text:
Blender Loop cuts and vertices measurement
I have some problems when adjusting loop cuts and when I extrude the vertices of loop cuts. When I do a loop cut I would like to place the cut at the position of an exact millimeter.
I have in the scene menu  ticked the box Units > Metric > Degrees
I have ticked the box Normals > Edge Info > Length
But I am facing those problems:

When I view the whole mesh which I want to place a loop cut on, then I can not adjust the loop cut to the exact position (in millimeters) where I want the cut to be. So I have to zoom down and move the cut. Zoom in once more ant move the cut again.
Is there a possibility to give exact numeric values to where I want the cut. Or can I move the cut to where I want without the need of zooming in?

When I extrude, the values is limited to my zoom-level, so I have to zoom in really deep, then, the numbers is not visible, because they are locked to horizontal axis which is not visible. So I have to guess if it is right, zoom out and check-then zoom in and adjust-and so on.
Is there a possibility to give exact numeric values for the height of the extrude? Or can I extrude so much I want without the need of zooming in?

I found how to do it.
First to mention, I maybe was pretty unclear in my question.
What I needed to do is extrude the vertices including the lines which they are connected to.
@sambler gave me a link in his answer where they told how to extrude the vertices with the lines untouched (at least, that was what happened to me).
Ok, here comes the solution.
I use the menu which comes up when I hit the N button, then if folding out the menu 'Transform' you see values for the vertex (at least one vertice has to be selected ).
Then you can move one vertice or a whole loop-cut, depending of what you select with your mouse before you change the value(s).
As a side note. To get the vertices correct distance from left and bottom, I found that
it is simplest to
1. Place the objects lover-left corner at coordinates y0 x0.
2. Move the 3d-cursor to that point.
3. In object-mode, choose menu 'Object->Transform->Origin to 3d Cursor'
Thank you @sambler . Even though you not gave me the precise answer, maybe because my question not was very precise. You gave me some correlated knowledge.

I also found that I got my question answered at http://blenderartists.org/forum/group.php?discussionid=839&do=discuss http://blenderartists.org/forum is a great forum, but I suppose you don't join the Architecture modeling group  where I posted if you not are in into architecture modelling. The answer is from TynkaTopi in post nr 3, with a link to a video of how it's done.

Blender doesn't offer exact dimension modelling tools that you may expect in a CAD program. There are some things that may help, start with this previous question.
Most tools allow you to type in numeric values while they are being applied, what that value represents may vary between tools. When using the loop cut tool you can enter a value between 1.0 and -1.0 that represents a percentage of movement towards the next vertex on either side with 0.0 being centred.
Extruding allows you to enter a length that is a distance from the original location. You can also cancel the extrude to leave the new vertices in the same location as the original vertices, then move the vertices (G) which allows you to enter x,y,z values as distance moved in each direction. The first number you enter is used for x then you can use tab to move to the y and z values.
Pressing Ctrl and Shift can also help - while you are moving vertices pressing Ctrl is a shortcut to enable snapping which by default will snap values to whole units (grid increment snapping type). Pressing Shift will slow down the movement to allow more precise placement. Pressing Ctrl and Shift will snap to 0.1 increments.
With loop cut Ctrl will snap to 0.1 increments, Shift will slow down movement and together will snap to 0.01 increments.

Thank you @sambler That was very helpful. Allthough the shift-key while extruding with the mouse is very helpful to know - and now helps me a lot, there is still some problems with the numerical extrude.
Maybe I was unclear in what I was asking for... I also would like to extrude the lines connected to the vertiges so they can be angled between the extrude-points.
Is that also possible to do with numerical input.?


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Array Caps (2 dimensions)
I am trying to use the array modifier. When I use the  object in the first image the result is a closed shape but it creates unwanted faces between the copies.

When I use the object in the second image the final result doesn't have a closed perimeter.

The use of caps is easily applicable in one dimension array. In a 2-dimension array things become complicated. Is there an effective and not over-complicated solution?

what exactly is your problem in the first case? because you know they are there? Do you have texturing problems?

I don't think there's any easy solution, is it a problem if at the end you apply the Array and fill the sides?

It is for 3d printing and the geometry should be manifold without internal faces.

@moonboots I want it to be non destructive. The size of the object will be variable.

Isn’t there an option in the array modifier that lets you add a cap object or something?

@TheLabCat Yes, it is very effective for 1 dimension array, but when  you add second array the result it's not as expected.

@artos use just a vertical wall as the cap object?

you could use geometry nodes. Use your 2nd option, and use GN with planes to fill your caps.

For the geometry you're showing, aiming for something non-destructive but simple, I would make the side walls with a rim-only solidify, and then weld the two copies of the sidewall that would be created by that solidify:

Showing 0 vertices non-manifold after convert to mesh.
For a small trade-off of non-destructive vs simple, you can drive the thickness of the solidify modifier from the distance between vertex-parented empties.
For different geometry, with normals that weren't at right angles to the main plane at the margins, this technique would still be possible, but more complex:

We do a miniscule solidify (because normals depend on non-zero-area-faces) with assignment to a VG, then modify our rim normals to point properly so we can do a displace from custom normals, weld (which will set some of our rim verts to weight 0.5) then finally mask away the unmerged rim verts.
The normals are measured from empty to origin, so the empty should be at the origin except for the Z axis, and should be parented to the object.

I want a more universal solution, that can be applied with more complex shapes.

i made just one side (the other can be made accordingly)

result:

Start with a cube, rescale it if necessary
Subdivide its top face into squares with loopcut
Select the square faces, resulting from step 2,  you want to extrude and extrude them down.

Done!
 I removed one face to show no internal faces were created. You need to calculate the number of sub-squares to match the size and number of the impressions, but it still is simpler than others presented here. If the above is still too much fuss for you then use array, your top image, with Merge option checked select all internal (or non-manifold) faces by hand and delete them with Faces Only option. Regarding your comment: use array as in your second and third image, extrude the edges of the mesh arrayed and close it with the bottom face.

Thank you, for effort. I know how to model a simple shape like this I want a more universal solution, that can be applied with more complex shapes and it has to be scalable. This was a simple object for reference.

@artos: No problemo, some speed modeling did the job.

source: Stack Exchange

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sort: votes


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Road / street network with geometry nodes: How to get all neighbouring vertices? Fit exactly instances on curves? Deform instances to multi curve?
Tried to make road / street network system with geometry nodes in blender. Plan is to instance street / road chunks on vertices and along edges in between intersections. Mesh topology have non manifold grid like topology with unequal edges and unequal columns or rows, I want to edit base topology by hand to fit the roads and intersections where I want, similar to cities skylines. I put junction nodes on vertex and straight road chunks in between them if they are connected with edge.

I will drop the file in a moment hope everything is packed right way.
Well blend exchange don't like the file, so here its 80MB google drive share:
https://drive.google.com/file/d/1DECLhFk0I8kH_-T0H6bTEF3wDGJOivIe/view
I have couple problems with that:

I can add junctions/intersections based on vertex neighbour count. Yet I can't rotate them toward sum of neighbouring vertices, it looks its impossible to get all neighbouring points of intersections to calculate orientation/sum of directions/vectors to them. And more exactly its hard to get neighbouring vertices ID's because indices are unpredictable and get scrambled when you edit mesh (for example subdivide or extrude verts). I would probably better of generate custom junction mesh for every spot like they did in matrix UE demo, but I would still need all neighbouring vertices for every intersection orientation. How can I get all neighbouring vertices, their indices / positions?
Another problem is I want to fit the straight road chunks along the connecting edge, so I turn every edge into curve with extra points but distance between them is rounded down to fit whole sample so there are always gaps between road chunks or they overlap + gap with intersections.
Road chunks would best deform to curve and snug fit the vertices. I found someone made custom deform array on curves, but it only works well on single curve not on geometry that have edges converted to n number of curves.

What I tried:

Edge Vertices Node + index node with field nodes but it outputs only 0 or 1 could
not pass needed vert index
I tried also some geometry selections nodes
I tried to guess the index of neighbours with field nodes but I can only get next and
previous one, but third or more is not simple index +1 or -1, and two
neighbours is not enough to calculate orientation.
tried a bit with Raycast node but I don't think it will work for non
grid parts of topology, reason is I  don't have direction to off grid
points to cast the ray there
I think maybe instead of converting edges to curves, converting them
to mesh lines would at least let me instance points at exact lengths yet I got
stuck when needed to angle them the same way as original edge, maybe its possible tho

I tried bunch of ways for couple days, but found no solutions, maybe someone can help.

Does merge by distance node help?

try like this perhaps
https://blender.stackexchange.com/questions/245282/how-to-bend-geometry-with-geometry-nodes

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how to stop light from going through glass
I'm relatively new to blender and I'm trying to make a solar system inside a sort of snow globe, is there any way to make it so that light from outside the globe doesn't come into it?

I'm trying to make the outside be white and the inside be dark without making the glass darker so it doesn't make the planets darker, is there any way to do this?
blender 2.92.0
cycles

Are you using Cycles or EEVEE?

@ChristopherBennett I'm using cycles

Sorry, i'm trying to figure this out here. You say you don't want light coming in, but you also don't want the planets to be dark - where are the planets being lit from?

@ChristopherBennett  they would be lit by the sun in the middle. when i said I didn't want the planets to be dark I meant that I didn't want to darken the glass

I've added a comparison image to my answer, maybe this helps to see the differences in the setup.

Try something like this - the refraction might suffer slightly, but overall it should perform as expected:

Here it is beside an identical setup, only with a plain glass shader. You can see the "modded" one is a little darker, but that could be attributed to "light not getting in". It still looks rather realistic, I would say:

I don't get it... I've made a comparison between my and your node setup, and although I suspected mine would be brighter than yours, I don't understand why it looks sooo dark when I've set it up. How bright is your environment? And the sun?

...I know you've just made it a solid glass ball whereas I made a glass material with a thickness so that the refractions look different in our answers, but I've checked that, it doesn't help with the brightness.

