look at the scale values in the transform properties. The object is scaled by 0.5 on the Z axis. With non-uniform scaling, any transformation done in a space influenced by this object's scaling will appear distorted. In an armature's case, bones in pose mode will be distorted by the object's scale. Likewise with other objects, if you have a cube parented to an empty, the empty's scaling will affect the cube's transforms. This is all because transform "space" is inherited from parent objects. A good explanation is in Nathan Vegdahl's Humane Rigging course.
The Solution
You need to apply the scale transformation on the armature object. With the armature object selected, press Ctrl+A and choose Scale. The appearance of the bones will change (some axes look like they scale), but the overall function should remain the same. For the sake of cleanliness, I would apply rotation as well. Before applying any transforms, it would be a good idea to unbind and unparent any objects influenced by the armature. This will keep them from being influenced by the transform application and keep their position in 3D space.
For the future, it is best to always leave your armature scaling and rotation unchanged, for this exact reason. To change the size of the bones, it's best to edit the armature in edit mode, or if you're doing animation, scale the bones in pose mode instead.

Thank you -- worked perfectly to solve the problem, and the detailed explanation and tips are very helpful !!

I found a much better alternative solution:

go to bone edit mode.
select the bone ex.: boneA
duplicate it: boneA.001
change its length to a minimum but dont let it reach 0 or it will mess up! the idea is to keep it aligned with the original bone and dont interfere on selecting that.
reparent it to the original bone: boneA is now parent of boneA.001
rename boneA.001 to boneA.adj (to help on filtering)
go to the mesh weight mode
create a copy of boneA weight
rename the copy to boneA.adj

Now you can scale every part independently without letting it mess on rotations!
I think this probably can be scripted too like by working on the selected bone. Will do some day. If you do it, tell us!

(Old answer)
In my case, in blender 2.93.4, for each bone that was messed, I had to go on:
poseMode/BoneProperties/Relations/InheritScale
and chose between
None or Aligned or Average (the one that looks better), but None will prevent all scaling inheritance.
Modifying scaling in pose mode is good to avoid further sculpting the mesh or creating new meshes, but needs these tweaks. Not sure if it is the best option tho.
Also, I found no way to apply the change to all bones at once, so I used this:
cat >FixActiveArmatureBoneInheritScale.py
# USAGE: select the armature you want to apply the fix and run this script

import bpy

bpy.ops.object.mode_set(mode="OBJECT")

iDo=2

if iDo == 1: # restore default to all bones of all armatures
    for ob in bpy.data.objects:
        if ob.type == "ARMATURE" and ob.users !=0:
            for bone in ob.data.bones:
                bone.inherit_scale="FULL"
                print('BONE: name="%s" inherit_scale=%s' %(bone.name, bone.inherit_scale))

if iDo == 2: # apply inherit_scale mode to active selected armature
    armature = bpy.context.active_object
    for bone in armature.data.bones:
        bone.inherit_scale="NONE"
        print('BONE: name="%s" inherit_scale=%s' %(bone.name, bone.inherit_scale))

if iDo == 3: # read inherit_scale mode from active selected armature
    armature = bpy.context.active_object
    for bone in armature.data.bones:
        print('BONE: name="%s" inherit_scale=%s' %(bone.name, bone.inherit_scale))


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how to create half circle surrounding in rounded column/pillar?
like this question, but my part is from the pillar body itself, how you create this rounded half circle surrounding perfect in rounded pillar?
here the pictures,  (picture from previous question above)

yeah you right, I didn't see the gif until finished :)
but the different is in the column profile, he create rectangle but what I need is half circle in top and bottom..
but thank, I think i can edit them manually to make half circle.. :D

You could add a cylinder and inset each face (I to inset, then F6 and change to 'individual'). Then extrude inward and bevel the edges as necessary.

The result looks like this. The geometry may be difficult to work with if you're using a subdivision surface, in which case I would add extra loop cuts on the edges between the insets to connect horizontally.


text:
why my curve shape become smaller than original source curve?
why my curve shape become smaller than original source curve?
How to fix it?

Blend file here:

Attach the file please.

I don't know how to do that :(

By this: http://blend-exchange.giantcowfilms.com/  From the image, it seems that the curve resolution is not quite enough to present that bevel detail.

here the blend file...

Curve control point's Radius ≠  1
Each control point has a parameter called Radius that controls the size of the object being beveled in the area of influence of that control point. You can see from the image sequence below how the parameter can be varied to alter the size of the section without a taper object.

In your specific case, the Mean Radius of the curve that can be seen in the Transform section of the Property Shelf is saying that the average Radius is different than 1 (size untouched).

By examining each control point you can see that none of them is set to 1, that's why the size of the beveling object is different from what expected.
The solution consist in restoring the Radius to 1 by calling the Set Curve Radius operator while all the control points selected in edit mode.
Result:

Oh, that's right Carlo

I think its because some of the dimension is lost while you apply the curve modifier. What you can do is try increasing size along any one axis to see if that works for you.

hmm... but I'm not applying the modifer.
the curve window frame is fresh curve, and when I use other curve as object bevel, it become smaller, so what I can do now is scale it up the source curve so the window frame become correct size.
wait, Im still editing, I accidentally press enter button :(
but, I tried using new curve, I create new curve, and it size correct (not smaller)
or, is that bug?


text:
How to move the handles of a sequence via scripting?
There are the following commands:
create sequence editor
bpy.context.scene.sequence_editor_create()
add strip (name, filepath, channel, frame_start)
bpy.context.scene.sequence_editor.sequences.new_image("coolName", "path/db.png", 4, 1)
Until now I have created a sequence on channel 4, starting at frame 1 like in the following picture:

I want to control the starting frame of the slider and the ending frame of this strip. How can I achieve this using blender script?

You can reference the sequence object immediately when creating it:
seq = bpy.context.scene.sequence_editor.sequences.new_image("coolName", "somePath/img.PNG", 4, 1)

Then you can edit the frame_final_start and frame_final_end to edit the sequence start and finish, same as the handles:
seq.frame_final_start = 10
seq.frame_final_end   = 50

A list of other properties you can control: https://docs.blender.org/api/blender_python_api_2_78c_release/bpy.types.Sequence.html#bpy.types.Sequence


text:
Can't make this glass bottom realistic
I'm trying to get this pint glass to have the same bulbous and curvy look as the tutorial I am following but it just won't work.
This is how it is supposed to look:

And this is how mine looks:

As you can see there is a lot different between the meshes.  I got the tutorial from blender guru: Blender Guru
I've attached the .blend

Have you tried scaling up the rings of vertices closer to the bottom of your mesh until you get your desired result?

