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Can i apply normal map & bump map & a texture on the same object
So I have these

I want to combine them all. Is it possible?

This seems to work, but i want to know if there is a better way to do it

There is a better way. With this method, you are applying the normal map to the glossy reflections, and the bump map to the diffuse. You should combine the normal and bump vectors with vector add node, and then vector normalize node.


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Getting an outline with backface culling blender render
I've been trying to produce an outline in blender render (Simmilar to this- from the show RWBY)

I am trying to do it using this technique: Duplicating an object, scaling it up slightly, giving it a black texture, enabling backface culling. However, this never apears in the render as it's aperently just used for the 3d view (as far as I know). I need help getting blender to render backface culling within the "Blender Render" engine, not cycles. I was wondering if anyone had tips, or perhaps a script that could help me solve this problem. Thank you

Yes, and it didn't work in a way I could use; the lines were all over the place for some reason, and they were way too thick no matter what thickness I set it to.

Related: http://blender.stackexchange.com/q/31191/599

Very nice video tutorial with this technique here, on Blender 2.8 and Eevee:
https://www.youtube.com/watch?v=hcn0G7GBVKk

The way they achieve the outline in the show rwby is unique in that it is not rendered at all.
They use what are called "playblasts" which is a feature in maya where the animation is recorded in real time and not rendered. This is why yours is not coming out right the outline will only appear in the texture view of blender. I like to animate in this style because you can have good looking low poly character but anyway how you achieve this is:

copy object in object mode
scale the object up slightly and while in edit mode press w and select flip normals(this will cause only the inside faces to show)
give the main object a skin color and make sure the shadeless option is selected
give the outline mesh a black shadeless color and adjust in edit mode where needed

It will not come out in rendered view and will only show in texture view (still pretty cool though)

Is there, perhaps an alternative way of actually "Getting" the footage without rendering then?

well i know that maya uses the play blasts... the equivalent in blender would be openGL render i believe. you could try that. also try different methods of cel shading this method is just one way the people over at RT do it but it is not the only way. you can use nodes and scripting to get an outline as well thought its much harder unless you know the scripts

Thanks for the tips with open GL, I would use nodes, but I really don't know enough about how to use nodes or python scripts.

I have been able to achieve this in the cycles renderer using this node setup for the outline object's material:

I haven't been able to figure out a way to do this with blender internal renderer, but you can use the opengl render mode to pull it off.
Here are the steps:

Create an object and give it a material
Duplicate the object

Enter edit mode, select all vertices
Press alt+s and scale the object up slightly
Press w and flip the normals
Go to object mode and delete the material
Give it a new material and make it shadeless black

In the 3d window, press n to bring up the right panel

Go to the shading tab and enable 'Backface Culling'
The outline object should now be just an outline
Go to the display tab and enable 'Only Render'

Render the movie

Make sure your settings are correct in the render panel (frame rate, etc)
Go to top left corner of blender's user interface and click 'Render'
Select 'OpenGL Render Animation'

The best way to achieve this method is the Solidify Shell method of outlining. It is the same concept as Antonio Garcia's answer, but is more dynamic as it is done through a modifier.
Here is a guide: http://blendernpr.org/solidify-modifier-contouroutline/
And a sample file download: http://blendernpr.org/toonery/files/SolidifyOutline.blend

Hello,
I was working on a project that involved outlines and I wanted to use Cycles. But I came across the same problem as most of people : in rendering mode, everything was black when working properly in material preview mode.
I'm a casual blender user, but for a long time now. Backface rendering for outline is a thing that's been in blender for ages now, so I thought "no way we can't do this". I know there's tutorials here and there over the internet, but just in case I'll make quick complete tutorial here.
The Setup :
2 cubes, one being slightly bigger than the other one.

A simple diffuse shader :

The Outline shader :

The Output :

Things you need to tweak :
Select the Outline cube.
In Properties Pannel, go to Oject Properties

Under Visibility>Ray Visibility, uncheck Diffuse/Glossy/Shadow.

And Tadaaaa, it now works!

See what happens when you check / uncheck the diffuse/glossy/shadow, you may use if for other things!
I hope this will help some people.
Happy Blending!

source: Stack Exchange

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Anime rendering; ray shadows odd results
I've been trying to render anime style characters in blender's internal render using opengl rendering; I can get things to look okay as long as things don't have shadows, but as soon as I turn shadows on things get weird. In particular, the shading freaks out and puts square shadows everywhere on the model and remove shadows from areas on the model where there would normally be shadows.

Anyone know how to solve this?

could it be a problem with the normals of the mesh?

First, open Object Data tab > Geometry Data rollout and press Clear Custom Split Normals if the button is called like that. Then in Edit mode W > Remove Doubles and then Ctrl+N to recalculate normals (all selected for both cases). If that doesn't help please upload at least part of the problem mesh.

Here's the model

Seems like it could be something with shadows on the material. If turning off ray tracing shadows for the sun lamp, these artifacts mostly go away (not all of them). Hard to tell more about Toon shader in BI though.

is there a different way to cast shadows while also keeping that specific node and shader setup?

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


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Texture shows in render but not in 3d view
What are reasons my UV map doesn't show up in 3D view?

3D view in object and edit mode only shows a wireframe.

However when I render, I can see the UV map applied.

Possible duplicate: http://blender.stackexchange.com/q/12078/599

@Gandalf3, the ~.blend file supplied by the original poster of question 12078 was uploaded to Pasteall, and is no longer available.

It will be helpful to solving your problem if you would please upload a copy of your ~.blend file to Blend-exchange, or another persistent file host, and link to it from your question. While other hosts can be used, it is preferable that the file  be uploaded to a site where you control how long the file is available, rather than one where the file is automatically deleted after some period.

Turns out it was indeed a duplicate question, the solution was the maximum draw type.  Is there a hotkey that changes this setting so I don't accidentally do this in the future?
Can someone mark this question as a duplicate of the question @gandalf3 linked?

This looks quite obvious to me: the normals are inverted, thus the faces get culled. In english, the textured view is optimised by showing only one side of the faces. This way the inside of the mesh doesn't get rendered.
For some reason you have the faces pointing the wrong way around (ie. Blender thinks that the inside of your mesh is the outside and vice versa.). To fix this, in edit mode select all vertices and go to the Shading / UVs tab (allready open in your screen capture) and under Normals hit recalculate. If this didn't work, you can try to manually invert them by hitting Flip Direction. Now the surface should work.
I hope this helps.


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Cycles Fake Absorption Setup Explanation
I would just like to understand why in the cycles fake absorption setup he ray length have to be multiplied against the backfacing value in order to tell Cycles when the ray starts and stops. I did the BlenderDiplom tutorial and there was no explanation as to why that does what it does. I can use the fake absorption setup with no problem, I would just like to understand exactly how it works so I can use it knowing exactly what it is doing.

What context is this node used in?  What would you plug the color output into?

@PGmath I think it can only really be used with a glass, translucent, or transparent shader. As for context, I'm sorry I have none. I have been using this with a translucent shader, but I would like an explanation for all three shaders if they are different. According to gandalf3, "it only allows you to control the shading of backfaces", so I think it is doing the same in all three shaders but I really have no idea.

Ahh, that's what I guessed, I'm working on writing an explanation for you now.

The way the node setup you are referencing works is by coloring the inside wall of a material based on how far the ray has traveled within the material.

The backfacing output gives 1 if the ray is hitting the side opposite the normal (the "front" of the face), and 0 if the ray is hitting the side with the normal (the "front" of the face).  So the output of the first multiply node (from the left) will be ray_length * 1 = ray_length if the ray is hitting the backside of a face (meaning it is inside the object) and ray_length * 0 = 0 when the ray is hitting the front of a face (meaning it is outside of the object).
The rest of the nodes just convert the linear falloff to exponential and use that result to mix the base color with the absorption color.

Okay, just for clarification: When the rays hit the front faces and return ray_length * 0 = 0, is the ray length value acting as if it resets to 0 and continues traveling, and then travels until it hits the back face and returns ray_length * 1 = ray_length?

@Wyvernul  ray_length is the distance since the last surface/volume calculation (i.e. it resets to 0 every time it interacts with a shader).

One thing to note is that for x^0 so you will get 1 as a result so for the case of a ray hitting the front of face you will get the base colour and for a ray hitting the back of a face the mix of base and absorption colour. Without that, you would get the length of the ray before it entered the surface for absorption when it hits the front face.


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Edge Sliding multiple verts/edges along a single edge axis?
I am looking for a way of using the GG edge slide feature to move multiple verts/edges with different normals, all in the same direction.
Attached are some screenshots of the issue...
I would like to move all the edges/verts highlighted up the angle of the faces above them (see red arrow), but need them to retain their own angles.
If I select them all and GG to slide, they all slide off in their own different directions, if I choose to move them in the 'Normal' axis, the axis is not the desired one due to them having different normal directions.
The only way I can find to do it is to just move edges with the same normal direction, but this then involves multiple selections and edge slides, surely there is some way of doing them all at once?
Many thanks in advance.

It works for me as expected, however you can try another method which involves using View transform orientation. Select face, along which you'd like to move selection and align view to it (Shift+Numpad1). Choose View trnaform orientation. Select your faces and grab them along desired view axe.

Thanks for the quick response, mine does behave the same as in your video but only when the selected faces are all facing the same direction. In my situation, I have added edge loops around the corners, so there are faces that are facing at right angles to the main faces, having these selected as well results in my issue.
However, your 'View' orientation solution works perfectly, I created a vertex group with the verts I wanted to move and moved them along the view axis of the faces above, not as simple as selecting and sliding, but the end result is the same - thanks!

The easiest way is to create a custom transform.
Select an edge that represents the orientation of your desired transform, in your case, this will be where the red arrow is pointing, then Ctrl + Alt +  Space bar  this will create custom transform using the orientation of the selected edge, now you can use this new transform to move your mesh along. For example if you want to move the selected vertices/edges/faces on the new Y axis, select them, press G to move, then press Y + Y, this will change the orientation from the default Global to the new custom transform. You can edit the parameters of your custom transform immediately after creating it in the tool's   shelf to the left of the 3D view, if you can't see it use T to show it. You can rename and delete the custom transform in the properties shelf to the right of your 3D view, use N to toggle it's visibility.