This is my node setup. It is quite simple and makes the reflections on the snow globe a little darker as if I were using only a regular Glass BSDF, but still it looks okay I think. I mix the Glass BSDF with a Diffuse BSDF set to black (so that the diffuse doesn't reflect light on the planets), as mix factor I use the Is Reflection Ray output of the Light Path node.
On the left, the sun and planets are in open space to see how they would actually be lit by the environment. On the right you can see the planets are dark where they don't get light from the central sun sphere.

To show this a bit better, I delete the central sun so that there could only be light from the environment falling into the globe, but it doesn't.

This also works if there is a bright point light outside the globe (I've taken down the environment to focus on other light sources):

And of course with other light sources like sun, spot or area light as well.

By the way, here is a comparison so you can see how the different node setups in Christopher's and my answer work out using my "snow globe scene":

Another difference between the setups is, with my setup the planets inside the globe get reflections on the glass inside, whereas they are not reflected in the other setup. But Christopher's node setup let's light from the sun shine on objects on the outside (at least when you make it very, very bright), but my setup doesn't let any light shine through to the outside.


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How can I improve the VSE preview performance (frame rate) with an inserted keyed/composite scene?

Blender 3.5.1
NVIDIA 3080 RTX
i7-12700F
The video sequencer cache limit is set to 16384 (I have 32G of memory)

I looked at this post which gave me the suggestion of increasing the cache limit.
I created a scene to chromakey (green screen) this clip: https://pixabay.com/videos/subscribe-button-subscribe-73041/
I converted the clip to 30FPS with ffmpeg to match the VSE project. The clip is Codec: H264 - MPEG-4 AVC (part 10) (avc1) (video) and Codec: MPEG AAC Audio (mp4a) (audio) (matches the original).

The composite preview area is set to a very small part of the 1920x1080 clip. You can also see that edit performance is set to low, "OpenCL" is checked, and "Buffer Groups" is checked.

Here is the VSE. Proxy render is set to 25%. The preview area is set to this small space around where the composite scene is inserted.
When playing the preview, as soon as Blender gets to the inserted composite scene, the frame rate drops to 8 from the target of 30. It doesn't matter if the preview has played once or multiple times. It doesn't ever appear to cache in a way that improves the frame rate, which contradicts the post referenced above regarding caching.
For a large or long keyed project, this seems like it can't be the way it normally works/normal performance.
Of interesting note, when looking at the composite preview area in the compositing tab and playing that scene, I never see the composite viewer move. It only moves when I click on an individual new frame in the composite scene, at which point I see an indication of "compositing" in the info area at the bottom of the Blender window.
Other than pre-rendering the scene to an image sequence and inserting that, what can I do to improve the frame rate on the preview here? I'm assuming I have something wrong either with my composite/keying settings or something else.
Update:
Pre-rendering the scene to an image sequence (with transparency) and inserting it resulted in marginally better performance, but it was still quite slow (~10fps) and would sometimes cache and sometimes not. I think the slowness may be because the output is a full 1920x1080 image that's mostly transparent.


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How can I add noise/randomness to an object position after sampling a curve with geometry nodes?
I'm working towards making an intro video similar to the old FIA F1 intro:
https://www.youtube.com/watch?v=qgiBkydMW8k
I had some questions about path following previously:
How can I have multiple objects follow a single path but maintain their original offset?
I've got a good set of nodes now for creating a "noisy" curve and causing the object to follow that path (original file):

I'm struggling now with adding "random noise" to that path follow. In other words, as the object follows the path, I want to randomly insert noise into the position/translation or rotation or scale. Unfortunately, I'm struggling to figure out how to do this. If I manage to get anything to "add," it usually ends up deforming the object and not actually moving the object.

adding an additional "transform geometry" works, but whenever I try to plug something into it, the line turns red:

using set position with the offset and a noise texture results in the object being deformed:

I'm not really sure how I can add some randomized translation/rotation/scale to this object after the path follow is implemented. Can someone help?
Updated file:

Updated nodes:

Add Noise Texture to the Position
You're using a Sample Curve node to get the position along the path. If you add noise to this position you should get the jitter you're looking for.

A General Case
For a more general case in which the object is being translated in world space rather than along a curve, use a Set Position Node:

The Set Postion node will set the position of each vertex in the geometry base on the inputs.
We want to offset the position of each vertex based on the object's location in the world. Use the Object Info node to obtain the object's Location. run that through a Noise Texture node to get some randomness to the movement. Plug the resulting vector into the Offset input of the Set Position node.
Now the cube will appear to wiggle randomly as it moves through world space.

Is this an additional geometry node setup that you've attached, or is this the only thing attached to the cube?
When I tried to use "set position" with my blenderfile (shared in the OP), manipulating the offset did not move the object (no input to set position other than me manipulating values directly)

Actually, set position will offset the object from the curve, but if you look at the edit/picture I just made, adding noise to the offset results in deformation of the object and not actually movement off the path.

OK, I've updated my blend file above and when I move the object in space (eg: g+x) it does jiggle around. However, as I manipulate the "factor" setting for the curve sample (which is how it's following the path), it doesn't jiggle around. Whatever the singular value of the original position of the object was is offset by some noise, but it doesn't update as it follows the path.

@ErikJacobs I updated the answer for your specific case where the desired object position is coming from the Sample Curve node. You can add in the noise right there

This is working almost perfectly, but in my particular case, it is now losing the "anchor to start" aspect. The noisyness needs to stop at the original position. The YT video has the noisy letters flying in and ending up in their final resting position, which is what I'm trying to achieve here. I tried plugging the output of the anchor to start block (map range) into various places before the transform geometry from your modification but was unsuccessful.
Q: How would I limit the injected noise to zero at the "start" of the curve?

Multiply the noise vector by the fac value of the curve. if the noise is multiplied by 0 (which is the value at the start), there will be no jitter there. I can add to the answer in a bit but I’m afk currently

I'm not sure where to pull the fac value. The "factor" output of the Sample Curve node appears to always be zero regardless of the factor setting of that node. I'd be thrilled if you could add it but a little more direction might enable me to figure it out on my own.

Well, I tried an experiment, and it seemed to work. Let me know if that's what you were thinking. I used a "value" node and then piped its input into the "factor" setting of "sample curve." I also piped the "value" output into a new multiply node that sits between the existing multiply and add nodes. This effectively multiplies the noise vector by the value (which would be 0 at the start of the curve and 1 at the end of the curve). When I slide the value node's value around, the object "finishes" at the curve origin and is noisily displaced as it moves!

Excellent! yes I was thinking along those lines! nice work


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How to UV-Map a complex plane?
I'm having trouble adding texture to a complex plane object, where can I place the seams so that the UV-Map doesn't appear very distorted and overlapped.
Here is the file

here is the file:

Please update your question with more detail to describe the issue you're having - preferably with screenshots - so that people can understand your issue without having to download your blend file and make assumptions. This will make it easier for someone to be able to help you while also making the question more accessible to someone else who may be experiencing the same problem.

@Rich Sedman I "edited" the question so that people can understand my problem better...

In your case, I would separate the pillars from the rest of the mesh, if they are buildings. Otherwise, they are okay.
There are lots of techniques for unwrapping, but here are a few things to keep in mind.

You can use more than one UV map on an object. For example, you could "project from view, bounds" for the top of the mesh, and use a texture for the ground surface, then unwrap the sides of the pillar on a different map, and use a different texture for that.
Smart UV unwrap usually does a pretty good job, and you can base your unwrap on that if you want.
It is not always necessary to unwrap an object, if you want it to be textured. Your best and simplest bet may be to use generated coordinates with box projection.
You usually want to mark seams on sharp angles, and places that are hard to see, like the bottom of your pillars.

I noticed you are using "Blender Render", not Cycles. Are you sure that is what you want to do? From my knowledge, texturing can be easier in Cycles and many of the tips I suggested only work with Cycles nodes, as far as I know. I don't know very much about Blender render though.
Just some tips, I hope they help. Here is an example of using box projection on your model.

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Split long thin faces into less elongated ones
I am processing OBJ files generated by another program. This involves tidying the mesh, marking the seam and unwrapping. It runs in background mode.
The input OBJ files often have very long thin faces in areas of tight curvature that cause issues with unwrapping. I have a solution that picks vertices either side of an area of long thin faces and uses bpy.ops.mesh.vert_connect_path to cut the faces. This works, and produces a minimally distorted UV. It's rather clumsy though, and generates so many Assert stack traces that I had to pipe stderr to /dev/null, but it does work!
So I am looking for alternative solutions. The basic intention is to identify all long narrow faces and then split them into smaller faces that are a bit closer to squares/equilateral triangles. bpy.ops.mesh.subdivide, and other functions such as triangle fill and poke are not useful because they split the face into more faces that are just as narrow. Looking at the bmesh functions, I came across bmesh.ops.bisect_edges, bmesh.ops.connect_verts, bmesh.ops.triangulate, bmesh.ops.subdivide_edge and bmesh.ops.triangle_fill, but the documentation is a bit sparse.
What would be the most efficient method? I can identify the problematic faces quite easily, but I'm not sure of the best way to split them.
Here's what I'm currently using. I have a list of tuples of BMVerts It was easier to identify them using bmesh, but the vert_connect_path operator uses MeshVertex, so I'm making the rather dodgy assumption that the indexes are the same:
    (looping around the X=0.05cm ring while in bmesh and pairing up vertices)
        vertPairs05.append((topLeft05XVert, bottomLeft05XVert))
        vertPairs05.append((topRight05XVert, bottomRight05XVert))
...
# more processing (which doesn't delete anything but does add faces to fill the other end), then save:
...
bm.to_mesh(me)

bpy.ops.object.select_all(action='DESELECT')
scn = bpy.context.scene
scn.objects.active = bpy.data.objects[0]
bpy.ops.object.mode_set(mode='EDIT')
bpy.ops.mesh.select_all(action='SELECT')
bpy.ops.mesh.customdata_custom_splitnormals_clear()
bpy.ops.mesh.normals_make_consistent(inside=False)

for pair in vertPairs05:
    bpy.ops.mesh.select_all(action='DESELECT')
    bpy.ops.object.mode_set(mode='OBJECT')
    me.vertices[pair[0].index].select = True
    me.vertices[pair[1].index].select = True
    bpy.ops.object.mode_set(mode='EDIT')
    bpy.ops.mesh.vert_connect_path()

This works, but takes about a half to one second for each path, and generates a number of Assert errors and stack traces, all apparently identical:
blender(BLI_system_backtrace+0x33) [0x560a2b4dfe93]
blender(BM_face_splits_check_legal+0x56f) [0x560a2b02dd8f]
blender(+0x163c365) [0x560a2b065365]
blender(bmo_connect_verts_exec+0x5ba) [0x560a2b0659aa]
blender(BMO_op_exec+0x31) [0x560a2b026901]
blender(bmo_connect_vert_pair_exec+0x1091) [0x560a2b0689f1]
 ...
BLI_assert failed: /build/blender-Nh0fvZ/blender-2.79.b+dfsg0/source/blender/bmesh/intern/bmesh_polygon.c:1164, BM_face_splits_check_legal(), at 'BM_face_is_normal_valid(f)'

Using Blender 2.79, the Ubuntu package for 18.04.4 LTS. No reason why I couldn't install a more recent version of course.
I'm using Bmesh for analyzing the mesh because it's a lot easier to navigate around with it. I'll do some more research on those functions I came across above, but my reason for posting was because splitting a face seems like an operation that others would hopefully have encountered before.