Yes but it looks horrible.  And I have a really hard time selecting inner vertices.

Yeah I added the lights that come later in the tutorial, but I must've missed something in the tutorial or he didn't explain everything because I've tried to make this glass from scratch several times and I just can't replicate what this guy did.  Also, I'm wondering if there is an inner mesh at all in my glass?

I'm putting my comment here to add images to better explain what I found.
I tried briefly the same tutorial, now.
I'm rendering the result of my short test, I'll post it here soon.
edit: here it is
left is with basic diffuse ground plane, right is identical but with glossy ground plane: look at the difference... note: I didn't even add a world hdr, and not even the "fluid" inside... all could add to the result.

Although render settings in the tut seem to be not disclosed, I think your glass shows a somewhat dim lighting, almost no reflections... why didn't you set the emissions planes off camera?
but mostly the mesh seems to have a weird bottom, and seems to have almost no depth... did you follow closely the modeling workflow?
Look at this image, which I got after bisecting (it is an edit mode tool) your mesh to make more visible the inside...

I'm sure you've never seen a glass like this...
here is my attempt in comparison:

Thanks.  The bottom was definitely weird!  I started over again and really really scrutinized the tutorial.  There's a video version on youtube as well that explains some things not mentioned in the site link.  However, it looks like I didn't apply the solidify modifier properly to the entire object, as well as learning to select loops with alt + RMB and alt + RMB + shift to select more loops.

Ohh right I thought you already saw the video, it helps out a lot. Andrew Price is excellent with video tutorials, I have found him useful for too much to recall.


text:
Geometry Nodes: Color gradient on moving instanced volume
I'm trying to get a candle flame to be colored with a gradient. My problem is that the candle flame move as the candle melt. Everything is made in Geometry Nodes. And the flame is a volume.
And so I find myself stuck because:

I can't use any sort of UV, they all seems to disappear because of the Mesh to Volume node. Even capturing attribute before using the volume don't work.
I can't use the generated UVs because the instance is moving. Therefore, the position also changes, and as a result, the gradient that changes the color of the flame color. But the gradient should always stay the same, even if the flame moves down.

Here is a quick doodle to show what I mean and want.
On the left, what I would like to have. On the right, what happens:

I am at a bit of a loss. Here is the file:
https://drive.google.com/file/d/1XgJRJ5Orqd1JZ0j3hTKhj9lNpxvtyAmO/view?usp=share_link
thanks in advance!

The first and most important part is that you first create the flame as a separate object in a separate node tree.
If you create everything in one node tree, as in your example, the position of the volume will change.
You can then integrate this standalone flame into the candle's node tree with Object Info and Instance on Points.
The main point is: You can't apply the UVs of your original mesh to a volume, because it has no faces and there are no UV-attributes.
But you can use the node Texture Coordinate in the shader, for example, and since the candle flame always stays in the same object space, the gradient always stays in the same area.

PS: Of course, you would then also have to design the movement of the flame a little differently, since the noise texture is no longer influenced solely by the change in position of the flame.
(Blender 3.3+)

Thank you so much
I was so focused on making it work in one single tree, I didn't even think of making the flame a volume in the object flame, and then instance that, that was so simple. Thank you!

@FelinaFaerlaingal You are welcome! For your peace of mind: I don't always think of everything either, and am sometimes just as surprised how simple some things can work ;-)


text:
How to change shortcut for snap to view?
When I hold  MMB  and pan/orbit and press Alt it snaps the view to front,right etc.
Is there a way to change that hotkey to Shift so that when I hold MMB  and press Shift I will snap to the view?

At the very bottom of this image you can see where the shortcut can be changed in User Prefs → Keymap.I searched "MM" (middle mouse) by Key-Binding to find it more easily.

It doesn't let me to change it but thank's alot, i was searching about an hour for this ;)

@Tasos I was able to change it after I expanded its tab. Fsr Blender collapses a bunch of tabs right after it gets changed but Shift did work for snapping the view after I changed them.

Finally got this worked, Thank's alot HISEROD !!!

I'm using this since Alt won't work with my tablet and Emulate 3 Button Mouse setup.
It took me a while to figure out but that seems to work like a charm.
To clarify, expanding the relevant tabs — Rotate View and then Axis Snap — and clicking Left Alt seen there, does give you a chance to change it; into Left Shift in my case.

Please don't add "thank you" as an answer. Once you have sufficient reputation, you will be able to vote up questions and answers that you found helpful. - From Review


text:
Ctrl + Alt + Num 0 Doesn't work
I've followed the doughnut blender tutorial on youtube step by step, but when it comes to rendering, Ctrl + Alt + Numpad 0 doesn't do anything.
I'm not sure if I changed something by accident, but even doing it manually doesn't work. I've looked up the problem and haven't found anything similar. I don't know what else to do, this is the first time I'm working with Blender.

You're already in your camera's perspective, as indicated in the top left corner of the viewport. What are you trying to do?

You should choose a camera if I not mistake

It shouldn't matter what object is selected, start blender with factory settings and see if anything changes.

If you want to add this feature to Quick Favorites you can follow these steps:

Press F3 to search for commands and type "active camera"
Right-click RMB on Align active Camera to View and select Add to Quick Favorites
Press Q to get the list of favorite commands and you can quickly select the Align Command from that list

Otherwise you can also follow these steps to quickly enable lock of the camera view:
Step 1
Press N in the 3d View to open up the right sidebar and go to View:

Step 2
Right-click RMB on Camera to view and Select Add to Quick Favorites:

Now you can enable Camera to View by pressing Q:

I had similar issues with Blender 3.0. If you are on a Windows laptop computer with limited keyboard keys, you can emulate desktop numpad.
On you top screen click on Edit> Preference> Input under Keyboard, check Emulate Numpad.


text:
Copy with base point (like Autocad)
Is it possible to copy an object on a base point and than paste it like it happens in autocad (ctrl+shift+c) and then paste it somewhere else in the scene?

you can duplicate with shift D or alt D (link-duplication), then put the 3D cursor wherever you want in the scene, then select your copy, shift S > Selected to 3D Cursor

Thank you. I used something like that, but I was wondering if there was something more intuitive and less cumbersome.

maybe an addon allows to do it, or maybe it needs to be created, you would like to have a shortcut for Paste To 3D Cursor?

maybe it could be a useful option

all suggestions to developers here: https://blender.community/c/rightclickselect/

done it thanks!


text:
Move to Collection command in context menu missing
In the latest 3.0 version the Object context menu has changed and the move to a new collection is no longer available. Any hints?
This is the old version

This is the new one.