Also check this tutorial https://www.youtube.com/watch?v=aaL05JYEP9o&feature=youtu.be
And a slightly related question here
http://blender.stackexchange.com/questions/33810/is-there-anyway-to-snap-to-vertices-while-using-edge-slide-with-clamp-off/52249#52249

Great tip, I didn't know you create a custom transform, that's must easier than the other solution. Thanks!

Glad it helped!

As detailed by Mr Zak, the solution to this issue is -

Select the verts you want to move
Make a vertex group of out them
Select the face along which you want to move your verts
Use SHIFT+NUM1 to align the view to that angle
Press 'A' to deselect the face and then select your vertex group
Change the transform orientation to 'View'
Now you can move the selected verts in the desired angle.


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Extruding square shape (from mesh) along curve results in a flattened mesh
I'm trying to extrude a simple square shape along a curve, with the view to making a set of steps go around a corner.
Extruding a circle works perfectly, but a square shape seems to extrude along the Y axis instead of the X and is therefore just a flat shape.
Steps
- Created cube shape

Selected 1 face and duplicated it
Separated the face so it is a single object
Transform/rotation applied
Alt+C - converted mesh to curve
Added Path
Gone to path object panel > Geometry and selected the 'Bevel Object' to be the square

Result
The Extrusion is a flattened mesh.
Doing the exact same steps with a cylinder works just fine.
Blend file here - http://pasteall.org/blend/index.php?id=47161
Many thanks in advance.

The problem is your object called "square". It does not have the same orientation as the "Cylinder.001" that you used to extrude the Cylinder. The curve will be extruded on the local Z axis so make sure its facing the direction of extrusion.
A quick fix is to open the object "square" in Edit Mode and rotate it on the Y axis by 90°.

That's fixed it, thanks for the speedy response.


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Do I need the camera object and the light object?
I want to create a 3d game with Unity so I started to learn Blender, but something that very annoy me in the 3d view window is that camera object and the light object. are they essential for modelling assets for my game or they are just for making movies?
so will it be ok to delete them?
thank you in advance.

Lights and cameras are only needed for rendering, if you are just modeling or texturing they are not needed for the moment, you can either hide or delete them for the time being . If you are modeling game assets then you are probably better off creating them in the game engine anyway.

@DuarteFarrajotaRamos it is a problem to use the game engine Unity for modelling because you can't really design complex shapes there, you can use only some primitive shapes for my knowledge.

Oh sorry, I probably didn't explain myself correctly, I meant creating the lighting and cameras in engine, not the models. It is quite OK to model in Blender and export, that is the common workflow, but cameras and lights are always better to be created in engine.

you can delete them now and readd any number of those later on if you'll need them.
also you can hide them - there is a list of scene objects in the upper right part of the UI, click on the eye icon next to those things to hide them.


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In proportional mode how do I pull together 2 vertices that are facing each other?
I want to create a blood cell model. So first I create a UV Sphere, then I select the top vertex and the bottom vertex of the sphere, and now I want to pull the 2 vertices closer together in proportional mode.
How can I do that?

"2 vertices that are facing each other" could you add some screenshots of how could vertices face each other? Also some references pictures of your desired result and what you have problem with

@MrZak "now I want to pull the 2 vertices closer together in proportional mode. How can I do that?" This is what he wants. I think it's clear.

Select both vertices and scale along the z axis. So press [S] and then [Z].

Take a sphere and enter edit mode.
Select the top and bottom verts.
With the proportional editing on (Press O key) select connected option
Press S to scale down and Z to Z axis and scroll the mouse forward and backward to change the shape.


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Bake Hemi Lamps in Blender Render Mode
I was wondering how I can bake my hemi lamps into a texture included in the shadow (Full Render mode). I'm satisfied with my lighting (a few hemis and 1 sun) and I don't want to use any lights when exporting it outside Blender.
I would appreciate any help, guide or workaround. Thanks.


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How do I do a video like this?
https://www.youtube.com/watch?v=XXW1dh2XH9Y Basically I want to make a video with a moving picture that moves with a person in a video's head.

This isn't 3d work... go get After Effects.

@AlexSafayan Actually, this can be done in the compositor, VSE, or movie clip editor.

@ShadyPuck Yes, I know, but why would you render that if you can just use a video editing software?

K now how do I do it?

@AlexSafayan He's asking how to. Blender's free. Blender has more possibilities.


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How to do a sprite animation in blender like undertale with good alpha channel
I tried to do a sprite animation but it messed up and the alpha channel doesn't work yes I used images as planes.


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2D video editing + Blender VSE + GPU?
I'm a small-time YouTuber, and I use the Blender VSE to edit / render my vid's. I'm currently running this on my laptop, but—especially if I apply transformations or multiple over-drop layers—rendering is slooooow! Would getting a box with a supported GPU help me get shorter render times? (And, is there a list of supported / recommended GPUs somewhere?) To be clear, everything I'm doing is 2D and via the VSE. I have a background in computing (so I'm not frightened by matrix transformations or technical terminology), but I don't understand what Blender's capabilities are vis-à-vis using a GPU to do 2D compositing.
While we're at it, it seems that if I, say, chain ten transform layers it's substantially slower than applying one … Why is this‽ I.e., I'd imagine that you'd multiply all of the transform matrices together once, cache that, and then apply it to each frame (in which case N transforms ought to take no longer than 1. To be more technically precise, I would expect that applying the same N transformations to M frames would take O(N + M) but it, empirically, seems to take O(N * M).).
//cheers
~K.D.P.Ross

authors: سيدعبدالرضا خورشيد


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Subdivision Surface on curved mesh
I'm trying to delete those ugly lines visible in the cylindrical shape of the lens. What is causing them is the added edge loops I made for the protruding detail with the switch. The problem is that if I delete those edges, it'll look even worse because of the n-gons. Any ideas?

I think your problem is how you place edge loops in your mesh over the curved surface.
Since it is a cylindrical surface edge loops cant be placed by simple subdivision, because that will yield a flat planar surface breaking the curvature of your otherwise cylindrical body.
When placing edge loops you need to make sure they are equidistant from the mesh center or use Subdivide Smooth for a curvature approximation.

Excellent. I'll make sure to do that next time. Although I just tested Subdivide Smooth on a cylinder and those lines appear if you make enough cuts. The lines are noticeable even when doing 2 cuts: Picture The thing is that I can't do it that way on my model without deleting the protruding detail. What would be perfect is an add-on that lets you line up the vertices with a desired radius from the origin of the cylinder. That would solve everything, if what you say is right. BTW, how did you slide the 2 edge cuts you made at the same time, at opposite dir?

Well I'll be frank, fixing your model probably won't be easy without remaking at least part of it. Unfortunately this kind of work is more suited for CAD like NURBS or Solid Modelling applications; Blender is particularly unsuited for this type of workflow unfortunately. For this I would suggest the spin tool Alt+Rthat uses the 3D Cursor and the point of view as center for generating flawless revolution geometry.

The two edge loops sliding were actually created using the bevel operator. Select one single edge loop and press Ctrl+B and it will create two parallel loops using absolute distances.

Alright, I'll remake the detail. Thanks for the bevel tip! That'll be useful. What do you mean by "this kind of work", exactly? What "type of workflow" are you referring to?

I'm talking about solid modeling of geometric shapes or "hard-edge" type of objects like mechanical parts, non deforming or non organic shapes, based on precise measurements and intersections of basic shapes. This thing is usually done in CAD applications like AutoCAD, Rhino, MoI 3D etc, where you can easily use Boolean operations, extrusions, revolutions, intersections, trimming and extending, and beveling for perfect geometry and smooth curves

I'm confused. I thought Blender was more suited for hard surface objects rather than organics.

It's quite the other way around, Blender is primarily aimed at animators and character creation and subdivision based modeling for animation and feature film production. That is not to say that it can't be used for hard-edge modeling. It's tools are actually quite flexible and versatile, but generally speaking mesh based geometry and subdivision modeling in general are largely regarded as less suited for CAD work. Hell I work primarily in architecture and mostly do CAD based work in Blender, but I have to admit that there always a certain resistance, and I often have to fight the technology

Well, every hard surface 3D artist that I know and that I've seen on the web use either Blender, 3Ds Max or Maya, so you're really confusing me here :P. Going back to the main topic. Even if you use Smooth Subdivide every time you need a loop cut (which would be a pain), it still doesn't solve the problem when you have to put the loop closer to another. The same line appears. This question is not yet answered. The only thing that occurs to me that would make the lines disappear is to subdivide the whole cylinder equally whenever you need a loop cut, but I refuse to believe that is the best opt

Well this very same problem that we are discussing is exactly why mesh modeling tools are not the most adequate for this kind of work, you should never have to deal with these problems in the first place. Anyway as I said no easy way around this, rotate your loopcuts instead of moving them. Place the 3D cursor at the center of the cylinder curvature and preform rotation with the center on the 3D cursor position.

Cylinders and spheres are prone to render errors when they contain faces of different sizes. In your case the switch also produces irregularities not only in the horizontal but also in the vertical direction (both top and bottom of the switch)
As far as I can tell your model is already made out of several objects/meshes. If it's not absolutely necessary to have the switch and the tube as one single object I would separate them and collapse the unnecessary edge loops.

I didn't bother about joining all the parts because this is just a high poly model to bake a normal map to a lower poly model, but I want to avoid dividing the mesh further because it may become cumbersome. I'll do it if it's the best choice, of course, but is there an easy way to even out the size of the faces of the cylinder without deleting any edges?


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Adding random tiny flakes (gold) to appear suspended in gel
I'd like to know the best solution on adding tiny floating flakes in a gel solution. I suspect array might get me there but everything I've tried is much to uniform

Textures would be best way i can think of off the top of my head.

Probably particle system with texture set to influence on particles' density.. This depends quite a bit on necessary amount of details though.

Given the advances in Blender 2.8, is this question now closer to being answered?


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UVmap spills over onto unselected areas
When upwrapping to make a uv map I did NOT select the edge, back or side faces of these objects and yet the image I'm mapping gets miniaturized and repeated to these faces as denoted in red.  Suggestions?