UPDATE 2:
Here's a Blend file showing the long narrow faces that have been produced, and the resulting distortion in the UV.

From a different blend file

Showing how my first attempts at cutting the faces have resulted in much less distortion.

Added some more info. Edge loops - had a look at this, but it looks as if it requires a 3D viewport - I'm using Blender entirely in background mode.

Sorry, meant Loop Cuts.

Searched the Blender docs for Modelling Tag for a while, until I worked out what you meant! I've tried gridfill a few times; I'm not sure how to select two pairs of edge loops since the region isn't particularly "square". But I'll persevere; there must be be a better way to do it.

Cheers for the edits.  Would consider taking out the error messages and replace with code your are using that creates these errors.  My guess is you are killing bmeshes and meshes with toggling modes.  If can find a bmesh way can dispense with this horror.  (and TBH Haven't DL'd and looked at files baulked at screenshots, sort of thing that might take 5mins or 5 life times to script.. but once I start...)  btw I use Ubuntu 18 too.  Don't let the so called "Software Updater" hold you back to v2.7.

Cheers for the bounty - I see you're the same one who answered my last question two years ago! Things have progressed since then.
Perhaps the simplest way would be to just bisect all long edges in bmesh, and use bpy.ops.mesh.fill() or similar to subdivide the faces. I might just try that.

As a side note... It seems you have too much area distorsion at the end of the board..., that's probably because of the cut... Your board is cylinder. It looks like you're trying to unwrap it with the caps on, by using a straight planar cut by the sides. That way the unwrapping algorithm is forced to squash everything down. Angle distorsion appears to be ok... Maybe with a better cut, much of the distorsion will go away...

I cannot get your script to run.

Half the problem is that the OBJ file I'm given has come from another program over which I have no control, and is just a topological cylinder. I can't give out full details of everything I'm doing on it (hence the script won't run by itself), but the OBJ mesh does need quite a bit of tidying up!

I've done some research and tried a number of methods, so I'll document them here. Feel free to improve on my rather basic Python!
First some code that identifies the long edges, and bisects them (adds new vertices along the long edges:
import bpy
import bmesh
from mathutils import Vector

...

# There's only ever one object in the data I'm processing. Could also specify by name
# e.g. bpy.data.objects['surfboard'].data
me = bpy.data.objects[0].data
bm = bmesh.new()
bm.from_mesh(me)

EPSILON = 1.0e-3

...

longFaces=[]
edgesToCut={}
for vert in bm.verts:
    if abs(vert.co.x-0.05) < EPSILON:
        for edge in vert.link_edges:
            leng=edge.calc_length()
            if leng > 0.4:
                for face in edge.link_faces:
                    longFaces.append(face)
                cuts=int(leng/0.2)-1
                # Categorise according to number of cuts, for efficiency because
                # bisect_edges can cut more than one edge at once.
                if cuts not in edgesToCut:
                    edgesToCut[cuts] = []
                edgesToCut[cuts].append(edge)

for cuts, edges in edgesToCut.items():
    bmesh.ops.bisect_edges(bm, edges=list(set(edges)), cuts=cuts)

This focusses on the edges connected to the x = 0.05cm line, which are the issue for me, and assumes that if a face has a long side, it must be thin, which is true for the cases I'm dealing with. This could be altered to suit, e.g. to actually measure the width and make cuts based on how thin the face is. But the idea is to find the problem faces and add extra vertices where they will be useful.
I use list(set()) to weed out duplicates.
Next, I could use
bmesh.ops.triangulate(bm, faces=list(set(longFaces)))

which will automatically split each face into triangles. However for me, that just creates lots of long and even thinner triangles than the faces I split, which actually makes the unwrapping worse. So I devised a manual solution by scanning the vertices on each of the faces and measuring to the nearest vertex on that face. If they're not already connected, then I can mark them for connection:
# For each face, test if each vertex is connected to its closest sibling
longFaces = list(set(longFaces))
vertsToJoin = []
for face in longFaces:
    edges = face.edges
    # Make a mapping of the vertices on each edge
    connectedVert = []
    lastVert = False
    firstVert = False
    for vert in face.verts:
        if lastVert:
            connectedVert.append((vert, lastVert))
            connectedVert.append((lastVert, vert))
        lastVert = vert
        if not firstVert:
            firstVert = vert
    # and join to the beginning
    connectedVert.append((firstVert, lastVert))
    connectedVert.append((lastVert, firstVert))
    for vert in face.verts:
        # What's the closest other vertex?
        minLength = 9999
        minVert = False
        for vert2 in face.verts:
            if vert != vert2:
                vec = Vector(vert2.co - vert.co)
                if vec.length < minLength:
                    minLength = vec.length
                    minVert = vert2
        if minVert\
                and (vert, minVert) not in connectedVert\
                and (vert, minVert) not in vertsToJoin\
                and (minVert, vert) not in vertsToJoin:
            # Only join if they're the closest and they're not connected already
            vertsToJoin.append((vert, minVert))

At this point I tried bmesh.ops.connect_vert_pair; it seemed logical! However it's actually quite slow; even though I give it two vertices on the same face, I suspect it may be pathfinding elsewhere too. If I set faces_exclude to [all faces minus the one I want it to use], it deletes the face and doesn't connect anything. I'm not entirely sure what the exclude parameters do; there are very few examples of their use. But I did find this tiny nugget in the source code regarding them:
/* tag so we won't touch ever (typically hidden faces) */

So I wrote the following code to take each pair of vertices and join them, thus splitting the faces, checking that there's exactly one face in common with each vertex pair:
for vertTuple in vertsToJoin:
    # Could use bmesh.ops.connect_vert_pair but it takes a couple of minutes.
    # This takes about 45 seconds.

    # Find the common face, which may not be the one we had earlier
    commonFaces = list(set(vertTuple[0].link_faces) & set(vertTuple[1].link_faces))
    if len(commonFaces) == 0:
        print('Vertices not on same face?')
        continue
    elif len(commonFaces) > 1:
        print('Vertices on multiple shared faces!')
        continue
    face = commonFaces[0]
    firstFace = []
    inSecondFace = False
    secondFace = []
    for vert in face.verts:
        if inSecondFace:
            secondFace.append(vert)
        else:
            firstFace.append(vert)
        if vert == vertTuple[0] or vert == vertTuple[1]:
            inSecondFace = not inSecondFace
            if inSecondFace:
                secondFace.append(vert)
            else:
                firstFace.append(vert)
    bmesh.ops.delete(bm, geom=[face], context=3)
    bm.faces.new(firstFace)
    bm.faces.new(secondFace)

That last code block takes by far the longest (of the identify faces / bisect edges / split faces process), but is faster than the other face splitting methods except triangulation.

Do I get to claim my own bounty? Perhaps I'll give them a sporting chance!

You are in the box seat.

Some way there
With regard to your answer so far, and with no chance of getting the bounty thought I'd add an answer to demonstrate the direction I would try
The concept is to find all the skinny faces and dissolve them and grid fill the resulting ngons.
Script below:

Removed doubles

Looks for faces that the long edge to short edge ratio is > 40  (Used this to select and check until a ration was found that fit, worth noting that the bad bits are, as I see it mainly on the ends.)

Disolved these faces to make an ngon.. in a "perfect world" could remove the gon and fill its edges.. but alas

Here is the script so far, result below.
import bmesh
import bpy
from math import sqrt # an area test?

context = bpy.context
ob = context.object
me = ob.data

bm = bmesh.from_edit_mesh(me)
bmesh.ops.remove_doubles(
        bm,
        verts=bm.verts,
        dist=1e-6
        )
# long skinny faces
def skinny_face(f, ratio=40):
    #area = f.calc_area()
    edges = sorted(e.calc_length() for e in f.edges)
    return (edges.pop() / edges.pop(0)) > ratio

'''
# make a select skinny faces operator?
for f in bm.faces:
    f.select_set(skinny_face(f))
'''

region = bmesh.ops.dissolve_faces(
        bm,
        faces=[f for f in bm.faces if skinny_face(f)],
        )["region"]

for ngon in region:
    ngon.select_set(True)
    continue
    edges = ngon.edges[:]
    bm.faces.remove(ngon)

    bmesh.ops.grid_fill(
            bm,
            edges=edges,
            )

bmesh.update_edit_mesh(me)

Until the ngon is more regular, (eg removing forms a nice edge loop) the grid fill operator will spit the dummy.
Instead of grid fill can also look at bridge edge loops by walking edges and splitting into 4 then bridging 0 and 3 or 2 and 4.

back of board
This isn't bad... and converging on the one ngon.  Could look for and dissolve faces that border an ngon on more than one edge.. to grow this to the shape till  good to fill.

front of board
Issues.  Possible fixes.

Dissolve the verts (one ringed in red) that appear to be a mirror modifier converge issue.. Look for verts with a high number of linked edges.