You have switched to Local View (as the menu option already indicates). Local View is entered by pressing the "divide" key on the numpad ÷ which then exclusively shows you only those objects that were selected in the moment you switched. Your 3D Viewport should also display "Local View" in the top left corner.
The Remove from Local View option lets you remove a then selected object from the exclusive view, without exiting out of Local View.
To get back the normal Object Context Menu, just switch back from Local View by pressing ÷ again.
Local View is for example helpful if you only want to see a single object you're working on without being distracted by other objects in the scene which might get in the view or anything. You only need to select that object and switch to Local View instead of changing visibility options for many objects (with the danger of forgetting to change them back afterwards for some objects).

That was the point. It works now.

@pippooooo You might consider accepting this answer then.

@pippooooo Oh, I just saw in your profile you never accept answers :(


text:
Why are some Blender UI elements blue?
In some tutorials I see that sliders, textboxes etc. in the Blender look blue like this one:

In my version of program these elements of UI are grey. Why is that?

These are called themes and they can alter the look and visual appearance of Blender UI.
You can change them from Blender User Preferences > Themes and choose from the pulldown menu on the top left.
You can also create your own, modify or customize existing ones or simply download third party created from the internet from places like BlendSwap or search in forums like Blender Artists


text:
Why does mesh behave like mirrored in Edit mode without Mirror modifier?
This is probably a very simple question, but the Mirror modifier keeps mirroring my model though i've applied/deleted it.
I read somewhere that I have to disable symmetry lock, but I'm assuming that only works in Sculpt mode which I'm not using because I'm trying to make a low-poly model. I'm not entirely sure why this is happening because I've done it before and I didn't face any problems.
If i can get some help that would be great!

Please post your .blend so it's easier to diagnose the problem

That could be this "X mirror":

You find that in Edit mode, on the Toolshelf (press T to toggle visibility), under the Options tab.

worked like a charm, thank you very much!!


text:
blender having trouble a consistent mesh for 3D printing

I imported svg file.
Scaled it up.
Entered the top ortho view with Numpad 7.
Press A twice.
In Object mode, on the Toolshelf pressed Geometry to Origin.
Applied the scale of the object with Ctrl+A.
Converted the curve to mesh with Alt + C.
In Edit mode selected all faces, pressed X key and choosed Limited Dissolve.

With all this done I'm left with one face which can't extruded to form a model for 3d printing.
Could anyone explain how to resolve this issue?

The problem area of the mesh is at the middle right corner of the flower.

If your mesh is just a plane then it is non-manifold geometry and won't be printed. If it really can't be extruded, upload it and edit your question with that link or add comment with it.

Why the limited dissolve? Sure there probably where lots of ugly triangles but who cares about them when 3D printing? My advice, skip the limited dissolve. Then extrude and run the 3D printing check.


text:
Objects turning black when colliding when in render mode in cycles
I'm having trouble on the latest released blender version (3.1.2) and whenever two objects collide or overlap the overlapping part turns black and it's really frustrating. this is only clearly seen in rendered mode. I've tried to look at the settings and preferences, but I can't find anything to fix it. It wasn't in the previous version as I just downloaded the new one.

This is called Z fighting, overlapping faces will be rendered black in Cycles. You need to slightly scale or move one of you cube for example.


text:
Subtitute 3D Object Texture in After Effects
Imagine a 3D animation of an open book surrounded by a hugely complex scene, with the camera slowly approaching and/or orbiting it in multiple different trajectories made to flow into each other to be later ordered in infinite combinations. The idea is to have a single reusable base render of this for saving render time, and then to composite different textures for the pages on each trajectory combination. The textures are actually footage, not images, so we have some magical moving text. Goal here to accomplish this in the most efficient possible maner, since it needs to be done over and over again in this project, not only once.
I've thought of a couple of solutions:
1. (Blender only). Use HDRI of scene to re-render only the book page with different texture, then comp it sustituting original's color passes. This bypasses rendering the whole scene dozens of times. Problem: will have to manually load textures of each book's page and manually position camera's NLA strips for each trajectory, or learn Python...
2. (Blender and AE). Use objects attached to vertices on the book's pages to generate motion tracking data, and then export to AE for warping and comping. Would need a way to directly convert these object's positions into trackers, instead of relying on motion tracking from the rendered video. Is this possible?
3. (After Effects only). Any of several tracking solutions. Will need to test one by one and see which is the best. This would only need to be done once for each trajectory, then I would simply swap the precomps for each new texture.

3.1. Native motion tracking on top of masks produced in Blender. Likely will fail due     to excessive labor or lack of pixel level
precision.
3.2. Use Blender script to transfer camera and book page object. Can texture be     changed natively in AE?
3.3. Mocha Pro.
3.4. GeoTracker. (Might work importing the mesh of the book page)
3.5. Element 3D. (Might work if I manage to transfer camera data from Blender)
3.6. Re:Map by Re:Vision. (Possibly the cleanest and fastest solution)

Even with extensive description I'm a bit lost in your goal ... Do you want to composite texture onto render image? If so try render also UV pass and use Map UV node ... https://docs.blender.org/manual/en/latest/compositing/types/distort/map_uv.html
...  https://i.sstatic.net/hfq5a.jpg

@vklidu This is a valid solution and is the Blender implementation of my 3.6 entry on the post using Re:Map. Also bonus for being free. I guess I will do it in AE though, because in Blender the Compositor does not seem to be directly tied to the Video Sequencer which slows work down, though I am new to this and might be wrong, need to study these editors more.

I'm not sure why to use VSE (Sequencer), but using composite in VSE is simple ... in current file just add a New Scene, switch to VSE Layout and add Scene strip. To se result of of compositor in VSE go to Preview editor's Side panel (N) and change on View tab Scene Strip Display to Rendered ... but if you feel more comfortable with AE ... sure go with what fits you the best :)

Render your model ...

... with enabled UV pass ...

In Compositor use Map UV node to map image in render ...

To continue in Sequencer - add a New Scene (in the same file) and add Scene strip into the Timeline. To see Compositor result go to Preview editor's Side panel (N) and change on View tab Scene Strip Display to Rendered

Notes:

In this example I used 3D scene as source for Compositor, if you want to pre-render scene and composite image sequence be sure you save your render OpenEXR Multilayerd so the image stores enough color depth info and UV pass for compositing.
Here I used Object ID to mask, but sure Cryptomatte should work better (especially at edges with semitransparent pixels).

