text:
Calibrate a FirstPerson movement combination
Given a script that listens for key inputs and checks which keys are pressed, how should I deal with combinations like up and right ?
up will increase local Y velocity and right local Y, but if nothing more is done the player can cheat his speed by advancing diagonally.
I'm sure I have to decompose the vector that is added to the speed and multiply X with a cosinus of the Z axis (the world one ?) and Y with a sinus of the same.
But I end up with a correct strafe only in two directions, it seems that the cos and sin get to zero in the same time on the two others since the motions is close to zero.

Normalize the vector. Normalizing means that your vector length is equal to 1, it doesn't matter where it's pointing.
Python example
from mathutils import *
v = Vector((1,1,0.2))

v.normalize()

print(v)
# <Vector (0.7001, 0.7001, 0.1400)>

Thank you merci.


text:
bpy add object in game
is it possible to add an object inside the game engine with upbge 3.X.X while having game physics work properly ?
What I'm doing is:
patch = bpy.data.objects['Patch1']

for i in range(4):
    for j in range(4):
        if i or j:
            copy = patch.copy()
            copy.data = patch.data.copy()
            bpy.context.collection.objects.link(copy)
            copy.location = (i*256, j*256, 0)

This is connected to an 'always' sensor set on tap and does add my patches of ground as expected, but there are no physics and the player goes through the objects.
I tried adding

copy.game.physics_type = 'STATIC'

But this doesn't sort my issue.

you have to use own.scene.convertBlenderObject(bpy_object) to wrap it in a KX_Object / convert its logic

Hi, thanks for the post. This site is not a regular forum, answers should be substantial and thoroughly explain the solution and required workflow. One liners and short tips rarely make for a good answer. If you can [edit] your post and provide some more details about the procedure and why it works feel free to restore it, otherwise it may be deleted or converted into a comment. Perhaps add a few images illustrating the workflow and final results. See How do I write a good answer?

This is what I found out eventually. There is also the call reinstancePhysicsMesh() that can come in handy if modifying the geometry in game.

source: Stack Exchange

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

sort: votes


text:
Blender game normal mapping
I have a ground tile for which I use a normal map, it reacts good when facing light, but looking in the Sun lamp direction kills the lightning. I'm using nodes, have a look at the pictures.
Can somebody tell me what's wrong with my setup ?
(connecting the texture normal output straight to the material gives the same result)

Normal mapping is a real pain in the node editor. In fact, it's an open bug. https://developer.blender.org/T41829
I seem to recall a few months ago someone mentioned made a new node to fix this, but I haven't seen it in official builds yet.

Blender is surprising sometimes... Thanks for the link it might help.

Is there a reason you are not using a Normal Map node in between the Texture node and the Material node?

Is there a reason I should do so ? I think the matter has been clarified. Thanks for your time.

Normal mapping is a real pain in the node editor. In fact, it's an open bug.  I seem to recall a few months ago someone mentioned/made a new node to fix this, but I haven't seen it in official builds yet.
The way around it I sometimes use (it's computationally expensive and a pain to set up), is to create a material for each normal map. Then you can take the normal output from the material and mix that together:

Sorry for not mentioning this in my comment earlier.

You could try advanced material node. This can be  found under the input menu. Otherwise you could just add the normal map in the texture panel and enable normal map at the bottom.

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


text:
Parenting with orientation constraint for the game engine
I am trying to set a lamp in my scene so that it will follow the player wherever he goes yet still maintains its orientation. if I parent it to the player object, when I rotate the cube, the lamp will rotate also due to its initial orientation and it messes up the lightning. Is there a proper way through this ?

Use Vertex Parenting to a single vertex.

Select child right mouse button
Add parent to selection shift+right mouse button
Switch to edit mode tab
Select a single vertex from mesh right mouse button
Establish vertex parent ctrl+P
Leave edit mode tab

Thanks, I was wondering why it worked this way ?