Back from another view showing the turn around, feel this needs a scale and edge slide approach but is a bit above my modelling ability.

Not sure if I can claim the bounty either! I've spent the last couple of days looking at the output of another program, which has different issues but some of the techniques we've explored here should prove useful. But it might also suffer from the "vertex with a million edges" issue, so I'll be scanning your post in the days to come. What did you mean by a "mirror modifier converge issue"?

No point in not awarding it.  The way the longitudes of the board converge to long axis, like a pole on segment of uv sphere. There was a comment re this.

I see you're not short on reputation. Righto; thanks for the boost - perhaps I can start answering other people's questions! Pardon me, I must go and polish my Tumbleweed badge.


text:
Render shows a different frame as the Viewport (Frame-Number is the same)
Hello dear Blenderheads,
I have a problem :)
I testet some animation stuff and when i render a frame, Blender renders some different frame instead of what i see in the viewport. But the frame-number ist the same in viewport and rendered frame (in ImageEditor). Does someone has a hint for me? There is only one camera.
Hope you can help, thanks :)

only an mp3 audio file. can it interfere? ps. it's already disabled

Maybe there's animation for the objects in the scene created and you moved them without saving new position into key frame?

unfortunately no. the only object that is moving is the camera, the rest only changes material property, as wanted.

When I've stuck this sort of thing I clear out Blender's Temporary folder and importantly, any cache files/folders it has inserted into the project's folder.  That often clears out the gremlins.

@Edgel3D  Never thought of that. I deleted all files in the temp folder (\user\me\AppData\temp) which path i looked up in "user preferences". Are there other files/folders that i missed? Still no change.

Daniel M   Another might be "Render Cache", and perhaps the "Textures" folder.

@Edgel3D how do i delet those?

Just had a look in my Blender folders, and apart from that ..\temp one you mentioned, I can't see any that might hold cache files etc  When the inexplicable is happening, I tend to question the codec of the video in the VSE, render or convert it in another application to e.g. avi, see if the same trouble occurs in Blender with that.  I've had problems with some mp4 videos and that's how I overcame those.  Nodes in the compositor can affect things also.  Untick it's box in Render Properties  at right-->Post Processing tab.

added to the above - could you be rendering from a camera or the scene (3D) window?  You appear to be seeing something entirely different to what's in the VSE.

I only render the camera (there is only 1 camera in the scene) and i have only this one scene. In the VSE there is only an mp3 to sync the motion with the sound and it (VSE) is deactivated for postprocessing.

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


text:
Renders not showing at all
So I'm working on . stupid noob question of the day here but I'm absolutely stumped. I was doing a tutorial on mist and volumetric lighting and only 1/2 following along and all of a suddenly I can only render in viewport. When I set up a render rather than a viewport preview render I get nothing but a black screen. The programme no longer goes round and collects and syncs the files, theres no little square boxes developing a picture.....nada! What button(s) did I hit that turned off the render function? What did I do? I've rebooted the whole system, I've gone back to previously saved files that rendered fine before .......seriously nothing......well a 5 second pause and then a black frame.


text:
Why do some bones look like boxes and others like arrows?
I've been looking at tutorials on how to rig a model and found this one.
Why does this guy's bones look like boxes while all the others look like triangular arrows? Is there a functional difference or just for ease of viewing? How do I enable/disable this display?

Here are the different shapes for an armature. Also the different controls for changing it. It is for you to decide what you want to use.

The one exception to this is that if you create your vertex weight from envelopes, you can view what will be affected with the envelope option. You must go into edit mode to see all details. More about it here:
http://wiki.blender.org/index.php/Doc:2.6/Manual/Rigging/Armatures/Editing/Properties

The boxes could also be Custom-Shapes. The tab shown in the image is only availabe in Pose or Object Mode. From the layer panel in your screenshot I would guess that the custom shapes are at layer 11 (The one under layer 1 which is currently selected).
Here is an example of a rigify-rig:

I assumed the boxes were boxe with rendering mode set to wire. Can you tell the difference?

@Gunslinger At first sight I was pretty sure that the boxes are custom shapes because they are displaced. But you're right it could also be the wire frame display option, I changed the text to make clear that it is only another possibility.


text:
Script to change Text Editor font display so Symbol Fonts and Extended Characters can be referenced
As asked and answered in a previous question,  Blender 2.6 handling of extended characters in font sets is bit awkward, aside from specific special characters
The workaround solution is copy pasting ALT### from other apps into the redo panel when editing text objects or copy pasting from other apps into text editor then using text to 3D Object.
Blender 2.4 had a character panel and 2.4 reference documentation mentions making fonts as well, where 2.6 reference omits these options.
So essentially, is there a script way to change/toggle the text editor itself to use fonts other than the default so that symbol fonts can be shown in the text editor in the process of modelling. This, as opposed to using several text objects with the font applied that sadly needs many copy/paste translation to get the full font character map set displayed.

Related http://blender.stackexchange.com/questions/3522/how-can-i-add-text-in-arabic/5118#5118 http://blender.stackexchange.com/questions/4801/how-to-write-all-characters-in-a-font-to-a-3d-text-object/4804#4804 http://blender.stackexchange.com/questions/6920/how-can-a-text-object-be-created-with-non-ascii-characters

You can enable International Fonts in CtrlAltU> User preferences > System to display special characters:


text:
Parent bone temporarily?
I asked a similar question before, except this time instead of parenting objects I want to parent the gun magazine bone to the left arms wrist for a bit, then set it back to the gun bones.
My arms and my gun are all one armature, so I only have one armature in the scene.

What about using a child of bone constraint? BTW, tags like "gun" and "clip" aren't really good blender-related tags..

All i see is "Child of" And then i can only use objects , i dont see "Child of bone"

OH ... FOund it ....lol

It's in the Bone constraints section

You can use the same technique as before, but using a bone constraint.
The only difference is that you must add the constraint from Properties > Bone constraints panel instead of the Constraints panel, while in pose mode:


text:
Use Blender's file browser via python, without a UI panel
I am trying to run a script that prompts the user for a desired directory and file name for export. Ideally, this script would be run from the File -> Export menu and pop up a file browser window similar to how the included export scripts function.
The only way I've found to call Blender's file browser is via a file path property for a UI panel (i.e. How to add a "select path" input in a UI addon script?). Is what I'm trying for possible?

Blender comes with a template for this, see:
Text Editor -> Templates -> Python -> File Export
Run the script, it will execute immediately (which is just for testing), but it also adds a menu item to the export menu.


text:
Is it okay to have more vertices on the hand then the rest of the body?
I'm trying to create a female model but I'm having a quite a hard time to create the hand from the wrist so I made it separated. Is it okay to do it with in the future I'm trying to rig them?
Example like this:

Why wouldn't it be ok? What problem is this causing?

Currently there's no problem. Just wanna know if there will be any problem if I wanted to rig it.


text:
How can I have multiple objects follow a single path but maintain their original offset?
Ultimately I'm trying to make something along the lines of:
That titbit. In an IDEAL dream scenario, I would like this with VWSC letters: https://www.youtube.com/watch?v=qgiBkydMW8k

I am trying to build up an animation where all of these letters fly in. There are a tremendous number of objects here. Trying to make a unique curve for each object to fly in and then set up all of the individual path constraints etc., seems like it would be a challenge. There has to be a better way.
Unfortunately, when I try to make the W follow the path of the bezier curve where the V already is, it all goes out the window.

You can see here that the W has been moved off into lala land. I cannot even get it remotely close to its original location. The cursor is at the original location, and attempting to move the W object to the cursor doesn't really do anything to improve the situation.

Selection to cursor moves the W off into another lala place
Selection to cursor (keep offset) doesn't improve things

I tried redoing the logo and not having all the objects share a parent axis, made a new bezier curve, set the end point of the bezier to share the origin with the "V," added a path constraint, and now the V is doing the same thing -- way off in lala land. "Selection to cursor" just sends the V off to some other crazy location, nowhere near the actual cursor.
I am really struggling here.

Why do my objects keep ending up off in space when attached to a path and told to follow it?
How do I get the objects back to their original positions, regardless of where the path is?

** EDIT
After calming down a bit  I used "Alt-G" to reset the object position, and now I have both the V and the W along the path:

However, what I really want is for the W to end up at its original location. Once it's attached to the path, trying to use G-X to move it at all even a tiny bit moves it A LOT. The "location" values also no longer really make sense.
When I get the W to the end of the path and then try to use "selection to cursor" to move it to where the cursor currently is, it zooms off to lala land. Selection to cursor (keep offset) does no better.

Hello please share your file

You would probably fare better by using several curves, then your objects would transition from A to B differently from one another and it would look more like your reference.
Regardless of whether you use a single curve or several, you should be aware that :
1.the curve object has to be untransformed, otherwise these (the transforms) will add up to the final transformation of the constrained objects.
2.the constrained objects' transforms will also add up to the constraint effect, so their relative positions before creating the whole setup matter. More specifically in your case, they should be placed in relation to the path's endpoint.
Here is an example using a single curve for several objects :

Note that I didn't use the constraint's "follow curve" option, because it makes the final placement of the constrained object dependent on the curve tilt, and it can be a pain to line up so that the object is oriented exactly like you want. If you still want to use it, you can work around that by easing in a Copy Rotation constraint on the object in the final frames of its travel.

Thanks for the tips and the blend file! I hadn't thought about the transformation on the curve object. When instantiating the Bezier, I was scaling it and not moving its vertices. That probably has a tremendous amount to do with it.
Do you have any thoughts on how to do this with multiple curves easily? Someone suggested geometry nodes. Individual curves is a TREMENDOUS number of curves (well over 30). Granted I can duplicate them and then reposition them, but, still, some kind of mathy way would likely be better.

Yes, usually don't transform objects unless you know what you're doing, prefer transforming the data (points, vertices...).
If you turn your individual letters to instances you can animate them along a procedurally generated spline (which can be any shape). But that is a completely different way to go about the problem.

I'm not sure what you mean by "turn the individual letters to instances." Each letter right now is an individual object that came in from an imported SVG. When importing SVG you get really tiny things, so I did end up scaling those before applying extrusions to make the characters 3D.
Do you happen to have a YouTube or blog-type link to the technique you're describing (procedural generated spline animation)? Are you suggesting procedurally generating many splines (curves) for the letters to follow?