Perfect, thank you.


text:
Python script to convert selected object to collection instance
New to Python, got as far as creating a collection with the same name as the selected object, now I just need to create a collection instance from it.
import bpy

selection_names = bpy.context.selected_objects
for i in selection_names:
     print(i.name)
bpy.ops.object.move_to_collection(collection_index=0, is_new=True, new_collection_name=i.name)

I believe this scripting for artists video fully covers what you are looking for.

The function you want is bpy.ops.object.collection_instance_add.  If, for example you had a collection called "monkeys", you could add it using this command:
bpy.ops.object.collection_instance_add(collection='monkeys', align='WORLD', location=(0, 0, 0), scale=(1, 1, 1))

All of the arguments except the first are optional.

Worked. Now I just need to create a mini addon, so that it can be assigned a shortcut to.

Managed to add shortcut with this addon.

@JohnNope Good job with the other addon.


text:
Rigid Body objects exploding without colision
I'm curently working on exploding part of a statue with fracture and rigid body objects. The shot I'm on is a close shot of the shoulder of the statue and I'm trying to explode some kind of "outer layer" of the statue to reveal something else underneath.
The outer layer has been shattered with the fracture add-on. I've managed to stabilise the rigid bodys (so everything doesn't explode right away) by adjusting the collisions shapes (some are on "Convex Hull", some are on "mesh" with a very low margin).
I have then added an icosphere (passive rigid body, animated) to explode the fractured part.
The problem is that some parts explode away at frame 1 without even being touched by the icosphere.
File can be downloaded here (blender 3.0) : https://we.tl/t-v49oAJVDcU
Here are a few screenshots :

Thanks for helping !

Apply the scale of your projectile and it will work:

Damn, I was sure I had done that already... So much shame I feel... Thanks a lot anyway !


text:
Activate rigid body by distance (3.0)
I have a model that I cell fractured and I would like the cells to fall down one after another from top to bottom, like a kind of wipe.
Is there a way to activate the rigid body simulation of these hundreds of shards depending on their distance to another object (an empty or anything else) ?
It's basically the same question as this one, but for blender 3.0 : Turn on rigid body by means of distance
Or this tutorial, but for 3.0 : https://www.youtube.com/watch?v=pEd0NuiMG3E
Thanks a lot for the help.

Is this question about Animation Nodes (links) or Geometry Nodes (tag)?

UPDATE:
if you change the script like this:
import bpy

# two sample functions
def calcActivating(object):

    objectName = object.rna_type.id_data.name

    location1 = bpy.context.scene.objects[objectName].location
    location2 = bpy.context.scene.objects["Empty"].location

    print("distance is", (location2 - location1).length)

    return (location2 - location1).length > 5

# Add functions defined in this script into the drivers namespace.
bpy.app.driver_namespace["calcActivating"] = calcActivating

And if you add an Empty with the name "Empty" (or adapt the script) it will react (change the animated property) depending on the distance.
possible result:

if you run this script:
import bpy

# two sample functions
def calcActivating(object):

    objectName = object.rna_type.id_data.name

    location1 = bpy.context.scene.objects[objectName].location

   return location1.z - (bpy.context.scene.frame_current / 30) > 0

# Add functions defined in this script into the drivers namespace.
bpy.app.driver_namespace["calcActivating"] = calcActivating

and then give to one fractured cell for "animated" property ....

this driver:

then select all cells, shift select your cell with the driver at last, press CTRL-L -> animation data.
then you can get this:

of course you can change the "30" to any other value to change the effect:

Note: I just took the location.z value as "timing" function. So your location.z values of all fractured cells should be > 0 in the beginning of the animation. Of course you can take also a distance to another object or whatever function you want to calculate the timing.

nice crumble effect!

@Blunder: thank you mate!!!

Very nice Chris!  :)

@Edgel3D : thank you ‼‼

Wow, thanks ! I've never used scripts and drivers in Blender but I'll look into it !

What should I change to use the distance to another object ?

i updated my answer

Fantastic ! Thanks a lot !

if my answer helped you, please click on the checkmark left of my answer. thanks.


text:
Shrink-wrap wrapping object half inside target the object
The shape is what I want but I need the star to appear on the surface, but SR keep placing  halfway inside the object and playing with offset makes it float above it.
Tried solidify but it added too much thickness to it

Have you subdivided your star a bit? Also have you thought about putting it on the texture instead?

It looks like your star shape doesn't have enough verticies to project onto that surface. Try add subdiv modifier to give the object more verts, this will help give it enough detail to project to the surface. You'll also want to adjust Shrinkwrap settings, especially "Offset" and "Snap Mode" will be helpful.

As also mentioned in the comment to your question, you could also consider adding that star as a texture. Here's a good explanation on how add an image texture to an existing material.

Tried subdivision and it helped a bit but still was inside too much. and I'm trying the texture method but the nodes don't match up up what I have going on
https://imgur.com/a/vWw0nAD


text:
Is this a v3.1.0 problem or did I break something? Some things are disabled in the settings
This is my first project in 3.1 so i just found this out. Back in 3.0 this wasnt a problem so im wondering if something changed between updates or if i did something wrong that made the render region setting to be unusable as well as the render device being locked up in the GPU with no option to change it.
Technically i can check the boxes but because its greyed out, nothing happens

Probably a 3.1 bug, especially if you're on Windows.  Edit preferences and go to the Systems tab. Check the Cycles Render devices.  You may have to toggle between None and Cuda or Optix to get Blender to recognize your GPU again.

@MartyFouts changing the settings in the render devices worked, thanks. Both options got active again


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if i put a high polygons object far away, will it still slow my render time?
i have a scene, where i need to use the dynamic paint to create waves. But the canvas has extremely  high polygon counts, and it would appear only on a fraction of the scene time. I tried baking the canvas and then remove the subdivide modifier to make it a plane, that doesn't work.
So i was thinking maybe i can put the object very far away from the scene, and hopefully it will not slow my render times. Will that work?

maybe you could even do a render then use it as an image in the background?

well the object ill be using is a bathtub, so it'll be kinda difficult won't it? to create an alpha especially if its inside the tub. Or am i wrong? i never used layer method before

Polygon count does not increase render times that much, at least if we're talking about a single object. You can use several alternatives to reduce the render times, but I think you're trying to optimize your scene a bit too early. I bet there are other things you can operate on that don't involve using workarounds to speed up your renders. eg reduce the light passes, compositing, etc.