A vertex has no orientation ... therefore the child can't inherit it.

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


text:
Reflection map baking
I have an Island and water on which i want to add fake reflections, I know I have to bake a map and use it as difuse color through reflection mapping but how do i create the map ?

This shows my render blender settings from wich i want to bake the reflection map to use in the bge

Not really my area of expertise, but depending on what you want you could try baking a texture from a glossy sphere.

Create a new UV Sphere, you may want to make it an all quads mesh
first by removing the top and bottom vertex, then selecting the
first open edge loop, and extruding it, then scale it to zero so
that all vertex merge at the center, but don't remove doubles.
Mark a seam along one of its vertical loops and select one random
face. Now Unwrap it using the Active Quads option. In the image
editor it should wield a perfect orthogonal grid mesh.
You can now assign a perfectly glossy material to the sphere and use
it to bake an environment map of your island.

I have not tried it myself, but it should work; I used a similar technique under Cycles render to create a cube map environment

Ok this is what i needed to know, now where am i to place the sphere in the scene and at what scale ? I'm having wrong reflections, i tried to en globe the scene, then i tried to scale it down and place it in the middle of the scene, i have tried also to flip normals but nothing will do so i think i'm missing something important.

Have in mind that baked reflections are always an approximation, they are never fully correct, not even from the exact point they were baked from. You can reduce visual errors by placing the sphere in a place as close as possible to the final render or image position, or if it's a game or real time user controlled environment, place it at the most common user eye height and centered somewhere in the user accessible area, or close to the most common view point.

It is always going to look more distorted the further away you are from the bake point. You'll have to test what scale will look best yourself, but I would say maybe around camera size, if it's a metric units scene perhaps a 1m diameter sphere.


text:
Looking for a correct formula
I have set up a scene in the bge where I need to animate the mist. I have an object that loops between 0 and 4999 and I assigned its action current frame number to a property called 'axisT'
Now I want to be able to modulate the result so that at frame zero mist color = [1, 1, 1] and at frame 1250 mist color = [1.0, 0.9, 0.8] and so on at each step until my loop starts back.
What is the correct way to do this ?

Sorry to answer my own question but here is how I got through it.
import bge
import math

scene = bge.logic.getCurrentScene()
A = scene.objects['Axis']['time']
mist = scene.world
F = math.sin(math.pi*A/2500)

if (A) < (1250):
    mist.mistColor = [1.0, 1.0-F*0.1, 1.0-F*0.2]
elif ((A) >= (1250)) and ((A) < (2500)):
    mist.mistColor = [F*0.8+0.2, F*0.7+0.2, F*0.6+0.2]
elif ((A) > (2500)) and ((A) < (3750)):
    mist.mistColor = [0.2-F*0.6, 0.2-F*0.6, 0.2-F*0.3]
elif (A) >= (3750):
    mist.mistColor = [1.0 + F*0.2, 1.0+F*0.2, 1+F*0.5]


text:
Python access to cycles' transparent film
There used to be a variable bpy.context.scene.cycles.film_transparent,
Not anymore but i'm working with an old script and need to retrieve the equivalent.
There are:
bpy.context.scene.cycles.film_transparent_glass
bpy.context.scene.cycles.film_transparent_roughness
But I need the checkbox "Transparent" variable's which appears under the film layout in cycles' render options.

In newer versions of Blender this property is part of scene data, you can access it with bpy.context.scene.render.film_transparent

Make sure to mark your post as the solution to notify others that this thread's question has already been solved.

Hi, thanks for the post. This site is not a regular forum, answers should be substantial, stand on their own, and thoroughly explain the solution and required steps. One liners and short tips rarely make for a good answer. If you can [edit] your post and provide some more details about the procedure and how it works, perhaps add a few images or short description of what the  code does. See How to write a good answer?, otherwise it may be converted to a comment.