If creating and animating 30 objects along as many curves seems like too much work, then yes, generating curves procedurally can be simpler. If you need to change something over all the objects, it can be done quickly instead of having to replicate the change on every object. This is the main advantage of the procedural approach.
Here is a file to get you started : https://blend-exchange.com/b/M7E36X4v
I've highlighted some of the nodes that are pivotal to this working (in orange/yellow).

How did you add the lone "dots" in the geometry node editor so that you could more cleanly route the node connection lines? I can't figure out a search term that produces a good result.

These are reroutes, you can add them with shift+click+drag over connections

Thank you so much!


text:
How can I temporarily follow a path that's animated via cycles?
I'm trying to have an object swoop in and then begin following a path. This post kinda sorta seems relevant, but I have an added hitch.
I've got a Bezier curve that is moving, and I'm doing so via a cycles modifier. This is part of an "infinite loop" animation where the roadway appears to be going on forever. Imagine an Outrunner-type video game-looking scenario where the road keeps coming.
The "road" is an array-modified plane that is deformed along the bezier. That whole thing is a collection:

All the objects in this collection are parented to an empty axis. That axis moves (which moves the roadway), and that movement is a cycled animation (every 60 frames).
The object moves into the frame, and at some point, the object should then begin to follow the path.
The challenge I'm having is when I get near the next cycle where the roadway "resets" and moves back to where it starts from. The object is "ahead"/in front of the camera a bit:

The object gets to the end of the Bezier curve and then cannot be offset any further, so it ends up leaving the path:

I tried using an array modifier on the Bezier curve to make it repeat, but the follow path constraint (for the object) doesn't seem to understand or acknowledge the array modifier (for the Bezier it's constrained to). While it LOOKS like the Bezier continues, that's actually a different instance of the "RoadObject" collection, so that bezier is not what we're following.
If I modify the transform (location/rotation) of the axis following the path at all in between the time where we are leaving the path and the time the path resets several frames later, it totally screws up the orientation of the object for future path following, so that doesn't seem to work, either.
I realize this all sounds like a mega hot mess. Here's a simplified example file that mostly achieves the same challenge. At frame 89, the Suzanne is at the end of the current curve, but it's not until frame 119 before the cycle resets again. The Suzanne should continue to follow the path "forever" (until some frame in the future where I'll essentially keyframe the influence back to zero).

why don't you just make the beziercurve longer (e.g. turn into mesh, array modifier), turn into curve again and then adapt your animation to that? that's much easier.

There is a stupid/simple solution to this problem: double the length of the path being followed, but "reset" the camera in the middle. In other words, the cycle is still looping at the same physical point in space, but the real object is now twice as long. This allows the real path (not another instance of the path) to extend much further past the camera, so now the follow path constraint can still work.


text:
Swirly bokeh like that of a Helios 44m 2/58?
I recently discovered the Helios 44m, a lense which produces some awesome swirly bokeh effect unlike anything else I've seen. I can't get one for myself, but I was wondering if there's a way to recreate this? I know the basics about DOF and I can somewhat achieve bokeh in Blender, but that kind of effect would require something else, probably some compositing? Or is it much more simple? Anyone out there capable of achieving something like that? It'd be lovely for some vintage renders.

Do you have an image of exactly what you are going for? Depending on the image, I am sure there is a way to fake it.

I added a picture of the swirly bokeh.

This answer will achieve a similar effect, not quite the same or as good as what you are probably looking for. The problem is I couldn't find a way to get the bokeh dots to 'light' up or contrast against the other ones more - essentially I couldn't get them to look more like bokeh dots... maybe less motion blur? I am not sure. With that being said, this may work well enough for whatever project you are doing. Hopefully, this answer can serve as a good starting point for you to build off of or give someone else an idea to build off of as they form their answer.
Essentially I will just be using tiny refraction circles with traditional depth of field combined with motion blur to achieve the swirling effect. Here are a couple of example renders that I added the effect.

How to achieve the swirly effect
We will follow these steps in making this swirly bokeh effect:

Make the small 'Bokeh Dots'
Adding Depth of Field
Adding Motion Blur
Compositing (Optional)

Make the Small Bokeh Dots

Create a circle and fill in the face
Put the circle close to the camera in your scene as shown in the pic with two array modifiers. Look at the picture for guidance on how big the circles should be and how to set up the modifiers. I find that the circle should be just big enough to fit 70 by 40 (array modifier values) on a 16:9 ratio camera.

Add a Material to the Circle and set the surface node to a refraction node with a Roughness value of 0, IOR value of 1.2ish and set the color to as white as you can go.
Apply the Array Modifiers and then go into Edit Mode and press p and select separate by loose parts - separating them may take a while!
In Object Mode with all the circles selected, go to View->Set Origin->Origin to Geometry.
Open search by hitting F3 (or space if you go legacy hotkeys) and type Randomize and click Randomize Transform.
On the bottom left, change the randomize transform settings and click "Scale Even" and change the x scale value to a value around .5 (or whatever you like). You could also mess with the random transform values a bit, not a lot, but a bit.

And boom you have small bokeh dots! (I skipped this step in the render with the white balls and monkey heads because the white balls were the bokeh)
Adding the Depth of Field & Motion Blur
Go to your camera and enable depth of field. Adjust the values to how you like. I find that distance values around .5 with F-Stop values of around 3 work well.
For the Motion blur

Press 0 to open your camera view, stay in camera view for the rest of the steps.
Select your camera and press i and click key frame rotation.
Go back one frame from the current, press r, type in -45, press enter, press i and click rotation.
Return to the current frame by going forward one frame. Then go foward one more frame and press r, type in 45 (this time its positive), press enter, press i and click rotation.
Return to current frame by going back one frame.
Go to the render panel and turn on motion blur. Set the shutter speed to around .05ish

 Optional Compositing
I noticed that the blur seemed a little more oil painty than the results so I attempted to make the render a little more oil painty using this post-processing trick. It is easier to set up than you think. For the color ramp, just select a point and keep pressing the plus button to add more points halfway in between. Then just change it to constant and duplicate it for all the RGB channels. This is the only post-processing that I could think of, maybe someone else will think of more.

It's like a Monet filter  8*)

Oh wow, the one with Suzanne looks awesome, it looks exactly like what I was looking for. I don't know if someone will find a "simpler" way, but yours is pretty good. Thanks!

You can use a panaromic lens type and play with the ratio of the aperture:

Sunny Vondelpark from HDRIhaven


text:
Cycles Realistic Lighting & Emission material
I've been reading a bit on realistic lighting in Blender and was introduced to realistic physical light values, as well as color management through Filmic Blender and the Exposure slider.
This excellent tutorial suggests that the value for direct sun lighting outdoors is a whopping 441 units. This completely blows up the lighting in the scene, making it look bathed in nuclear fire.
A swipe of the Exposure slider in color management fixes that. However, if I'm not mistaken, this also messes with other light-related things which are organized around more "relaxed" numbers, including...
The Emission shader.
I have a character with glowing eyes. In my "regular", unrealistic, "if it looks good it works" lighting setup, I used a Strength of about 4 to control the emission on her eye textures (combined with the Diffuse via an Add shader), which made them look sufficiently glowy. However, with sun lighting cranked all the way UP and exposure all the way DOWN, it feels like they barely glow anymore.
Blender docs say the following about Emission shader strength:

Strength of the emitted light. For point and area lamps, the unit is Watts. For materials, a value of 1.0 will ensure that the object in the image has the exact same color as the Color input, i.e. make it ‘shadeless’.

This confuses me. Does this mean that Emission material strength doesn't change regardless of the lighting? How can you even go beyond "shadeless"? Does this mean Emission materials don't use Watts as a unit, and so I can't apply the realistic lighting technique?
TL;DR

Do materials need to be changed according to the scene (lighting, exposure), or is the simulation realistic and materials only need to be configured for their realistic physical properties?
Is it normal that realistic light values completely destroy the scene when using default Exposure, and it needs to be dialed way down?
Is there a way to calculate realistic, physically correct emission for materials? (Ex. the emission of an LED lamp on a monitor)

Strength of the emitted light. For point and area lamps, the unit is Watts. For materials, a value of 1.0 will ensure that the object in the image has the exact same color as the Color input, i.e. make it ‘shadeless’.

This is junk documentation, written by someone that clearly doesn't understand scene referred values.
A material albedo value of 1.0 means that 100% of the light is reflected back. This does not result in the exact same value as the colour input, which depends on the transfer function and other potential sweeteners in the transform from the scene referred to the display referred domain.
While I can't answer the wattage question any better than the other answers on this site already well written, I can speak to exposure. Exposure is always a creative choice. Glowing eyes will likely always be less glowing than a screaming ball of fire in the sky that is gargantuan. That is a creative issue that could be negotiated with creative compositing or creative exposure within your scene.

Does this mean that Emission material strength doesn't change regardless of the lighting?

Emissions are scene referred. That is, the effective range of a value is some potentially infinitely small value to some potentially infinitely large value. If you set an emission to 146281.8, it is that value. How that value ends up in your image is a complex byproduct of the aforementioned transform from the scene referred to the display referred domain. That is, think of the transform as a sort of film stock. Various film stocks may have different colour responses, different dynamic ranges, and a few other aesthetic elements that will take a physical scene quantity of light and convert them into an aesthetic output.

Do materials need to be changed according to the scene (lighting, exposure), or is the simulation realistic and materials only need to be configured for their realistic physical properties?

Starting with physically plausible values is a great entry point. Ultimately however, materials should serve the creative needs.

Is it normal that realistic light values completely destroy the scene when using default Exposure, and it needs to be dialed way down?

Is it normal for a camera to take an overexposed photo when set to manual? Same idea applies here; exposure is a creative choice, as is balancing lighting in a scene, either starting with realistically plausible values or creatively lighting a piece with artificial sources.

Is there a way to calculate realistic, physically correct emission for materials? (Ex. the emission of an LED lamp on a monitor)

Yes. This is a duplicate question with more than a few good answers on this site.