@Gorgious it all depends... Some things are really subdivided so much it matters :D But to my knowledge this affects scene building, not each sample, so it matters most for rendering animations with few samples per frame.


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how can i mix NLA with my manual animation?
i just started to mess around with NLA, but what i can't seems to figure out is how do i mix NLA action with a manual/custom action
like for example, this is the setup for the nla, it start with idle, and then he walk and then hand raise while walking, it works okay
but when i add keyframe, the entire NLA stop working, i was thinking maybe adding a more custom keyframe animation
i've been reviewing tuts, but it seems none of them showed about it(well maybe because i mostly just skip past a lot of the tutorial because its too long, maybe i missed it, or maybe they dont show it)
i was thinking maybe about adding animation that dont need repetition, maybe like he talks, or he stop to grab something and then i can place the NLA action with walking again. how do i do this?

You can play both the NLA and the keyframes in the Dope Sheet if they are not the same kind of keyframes, otherwise the action of the Dope Sheet will play over the NLA

not the same kind of keyframe? you mean the bone? i cant use the same bone on NLA editor on the dopesheet?

I mean if you keyframe the rotation of the bone in the Dope Sheet, it will cancel any rotation keyframe coming from the NLA

oh. so there is no way to mix nla with dopesheet.  so basically its more complicate to animate with nla huh.. i guess ill just stick to classic dopesheet, if i need my character to walki guess im just gonna have to copy paste the walk cycle. thanks

no, it's not more complicated to animate with NLA. You just have to know when (!) to use what(!). And how both work.


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Fixed scale snap increment
How do I lock the scale snap increment to +/- a specific value?
While scaling a object using snap to increment, the increment is 10% of the current scale. For example, with a object with scale [0.1, 1.0, 1.0], while scaling in the x-direction the snap will be +/- 0.01 (first picture) and while scaling in the y-direction the snap will be +/- 0.1 (second picture). Instead, I want it to always be +/- the same value.
I will note: Holding shift only changes the scale increment to 1% of the current scale, it doesn't lock it to a value. I've already set the display grid's subdivisions (View -> Properties -> Display) to 1, so that's not the issue. I could scale and snap the object's vertices while in edit mode, but I specifically want to change it's scale value, not its vertices.


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How to gamma, remove, or increase of alpha channel of a strip
I'm using a glow effect to add a outline to text. I'd like the outline to have sharp edges, but after setting all the nobs on the glow to max, the edges are still somewhat blurry.
If I could set the alpha of the strip to more than 1 that would work... but you can't. If I could add a curves modifier to the strip that would work, but you can only apply it to the R, G, or B channel, not the alpha. There's a "blend mode" "alpha clip" setting that could be used but its for materials not for video editor strips.
Example file with outlined text

pls provide a blend file with just the text and the result you are showing in your question. thanks.


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Scripting: Separate by loose parts and get created objects
I am looking for a scripting/code/api way to do a separate by loose parts and get a list of the resulting separated objects. There doesn't seem like there is a direct way to do this?
You can do bpy.ops.mesh.separate then loop through all objects and check for new_obj.name.startswith(old_obj_name) but that could select unwanted objects in certain scenarios. You could... make a collection, set it as the active collection, do the separate, and then get all objects in the collection? I'm not sure if that would work 100% of the time?

Or check which objects are selected?

Get created objects
import bpy

old_objects = set(bpy.data.objects)
bpy.ops.mesh.separate(type="LOOSE")

new_objects = set(bpy.data.objects).difference(old_objects)

print("The new objects created are:")
for ob in new_objects:
    print(ob.name)

Get separated objects
import bpy

old_objects = set(bpy.data.objects)
original_obj = bpy.context.object
bpy.ops.mesh.separate(type="LOOSE")

##
new_objects = set(bpy.data.objects).difference(old_objects)
new_objects.add(original_obj)
# Or:
# new_objects = {ob for ob in bpy.context.selected_objects if ob not in old_objects}
# new_objects.add(original_obj)
##

print("The separated objects are:")
for ob in new_objects:
    print(ob.name)

Nice. Also, one of the separated objects will be the original object, which won't be in the new_objects set. Can you edit your answer and add original_obj = bpy.data.objects.get('object_name') new_objects.add(original_obj) at line 7. And then change the print statement to "The separated objects are:"


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Selecting similar following groups of faces
How can I do this kind of selection without repeating the same operation several times until the vase is selected all around?

At the moment I select the first face on top and than the last on bottom holding ⎈ Ctrl + ⇧ Shift +  RMB and than I pass to the following strip, leaving one unselected.
Is there a faster way? Maybe a "repeat" like function or so?

This route may seem a bit long-and-winding.. but it's the kind of habit I've got into, until someone comes along and points out what I've been missing all along...

Select one of the edges you will not want, and the next in sequence.
CtrlShiftNumpad + 'Select Next Active', until the  interval-selection is complete
Header > Select > Loops > 'Edge Rings'
H hide the selected edges
A select all, (Switch to Face Mode, if you like)
Alt H 'Reveal Hidden', with 'Select' unchecked in its  F9 Adjust Last Operation panel.

It works, thank you.

Okay, this is old but just as a tip: after hiding the edges with H, everything remaining visible should be unselected. So instead of selecting all and unchecking "Select" after revealing the hidden faces, just leave everything at default. This way it's just two steps after selecting the edges H, Alt+H instead of four H, A, Alt+H, Uncheck "Select".

@GordonBrinkmann Doooh! Of course. Sometimes I can be very 'clunk'... 'clunk' ... 'clunk' literal.

Just select the top loop, and let Blender do the rest

Select the top loop using Alt + Left Click
Go Select > Checker Deselect
Go Select > Similar > Coplanar

This does not work in my case since the faces are non coplanar.

Hi :). There's a threshold value for faces that aren't perfectly coplanar. I don't have your exact mesh, just showing the tools available that might make you work easier ;)

This still wouldn't work because it would start selecting faces around the curve. @JachymMichal

If you change the threshold the result will not be ok because also the top ring will be all selected again


text:
Why can't I bake any kind of functional normal map?
I first noticed this issue when trying to bake a sculpted base mesh man to a retopologized one. I can't seem to achieve any kind normal bake that works at all. I've tried following multiple step by step baking guides on Youtube as well as the instructions in the Blender manual itself.
I've tried baking everything from the most complex shapes to smooth shaded high to low poly spheres. I've even tried exporting both high and low poly meshes to Xnormals for a different result with no luck. I'm sure its something simple and obvious, but I have been struggling with this for months. I prepared this hansom devil to demonstrate my problem.