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


text:
Non uniform unwrap on beveled mesh
I have a beveled model, and need to use cube unwrap, the issue is with subsurface modifier which, when is set to catmull clark, smoothes the beveled part in a unwanted way.
here is a picture of the issue:

Same with options smooth to to 'None':

And the desired result with the subdivision set to simple:

Why is the smooth uv option not being effective ? How can I solve that ?

Is the unwrap correct? Please pack your image and share your file

I would use some support edges. Do you have some crease value set up >0?

No, no crease set. What do you mean by support edges ? One more cut ?

Ok got it, unwrap is behaving as expected with support edges

@Yvain If the answer solved your problem, kindly accept it.


text:
AddObject Actuator scripting
I have set up a camera with a script and logic bricks so that when I use left mouse button it creates an object and places it at the specific click location.

Nevertheless, I encountered an issue with that the first of my created object doesn't care about the lines following cont.activate(Add)and leaves it at the camera location, just as seen in the picture below (the cube and rectangles are other objects, the one I'm calling is the cone).
Why is that ?

You need to take care of the timing.
Within a single frame (over the complete scene):

sensors evaluation
controllers execution
actuators running
physics, render etc.

The code always runs with "controllers execution". This does not mean that all operations have immediate effect.
Activating an actuator, does not make the actuator running at the moment of the call. The actuator gets a signal to activate. The actuator will run within "actuators running". Which is later than your code.
KX_SCA_AddObjectActuator.objectLastCreated provides you a reference to the last created object by that actuator. That can be last frame or any frame before.
Within the first execution of your Python controller the actuator never added a new object. This means you get None. I expect you get an error each time you trigger the controller the first time as None has no "worldPosition" (always have the console window open when you run Python code with the BGE).
There are several ways to solve the timing issue.
A) Two step processing. You store the position and adjust the position of the new object within the next frame. The drawback is, that you can see the unchanged position for a single frame. This can be annoying.
B) Do not activate the actuator, but let it add the object via instantAddObject(). AFTER that call objectLastCreated will return the just created object.
You code could look like that  (supposed to run in script mode):
import bge

controller = bge.logic.getCurrentController()

mouseSensor = controller.sensors["Ray"]
activationSensor = controller.sensors["Clik"]

if activationSensor.positive and
   mouseSensor.positive:
    addActuator = controller.actuators["add"]
    addActuator.instantAddObject()
    addedObject = addActuator.objectLastCreated
    addedObject.worldPosition = mouseSensor.hitPosition


text:
Blender Multitextures Normal maps
as says the title: is it possible to use normal mapping in Multitexture mode, if yes how ?

No. It is not possible.
Multitexture is a fixed-function pipeline which can do multiple layers of diffuse textures, but lighting information is calculated per-vertex. This means that maps that contain information that should influence lighting have no effect (eg specular hardness, specular intensity, normal, height).
In GLSL mode, lighting is calculated per-pixel, and so these maps can be used.
In short: In multitexture, the only maps supported are emit, diffuse (with some trickery) and transparency.
I highly recommend GLSL. Most hardware made in the last decade or so supports it. If you are concerned about the performance of GLSL, I will point out that it depends mainly on the complexity of your shaders. If you simply use diffuse, emit and transparency maps, the performance is virtually the same as multitexture. GLSL offers more functionality, allowing more effects, and it is these extra effects that cause performance loss.
That said, I used multitexture for many years because my hardware didn't support it. You can do some great looking stuff in multitexture mode if you are clever.
EDIT:
Apparently if you have old enough hardware, the performance difference between GLSL and multitexture is noticeable, even on simple scenes.

Great answer yet you say: "the performance is virtually the same as multitexture." It's not true. my computer is not handling GLSL as fast (I should say it lags more) as Multitexturing, even with a simple solid color. Thanks for claryfing.

Oh! I am surprised! What hardware is this on, and how many lights do you have?