I have received an answer by /u/Edgarska on Reddit which, I find, answers everything.

That 441 strength seems correct, the reason it was never used before was because of the lack of the filmic view, but now that it's there we can use real sun values. When you take pictures in sunny weather you also have to adjust exposure accordingly.
As for emission shaders, they use the same unit as the sun lamp, W/m2 .
To answer the questions, if you're using the principled shader then it should be ready to use in any lighting situation as long as your textures are correct (no albedo values outside the realistic values), but if you're using the other shaders then you might have to adjust them per scene.
As for the strong light destroying the scene with default exposure, that is the point of having control over the exposure, you wouldn't use the same camera settings for a picture in the sunlight as you would in an interior shot.
I would also recommend installing the "real camera" addon, it enables you to use real camera settings so the picture comes out just as it would if you were using a real camera in real lighting conditions.
Yes, there is a way to get realistic values for real light sources, although you have to hope the manufacturer makes those numbers available, or you have a way of measuring it. Most laptop screens are equivalent to about a 5-10 on emission strength, so you can use that as a starting point.

That's really interesting. Thanks for coming back to post that.


text:
What is the way to move a material above another?
When I create a new material it is listed last and I don't know how to move it.
I'm trying to render a material together with a "Wire" material and I think that the way that works is when the "Wire" material is on top of other materials and then assign the other materials. In that way on the render the other materials will be on the object together with the "Wire" material Here is an example from blendswap -

http://www.pasteall.org/blend/31068

http://www.blendswap.com/blends/view/67420 (read the description)
What is the way to move a material above another?

I don't think you can. Why do you want to? AFAIK the order of the list doesn't have any effect on the render.

I'll make an update

I thought of that too, but when you have the "Wire" material first, then when the other material is assigned, in the render the "Wire" material will be shown together with it. Pretty cool.

Delete the top material slot, then add a new slot and select the material from the deleted slot.

In your case, you'll then want to assign the surface material (bottom slot) with everything selected in edit mode.

Thanks. So basically, the material is not deleted when pressing it on the "-" sign? I'll try it in a sec.

@Vladimir Yes. Pressing the - button only deletes the material slot. The material will stay around until the blend file is closed, and even then will only be deleted if no objects are using it. Materials with no users (no objects using them) have a little 0 before them in the selector drop down.

Thanks. I'm more comfortable with the node editor so my knowledge on the standard materials is a little limited.


text:
Textures won't show up when I render an animation
I have a problem with Blender and its animation process, I want to do an animation and to do that I rendered all frames of my project. Textures on all of my frames are visible but when I do the render animation, my textures won't show up. I used UV/Image editor, I applied the materials to the objects and I did the exact same thing for 3 other animation and it has worked on all of them..
Here is a rendered frame where we can see that textures show up.

On this screenshot we can see that there's no textures when I do render the animation but on the right screen we have a view in "Render Mode" which shows us textures...

If anyone can help I'd be very grateful

Could you upload your blend file if possible? http://www.pasteall.org/blend/

Here it is https://www.dropbox.com/s/n0iqdwr8g7dacls/Building_courbe2.blend . I couldn't upload it on pasteall because my file is too big .

I don't know what to tell you. For me both f12 (render) and ctrl + f12 (render animation) work just fine.

Yes for me too but if you use the video sequence editor by using all the frames you have rendered, textures won't show up. That's my problem :/

You should save out the images and than after rendering them you should load them back in.

This is because you have a scene strip above your rendered image sequence, which will display the same thing as the default viewport in solid shading (no textures), unless you set it to something else like textured or rendered (rendered will be very slow because it has to render each frame. You also have to disable openGL preview for rendered to work):

However, assuming the image sequence below it is the rendered animation, then you can just remove the scene strip.


text:
How do I get a very soft lighting effect in the Game Engine?
I'm creating a game that I would like to have very, very soft lighting. Here's an example of a game with a similar lighting to how I would like it:
What sort of render effects could I use to make a similar lighting effect in the Game Engine?
(I will be having a lot of questions about the game engine, thank you for putting up with me.)

Soft shadows like that are hard to calculate with standard approaches.
The only out-of-the-box realtime solution i know for Blender is using a sun- or spot-lamp with a low-resolution variance shadow map in GLSL shading mode. Note that this technique might "detatch" the shadow from an object.
Lamp settings:

Result:

If you do not need real-time solutions you can also bake all the lighting of the scene into textures. Then you have the full rendering capability of Blender at your hand and can use lamps with soft shadows. But you will only be able to apply this effect to static objects in your scene. You would probably still have to combine baked shadows with the variance shadow map approach for your characters.


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How can I create an Empty in Blender 3D 2.73?
In "Mirror changes to side of cube across all six sides", it is advised to add an Empty. However, I cannot find that option in Blender 2.73. How can I add an Empty in Blender 2.73?
When I do a Shift+A on the 3D View the context menu displays:
[Mesh||Plane|Cube|Circle|UV Sphere|Ico Sphere|Cylinder|Cone|Torus||Grid|Monkey]

It does not displays all of them, when you are working in Edit-Mode. Switch to Object-Mode to add an empty.

Shift+A > Empty > Plain Axis

Note that you must be in Object mode for this to work, in Edit mode you may only add mesh elements.

As in the update of my question, Shift+A only displays inner elements of the Mesh menu item.

While in edit mode add only lists mesh items. Other options are visible in object mode.

This problem bugged me for a while too, but it is not specific to Blender 2.73 it goes way back to the first Blenders I used 2.5x (and maybe earlier). It's not a bug, but in my opinion it is a missing feature.
In Edit Mode, the default setup has no feature to add an Empty. An Empty is an object in its own right, adding an object while in Edit Mode may make sense to us, but to Blender it doesn't.
The available options are all meshes (verts+edges+faces).
A solution is to:

Move the 3d cursor to where you want the Empty;
Drop out of Edit Mode into Object Mode;
Add the Empty; then
Go back to your original object and continue working.

3 years ago, I wrote a small Python add-on which allows me to remain in Edit Mode and add an empty at a selected vertex, or multiple empties when multiple vertices had been selected. It does this by collecting the location data and jumping out of edit mode, then adds the Empties to the scene, then returns me back to the original object in Edit Mode.

Edit v1.1 for Blender v2.73+
Here's an easy to install one file version of the add-on:
objects_place_empty_in_edit_mode.py.
Here the code inline in case it gets waxed on GitHub:
import bpy
import bmesh
from mathutils import Vector

bl_info = {
    'name': 'Add Empties',
    'author': 'Dealga McArdle (zeffii)',
    'version': (1, 1, 2),
    'blender': (2, 7, 3),
    'location': 'Add > Empties',
    'description': 'adds new Empty while in edit mode',
    'wiki_url': '',
    'tracker_url': '',
    'category': 'Mesh'}

def add_to_selected(context, kind):
    D = bpy.data
    scn = context.scene
    obj = context.edit_object
    obj_name = obj.name
    mesh = obj.data

    bm = bmesh.from_edit_mesh(mesh)

    def add_empty(coordinate, kind='PLAIN_AXES'):
        empty = D.objects.new('MT_' + obj_name, None)
        empty.location = coordinate
        empty.empty_draw_size = 0.45
        empty.empty_draw_type = kind
        scn.objects.link(empty)
        scn.update()

    coordinates = [v.co[:] for v in bm.verts if v.select]

    # must be in object mode to add objects to the scene.
    myob = D.objects[obj_name]
    bpy.ops.object.mode_set(mode='OBJECT')

    if not coordinates:
        coordinate = context.scene.cursor_location
        add_empty(coordinate, kind)
    else:
        for co in coordinates:
            vert_coordinate = myob.matrix_world * Vector(co)
            add_empty(vert_coordinate, kind)

    # set original object to active, selects it, place back into editmode
    scn.objects.active = myob
    myob.select = True
    bpy.ops.object.mode_set(mode='EDIT')
    return

class AddEmpties(bpy.types.Operator):
    """Add a vertex to 3d cursor location"""
    bl_idname = "object.empties_add"
    bl_label = "Add Empties"
    bl_options = {'REGISTER', 'UNDO'}

    kind = bpy.props.StringProperty(default='PLAIN_AXES')

    def execute(self, context):
        add_to_selected(context, self.kind)
        return {'FINISHED'}

class EDITMODE_MT_PlaceEmpties(bpy.types.Menu):
    bl_label = "Adding Empties.."

    def draw(self, context):
        options = [
            'PLAIN_AXES', 'ARROWS', 'SINGLE_ARROW',
            'CIRCLE', 'CUBE', 'SPHERE', 'CONE', 'IMAGE']

        layout = self.layout
        for opt in options:
            layout.operator("object.empties_add", text=opt).kind = opt

def menu_func(self, context):
    self.layout.menu("EDITMODE_MT_PlaceEmpties", icon='EMPTY_DATA')

def register():
    bpy.utils.register_module(__name__)
    bpy.types.INFO_MT_mesh_add.prepend(menu_func)

def unregister():
    bpy.utils.unregister_module(__name__)
    bpy.types.INFO_MT_mesh_add.remove(menu_func)

if __name__ == "__main__":
    register()


text:
Adding Labels, Angles, Domains on Objects for Making Math Models
I am very new to Blender.  I have been looking for a program to create a model for visualizing different math concepts.  Blender looks promising as it provides the possibility for not only this, but graphical modeling far beyond as well, so I would like to learn it to build upon this knowledge continually.
To begin I would like to start by making an image similar to this:

I have been able to get some objects and planes created with some coloring and shading, but I haven't been able to find out how to get certain domains to be addressed individually, or how to get angle labels on these domains.
For example, in the image above, the ABC region has a different texture than the whole sphere. Is there a way to select a region where to objects intersect, etc. in blender?  How would this triangle on a sphere be created and labeled in Blender?
Thank you very much for any help, I greatly appreciate it and will continue to update this thread if I find any answers in the meantime.