Mark Seam. Select [all] vertices. UV unwrap. Then move those islands that you desire to be [not affected] off the UV Map, to the side.
Set Mapping Mode to Clipped, Not Repeat.
You can see this How do I put a stencil-like texture across a sectioned object?
Know that no matter how you UV Unwrap all vertices have a texture coordinate. Even if you can not obviously see the vertices,  they still exist.  You may have seen where some mesh models have duplicate vertices that are difficult to see.  A similar lack of obvious problem can occur with UV Maps. UV Vertices can exist in the same location and be a vicious trap for the unwary Blender user.
You can identify the UV location of a face by selecting it. You can see this How can I tell what part of the model the UV map is from? (In Blender)
UV Map data Can be built with Multiple UV Unwrap user operations.  When you select [part] not [all] of mesh to UV Unwrap ... this really means ... take the explicit command for the current selection and do not change the other locations of the unselected vertices ... and use a default location for faces if the UV Map is entirely new.  Selecting part of a mesh to unwrap does not mean ...... the unselected vertices should be unaffected by the texture.


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Selecting only the bottle's INSIDE bottom face, to form upward creating a 'hill' of glass in the bottom
Looking at the picture I added to model by, you can see the bottle has a "hill" of glass in the bottom. My question is how do I 'get inside' the bottle to select only the inside bottom's top face to form upward, thereby creating a hill? Currently I have a solidify modifier added (but not applied).

Blender allows you to hide vertices for convenience in Edit Mode
Apply the Solidify modifier.
In edit mode select the vertices you do not want to edit.
Hide those vertices.  Edit the visible vertices.

Alternative.
Change to wireframe mode.  Edit mode. Select the top of the hill vertex which you can see with difficulty.  Press Control [Numeric Keypad + ] to grow your selection.  Then hide the unselected.
[Control I] can invert your selection.

The bottom I found is one solid face. And Tris to Quads does not make it into a mesh. How can I make a solid face a mesh object so I can thenproportional pull it upward?

You could try Alt + P to poke the face, then add a loop cut if needed. (Ctrl + R)

@Marc You can delete the unwanted face in center [face only]. Extrude the desired edges and scale as may times as needed.  Extrude a final time and [Merge to Center] to close surface in triangle fan.

After you hide the outside vertices and add the loop cut to the bottom as Atomic suggested select just the middle vertex > enable proportional editing "connected" > choose a type of falloff from the dropdown menu (I used “smooth” in this example). Grab the vertex up > scroll the mouse wheel to determine how many vertices are affected.

GREAT answers. Thank You. As an alternative, after I hid the outside bottom face, I selected the inside bottom face, deleted it, selected the loop of edges, and did a Grid Fill, selected a few center faces and then pulled upward using "O" with the proportional Smooth Falloff.


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Material skews and stretches when placed on a new object
I created a galvanized texture. Worked great on one object. The next object I applied it to it stretched for some reason. I tried Cntrl A / Scale thinking that might reset the stretch but it did nothing. So here I am. I'm thinking a coordinates node or something?

Object Texture Coordinates with uniform scale
If a procedural texture has no input, by default it is mapped with Generated Texture Coordinates type which basically have a Z coordinate value of zero at the bottom face and 1 at the top faces.
As your object is tall, between the two faces there is a lot of space to be filled compared with the other object where the texture looks un-stretched.
To get rid of the dipandency from the geometry size I would suggest to use Object Texture Coordinates, which is based on the Origin location and Scale. Using a uniform scale for the object (e.g. 1,1,1, 0.2,0.2,0.2...or applying the scale with Crlt+A) will result in a isotropic texture mapping too.

I tried using Cntrl + A but that didn't work. I'll try Object Texture Coordinates. Where do I plug that in? At the beginning (left) of the node tree? And should it be the purple "Object" dot to the purple "Vector" dot?

You should both Apply scale & set Object Tex Coordinates. Yes, at the "beginning". Yes, exactly as you wrote. Obiuvsly should be done for all the procedurale texture of the nodetree.

Sorry, I did just as described: selected the object with the stretched materials problem, did a Cnrtl + A + Scale and then added "Object Texture Coordinates" at the beginning ---and there was no change. As seen here: http://www.aworkofmarc.com/1/blender/Untitled-4.jpg

There are two procedural texture nodes in the setup: noise and voronoi. Both of them should have the object texture coordinates as their vector input. After that you'll probably have to adjuste their scale, to match the previous look.

Ahhhh. ok. It worked when I added "Object Texture Coordinates" to the Voronoi. Before I had only added Object Texture Coordinates to the Noise.. and in fact, it seems to have little or no effect when I messed around with the Object Texture Coordinates as connected to Noise. And of course now.. other problems have developed but I guess that's a story for posting anther question.... ha. Thanks.


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Object visible in preview disappears when I render
I had accidently deleted the Render Layers and Composite nodes in the Compositing nodes section. When I discovered this problem (as it wouldn't render of course) I re-added those nodes. However now when it renders it only renders the white cap part and not the glass bottle of my scene. Any suggestions please?


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How to join vertices of 2 separate parts of one object
I have 1 object, with 2 separate parts. How do I connect the vertices to basically create a bridge joining the two? Contrl + J does not work.

Related - http://blender.stackexchange.com/questions/14969/how-to-connect-faces-between-2-edge-loops ?

What you want to use is F.  Select the vertices you want to join and hit f.  Ctrl + J is for joining two different objects together, not individual mesh components.

Ok. Just realized that only works with 4 vertices at a time (2 from each each sphere) When I first tried F, I had selected 4 vertices on each sphere (8 total) and clicked F and it did not fill. Thanks.

Select the faces of the areas you want to connect then hit Ctrl+E and select Bridge Edge Loops from the menu.


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Forcing Subdivide to create non-zig-zag edges
Is there a way that when something is subdivided, it can be constrained from making the zig-zag flower petal pointed edges?

While I mostly agree with the answer offered by cegaton, in my opinion, it has one characteristic that makes it undesirable in some circumstances. That characteristic is that the center point has a number of duplicate vertices in the same location. In this class of cases, I have found a useful solution in turning the triangle fan into a quadrangle fan.
Starting with  cegaton's first illustration, instead of deleting the center vertex, (as at 'A' below), instead deselect everything, switch to edge select mode, and select every other edge between the center vertex and the surrounding edge loop, (as at 'B' below), and delete those edges. Then create quadrangles with the remaining edges, with the result as in 'C' below.

This achieves a similar appearance to the option provided by cegaton, with the exception that it has only a single center vertex.
One warning: this works best with meshes which have an even number of vertices in the circumference.


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How to clean up mesh after using Knife Project on a curved surface
How can I clean up this Knife Project operation so the bad shading disappears?
The edges created by the Knife Project operation will be used to create a hole in the mesh using the Inset operation.

The cut seems to have an impact on the (future) hole part. So, try to make the hole (inset). That can also give you the ability to add more vertices along the mirror axis. But to help you more concretely, you should upload your file here http://blend-exchange.giantcowfilms.com/

try to make a strait line as on the pictur it shuld atleast look better.

if you whant to kep the shape add a new edge close to it and work whith it insted.

the last thing I whant to say is if you combinde the subsurfes and mirror modefiers. Put the mirror modefier firs if you don't whant a sharp edge on the mirror point.

Don't you thing that the curve, as it is in the question, is a will ?

My answer is not spesific for you'r case and it shuld solv you'r problem if you edit the shape


text:
How do I get out of a node group?
I did something I can't get out of! I selected nodes and thinking I'd group them I did a Cntrl + G. Not liking (or understanding) the result, I deleted the nodes. And I'm still left with a green cover that does not allow me to select nodes. :(

this is the most problematic bottle of Jack Daniels ive seen since new-years

@Marc Please pay more attention to the tags you use. Twice I've noticed you put the modeling tag on a question about materials. The modeling tag is for actual modeling of surfaces and things similar to that. It's important that we tag things correctly because it effects how things appear when searching. We don't want a bunch of materials questions to pop up when someone searches for modeling. Please keep an eye on that in the future. Thanks

Short cut to get "Un Group" Press "ALT" + "G"
Or,

Tried both! Neither work.

Try what Cegaton suggested above. Press "Tab" go get out of the Group.

Sorry. didn't see that comment. That worked. TY.


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Bottle is not showing up clear in render mode
I know this has got to be the dumbest question ever --but why is my dang bottle not showing up right? Clear.. with the label I just learned how to apply.

try adding more light, and also put a HDRI/skybox in world settings

Have you UV unwrapped your object?

Lighting or HDR does not help at all.  See image placed into a previous doc --the cazadores bottles right behind the black bottles are showing up correctly... Yes Sir.. it was UV wrapped.   Image: http://www.aworkofmarc.com/1/cazadores/untitled.png

Bottle is here if anyone feels like deconstructing it. http://www.aworkofmarc.com/1/cazadores/Kimo_Bottle_Backup.blend
And here is the scene with the bottle in it showing that it still shows black even with good lighting / HDR background (Don't laugh at my scene set up  --I'm obviously a total novice :)  http://www.aworkofmarc.com/1/cazadores/Kimo_Sabe_Stand2a_Silver.blend

Oops. Ok. By "pack" do you mean upload it with the blend file? Or is that a feature I click in Blender as in "Pack File" ...?  Anyways... the label is here: http://www./aworkofmarc.com/1/cazadores/azoth_front.png --thank you.

Ok. Back to the drawing board i guess. thank you.

@Marc If cegaton has solved your issue, please mark it as accepted for future visitors. See the tour: http://blender.stackexchange.com/tour Thanks.


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Label not showing up as transparent... or showing at all
Any ideas why this label is not showing up transparent? I believe I have all my nodes correct. These nodes are so complex someone should start a online Blender NODES academy...


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Extruding outward from center point to create the Bottle Cap Grip
I have a bottle cap that I wanted to create the look of a grip by selecting every few other faces (having used the Select/Checker Deselect option to do that) as seen in the pic below. Now I'm stumped on how to extrude those faces outward from the center. Even better would be a way to round the edges slightly at the same time.

There are many ways to approach any modeling task, but knowing what the end result needs to look like will influence what is suggested. if you are working from a reference you should include it in your question, preferably a close-up shot of the cap to allow more accurate suggestions.

Extrusion:

Way 1:
Select the faces, hit "e". Rightclick immediatly afterwards (that creates the extrusion but doesn't move it). Then hit "s" and "shift z" and move the mouse to scale them outwards.
Way 2:
Hit "i". Move the mouse to scale the new faces the same size as the original one. Now press & hold "ctrl" and move the mouse.