This is the .blend file if you want to take a look.

https://snipboard.io/omFyzR.jpg I did;nt see that option

I think i might've deleted you ranswer accidently

Switch from Blender 2.8 to 2.7 or 2.9, because 2.8 may be buggy with regard to baking.

Create a new image for the normal, enable the 32 bit Float option:

Your bake Extusion value is much too high, bring it back to 0.1:

In the Shader Editor, use a Normal Map node, not a Bump node.

Bake:

The low-res without the Normal map:

With the Normal map:

https://snipboard.io/rcZ8ei.jpg      I followed all of the steps above, but result looks like this.

Also, under selective to active I  don't have the extrusion distance option. Just ray distance.https://snipboard.io/LuFJ1z.jpg

yes just use the Ray DIstance value, give it 0.1 (it's in world unit)

Yeah I figured I'd try that. That's this result. https://snipboard.io/GTaFhV.jpg

have you followed each step I describe? I've edited my answer... Also, are you using 2.8? I'm not sure but it may be buggy... Switch to 2.9 if you can (or use 2.7)

I used 32 bit float for the image, changed the bump node to normal map, and brought my ray distance down to 0.1 for that latest bake .jpg. I am using 2.83 which is supposed to be the stable long term solution one, but I will try it on2.9 now.

Yes I had problem with baking in 2.8, I'm not sure 100% but it may be buggy with baking

Well... It looks like this in 2.9. https://snipboard.io/jCwJeV.jpg .................I was able to bring extrusion down to 0.1 in 2.9 though.

please share your 2.9 file

Let us continue this discussion in chat.

I had to starte over in 2.9 because the file was too big for blend exchange. In doing so it seems to have worked.https://snipboard.io/UuFd0s.jpg .............Maybe 2.83 was the problem after all

Yes it may explain  ;)

Thanks for stickin with me friend. I really appriciate all your help moonboots.

Good luck for the rest, not sure about your topology but that's another topic  ;)


text:
Unable to get holes in centre of object
Not sure if this is an issue of non-volume geometry, but I'm trying to get holes in the centre of my object (film reel)and when I use a second boolean modifier in the plane object to difference of circle.001 it makes the entire reel disappear.


text:
Unable to explode object
I haven't been able to get the fragments of the green object to explode.  I'm not sure why, since I added physics, rigid bodies and made it active.
Here's a screenshot:

Here is the .blend:

Your object that you want to explode is one solid object. In order for it to explode you must first break it up into pieces.
I took the following steps:

Edit mode >Remove doubles
Object mode run cell fracture
Move object on layer one to a secondary/ unused layer and
move fractures to layer one
Add active rigid body physics to all fractures with collision margin
enabled at 1

Bake simulation then play the animation


text:
Cell fracture producing warped faces
I have a plane that I have been trying to fracture (similar to the way glass can break).  I used the grease pencil and solidify modifier with the default settings.
For some reason, when I use cell fracture it causes the faces of the shards to have convex surfaces rather than flat like the plane had.  How do I get them to look flat?  I tried using the debug boolean option which produced the look I want, but the shards seemed to disappear into thin air when I apply active physics to them.
Here's the pic of my results:

These are my settings:

Any help would be greatly appreciated!
Here is the .blend:

You could try out the Fracture Modifier Build.
Make sure to use the "latest development build", or just use the more recent graphicall build.
I also had to edit 3 points or so of the greasepencil strokes, because the FM (fracture modifier) created some holes in the mesh there (points were too close to each other)
For the simulation I made the bullet a trigger and the plane animated and triggered. Furthermore I played a bit around with constraints.
If you have further questions, please post either here on stackexchange or here :
https://blenderartists.org/forum/showthread.php?343637-Custom-Build-Blender-Fracture-Modifier

I wasn't able to install the add-on for some reason.  I see though that it comes built in to one of the latest versions of blender from your links.  I'll have to try that.

well, technically it is a standalone build of blender. It involved lots of changes in the C source code. there is an optional addon bundled with this build, but only to automate things a bit within this build, regarding to FM.

Turns out that the problem was that the solidify modifier was too thin for the plane.  By increasing it slightly, cell fracture produced the desired normal flat faces.


text:
Why is my cloth material not rendering properly?
I'm trying to get a background material (flag) to move with the wind and whenever I render a specific frame, it's OK.  But if I render as a video (xvid), it stays completely still.  Any idea why this might be?  Attached is the .blend file.

Thanks

When rendering an animation you need to press Animation instead of Render of pressing F12. (found here http://i.imgur.com/P7Yaitg.png) Did you press Animation or something else?

Yes I pressed Animation.  Good point though.

Is this what it's supposed to look like? http://sendvid.com/6nid80fq

Sorry for the misunderstanding - you meant that the flag does not move. I thought you meant the image. It is good habit to cache all physics simulation before rendering, so the renderer has all the data needed to render the animation. Go to the Physics pane with the flag selected check 'Disk Cache' and after that hit 'Bake' in the Cloth Cache tab. After completing the caching process you can render and everything works just fine. It should look similar to the image below before rendering

It worked! I never knew that about physics...man what a lifesaver!

I did select RGB as an output color format. Not sure why it is not selected by default, but it solved the problem for me. I can open it in the movie clip editor in Blender just fine. What software did you use to watch the rendered clip?

Thanks for checking it out.  I used VLC media player.  It definitely played properly but the flag didn't render with the wind effect (just stayed as a plane).  Are you saying when you selected RGB as an output, it allowed the flag to have motion?

Could you send me a screenshot?

misunderstanding - I posted the solution below


text:
Trying to join curve and plane together, but boolean won't work
Been trying to get this vector showing in the screen shot to be welded together with the plane and I'm not able to join them using difference in the boolean modifier (assuming that's the correct way?).  The idea is to make the film strip look like glass and I added the plane to make up for the hollow parts (which would also be glass)

Got it thanks.  However, after converting to mesh it still didn't join the plane and vector when I did the boolean...why is that?

it looks like the file you uploaded is not the same as the file you are showing in this screenshot. it's difficult to tell you how to fix this without knowing the geometry in question.