One Sun in the scene...I'm using an Asus Eeepc from 2008. CPU Intel Celeron M 900Mhz,
1gb ram,
OpenGl Renderer: Mesa DRI Intel(R) 915GMx86/MMX/SSE2
:)

Hmm, 8 year old netbook. Yeah, I can see why performance is suffering. I'd say stick with multitexture unless you get better hardware.


text:
Blender Alters .Obj vertex list
I have a wavefront .obj file and a sharp edge list which are mapped with the vertex index form the .obj file. Now I want to add some functionality in the .obj file based on the sharp edge list. But the problem is when I load the .obj file in blender, blender changes the vertex index. So I can not map the same edge list from the .obj file in Blender. Is there a way I can prevent Blender from changing the vertex index and keep them same as the original .obj file(e.g. in .obj file, vertex index starts from 1 and the index increases by one for each subsequent vertex)? I am wondering why Blender has to change the original vertex index rather than giving the index sequentially?

There is an option for Keep Vertex Order in the .obj importer. Use that and you should be fine.


text:
Branching Bezier Curves
I am trying to model the "root feet" in the picture below.

I have used a bezier curve for the body -

But since bezier curves cannot branch, how should I continue the "feet"? I've tried blocking them out with multiple curves, but then I don't know how to combine them while maintaining good topology. Any help, advice, or ideas would be greatly appreciated.

If there's something to be learned from the sapling tree and ivy generator addons, both of which use curves to generate objects that branch a lot, is that the way to go is with separate curves. If you don't want to convert this to a mesh, it shouldn't matter much. If you do, maybe curves aren't the best way to model this object (or you can just use mesh modeling techniques to combine the rootlets).

If you want to go with easily edited base structure and still have good topology on the model, maybe just a skeleton of edges, skin modifier and subsurf on top would be the way to go.

If you want it to branch you need to use a mesh, not curves.
If you want your mesh to have an all-quad topology, here is the simplest way:

You can then further subdivide the edge rings to add detail and round off the roots more:

And with some additional fine-tuning of vertices and edge loops you can get something like this:

If you really want to use Bezier curves I recommend using the Sapling Add-on, which is packaged with Blender and just needs to be enabled from Preferences. It's ideal for making trees and other branching foliage. Although for a character such as the one you posted, I would model it as a mesh.

Wow, this is some good topology info! You made me rethink the whole process and realize hand modelling the roots isn't as intimidating as I thought. I'll have to give it a go without using curves. Thank you!

@keeweee Great! Glad I could help. :-) Yeah, having it as a mesh is much better in this case, especially if you plan to rig and texture it.


text:
Expanding plane size while keeping existing vertices
This is a workflow question. What is the fastest way to get the plane on the right starting with the plane on the left? I think in 3ds max you can select the vertex I have selected in the picture and "drag" out the plane, creating a plane inside a plane. Can you do this in blender? I know you can start with a larger plane and inset (I) but there must be a more efficient way.

So you can use the extrude tool to expand a plane laterally? I don't see it on the page.

Fastest way (albeit not the best) of all current answers is to just extrude and scale a bit by some eyeballing based on object size then move the extrusion into place with G. No fancy 3d cursor tricks and keyboard shortcuts/tools needed. ;)
The reason it snaps into place when freely moving is because snapping is on (ShiftTab) and set to move in increments which is based on the grid.

@ iKlsR : Looks like you are using a snap to ensure alignment of the new geometry. You should add that to your answer. Simply 'eyeballing' it will likely lead to unsatisfactory results.

@MikeMetcalf Ah, yes, added. Snapping is on and set to increments by default. By eyeballing I mean when creating the extrusion, easily achievable in a couple attempts at least.

@iKlsR♦ you're a real speed demon ;). the fastest way indeed. I wonder if there'll be a possibility to do it using just scaling in the future blender releases. +1 from me.