Further adjustment (optional)
Set "individual origins" and hit "s" to scale them smaller
Bevel
Hit "ctrl + b" to bevel them, use mouse drag + mouse wheel to adjust number of steps (roundness) and shape.

Alt+S moves something along it's normal. If you have several items selected, they will move according to their own normal. Think it makes the selection fatter or slimmer.
So select the desired geometry and Alt+S. Move the mouse up and down. It looks like this:

Set individual origins as pivot point:

after that you can extrude along the normals

Close.. but I need it to have the faces on either side also extrude with each face so it's not so abrupt and more slanted outward.

Based off of currently selected faces from your image:

Hit NUM7
Set Pivot Point to Individual Faces
Press R and rotate all the faces to the preferred angle. (To create the ridges like a water bottle.)

Reference Picture:

authors: Корнильцев Константин


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adding a transparent label on material
I am sure this has something to do with my nodes... but I got the label to be transparent.. however.. it's making the actual object it's placed on transparent NOT the label itself.. I think. Please see picture.

Unplug the transparent node from upper Shader socket of the Mix Shader and plug it below.. Diffuse BSDF goes to the upper socket of Mix Shader. Transparent BSDF goes to the bottom one (if it doesn't work set them inverse). Diffuse BSDF and Transparent BSDF don't need to be connected. The rest stay the same as on your picture. Quite long instruction manual, but it should work :).

Even when going with the "transparent BSDF goes to the bottom one (if it doesn't work set them inverse)" or going the reverse -- Still having issues. The background of the label makes the object transparent OR the switching the nodes pulgins as directed just makes the letter go transparent of the object.  See the screen shot... http://www.aworkofmarc.com/1/blender/uvmapping.jpg

Try to set the Image Texture type from 'Color' to 'Non-Color Data'. Maybe this will help?

Changing to non-color made the black label text a light gray is all -- same issues remain as before.

Marc, your .blend doesn't contain textures. Please pack the textures into your file and upload it again (http://blender.stackexchange.com/questions/30906/how-do-i-pack-textures-for-sending-off-to-a-render-farm).

I'm Sorry, I'm not sure what you mean by pack the textures, is that something I do inside Blender? Because I added the label in the zip file but maybe because it's not that same directory structure as was on my computer it doesn't show up in the blender file and needs to be reassigned or placed?

Packed and Reuploaded. Thank you. Oh.. and I switched label graphics  thinking it might be something with the graphic.. but the same thing happens.

How do you overlay an image on a shader in Cycles?


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OpenCV and Blender for use in Broadcast
We are a high school broadcasting team looking to up our productions for all of our shows. We are looking to specifically improve our american football productions, as those are some of our big shows. One common element in an American football game is the yellow first down marker. As you can imagine, this is an extremely difficult thing to accomplish for two main reasons:

Keeping the line in the same place as the camera moves is difficult to achieve.
Getting the line to go under the players and not on top of them is difficult.

We have figured out how to place the line under the players using chroma keying on our switcher, so no problem there. There problem is keeping the line in place. We are looking into motion tracking to achieve this, and stumbled upon something called OpenCV. It is essentially an open source video tracking/interpretation software. It has enough power and acceleration to run in real time.
We are looking to do something like this:

Take live video feed from a Decklink card into Blender
Place a 3D model of the football field over it, and use OpenCV to track it to the field.
In the 3D model layer, or with a layer parented to it, have our graphics play.
Send ONLY these graphics back out to our switcher for use in broadcast.

Everything having an SDK (The video card) or being open source (Blender, OpenCV), does this sound like something that could happen? What issues could arise with it?
Thank you

afaik Blender doesn't handle live footage...

I am looking to incorporate this as the intake from the grabber card, does this sound like something that can be done?

i've been looking for the same thing for some time, the only plosable way to do it is to duplicate a window with clean UI have teh background set to green and mirror that window to OBS so you can source it out as a video output.

This question was one I asked very early on. This paper details how we ended up completing the project.

https://drive.google.com/open?id=1deBHSbWQEG0gIO_ZPd8jKtOnZp0k2a_F

This paper details the solutions and challenges, as well as some technical information to how we completed the project.
https://drive.google.com/open?id=1deBHSbWQEG0gIO_ZPd8jKtOnZp0k2a_F


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Blender Graphics On/Off
we are currently working on making blender for a real time application for use in broadcast. We are using it to play on graphics in American football, layered over top of the field and played back using Blender's decklink capabilities in the BGE. What I would like to know is is it possible to have a graphic fade on screen at a command and fade back off at a command?

you can animate transparency in the BGE, but not opacity. This means that you can have solid colors fade on/off, but you won't be able to have partially transparent textures fade in/out.

Let me make sure I get you right: It is only 0% or 100%, nothing in between? Additionally is it possible to do more than fading, like animated transitions?


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Mark sharp does nothing
I understand this is a very basic question, but I cannot find the solution. Google & other Stack Exchange gave me no solution either.
I am following Blender Game Asset Creation guide from Blender Cloud, at some point Aidy selects his whole model and does Shade Smooth. Then he selects some edges and marks them sharp.
In Aidy his tutorial you can clearly see the difference between marking sharp and not. As seen here (this is taken from his tutorial)

When I do this in my Blender File, I see no difference. I've tried removing any doubles, but I can not think of anything else. What could be causing this?

Did you add Edge Split modifier / checked Autosmooth option ?

As MrZak said,  Make sure Auto Smooth is turned on, (for manual edge split, the angle should be 180) ... For Auto edge split (Ie: blender decides where to split the edges) I find that an angle of 60 to 80 degrees works mostly, although it depends on the mesh :)

Thank you, and MrZak. It seems Aidy did indeed mark that checkbox, but I failed to see it. I can now continue with the tutorial!


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Some edges on model won't Bevel
I'm very new to Blender. I've used a loop cut and slide to make the shapes I want to indent in this object, then extruded them inward to get them how they look now, then dissolved the unnecessary leftover edges. I wanted to apply a bevel to some of the edges, so I used Tag Bevel in Edge Select Mode and marked the edges I wanted to Bevel, added the Bevel modifier and set the mode to weight.
On one side, it looks exactly how I want it:

On the other side though, some of the edges aren't being bevelled despite being tagged (the ones closest, on the left side):

Why is it working for every edge other than these ones? This is the wireframe of the object and it doesn't appear to be any different on the side that works to the side that does not:

And these are the bevel's settings just in case (I've tried fiddling with the width and it doesn't seem to have any effect. Incidentally, if I change limit method to None, those edges bevel fine):

That is unusual. Can you use a mirror modifier on the mesh? That might get you up and running until we figure out what is going on.

Is there any chance for you to upload the file or paste a link?

@NoviceInDisguise Not sure whether this is quite what you mean with mirroring, but I made a duplicate, bisected it, deleted the half that didn't work then mirrored it. That makes it look OK, so I'm assuming the problem is with the mesh? (top one is the mirrored one)
http://i.imgur.com/xehfDsM.png

Here's the blend file:  https://www.dropbox.com/s/pf6k57cqa7ylp9q/Pistol.blend?dl=0

you have a loop cut inside that part "overlapping edges"

select all the mesh in edit mode click remove double in tools
re-assign  the bevel weight again

Note that remove doubles is now called merge by distance.

(On Mac, Blender 3.5.1) I didn't find it on the toolbar, but under the Mesh menu > Merge > By Distance. However, in my case, this didn't do anything ("Removed 0 Vertices"), and didn't solve the problem of being unable to bevel.

This can happen when you scale a mesh in object mode. The solution is to apply the scale (⎈ CtrlA) in the aforementioned mode.

It is not a scaling issue, read the question and the accepted answer.

@Denis However, something like this can happen when there object scale is close to 0. See for example: https://blender.stackexchange.com/q/12288/599

@gandalf3 true, but it would be uniform over the mesh, unlike it is presented in this question.

@Denis Fair enough :)

Actually, I had the same problem as the OP: one edge refused to bevel, while all the others in the mesh worked fine. "Applying all transformations" to the mesh solved the problem. I don't know why.

You may have hidden geometry that prevents a bevel operation. Press "Alt + H" to reveal hidden geometry, and delete geometry that is connected to the area of your bevel. Hanging edges, interior faces, and other non-manifold geometry will prevent a bevel. Here is an excellent thread explaining non-manifold geometry:
(What is non-manifold geometry?)


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How to make brick texture appear bumpy
Which node should I add to this material to make the structure appear bumpy (mortar inset relative to the bricks)?

I tried various combinations like [Brick Texture] Fac > [Bump] Normal > Normal [BSDF] and [Brick Texture] Fac > [Bump] Normal > Displacement [Material Output] and [Brick Texture] Fac > Strength [Normal map] Normal > Normal [BSDF] and so on, but I didn't find one that had any effect.

The bump node converts a height to a normal map by reading grayscale gradients. If the height map is too sharp there isn't anything to create surface angle shifts.
Increase the mortar smooth to get a broader gradient at the brick edges

Oh, ok. Now I see that both the Bump and Displacement node only change the color of the object. Makes sense.

Jackdaw's answer is good if you only want it to appear bumpy, but there is actually a way to make it bumpy, but it only works with the Cycles rendering engine.
Connect the Brick Texture to the Displacement input of the Material Output (possibly passing it through another Displacement node) and then in the Material Properties under Settings set Displacement to "Displacement and Bump":

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


text:
Lock transformation in local coordinate system
I want to lock the transformation to certain axes only, but when I just lock the axes in the Transform panel, they seem to lock global coordinates, even when Transform Orientation is set to Local.

Note that locking the axes removes the arrows from the local gizmo, which makes this all the more confusing.

That's what the Transform Location locks are for, they lock the objects on the Global axis, the fact that you switch the Transformation Orientation from Global to Local won't change it.
If you want to constraint an object on its local axis, use a Limit Location constraint, switch the Convert to Local Space and choose on which axis you want it to be constrained.

Not super convenient but it is a working solution.

One question though: If the locks are for locking on the global axes, why does it also remove the local axes from the gizmo in the viewport? What's the use case for that?


text:
How to close an area?
With a UI layout like this:

How do I close the bottom area?
These are the context menus of the header, the split, the editor type selector and the type selector itself:

There's an item that allows me to maximize the area, but there is nothing to close it.

@rjg Not a duplicate. The answers to that question are to use the "Join Areas" command, my question is because that command is missing from the context menu.