There are many possible approaches. If you are going to animate this or want to play with the angles for the final render one possible solution are modifiers. Please bear in mind, that these are very specific questions and the solution might be somewhat complex, so I can only outline the basics and not every step. I will try to keep it simple.
First goal is to create a region ABC that auto-updates when we rotate the tori.
Make sure the 3D cursor is at the centre.
To create region ABC add a UV Sphere and a cube. Select the cube and scale it up a bit, so that it contains the sphere completely with a margin. Move one of its sides to the centre of the sphere in "Edit Mode". Back in "Object Mode" copy the cube two times and rotate the copies by 90 degrees around 2 different global axes. Lets name the cubes Cube.A, Cube.B and Cube.C. Move all cubes to layer 2. (ok, mathematically these cubes are now cuboids.. but lets call them cubes for simplicity)
Copy the sphere 2 times. Lets name the spheres Sphere.Fill, Sphere.Wire, Sphere.ABC.
Move Sphere.Fill and Sphere.Wire to layer 3. Select Sphere.ABC and add a "Solidify Modifier". Change thickness e.g. to 0.060 or less and offset to 1. Add 3 "Boolean Modifiers" and set the target to the 3 cubes respectively. Set "Operation" of all 3 modifiers to "Difference". This is, what it should look like:

For the angle labels add another UV Sphere and scale it down e.g. 0.5 and move its centre to one corner of ABC on the surface of Sphere.Fill. Lets name it Sphere.Cut. Add another "Boolean Modifier" to Sphere.ABC and set its "Operation" to "Difference", target to Sphere.Cut. Add an "EdgeSplit Modifier" to Sphere.ABC. Copy Sphere.ABC and change the Operation of the last "Boolean Modifier" to "Intersect". Lets name the copy Sphere.Angle. This is what it should look like:

For the text label of the angle add "Text" and tab in to change it to whatever you need. In the text properties under "Paragraph" change align to centre. Place the object centre of the text slightly above the surface of Sphere.Fill inside of Sphere.Cut and parent it to Sphere.Cut. Add a "Shrinkwrap Modifier" to the text and set the target to Sphere.Fill. Tick on "Keep above Surface". Change the offset until the text is above the surface of Sphere.Angle. This is what it should look like:

Some notes about materials. Enable Z Transparency for all materials. This allows to set "Z-Offset" which avoids unwanted flickering for overlapping geometry (also called Z-fighting). For Sphere.Wire switch the material type from "Surface" to "Wire" and "Z-Offset" e.g. of 0.1 or less. Increase the "Z-Offset" slightly for Sphere.Angle and Sphere.ABC and then again for the Text. For this simple example its enough to set "No Shadow" for the single sun lamp.

For the tori you can use bezier circles with another bezier circle as Bevel Object. Then you can parent those circles to the cubes respectively.
Afterwards rotating the cubes should update region ABC automatically. Sphere.Cut must be tracked manually. A rig might be needed for animation but this is beyond the topic.


text:
Lens settings missing from camera settings
The lens settings such as these, specifically the Clip start and end buttons,:

Are completely missing from my panel. This is what I see:

Does anyone know why this is happening?
EDIT
I have found where they are located but upon changing them nothing happens to the preview.
https://i.sstatic.net/hPnWK.jpg

In the image at the bottom you just need to scroll up to find the lens settings, or enlarge the window.

That doesn't work. I tried any can't scroll and enlarging it does nothing

This was a bug in an early pre-release version of Blender 2.80 which was fixed in February 2019.

https://developer.blender.org/T61499
https://developer.blender.org/rB5e3838faa2e6dae0ac52860085f5dc4b7a000ea5

You should at least update to the proper release of Blender 2.80 or, if your hardware supports it, the current long-term support (LTS) version Blender 2.83.6 or the most recent release Blender 2.90.
The LTS is a version of Blender that will continue to receive bug fixes for a span of 2 years after its initial release, while the 2.90 release will be superseded by 2.91 in November 2020.

The Blender LTS program is aimed at ensuring that long-lasting
projects can be executed using a stable Blender version, which will
provide critical fixes throughout a 2-year time span. The LTS version
will not have any new features, API changes or improvements. Any
critical fix that is applied to the 2.9 series will be regularly
ported over to Blender 2.83 LTS.

how exactly do i update it? Is it like installing a completely new version of blender? Will all my old projects not work? And which one do you recommend

Blender doesn't auto-update, you have to download a newer version from the website. Multiple versions of Blender can be installed alongside of each other. You can also use the portable version (.zip) if you don't want to install it, just extract it and run. If you want Blender projects to be automatically associated with the newer version, you should use the installer. Old projects should open in newer versions without issues. However, once saved in a newer version they might not open properly in older versions.

If this answer solved your problem, please consider marking it as accepted by clicking on the checkmark next to it.

so i want to download the .msi file for the installer?

Yes, that is correct.

Now my fluid simulation is gone when I open up the file

Right, in Blender 2.82 the old fluid and smoke simulation engine was replaced with Mantaflow. If you need the old fluid simulator you will have to use 2.81 or earlier.

Yeah I got it to work now. I am just using the completed 2.8 link you sent and I had to re-bake it but now its working and I can see the camera settings so ty

The options are there, you just need to scroll up or down to find them, or make the properties window larger.

Note that you can visualize the  clip distance if you enable viewport display > Show limits.
The line that appears shows clearly the start and end points for the clip distance. Any object that is not within that range will be ignored or clipped.

Note that the camera clip distance and the clip distance for the viewport are independent.

I can't scroll down


text:
Video material not rendering?
I gave my character his face with a material that uses a video file in an image texture node. In material view, it looks fine, but in rendered view, it does not appear. Can anyone help?

Here are the nodes BTW:

Is it possible you could upload a screenshot of your node setup, or (better yet), a subset of your file which demonstrates the problem?

@gandalf3 I uploaded the .blend file for you to check out, sorry I forgot to do that the first time

@cegaton I'm not sure what you mean by this... can you explain?

Looks like the normals on the mesh are wrong/inverted. UV mapping has to be resized and offset completely for the texture to show up and Unwrapping shows an "warning" message. I suggest to rework your mesh and generate a clean UV Map.

Thank you so much! Turns out, me being an idiot and all, I made my entire character model on a negative scale. I opened a new file, loaded a character, flipped it and tried the movie and it worked. I have to redo the animation, and go through all of my characters and flip them, but at least it works.


text:
Glass material becomes white (Cycles)
I made some glasses for my character, and gave the lenses a glass material, which works fine, except for the fact that at some angles, when rendered, the lenses turn completely white. I don't think this is reflection, because it does not gradually turn white. One angle it's fine, and turn it ever so slightly and it goes completely white.

I have no clue what could be causing this.
EDIT: I have posted the Blend file on the Blend Exchange so you guys can check it out!

It's probably because of environment which is solid grey and that's way you cant see any gradient. Try to add some lamps or HDRI map and it should look different. Or maybe you are in Ortographic view? It's hard to tell just from the screenshot.

@LukeD I changed to perspective view and added a lamp but the problem is still there...

Could be also normals, try to recalculate or invert them, or just strip the file from everything besides glasses and upload it to: http://blend-exchange.giantcowfilms.com/

You can post your file using Blend Exchange and then others will be able to actually examine your file instead of just guess.

@cegaton It is taking forever to upload so I will post the link when it is done

@EVERYONE I messed with the IOR slider on the glass material and now it doesn't happen anymore... I will still post the blend file in case but I think it's fixed!


text:
Baking path animation deletes poses?
Ok, total edit:
I found out that I have to bake the entire length of the animation to keep all of my keyframes. BUT, now that I've done that, now all of my poses are deleted. The movement stays there, but my character is just in the T-Pose throughout the whole animation. Any help?

I downloaded your file and still I don't understand your question, which is the character in the T-Pose throughout the whole animation? Maybe you were in edit mode (if so switch to pose mode and run the animation).

@joshsanfelici Im trying to say that when I bake action to convert the path movement to keyframes, the rest of the posing that I had done earlier in the animation (the door being kicked open, him walking into the room) is removed.

Ok, I basically messed around with it until I figured out that selecting the 'Pose' option in the bake settings only works if you have a bone selected in pose mode, so I just selected all my bones in pose mode, chose 'Pose' and 'Object' in the bake settings, deleted the path, and now it works. Thanks to @joshsanfelici for giving me the idea to check edit mode, which made me think of selecting the bones.


text:
how to control particles position
i am trying to emit some particles to create a logo. i have tree different emitters (red, yellow, blue) and i'm trying to determine those particles to arrive at certain locations. I tried using magnetic force and stickiness, but it doesn't seem to work. What other tools are there to control where particles go and how to make them stick to that position?
Thank you.
This is what i'm trying to achieve. i also needed the particles to bounce of the ground and then settle while respecting the 2 different areas. I kind of manage to do it using molecular addon, but i cant control the bouncing so in the end i made a mesh cage for the middle area and a cylinder cage for the outer area.

Probably you will want to search for "Particles Curve Guide" or provide some screenshots of what exactly you want to achieve. What you have and what it should look like.

Keyed particles is probably the best solution Keyed — Blender Manual

thank you for your comments. i managed using meshes with collision that force the particles to keep into the shape that i need.


text:
Purple texture in cycles problem
i've got the problem with cycles. Evee works fine, but all textures in cycles are purple. For example simple checkers. I'm new to blender, but saw a ton of videos about missing texture files, but thay all in place. I've completly lost there.

hmm your material output in the first picture is set to cycles only but the second one is something different set to All? That shouldn't be the problem, I am just a bit confused, can you share this file with https://blend-exchange.com/ ?

The first picture. You are not in render view.

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.

From https://docs.blender.org/manual/en/latest/editors/3dview/display/shading.html

Material Preview
Render the 3D Viewport with EEVEE and an HDRI environment. This
mode is particularly suited for previewing materials and texture
painting. You can select different lighting conditions to test your
materials.
Rendered
Render the 3D Viewport with the scene Render Engine, for interactive
rendering. By default the scene lights are used for lighting. An HDRI
environment can be used as well, with the same options as Material
Preview mode.