@Gonzou When I came to Blender from max years ago, my most missed feature was the shift extrude that op mentions where you just select, hold shift and extrude. It would have done this in one step. Might be, who knows. ;)

Here is the fastest way:

ensure the Pivot Center is set to '3D Cursor'
select only the vertex at the top right
hit ShiftS then 'Cursor to Selected', which moves the 3D Cursor to that vertex
hit CtrlI which will invert your selection
hit E to extrude, then S to scale
hit Enter when satisfied

This prevents the necessity of repositioning the two edge vertices.

After reading iKlsR and Gonzou's answers I was surprised that nobody had posted this yet (it is the answer), well you and brasshat had.

Here's an alternate method that might be useful in some circumstances. In edit mode, select one of the vertices of the plane, and from the context menu of the snap tool (SHFT - S), select "Cursor to selected". Next, invert the selection (CTRL - I), to deselect the original vertex, and select the other three. Then set the pivot point to 3D cursor, extrude the selected vertices, and scale to the desired size.

ha! 'great minds...' and all that...

As cegaton said, you may achieve it using extrude tool. Place the cursor in the center of a plane, select 3 vertices, press E to extrude them, then S to scale (you may input the scale value from your numerical keyboard). Next enable the Snapping Tool (click the magnet icon) and change the snapping element type to Vertex. Select the vertices as pictured below, press G and input the proper axis. Move the mouse until they snap to others.

If you want to make a reverse select the whole plane (A), hit W-->Subdivide. Select two vertices as pictured below and press G twice to merge them. Select the whole mesh again, press W-->Remove Doubles. Press G twice to slide the selected vertices.


text:
Blender Fluid Simulation With Moving Container
For this project, I'm trying to have a rigged character move while holding a bottle (simply parented to the hand bone).
I see many posts on this website referring to issues with fluid sims that are eventually resolved by someone telling them their normals are flipped, or they have to add thickness.
That doesn't appear to be the case in my scenario since my object has a natural thickness that I even increased in the Effector parameters. If the thickness is the problem, is there some way I'm supposed to up the quality of the simulation or scale-up my scene so it detects a smaller thickness? And if this isn't the case, is there something I'm missing that they don't tell you in the youtube tutorials?
I'd rather avoid turning up the resolution any higher considering I've got a fairly new gaming laptop with pretty dang high specs and setting the res to 150 resulted in a bluescreen.

Ver.: 3.0.0
Date of Issue: 2/27/22
Blend File: https://www.dropbox.com/s/oyt4n9maxtgw3qw/FluidRigDemo.blend?dl=0

without seeing any of your settings and not knowing what you models/geometry looks like, we can just guess. So please provide blend file so we can check it out.

@Chris I had it set up, completely forgot to add it to the post though, sorry for the trouble. Should be updated now

although you don't wanna hear it...it is a resolution problem. If i raise your resolution to 300, i got:

so it is better...but not perfect.
or you take resolution 200 but use these collision settings for your bottle:

so you get this (i stopped at frame 14 because i was impatient) but until there it worked.

welp, knowing the source of the issue is better than nothing. Let’s just hope the issues from before were purely coincidental. Thank you for letting me know


text:
Baked image is missing some objects
I made a building with many different objects and for baking in Blender internal i joined all those objects (with Ctrl + J). Then the door animations were gone!
In the baked image the textures of the doors could not be found. All textures were messed up.
Was there any problem in my baking process? Should i not join different meshes together for baking? I want to use it in Unity.
The house before joining all the meshes and doors with different textures and the baked image.

Please take a look at the original model, prior to joining all the meshes.