Alright, my bad.

Subdivide the bottom part to match the upper one then merge

Ok, I found one weird way:
I can split the bottom area vertically as well and then align the split borders of the top and bottom area pairs:

This alignment is easily possible because the split borders snap to a grid.
As soon as they are aligned, the context menu of the border between any top and bottom area gets a new item "Join areas":

After joining the left pair and the right pair, the bottom area is then gone.

yes I think it's a new feature, but instead of Join Areas you should be able to grab one of the window corner and push it / pull it to collapse the other window

@moonboots Nope, that also only works after aligning the splits.

Oh ok didn't know that

Hello :). This question keeps popping up as unanswered. Please mark your question as accepted, to keep the site nice and tidy.


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Combining Translucent and Volume Shaders
I would just like to know why when using both a translucent shader and a volume absorption shader the volume absorption shader will darken and color the look of the translucent shader. I understand it has something to do with the way the translucent shader works, but I would really like to understand exactly why this happens.

Translucent shader gets power (brightness) from the light rays that enter the surface scatter inside and come through the material.
When the rays coming through the volume are absorbed by volume absorption, the translucent shader gets less energy and is darker.
The scattering is also an approximation and you will get much more accurate results with volume scatter or subsurface scattering shaders.


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Get Object Width In Cycles as Value
Is there a way to get an object's width in Cycles as a value that I can use, for example, as the color input of a diffuse shader? Basically, is there a way I can get the volume absorption shader's output as a value?
Here is an example of what I mean:

The thicker the glass, the more subsurface scattery it looks.
I was able to achieve what I wanted by creating two renderlayers; the first renderlayer would render some object with just a volume absorption material and output the image to a folder, and the second renderlayer containing the same object but with a material using the first renderlayer's output as an image texture. But this is pretty annoying because I have to use two renderlayers and an image sequence.
I have tried using the fake absorption method (The one that utilizes the Beer-Lambert law) to do so, but it seems I cannot invert the output value or even use it at all on a surface shader that does not have light pass through it. Maybe there is a way to alter the math behind the nodes so that it outputs an inversed version of itself?

You can sort of do this with the ray length output, but AFAIK it only allows you to control the shading of backfaces. If you only want to mix diffuse colors based on thickness or something, then that may work.

Related: http://blender.stackexchange.com/q/4969/599 and http://blender.stackexchange.com/q/3573/599

@gandalf3 I found both the related links very helpful, but I feel like in both of them the issue was not resolved. Also, in your first comment what is the 'that' that may work?

Indeed. If all you want to do is mix between two solid colors, then this answer describes it in more detail.

This may also interest you or future seekers https://www.youtube.com/watch?v=qkqsx951gcg it's about glass absorption in blender cycles using scientific study to recreate the real world glass shader.

Related: http://www.blenderdiplom.com/en/tutorials/419-tutorial-absorption-in-cycles.html

Open Shading Language
You can enable OSL in the render tab of the properties panel.
Create a text either externally or in Blender, write your
OSL code in that text and save if necessary. In the node
editor, add a script node and select the mentioned text.
Based on the Blender manual using trace in this case is OK.
Simple depth
These shaders need only one trace per sample and get
precise values. Can be used anywhere without any bias.
Normal dependent depth
shader depth(output float depth = 0) {

    if(trace(P, - N))
        getmessage("trace", "hitdist", depth);
}

You can use this code to get the depth along the normal of the surface.

View dependent depth
shader depth(output float depth = 0) {

    if(trace(P, - I))
        getmessage("trace", "hitdist", depth);
}

You can use this code to get the depth from the point of view.
Plugging in the proper function of this depth to a transparent
shader you can create a uniform volume absorption for example.

Stochastic depth
These shaders trace one random direction per sample which average
out over the rendering process. The output of these have to be used
carefully: They can be used to mix colors or shaders and probably
well enough as the roughness of a glass for example. But they can
not be used for a color ramp with lots of color stops for example.
Mathematically: They are unbiased if the resulted color of
the sampled pixel is a liner function of the depth value.
I could add multiple sampling, which would dramatically reduce
the bias for those non-linear cases, but using those would slow
down rendering. I will write those versions if you ask me to.
The random
float random(int seed) {

    return cellnoise(P * 732283.511 + seed * 138257.835);
}

This is a position dependent direct seeded pseudo-random number generator.
Somehow I did not get too much luck with the built-in random function.
Works because the position is already pseudo-random with small variance.
Uniform depth
float random(int seed) {

    return cellnoise(P * 732283.511 + seed * 138257.835);
}

vector hemiRandom(vector direction) {

    vector result;

    int seed = 0;

    do {

        result[0] = random(++seed) - 0.5;
        result[1] = random(++seed) - 0.5;
        result[2] = random(++seed) - 0.5;

    } while(dot(result, result) > 0.25);

    if(dot(result, direction) > 0)
        return result;

    return - result;
}

shader depth(output float depth = 0) {

    if(trace(P, hemiRandom( - N)))
        getmessage("trace", "hitdist", depth);
}

This takes every direction equally into account.
Semi-mathematically: Every direction inside the mesh is sampled with the same chance.
You could considere this as one general view independent depth.

Lambert depth
float random(int seed) {

    return cellnoise(P * 732283.511 + seed * 138257.835);
}

vector lambertRandom(vector direction) {

    vector result = 0;

    int seed = 0;

    do {

        result[0] = random(++seed) - 0.5;
        result[1] = random(++seed) - 0.5;

    } while(dot(result, result) > 0.25);

    result[2] = sqrt(0.25 - result[0] * result[0] - result[1] * result[1]);

    vector a = 0;

    if(direction[0] == 0) {

        a[1] = direction[2];
        a[2] = - direction[1];

    } else {

        a[0] = direction[1];
        a[1] = - direction[0];
    }

    vector b = cross(a, direction);

    return result[0] * a + result[1] * b + result[2] * direction;
}

shader depth(output float depth = 0) {

    if(trace(P, lambertRandom( - N)))
        getmessage("trace", "hitdist", depth);
}

Takes depths towards the normal more into account, the same way a transulcent shader samples the light of its environment.
Mathematically: The density of the random is linear to the dot product of the sample and the normal.
You could considere this as another general view independent depth.

Rough depth
float random(int seed) {

    return cellnoise(P * 732283.511 + seed * 138257.835);
}

vector roughRandom(vector face, vector direction, float roughness) {

    vector result;

    int seed = 0;

    while(1) {

        result[0] = random(++seed) - 0.5;
        result[1] = random(++seed) - 0.5;
        result[2] = random(++seed) - 0.5;

        if(dot(result, result) < 0.25) {

            result = normalize(direction) + result * roughness;

            if(dot(result, face) < 0)
                return result;
        }
    }
}

shader depth(float roughness = 0, output float depth = 0) {

    if(trace(P, roughRandom(N, - I, roughness)))
        getmessage("trace", "hitdist", depth);
}

This is a poor roughness model but could be good enough for your use.
This is general view dependent depth with roughness control.

Nodes
These are the nodes used for the renders:

I kind of got caught up in this, spent some time to develop it also for my possible future use. :)

To get the thickness per pixel, would use many many raycast,
You can do that with bvhTree.castRay, then raycast backward along the same angle, from behind, the distance between the two points is the thickness.
You could save the data as a map but it would be view dependant


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Rotate background procedural texture
I want to put a procedural texture in the background of my image. I set the "World" color to a texture I like, and I would like to change the angle of this texture. How can I do this?

What you want to do is edit the World nodes. Go to the Node Editor and click the globe icon:

Makes sure you check the Use Nodes checkbox as well.
Now add an Input > Texture Coordinate and a Vector > Mapping node and connect them as shown:

Now the three rotation values will adjust the orientation of the texture.


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Make photo fade out to black in the middle of a circle
I need to have a photo fade out to black in a tunnel effect.  Kind of like the edges are becoming all black and you only see the circular photo in the middle which then goes to full black.  Can't find the term for it and not sure if this program will do it.  Any ideas? Thanks.

Should be possible by animating a Vignette sort of effect

Would this allow me to have it stay as a gif?  I don't want it to turn into a video file.

Blender can't out put GIF's (?), but you can export the images as, say, PNG's and make a GIF in for instance GIMP (open first image, then open the rest of the images in the sequence as "Layers").


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Why can't I export a curve to Collada?
I want to export a Bezier curve object to Collada (to load with Three.js). When I export my scene, the curve won't show in the Collada file, unless I convert it to a mesh first.

i don't think collada supports cuves.

Does .OBJ support them?

try STL. i think i've seen it work in there before


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Trying to create visualization of EM waves
I'm trying to create a visual representation of EM waves traveling through space and I'm having a tough time.  I found these images I like but I am having trouble coming up with a good way to render them.  I'm using cycles and it is a still image so I don't need to worry about animating.
Thanks.

You can recreate the first image fairly well using the math function mesh (Add --> Mesh --> Math Function --> Z Math Function).
This is what we're aiming for here:

First, you need to enable the AddMesh:Extra Objects add-on (press CtrlAltU to access the system preferences)

Type in the wave function you want to display in the input box (I used Z = sin(x) + sin(y) for this example).

Then, delete the edges along one axis (I deleted the ones along X):

Select and add each edge loop using AltShiftRight Mouse Button.
After you've got 'em all, delete edges and faces only (X --> Only Edges and Faces).

From here you can take it to many different places, but here's a suggested workflow:

Convert the mesh to a curve, then add a fill.

Add a taper object (bezier curve with an arch shape along the Y axis), and set it as a taper object for the wave curve.

Add a subsurf modifier to get smoother curves.

In Cycles, set an emission material to the wave object and choose a proper color.

If you want to add particles for added effect, create another copy of the original wave mesh, then add a particle system to it.

Add a simple mesh circle (Add --> Mesh --> Circle).
Set Fill type: Triangle Fan
and Vertices: 6

Then rotate 90 degrees on X so that the circle faces the Y axis.
Apply rotation (CtrlA --> Rotation).
Apply the same material you created for the wave to this circle.

Use the following particle settings:
Emission:
Number: 50000
Jittering Amount: 2
Velocity:
Random: 2
Rot: 1
Physics:
Size: 0.025
Random Size: 1
Mass: 0
Render:
Emitter: False (uncheck)
Render type: Object
Dupli Object: The hexagonal circle you created earlier.
In the Scene tab on the Properties Window, turn Gravity off.