The material preview mode using the EEVEE engine. Regardless what is your selected render engine in the drop down list.
Press Z, select Rendered.
Or

Some times if Blender crashes or shuts down unexpectedly you need to reload your textures.
In top menu File > External Data > Reload Missing Files.
In the Image Editor you have in  N key tool panel, under Image  you can check the path to image is correctly

The OP is using a Checker procedural texture, which doesn't use image based textures or external files.

did you use enviromental texture? If he is not loaded it shaining purple to object.


text:
Shadows that are pretty when rendered with eevee look wrong with cycles
I am trying to render a donut.
This is my render with Eevee

This is my render with Cycles

The shadows in the left side of the donut are very odd since that is the side light is on. My render setting are:

I have tried without denoise, same thing. I will appreciate any help on how I can fix this. Thanks
Blend File
https://drive.google.com/file/d/1QKYHmJjBYdekITTQbgccOBC2aTegfXY0/view?usp=sharing

pls provide blend file

Added it, sorry

although i am not a shadow export, i would guess because your mesh looks a bit weird at these places...if you clean it up, it would look better:  [1]: https://i.sstatic.net/FRreN.jpg

weird because I don't see such a difference on my computer


text:
Blender-GIS Get SRTM wont work
Hey I'm running Blender 3.0 and every time I try to get the elevation Data from the Website it shows me this Error: "Cannot reach OpenTopography Webservice, check logs for more Infos".
So if i look into the logs it only says multiple times: "2022-02-20 22:21:36,228 - BlenderGIS-master.core.basemaps.mapservice - ERROR - Can't download tile x136283 y87646. Error <urlopen error [Errno 11001] getaddrinfo failed>" and then "2022-02-20 22:26:25,578 - BlenderGIS-master.operators.io_get_dem - ERROR - Http request fails url:https://portal.opentopography.org/API/globaldem?demtype=SRTMGL1&west=7.144606444922421&east=7.167832519360552&south=51.089448021248955&north=51.100347790999045&outputFormat=GTiff, code:401, error:401". Does anyone know what I'm doing wrong? In another post someone said that i need an API Key. Can someone tell me how to add this key into the addon?

https://github.com/domlysz/BlenderGIS/issues/305

its not a network issue

I'm getting the same error you are. When I went to the web address in the error, it shows me the following message:
"Error: This dataset requires an API Key for access." Looks like it needs a key that isn't being provided, but I'm not sure how to fix it.

Get an API Key by creating an account with opentopography.org
In Blender on the GIS tab click "Preferences" then "Add-ons"
Find the "Elevation server:" Use drop-down menu and select "OpenTopography SRTM 30m" Click "Edit."
In the "url template" add "&API_Key=[your key number]" at the end of the existing url.
Click Ok

You can do this for both the OpenTopography SRTM 30m & SRTM 90m

BINGO - Error FIXED on SRTM!!!! .... I did a new install, loaded the GIS addon and same constant error on new and old versions.  Read all the threads and finally figured it out myself. When I copied and pasted the API code, I didn't notice there was a single empty space in the beginning of the code, far left.  Once I deleted the space you could hardly even see, it worked like a charm as it should. Here is the fix: https://github.com/domlysz/BlenderGIS/pull/840
Many people say it's the new version but my fix worked on all old and new versions mac and PC


text:
Compositing: low quality scaling of Transform and Scale nodes
I want to use Compositing to get a second smaller image from a 3759x2800 pixel render. The second image must be 537x400 pixels. But the quality of the result is very low. I tried with both the Scale node and the Transform node (with Bicubic filter). This is the result with the Transform node:

As a comparison, this is the same image scaled from 3759x2800 pixels to 537x400 pixels in Photoshop:

I don't mean I'm looking for the exact same Photoshop result. But it seems impossible to me that the bicubic filter of the Transform node generates such a jagged image. Is it a bug?
These are the nodes used:

Suggestions?

Hi :). Adobe's scaling algorithms are a bit of a trade secret, since it's a lot more complicated topic. Related: What is the best image downscaling algorithm?

just a dumb question: did you try to do a new render with just lower resolution? Or does that take too long?

@Chris you're right, what you propose is a solution. But the image I need at various sizes is already a composition of 3 renders (composed by the Compositing system). So doing it twice would mean doing 6 renders. And if I wanted other dimensions, how much render should I do?
What I would like to understand is why the Scale and Transform nodes do such a bad job. Am I doing something wrong? Is it a bug?

@Michele: I don't know. I think Jachym is right - looks like scaling is a myth for itself....

all i can offer, i could try it out if you provide your blend file with your images...but i think you don't want that

@JachymMichal thank you MIchal. I don't mean I'm looking for the same Photoshop result. But it seems impossible to me that the bicubic filter of the Transform node generates such a jagged image. The Scale and Transform nodes are fundamental in a Compositing system. I can't believe that these Blender nodes do such a poor job, surpassed in quality by any image processor I know (out of curiosity, I also tested it with Microsoft Paint and it is closer to Photoshop than Blender ).

@Chris thank you very much for your kindness. Tomorrow I am in the office and I prepare the file to send it to you. I need to remove an item that is a customer confidential product, but the problem will show up anyway. How can I send you the file?

you can use https://blend-exchange.com/ and follow instructions (but in the last few days this doesn't work) so if it doesn't work use any cloud service you want like google drive, dropbox...whatever. But please don't let us ask for permissions...you can delete everything in your blend file which isn't necessary for reproduction of the problem. So you have quicker uploads, we have quicker downloads ;)

Hi @Chris. I have prepared the file, you can download it from here: https://www.dropbox.com/t/Xw4vGtuWuNgz3lES
Compositing uses the Transform node to scale the high resolution image. The shrunken image is jagged with a worse quality than any even basic image processing software. A bicubic filter should do much better, I think there is something wrong.
Thanks for the help.

@Michele: thank you for providing your blend file. I could reproduce your problem. What computer are u using? If i scale down on my mac just in "preview" it got this: [1]: https://i.sstatic.net/oKf7L.png which is better than blender scaling...and this was a 10 sec render result...

@Chris: I use a Windows 10 workstation, and the "small" rendering is fast. In fact, to overcome the problem I am doing a lower resolution render. But for some projects I will have to generate various images of different resolutions, and I would like to understand if the problem is my error or a Blender bug. In the second case I would like to report the bug because having such a basic node that works badly is a problem in the use of Compositing. What do you think?

It’s worth a try. I also reported some bugs. Hopefully they improve it. But maybe the answer will be „works as designed“

@Chris:  Does the problem occur to you too? Isn't that my mistake?

What happens if you just scale it down on windows with „normal“ windows tools?

@Chris:  OK, if I have to generate many images at different sizes I will create an automated process with an external tool.
Thanks for your help, you were very kind.


text:
I can't paint the whole model in texture paint mode
I have a problem in texture paint mode. If I unwrap the model, I can't paint the entire mesh. It remains entirely white. More details in this picture.

If you can answer too why is it stay black :/ but the properly uv texture changing transparent white.

If it stays 'full white' then quite possible you don't have an image texture assigned to the UVs yet - in the Tool Bar, check for a warning to 'add paint slot below' as in the attached picture.

Thanks for answer Jones :). it's can cause the error too, but i had uv map and i could paint it. My problem was that if you union two object and if you had material one of them you have too assign the object material what you add later to the object or make a new material but i didnt know this :/. Thanks a lot Jones for answering!!


text:
How do I Make a Spawner for Enemies in my Game?
I'm making my first zombie game in the Blender Game Engine. It is a first-person-shooter style game with zombies and stuff like that.
I am having trouble making an enemy spawner for the zombies however. I got it working somewhat before but after a certain amount of time the zombies just start to stack up on top of each other because I cannot get it to only spawn the zombies at the start of the game and after one dies. I changed it up some but now they don't spawn at all.
It really would be nice to have zombies spawn randomly within a specific area of the game but far away from the player. I don't know how to code in python so I'm making my game only with logic bricks. I have an empty currently that is supposed to spawn the zombies but it doesn't work.
Can you please help? You can download the game here: Undead Fields

making a game only with logic bricks will be quite hard and challenging.

Luckily I've gotten pretty far over the past few days! I'm sure there's a way. I just dont know how. With a recent version I was able to get a spawner working pretty well. It would spawn a zombie if the player was far away and if there were no zombies by it. I however would prefer something that would detect if there was a max amount of zombies on screen and if not it would fill in for the extras by putting them in a random place in a set zone. If I need a script for this that's fine, as long as it's a copy/paste sort of thing.

I also think you will find a way with logic bricks but you may want to learn using scripts because they will make your work much easier. GL

Is there a sensor to detect a max amount of objects? I would really probably only need that and it might work.

I keep getting this error in the console Warning, object "Empty.014" from AddObject actuator "Edit Object" is not in a hidden layer. even after moving that object to a hidden layer

Strange. I tried making an updated version of this. Maybe that'll work.

Try this version. It's a bit different but it is working on my computer. (It's not on GitHub because I barely know how to use it!)
https://drive.google.com/open?id=0B5LVYjOK5wy6TGV4ZzZ0V0NFczA

As non-python solution I suggest following:

create an action with location keys. Each frame the action should contain a single spawn position. e.g frame 1 = position 1, frame 2 = position 2 ...
when you want to spawn an enemy
2.a. create an random integer number in a property via random actuator.
2.b you play the action frame at the emitter (empty) via Action Actuator in property mode (using the random property).
2.c with a collision/ray/near/radar sensor check if the spawn point is empty. If so add an enemy and continue with 2. If not continue with 2.a


text:
How to change radius for proportional editing using industry compatible keyboard mapping (v3.0)
How do you change the influence when using proportional editing in Blender using industry compatible shortcuts?
What I've Tried:

Reading similar question here this article, but with the industry compatible shortcuts.
Looking up keymaps in blender preferences, but I must be using the wrong search term. Tried radius and influence.
Examining their docs on the subject

use 'B' to enable/disable and while dragging use PgUp/PgDn or mouse wheel

The mappings are the same. Mouse Wheel Up/Wheel Down or Page Up/Page Down after hitting B to enable proportional editing.
Make sure you are actively holding down the left mouse button while scrolling. More details about that..
You can confirm the keymap by going to Edit > Preferences > Transform Modal Map > Increase Proportional Influence.

Works Cited: developer issue T87869, @alambre's comment.