Most of the time the Boolean Modifier is not the answer. Here too.


text:
Does Higher light power effect render times?
does light power strength effect render times?
because i also use blender's interior hdri to light up my scene. But i figure i would use higher light power to create a better lighting than the hdri.
Should i mix it up the two or just use the light with higher power strength to reduce render times. Because the change in detail is minor, but it looks more dramatic with the actual light.
oh another question, does the hdri also cause the light to bounce?

The ray starts at the camera and goes backwards until it seeks a light source.  In the hdri's case, any time a ray bounces off to infinity it reports back the color and light intensity of the hdri in that direction.

So multiple lights can increase noise, therefore render time, since a ray will only report back color info for one light per ray.  Multiple importance sampling may help here, I haven't dug into it far enough.

Consider this camera ray light path solution to brighten the hdri while displaying normal intensity to the camera - https://blender.stackexchange.com/a/49403/110840


text:
How do i pack a video into blend file?
i'm using sheepit to render my project, which require for me to upload my file externally. but the problem is, i can't seems to find a solution on transferring the video into the blend file, even though i already mark the "automatically pack resource" in external data. Is this feature available? is there a solution to this? anybody found a workaround for this?

I don't think so, you can't pack the images in the Video Sequencer either

I suspect that's one for Sheepit to answer in view of moonboots' comment!

aww, so theres no way to do it?

i've found it :D

i've found a way. you have to pack everything in the same folder as your blender file, and select relative path. It must be inside a folder. Then select the folder with your video/image and select the blender file, and then zip it. Then it can be send to sheepit(again, the video/image must be inside folder, and pick relative path on external data)

You can easily do that by first packing everything, setting relative path, then unpacking everything with the option to create your own files and folders near the .blend file. Then pack all again.

I was about to give up until suddenly found this post and saved me. Thank you for your answer. Helped a lot


text:
is there a way i can edit particle mesh texture?
I use the particle instance modifier on a texture mesh, and then i apply the modifier. But now, i wanna edit the the texture to make it a bit darker. I've open the shader tab, but theres only the principle bsdf in there. Ive tried playing around with it, it doesnt work.(i thought about mixing the texture with MixRGB node, but there is no texture connect to the principle bsdf)
What would you guys suggest i do?

Combine your Principled BSDF and a Black Emission BSDF through a Mix shader. The mix factor will control the "darkening":


text:
i'm having a very complicated(by my standard) issue on baking
i want to bake a whole scene of multiple object, i'm having quite a few issue with this.
first off this is my scene
first issue, it has multiple object on it. do i have to bake every single one of them? or is there an easier way?(join and then uv unwrap or some sort while keeping the texture intact?)
second, if i decide to bake them one by one, how do i handle the uv unwrap on the object without ruining the texture. like the road tiled texture

third, how do i bake an object with multiple material? do i have to put new image on every material? or is there an easier way(i know it has something to do with making a second uv map for baking, but thats about it, i have no idea how to use it on the node editor
and last, why do my baked image always turns to black, even when i uv unwrapped it?( i create a second uv map for baking, smart uv unwrap it, i highlight it, and i highlight the new image, but it still came out black. what am i doing wrong?
just a heads up, im still getting use with baking, i've seen the tutorial on baking before, but never actually put it to use until this project. so please have mercy on thy soul and explain to me like youre trying to explain to a person with half a brain cell. Any help would be appreciated :D

hello, first off, do you really need to bake the texture?

yes i do, i have around 80 spot light on the scene, and the light stop working after 30 or so( stop emitting light), not counting the particle emitting from the top(im making it snow). when i rendered it, the light only lights up on the few first tenth frame, and then suddenly stops emitting lighting on the 30th frame when the particle starts showing(even the snow particle didnt show up on render). so this is a very heavy scene, and i need to lighten it up. it is a urban environment

You can duplicate your object in order to keep a safe version in a collection, then join all the objects, create a new unwrap for the whole object, and bake onto a new image.

Solutions:
1st issue: if you don't use any addons that speed up baking workflows, then yes, you will need to proceed the bake for each. (if packing all uvs onto one meets your needs, then yes, you can do that)
2nd issue: You can try Smart UV Project if you need uv. If the bake is not necessary here, you can keep tiled texture material without any baking.
3rd issue: Place an image texture node referencing the same image file into every material you want
4th issue: Not proper bake settings, not the right active uv layer.
How to have one bake for all objects:

Ready

1ST ISSUE : do i have to join them in that case? but if i join them, and smart uv unwrap them, wont that mess up the texture? unless i use a second uv? then how i do that with bakng? 2ND ISSUE: i did tried smart uv project, and it turn out just like in the picture. 3RD ISSUE : so i do have to put an image texture to every single material? do you happen to know if theres a way to unwrap everything in one image? i dont wanna use to much space for the blender file with a lot of image, its already 500mb. 4TH ISSUE, i tho i already did everything right? what am i missing ?

I will add video in a minute

thanks my friend, ill try this later, i'll let you know if it works :D


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Cycles fire/smoke render - black particles
I trying to make jet exhaust for short jet animation, but when i trying to render it, fire and smoke are rendered as black particles.

Here's the node setup for the domain material:

EDIT
After I followed instructions to add shaders for the fire I got this result:

Here is modified node setup:

Please show the node setup for your domain material. It's likely that there isn't any attribute for fire to show which should be flame.

You have right, i didn't change anything in node editor. http://i.imgur.com/MTnQbDe.png
This is first time when i trying to render fire so i dont thought about it.

To render fire with that material either add shaders as in the linked answer or just after running Quick Smoke operator choose Fire + Smoke on the Toolshelf in the operator options (note - the latter assumes rebuilding current smoke setup).

I used nodes from linked question, but still i'm doing something wrong.
Nodes are on Smoke Domain. On cone, which is "flow" i don't have any nodes.
http://i.imgur.com/7mvvojz.png
http://i.imgur.com/1HxAEey.png

Generated factor for the fire is not used, so it emits all over the volume. Type in flame as is described already in the linked question in the last screenshot (Attribute node contents).


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How to split meshes created with the array modifier?
How to split meshes created with the array modifier? It didn't split them in Edit mode with P -> By Loose Parts.

Probably you didn't apply the Array modifier.

I took a cube ... added the modifier array ... created 3 cubic .... now I want to have individual objects .... I go in edit mode ... p -> By loose parts but does not work..J tried in every way ... thanks

hit the apply button of the array modifiers


text:
Transparency shader causing problems (Viewport render different than final render)
I've set up a shader to render a fire/explosion looking material, which ended up quite good when rendering in the viewport. When I hit the render button it looks completely different and I am convinced it has something to do with the transparency, but I couldn't figure out what I'm doing wrong.
I've attached some screenshots to make it easier to understand what exactly is happening. Here is some additional information (if it makes any difference):

using Blender 2.78b
using Filmig Log Encoding Base color management
using a hair particle system which creates multiple transparency layers
using Cycles render engine
rendering on GPU

Thank you for all answers in advance!