Run the animation (AltA) for a bit until you have a nice distribution of particles around your mesh.

That's about it!
You can enhance this further by adding depth of field or motion blur, but I'll let you find tutorials or other answers to find out how to do this.

@gtbuzztim Thanks! And if this answer works for you, please mark it as accepted: http://blender.stackexchange.com/tour

For anyone else reading this: Z Math Function is not enabled by default. You need to go to User Preferences > Addons and enable the "Add Mesh: Extra Objects" plugin.

You can similar effects using procedural shaders.
The second example image is similar to that produced in this answer, specifically :

Also, consider this related answer which uses similar techniques but in 3 dimensions and would be relevant to your first example image.
For example, this material :

Can produce this :

Tweaking the parameters and Color Ramp should be able to produce the desired result.
EDIT : Another technique would be to use a similar method to generate the waves on a surface generated from a Noise texture (although you could also use a Wave texture for more regular waves) and to use a Modulo function to use the Y coordinate to generate multiple contour lines as shown. Tweaking the Scale in the Mapping node allows the effect of the Noise texture to be varied independently along each dimension.


text:
What are the shortcuts for the pie menus?
The shortcuts for the pie menus aren't shown in any tooltip, so I can never remember them. What are they?

Mode
Ctrl+↹ Tab

Proportional Editing Falloff
⇧ Shift+O

Snapping
This one is not a pie menu, but its shortcut seems to be missing from the tooltip as well, so I included it in the list:
Ctrl+⇧ Shift+↹ Tab

Snap
⇧ Shift+S

Pivot Point
.

Transform Orientation
,

Shading
Z

This should be the first page of the Blender manual +1

On Azerty keyboard, the period "." is obtained by Shift+";" and it doesn't open the Pivot pie menu. I didn't find how to open it.

` <-
The backtick opens the Snap To View Pie Menu

The backtick `opens  the viewport align pie menu, eg Top -> Numpad 7

SHIFT+Spacebar for tool menu is yet another one.

on an azerty keyboard it's "ù".
it will be cool one day blender takes in charge other keyboards. I mean precisely...but maybe it's quite impossible when a key doesn't exist in English... or a table of conversion? no idea in fact how to program this. nothing is simple in this world. between languages, OS ...

On my Azery keyboard (Lenovo running Gnome/Linux) the View pie menu opens with the "²" key (top left, just below Esc)

A on Sculpt Mode brings Masking related shortcuts.

View pie menu opens up with ö on a German keyboard.


text:
Extrude rectangular area from face
I have this shape from whose top face I would like to extrude a rectangular area of 5 by 5 mm, as I have expertly illustrated here:

How would I go about this?

I would create an open rectangle of the 5mm by 5mm and the then use the Knife Project to create those cut on the Mesh. Then you can just extrude from the result. Knife Project works on your view, so make sure you are in orthographic.

@rob Knife Project works!


text:
How to smooth a mesh?
I have this terrain mesh with some mountains, but also some plains between the mountains.

I would like to smooth out the plains, because when 3D printed they cause a lot of unnecessary walls:

Basically if you'd represent this as an image with white = high and black = low, I'd like to blur the image.
I tried the "Smooth Laplacian" modifier which does nothing and the "Smooth" modifier which does this:

Try the Smooth command in edit mode in 2.79 hit W, in 2.8 hit Ctrl+v. Or use the smooth sculpt brush in sculpt mode.

Apparently there was something wrong with my mesh (although it looked completely fine in edit mode). I activated the Mesh: 3D Print Toolbox add-on and then used the Make Manifold button on my mesh. After that all the smoothing tools (Smooth modifier, Smooth sculpt brush) began to work properly.


text:
World map as displacement map on a sphere distorted
I am trying to use an image of a world map as a displacement map for a sphere. Later I want to export the mesh for 3D printing, with the continents looking like engraved into a sphere. I am new to Blender.
This is the image I am currently using:

This image is basically the "Land/Ocean map" from this Blender tutorial, just with an erode/dilate filter applied. Because this guy is using it as a texture in Blender I am assuming it is a suitable projection.
What I tried so far:

Create a UV sphere
Add a Subsurf modifier with 7 subdivisions
Add a Displace modifier with this image as texture and a strength of 0.02

The problem is now that while Europe and Africa are squeezed horizontally...

... Australia's east coast is extremely stretched out.

What am I doing wrong? Or is there a completely different, better way?


text:
Fill hole with spherical cap
I had some artifacts at the pole of a sphere, which are the result of a Displace modifier with a slightly messy UV map:

To get rid of them, I Alt-selected a loop around them and did Select > Select Loop Inner-Region:

When I now hit Del and choose "Dissolve Vertices", I get a single flat face:

Is there a way to instead fill the hole with something like the cap of a UV sphere?

Possible duplicate of Fill cylinder cap with quads

Not a duplicate. The cylinder in that question already has (almost) what I want and they ask how to change it into quads. If at all it's a duplicate of this question but Grid fill does not work for sphere caps.

Possible duplicate of How can I fill a cylinder cap?

Actually, this is kind of a duplicate of this question, except that I not only need the fan, but also regular loops around the (poked) center.

Any other way will leave a flat face. The way I do it is to create the exact size UV sphere with the same amount of segments, delete the unnecessary faces, and then manually connect the vertices to the cap of the new UV Sphere.
But I'm guessing since you have so many segments that would take forever. So another more inaccurate way- since it's a sphere is...
Extrude the opening's edge 2 or 3 times. Then merge the smallest loop into a single vertice.
From there you can adjust the height of the new vertice loops until the smooth operator or subsurface takes effect visually.


text:
How to select specific edge loop?
I have this rectangular hole. I want to select the edges that I have marked in green.
I tried using Select > Select Loops > Edge Loops but depending on which edge I click I get one of the edge loops I have marked in red. How do I specifically select the green one?

Doesn't Alt-clicking on one of the edges work? If not there may be something odd with your topology.

I think if you can't select by alt+clicking, then this is because the set of edges doesn't satisfy the definition of an edge loop.

You have 2 options:

Option 1: Just manually select the edges
Option 2: Use the Pick Shortest Path Tool. You can activate this tool in edit mode by clicking on the first edge and then Ctrl +  Left Click the last edge. In this case you would probably select the first long edge then Ctrl +  Left Click the other long edge which would also select one of the short edges. You would, however, have to manually select the other short edge.


text:
OS freezes while using Blender (in edit mode)
I am very new to Blender and ramping up my learning. But I am constantly facing a problem in Blender. Whenever I am modelling a cylinder (with just 8 vertices and mirror+subdivision surface+smoothed) the OS freezes I cant move the mouse at all. I am running Blender in my Dell Vostro 3350 with 6GB RAM along with AMD+intel Graphics. The OS I am using is Ubuntu 17.04. Please let me know your thoughts on how I can solve this.

check the settings of your subdivision surface - if the subdivisions in "view" are too high, your computer will run into these problems.
i would start with 1 and then increase whenever you really NEED it.
Ps. the "render" subdivisions are the ones that will be calculated when you apply the modifier or render the scene

I thought so as well, but value of view for subdivision surface was always 1. Could it be that I am applying smooth and subdivision surface together?

it's a bit hard to tell, but generally it should be no problem to stack multiple modifiers (they always work on top of eachother)
maybe you can edit your question with a screenshot of your modifiers? or add your blender scene

I think I figured out , my hardware is just over minimum requirements. I think its just too much for it to handle. Its a 4 core processor with 6 GB RAM and integrated graphics not dedicated.

Funny you should mention that; I was just about to point out that GLSL rendering can occasionally do this when it needs the whole graphics card. However, I wasn't sure you were using that--but at 6 GB on a quad core, it might not matter. Start with a dedicated graphics card, and if that doesn't do it, up your RAM to a minimum of 8 GB; then you should be fine.

Yeah sorry wasnt really sure before posting it :( anyways thank you very much for your advice :)


text:
How to make the object follow another object's vertex
How to make the object follow another object's vertex?

related to http://blender.stackexchange.com/questions/34324/how-do-i-stick-an-object-to-another-objects-vertex?rq=1

Select the 'Follower', then the Object containing the vertex to follow. Tab into Edit Mode then press Ctrl+P, a popup menu for 'Parenting' should come up (Set Parent To) with the options Object or Vertex. See the Manual for further details.


text:
How to make a circular set of verticies square

Is there any way to take my circular vertices, and make them square so that they match my cube? I want it to be a cone with a circular base and a rectangular top.

Are you aiming to merge the cube and cone, or do you want a cone with a circular base and rectangular top?

cone with a circular base and rectuangular top

I'd suggest creating such a cone by starting with a cube and using the subdivide and circile tools:

Add a cube.
Select the bottom face.
Subdivide 3 times (don't worry about the Ngons above, we'll take care of them later). Use the specials menu (W > Subdivide) or the Tools shelf.
Use the Looptools > Circle tool to turn the base into a circle (W > Looptools > Circle). If you don't see the Looptools activate the addon through the User Preferences Window (CtrlAltU > Addons Tab).
Select the top face and scale down as much as you need.
Select the central faces (everything except the top and bottom faces).
Triangulate (CtrlT)

Thank you, that seems to be exactly what i want. Since i want to 3D print this later, do you know a way to change the exact measures that appear when creating a mesh, i.e the radius and depth of meshes / objects?

You can use the object dimensions to control the base size (X and Y dimensions) and the overall height (Z dimension). After you get these right, you'll need to do a bit of math to get the top cap right (more about that here: http://blender.stackexchange.com/questions/1674/how-to-get-selected-edges-length/1676#1676).

After subdividing the cube/square to match the circle subdivisions number (with W-->Subdivide) you may try to join vertices using the Bridge Tool. Select the vertices with Alt+RMB as pictured below, hit Spacebar, type 'bridge edge loops' and then dissolve the newly created edgeloop. Select it with Alt+RMB, then hit X-->Dissolve Edges. At the very end select the vertices of a square, hit Spacebar, type Grid Fill and set up the settings as pictured below.

subdivide your cube until you have the same amount of verticies as the circle has and then you can snap the verticies from the circle to the right verticies on the cube.

You're right. After subdividing the cube to match the circle subdivisions number he may also try to join vertices using the Bridge Tool and then dissolve the newly created edgeloop.

Would you kindly expand on how that process goes? I know where Subdivide is but i'm having problems using blender.


text:
Why does exporting FBX to Unity mess up my UVs
would love some help with this as Im probably missing something simple so here's the issue...

I save a UV map (from UV master) on the low res in Zbrush and polly paint my high res and create a normal and diffuse map from it. I then hit GoZ and all goes across to blender perfectly
In blender I can view my textures by pressing alt z and they look fine, and also when I render. I then put in a meta rig, rig it, weight paint, animations etc.
Now when I export FBX to unity the model comes across fine with anims etc. But when I drag my textures (normal and diffuse) onto the FBX mesh (which should have exported with the UVs) its like the UVs are completely different or massively messed up, we are not talking a few stray seem artifacts, but rather a complete picasso, with large sections of black on the model where the bg of the diffuse is being used. Hence I am assuming my UV has issues (or blender has created a new default one in the export?. I thought that the Zbrush UVs had come across fine as the texture is displayed properly in blender, but perhapse they are not assigned as UVs in blender? I have no idea about UVs in blender.

This happens with multiple meshes (static objects and rigged characters).
Also just going from Zbrush (with an x normals bake) to unity with no blender involvement works fine on the mesh (it just isn't rigged :( ).
Thanks so much for any help.

are the UVs OK if you re-import the fbx to Blender? If so, the export works at least, the problem has then to be searched for on the Unity side. Otherwise you'll know there's something to look into on the Blender side.

Have you checked the texture size and settings in the inspector in Unity? Also have a look at the 3D model import settings for that model in Unity. As aliasguru mentioned, it's more likely to be a problem on the Unity side.

I'm having this exact issue, only iv'e used Maya. I created my high poly sculpt in zbrush, then rigged, animated, and UV mapped him in Maya. But the exported fbx has broken UVs in Unity... its maddening.
solution for you there are two UV layers in all imported assets in Unity. In the material inspector, try switching from UV0 to UV1 (in drop-down menu). Hopefully this fixes your problem... If not then you and i are truly in the same boat. Which tells me its likely a Unity problem, since we're using different modeling/animation software.

Unity imports the 1st UVMap it finds. If you have 2 UVMaps made in your 3D editor, likely Unity is using the first wehn you want to use the second one.
Try ticking Swap UVs in the inspector with your model file selected. I just tested in Unity 2019


text:
reconfigure roll of bones without losing waightpaint
I need to change roll of some bones in my rig and would like to save my weight paint so I does not need to re-do it again. Is this possible. I know that I can change roll of finger bones with out deforming mesh but I cant to the same on legs :) Any thoughts :)

Changing the roll of bones will not effect your weight painting and your model in rest-position will be exactly the same.
What will change is your bones pose transformations -> your armature in pose mode will look different. That's because such transformations are in local space and changing the roll of bones changes the bone's coordinate system base around it's Y axis.

Yes that's right, and how can I then switch x axis in order to have flipped pose across axis where I need them :) Tnx for helping out :)


text:
Play two nlatracks simultaneously
I run in to problem with nla editor, I cant play two tracks simultaneously if they start and end at same time, the track on top is only which is played, if I move only one to side I get transition from one to another but not both played simultaneously ? Any suggestion tnx


text:
Select overlaping vertices from vertex groups
Does anyone know how could I select and view vertices which overlap from two vertex groups ?

Deselect all the vertices, with A.
Select the first vertex group with the Select button under the vertex group list in the properties window.

Invert the selecting by pressing CtrlI.
Hide those vertices, with H.
Select the second vertex group (same way as in step 2).

Any vertices that are now selected are in both vertex groups.
After doing what you want with the double grouped vertices, you can show the whole mesh again by pressing AltH.
Animated gif showing first the two vertex groups, then how to find double grouped vertices, using the procedure listed above.

tnx, the answer is awesome :)


text:
How to fix this verterx which sticking out
I have my crharacter which is riged and waight panted but pinky finger have one verterx sticking out even its 100% painted in red

An other bone has also influence on that vertex. Turn on the "Vertex selection masking", then select that vertex, and remove it from all vertex groups, then reassign to the pinky or repaint it with the weight brush.

Tnx mean you saved my day


text:
How can i save already done UV maps when merging two objects
I have two objects which have already unwrapped UV's and I wont to merge them
in to one object but when I do that I lose UV's map from one object, so is there a
way to merge them with preserved UV's ?

they should not lose their UV map

https://youtu.be/jhGJt4jEFfk

could you please share your file (only these 2 objects)?

https://pasteall.org/blend/f93a7929258f4a1d91f58f01a86f0b8d

So you're using Blender Render but I've got the solution. First merge all the columns, then in the Properties panel > Object Data > UV Maps, change the name of the UV map you're currently using, use the one you're using for the temple itself (it is called UVMap). Join everything, it works.

Yep that's it tnx


text:
Blender wont find python in usr/local/bin
I wont to run blender2.49 and I have compiled and installed python 2.6.6 under /usr/local/bin and when I start blender in console it says
Compiled with Python version 2.6.2.
Could not find platform independent libraries <prefix>
Could not find platform dependent libraries <exec_prefix>
Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>]

when I run python in console it says python 2.6.6
How can I add python to library path or $pytonhome ?

Are you on mac or on linux?

Im on ubuntu 18.04

No need to compile or install, there are ready to use self-contained versions in the release archive https://download.blender.org/release/

On OSX, open a terminal session.
In your user directory (e.g. mac/users/doeke) make sure you have a file named .bash_profile If it is not there then create one.
Open terminal.
sudo nano .bash_profile
add:
export PYTHONHOME=/usr/local/bin/python_whatever_the_fing_path_is
press ctrl + x to quit and hit y to save the file.
Now log in and out or reboot. Hopefully it is fixed now.


text:
Blender 2.49 from os import urandom as _urandom ImportError: cannot import name urandom
I searched whole 5 pages on google but did not find answer, I have old blender script that I need to run on blender 2.49 but Im getting an error
from os import urandom as _urandom
ImportError: cannot import name urandom

Blender reqire python 2.6 which I have installed and I have confirmation from blender
Compiled with Python version 2.6.2.
Checking for installed Python... got it!

I'm not using virtualenv, so it should not be the issue here.
I did like described here and added "print 42" to end of /usr/lib/python2.6/os.py and I'm getting printed 42 when I run blender and that os.py does not end with definition of urandom, precisely
Does anyone has any suggestion tnx

Can you import it when running python in the shell?  Recall  blender 2.49 used python 2.7

No I cant import it in shell. No python 2.49 comes in two verisons python 2.5 and python 2.6


text:
Keeping array objects straight when duplicated along a twisted curve
I have a fence curve which goes down a hill and fence posts duplicated along it using the Array and Curve modifier.
How do I stop my fence posts tilting with the angle of the fence? I would like them to remain realistically upright as they go down the incline.
The post's origin is on the exact same place as the fence's and duplicated with the Array modifier, using the fence curve in the Curve modifier.
Issue

Fence properties (Bevel Object 'fence to curve' is the shape extruded along the curve to make the fence itself)

Fence post properties('Fence Curve.RIV...' is the fence curve)

There's some unavoidable degree of curving effect when arraying with Curve modifier, see https://blender.stackexchange.com/questions/5910/how-do-i-prevent-object-distortion-when-applying-a-curve-modifier

Array a simple plane object then use particles to place posts on every face instead, that way you can place them upright or in any other direction. curves will always deform the face, no way around it.

I finally have an answer to this. I wanted to make pillars for my roller coaster track, and I needed them to be vertical as well and after a lot of search found the solution. Here is how it looks

The way is to NOT use Array Modifier/Curve Modifer but instead parent the object (fence posts) to your curve ( Ctrl P), and then use DupliFrames (after disabling speed). This way, it treats each of your posts as separate objects and then you can use Limit Rotation to zero degrees on all axes. This will keep them vertical.
I just implemented this and it totally worked. Let me know if you need more details. I think the idea is that modifiers treat the set of fence posts as a single object and thus you cannot Limit Rotation on them separately. Using DupliFrames treats them as separate objects and thus you can limit their rotations afterwards. Sorry for the wordy reply without any images. Other blender experts can comment if this should work.


text:
How to add a Jiggle Bone in Blender Game Engine?
Basically, I want to add a jiggle bone in the blender game engine. I have tried to use a jiggle bone method that works in Blender Internal with a cloth simulation, however, when I place that method inside the BGE, it does not play back.
How would I add a jiggle bone inside BGE? Is this because BGE doesn't support any way to make jiggle bones, or that the game engine is not playing back anything?

what do you mean with "Jiggle Bone"?

A bone that reacts to movement. Its used for hair, loose mechanics, panels, etc. for characters you control and stuff.

You can use bone constraints. Be aware not all constraints are supported. This means certain mechanics from Blender will not work in the BGE. Maybe this one helps: https://blenderartists.org/forum/showthread.php?370349


text:
How do you prepare a model for 3D printing?
Ive no idea how to prepare a model for 3D printing.
Is the model supposed to be prepared in a specific way? If I want to print a model with meshes that intersect other meshes, would blender be able to print that? or does it not have to have any intersecting geometry?

I have heard that 3d printing favors the STL format and that it's really important that your mesh is closed. Meaning no openings between vertices or polygons.

Just put your title into google. Plenty of tutorials and instructions. This topic is very complex and out of scope of this site. If you have specific problem with 3d printing or mesh preparation then ask it here pls.

Enable the 3D printing toolbox addon to help check for many common issues.

I think my answer here still stands. https://blender.stackexchange.com/questions/253/what-exports-does-blender-have-for-3d-printers


text:
Is it possible to update a StringProperty as it's being typed?
I'm building some text editor tools. I would like to have live access to a string property as it's being typed. I can assign an update function within a string property but it only updates after the user has pressed enter. I want a way for the update function to run with every key press. Legit ways to do this? Hacks?

There is an option for this.
Create the StringProperty with options={'TEXTEDIT_UPDATE'}:
prop = StringProperty(name="Test", options={'TEXTEDIT_UPDATE'})

https://docs.blender.org/api/current/bpy.props.html#bpy.props.StringProperty


text:
How to populate a menu using "path_menu"?
There is an option in class bpy.types.Menu(bpy_struct) called path_menu which says it can be used to "Populate a menu from a list of paths."
I'd like to use this to populate a menu from a folder of text files. I can't find any examples of how to do this though. Could someone point me to a menu example that uses path_menu or demonstrate how I can use this? Thanks.