Thank you for your quick answer! You were right. When I'm using a black instead of a transparent background everything is fine.


text:
Face intersect while keeping objects separate
I want to do a "Face" -> "Intersect (knife)" between two objects, but keep the objects separate. This intersect seems to only work if the objects are joined? As far as I know separating joined objects after a face intersect can be arbitrarily difficult for complex meshes.
If joining the meshes is unavoidable... is there some trick for selecting only one of the objects? "Select linked" can be arbitrarily difficult for meshes with many separate parts and internal pockets. Using a Boolean modifier is out since on the current version of Blender (4.2), the Boolean modifier officially does not support non-manifold objects (it will produce a sometimes right, sometimes bugged, output).

Enter edit mode on the first object
Select all its vertices and add them to a vertex group
Join the two objects and enter edit mode
Use the vertex group to select the first object
Perform the "Face" -> "Intersect (knife)"
Use the vertex group to select the first object
"Select" -> "Select linked" -> "Linked"
"Mesh" -> "Separate" -> "Selection"

This does not work when using "Intersect (knife)"'s "Separate mode" "All".

Why don't you use the knife tool instead ? I suppose it can do what you are trying to do just fine while keeping the object separated.

Here, the two cubes are two different objects and knifing them don't join them in the hierarchy.
For the selection part, using the L keyboard selects objects over your mouse cursor, might try that aswell ?
Not sure it will help you but can't tell without more context.

In edit mode, "Face" -> "Intersect (knife)" is a different feature than the "knife" tool. I need the precision/complexity/automation of not doing the operation by hand. I updated the question to be more clear.


text:
Object not appearing in Render View or final render
Thanks for reading.
I started sculpting a mesh and noticed I wasn't in Cycles. After switching, the object no longer appears in the final render or in Render View. The object shows up just fine in the other 3D view options.
Things I have checked:
 - The object is selected for viewing in the Outliner.
 - The shaders are linked to the Material Output and Alpha is set to 1.
 - Viewed by camera in cycles is checked in the Object tab.
If anyone knows a solution to this issue or the reason behind it, the info would be greatly appreciated.
Update:
Image as requested.
Camera is checked and in position.
Shader and Texture Nodes Connected to Object's Material Output.
3 Point lighting using soft hemi's.
All objects (even lamps currently, sigh) are on same layer.

"The object is selected for viewing in the Outliner" this doesn't mean it's enabled for rendering. Did you check camera icon? DId you check materials? (which are not converted to Cycles materials dy default) Did you check lighting? Your question is too vague without any screenshots or more info about your project.

Mr Zak, yes, camera is checked, materials scanned over in materials tab and in node editor, lighting is fine. Hope this covers my bases but if I need to give more info I will.

Go to Layers and see what is wrong. Generaly this is the problem. Maybe your object is no more on the render layer

Object can't be not included in at least one render layer

I have attached an image of the situation, but the objects are indeed visible in the layer and the correct layer is selected.


text:
Why can't I delete this face?
I'm trying to clean up the letter "k" here and can't delete the faces where I've circled.  I tried selecting the vertices and holding shift, but it just won't select all of them.  How can I do this?  Thanks

Could you please upload your .blend file to be able to help you?

Ok I've uploaded.

I downloaded your file and after converting the text to mesh (alt+c) it allowed me to delete any of the faces I want.  What is it doing when you try to delete it?

You might find the edge along the bottom of the target face the easiest to select and delete.

Convert the text to mesh using Alt+C
Switch to Face Selection as shown below

Select the face you want to remove, and choose the Knife tool to cut the part you don't want as shown below and then hit Enter:

Select the part you want to delete then hit x and choose delete Faces as shown below:

Do the same with the other faces and you will get the desired look as shown below:

Updated .blend file can be found here:

But for some reason I am unable to select the actual area I want (where I highlighted in my screenshot).  I tried limit selection to visible but no matter how slowly and accurately I try to select the vertices, it just won't do it.  Is there something else I am missing?

@lakerice answer updated and provided screenshots and an updated .blend file. Please accept and Upvote the answer :)

Totally worked.  You're a genius @Tak


text:
Object somehow reversed in position
I'm not sure how this happened, but my object appears to have been reversed completely in it's direction.  I tried using mirror (both the modifier and transform tool) and all it does is revert back to its current position.  Any idea why this has happened?  It's like the object has somehow been mirrored but I can't make it face the right direction.
This is how it's currently facing:

As you can see from this picture, it's reversed somehow from the reference photo:

If I got what you say (not much clear imho) your "mechanical" model has a front part, roughly shaped like a "b" letter, that in the reference is roughly shaped like a "d" letter - thus "reversed" on X axis.
but if you try to mirror on X on your model, after confirming the command it gets reverted, as you say. This is weird, and it happens because your model is set as rigid body - active (dynamic), and a Z180 rotation, imho.
Something like this:

Try

removing rigid body
mirror the model on X - it should now stay mirrored
apply "rotation&scale"
check normals
if you need it, now set rigid body again

something like this:

Yes it was definitely the rigid body and lack of rotation and scale.  After removing the rigid body and following your steps (normals definitely had to be recalculated) it worked.  This is a good lesson in remembering to create my object in scale!

You can mirror your object along its pivot point by pressing , then CTRL+M and in this case pressing X to mirror along X axis.
It appears that the problem was due to a rigidbody on the piece interfering with transform operations.
Your rotation and scale are unapplied, be aware that modelling on a non uniformly scaled object will cause problems.

Thanks for the super quick response!  However, I tried to apply rotation and scale, but it made my object look deformed and mirroring didn't do anything.  Not sure what I'm missing here.

are you using a 2.8 branch?
I had some problems with transforms in 2.8, I did check your file beforehand and found nothing strange, I just double checked and everything is in order, your rigidbody settings seem to interfere with applying transforms, even tough it didn't prevent me from mirroring it might be related in your case. Try disabling the rigidbody on the piece before attempting to mirror.

@Firewill in the above screenshot version 2.78 is visible...

Yeah I'm using the latest version of the fracture modifier build.  But it looks like it was the rigid body that was the issue.  Once I turned that off and applied the mirror, it worked.  Thanks again!!