Ok. Seems there's a pretty straight forward example in space_text.py
class TEXT_MT_templates_py(Menu):
    bl_label = "Python"

    def draw(self, context):
        self.path_menu(
            bpy.utils.script_paths("templates_py"),
            "text.open",
            props_default={"internal": True},
        )

path_menu can be used within the main draw function. Would be great if I could figure out how to make the contents of self.path_menu a sub menu item (rather then enumerating out directly into the menu).
EDIT: Just to be clear, I mean "would be great if I could" create a sub menu from the path_menu contents directly within the original menu itself (without having to create a whole separate, other class menu to call on).

Is this an answer to your question?

Hi. Yeah. Sorry, it's telling me I can't accept my own answer for  two days (otherwise I would have marked it answered). I would like to figure out if it were possible to collapse the contents of path_menu into a sub menu, but not sure that warrants creating a another entry.


text:
How can I access view3d.select_circle radius value?
I thought this would have been stored in context.tool_settings or scene.tool_settings but it doesn't seem to be. I can access the default keymap value like this:
km.keymap_items['view3d.select_circle'].properties.radius

But this doesn't update after decreasing or increasing the radius any time durring or after you use the tool. Should also mention I'm not interested in accessing the Toolbar version of Circle Select radius property. I'm interested in accessing the radius property of the operator itself (view3d.select_circle). You can demonstrate to yourself how these properties differ by pressing the C hotkey vs accessing Circle Select via the Toolbar and changing the radius value on both.
Presumably the value is being stored somewhere because both the Toolbar version and direct operator radius values are stored separately. Also bpy.types.VIEW3D_OT_select_circle doesn't seem accessible, so I'm assuming I'm out of luck but thought I would double check.

Operator Properties Last
The window manager has some useful methods re looking up operators and their properties.  Of particular use is WindowManager.operator_properties_last(...)
If we feed in the operator, in this case "view3d.select_circle"
>>> sc = C.window_manager.operator_properties_last("view3d.select_circle")
>>> sc.radius
273

it will return the last used properties of the operator.
If the operator has not been used (or does not exist)  sc will be None
This is not read only. Changing the value will set it for the next run of the operator
>>> sc.radius = 40

Defaults
Possibly worth mentioning too, to get the default value use
>>> rna = bpy.ops.view3d.select_circle.get_rna_type()
>>> rna.properties['radius'].default
25

as it does seem that although the class name is as expected
>>> bpy.ops.view3d.select_circle.idname()
'VIEW3D_OT_select_circle'

after a change in API (around 2.79 IIRC) not all classes are accessible via bpy.types
>>> getattr(bpy.types, 'VIEW3D_OT_select_circle', None) is None
True

By looking into Blender source was able to write this
bpy.context.workspace.tools['builtin.select_circle'].operator_properties("view3d.select_circle").radius = 10
you can set mode as well
bpy.context.workspace.tools['builtin.select_circle'].operator_properties("view3d.select_circle").mode = "ADD"
Sources
https://github.com/blender/blender/blob/d8edc2c6345306b943d73d2806bea18b67c66bc3/release/scripts/startup/bl_ui/space_toolsystem_toolbar.py#L432


text:
Why doesn't the draw callback update with mousemove?
I've taken the "Operator Modal Draw" template example and edited it. I wanted to see if I could pass the modal "event" through "args" in the draw_handler_add function. It works and the draw_callback_px function updates and draws the event type every time I press a key or do something with the mouse except for when I move the mouse (never prints "MOUSEMOVE" like it would if I were printing "event.type" directly within the modal function).
Anyone know why this is? Would be great If I could pass "event" entirely through to the draw_callback_px (not that I would want to run it every time the mouse moved, I'd control it with a conditional, but would like to have full power of the modal event within my bgl,blf drawing). My knowledge is pretty limited about the draw_handler and callbacks.
import bpy
import bgl
import blf

def draw_callback_px(self, contex, event):

    font_id = 0
    blf.position(font_id, 15, 30, 0)
    blf.size(font_id, 20, 72)
    blf.draw(font_id, event.type)

class ModalDrawOperator(bpy.types.Operator):
    """Draw a line with the mouse"""
    bl_idname = "view3d.modal_operator"
    bl_label = "Simple Modal View3D Operator"

    def modal(self, context, event):
        context.area.tag_redraw()

        if event.type in {'ESC'}:
            bpy.types.SpaceView3D.draw_handler_remove(self._handle, 'WINDOW')
            return {'CANCELLED'}

        return {'RUNNING_MODAL'}

    def invoke(self, context, event):

        # the arguments we pass the the callback
        args = (self, context, event)
        # Add the region OpenGL drawing callback
        # draw in view space with 'POST_VIEW' and 'PRE_VIEW'
        self._handle = bpy.types.SpaceView3D.draw_handler_add(
        draw_callback_px, args, 'WINDOW', 'POST_PIXEL')

        context.window_manager.modal_handler_add(self)
        return {'RUNNING_MODAL'}

def register():
    bpy.utils.register_class(ModalDrawOperator)
def unregister():
    bpy.utils.unregister_class(ModalDrawOperator)

if __name__ == "__main__":
    register()

Use the event from the modal method.
Will get back to this when I find the link about full event.  The event in invoke doesn't much care about mouse moves, rather a shift click or which button, where as the "full event" is available to the modal.  Try script below, a quick hack to use modal event when setting up handle.
import bpy
import bgl
import blf

def draw_callback_px(self, contex, event):
    font_id = 0
    blf.position(font_id, 15, 30, 0)
    blf.size(font_id, 20, 72)
    blf.draw(font_id, "%s %s" % (event.type, event.value))

class ModalDrawOperator(bpy.types.Operator):
    """Draw a line with the mouse"""
    bl_idname = "view3d.modal_operator"
    bl_label = "Simple Modal View3D Operator"
    _handle = None
    def modal(self, context, event):
        context.area.tag_redraw()

        # Add the region OpenGL drawing callback
        # draw in view space with 'POST_VIEW' and 'PRE_VIEW'
        if not self._handle:
            args = (self, context, event)
            self._handle = bpy.types.SpaceView3D.draw_handler_add(
            draw_callback_px, args, 'WINDOW', 'POST_PIXEL')
        if event.type in {'ESC'}:
            bpy.types.SpaceView3D.draw_handler_remove(self._handle, 'WINDOW')
            return {'CANCELLED'}

        return {'PASS_THROUGH'}

    def invoke(self, context, event):

        # the arguments we pass the the callback
        context.window_manager.modal_handler_add(self)
        return {'RUNNING_MODAL'}

def register():
    bpy.utils.register_class(ModalDrawOperator)
def unregister():
    bpy.utils.unregister_class(ModalDrawOperator)

if __name__ == "__main__":
    register()

I think I understand the thought behind your code. However when I run it event.type only draws "SELECTMOUSE" or nothing and event.value only draws "NONE" or sometimes "ANY" regardless as to what mouse or keyboard button I press. When you run the code does it work as it's supposed to? Perhaps I've got something else weird going on with my system.

Put a print in the draw callback and check the output to system console. On ubuntu I get a  list of mostly  'INBETWEEN_MOUSEMOVE'

I did. Same problem. I changed the space type to the text editor as well. Same issue. I'm on Windows though.

Dunno, not on windows.  Wouldn't do it this way anyhow. You need the operator for the event -- can't see the benefit of passing event to drawcallback which "lives and dies with operator anyhow"..  [See this answer])https://blender.stackexchange.com/a/110689/15543)  to set up a drawing class.


text:
Communicate with modal operator from an app handler function
I'm making a custom modal rotation operator which raps around a standard bpy.ops.transform.rotate() operator. The purpose is to create a pause when the object being rotated by the user gets close enough to a base of 30 degrees (visual auto contextual snapping).
Would like to do this without completely writing a new rotation operator. Or losing the visual bgl elements provided with the existing transform.rotate operator. I'm currently invoking transform.rotate from within my modal operator. I'm aware I could not invoke transform.rotate and instead feed it incremented values from my modal operator and mouse screen data, but I'd lose the bgl elements from the standard rotate operator (dashed lines, arrow icons etc). Would also turn this into a much more complicated project...
The issue lies in trying to monitor and affect the main modal operator (my custom rotation operator) while running transform.rotate within it. I've discovered this can be overcome with a scene_update_post app handler during initial execution of my modal operator. In this way, I'm able to retrieve live data about object rotation (or anything else I want) while running transform.rotate (itself a modal operator) from within my modal operator which is awesome!
Now that I have access to the rotation data as it's being performed via scene_update_post is there any way I can use that to finish or interrupt transform.rotate? Is there a better way to monitor modal operators like transform.rotate from within your own modal operator (while being used, not post or pre)? Sorry, for not having a code example, the overall system's pretty verbose. Don't fret to much over this one. Just curious if any experts know of some fancy tricks.

Stupid question: Have you tried a global variable?

@B.Y.O.B. Not stupid at all. Yes, tried using bools attached to scene and the window manager (assuming you meant something like that).
I didn't frame this question very well. The issue is not really "how do I communicate with the modal operator", it's more how can I interrupt (finish or cancel) a modal operator via code... rather than waiting for the user to finish (in this case rotate).
I'm trying another approach now though. I should have recognized this question was to mushy. Over stepped my reach a bit. I'll try to be more condensed & have a code example next time.

Any progress on this? I'm looking to do something similar.


text:
How to display a world texture as a spherical icon via Python?
I'm building some viewport display tools within a panel. I want to have a spherical icon display for the active world environment texture similar to the Material viewport HDR display. The material viewport hdr display uses template_icon_view:
layout.template_icon_view(shading, "studio_light", scale_popup=3.0)

So far, I've been unable to find any combination of data to feed this function to make it display the active world texture environment. I can use layout.template_preview(world) but this only displays a flat image sample of the environment. template_preview() has a parameter preview_id presumably to change the preview display type for input values like "MATERIAL" or "TEXTURE" etc. but no value I try here seems to change anything and I can't find a list of preview_id options. Is there some way to use either template_icon_view(), template_preview(), or some other template option available here: UILayout to display the world environment texture as a spherical icon in a panel or menu?