"Should i not join different meshes together for baking?" Probably not blindly, especially if there were animations involved. You will just end up with a needlessly huge texture with lots of repeating parts and blurry quality, instead of smart reuse of tileable patterns

I have a tendency to create different materials for outside wall and for inside wall of only one wall mesh. I think there was a mistake, I did not select the correct image for each materials in the texture menu. May be that's why the images for the doors (there are 3 doors all total) are messed up with some other image in the baked image.Could you please tell me the correct way of baking in Blender internal where there are many materials for each meshes.

https://www.google.com/search?tbm=vid&q=blender+internal+baking Also there are several addons to simplify the baking process, do a google search


text:
My vectors are gone
I think I pressed a key and now:

My vector and main grid are gone
Blender doesn't show me my background image.

How do I fix it?

Hi. Please add an image to your post to show what you mean. See: https://meta.stackexchange.com/questions/75491/how-to-upload-an-image-to-a-post

I am not sure if this will solve your problem but try clicking on the button showed in the image :) That will hide/unhide your overlays (main grid included)


text:
mesh object has no attribute calc normals split
I just started using the application. I applied texture to my 3D model. I am currently trying to save as fbx but most of the textures are not saved as fbx. I also tried the solutions on the internet (I made a copy and checked the box next to it. It still didn't work). Now I am trying with Better Fbx Exporter and I am getting this error. Can you help me please?

This function has been removed in Blender V4.1 and changed (I think) to https://docs.blender.org/api/latest/bpy.ops.mesh.html#bpy.ops.mesh.customdata_custom_splitnormals_add. You can either go back to Blender 4.0 or ask the addon maintainer to update its code. Or do it yourself if you feel like you can. Cheers

I'm back to version 4.0. It didn't work again. How do I save it as fbx without breaking the texture of my model?

https://blender.stackexchange.com/questions/57531/fbx-export-why-there-are-no-materials-or-textures


text:
Is there a way to turn these photos into useable anchored Brushes in sculpting mode?
i was wondering if there is a way for me to get these drawings (ornaments/spikes) into a useable brush for sculpting, with the anchored way of useing a brush, since i really want to use them as texture, but they have to be pretty much exactly the same as the photos (either one, not sure which one is the most suatble for the brush) - Does anyone know if that is possible?
Best regards and thank you in advance! :)

Use Photoshop, Krita or Gimp to create a new 2048*2048 file, import the second image, invert it and blur it with a 2 to 6 pixels ratio, save as PNG RGB.
In Blender go to sculpt mode, select draw brush, clic on New Texture button, click on its texture button (icon with two little "sliders"), load the PNG image, set draw method to Anchored, Area Plane, Constant Falloff, 0.15 Strenght.
This is the result on a 1.6 Milion Sphere, you can play with the Auto Smooth value too.

thank you so much! it works perfect :)


text:
Compositor - Disable rotation of streaks with camera rotation in Glare node?
Is there a way in the compositor to get the streaks added to bright objects (stars here) using the glare node to stay at a set angle in the scene, rather than maintain the angle that the camera is at?
I have an astrophotograph, where I have stars with diffraction spikes in the image already and I always like some rotation in my camera animation, but the image stars will stay fixed obviously whereas composited streaks on 3D stars will move which will look weird, so I’d like composited streaks to remain static.

You can animate the angle property. If you know the rotation of the camera you can adjust it at the same pace to simulate a fixed angle

Thank you! I did not realise that was possible


text:
Geometry Nodes - Instance on Points with vertical Array
I currently have spheres that have been instanced along a curve, and would like to make a vertical array of said geometry?

Create another "instance on points" node.
In the "points" socket, connect the mesh line
In the "instance" socket, connect the output of the "instance on points" you already created.

Amazing Thank you! Would you be able to confirm whether this is possible with extra object? i.e introduce a random series of cubes as well as spheres along this curve?

@TheVisionTunnel, it is. If you create these objects individually, you put them inside a collection, and for the "instance" of the "instance on points" you connect a "collection info" node. (The collection info node must have "separate children" enabled).    ---- If you create the objects inside the geometry nodes as you did with the sphere string, you must convert them to instance, and join geometry, and they will behave as a collection.

This worked! Thank you very much


text:
Faulty Node Setup
I'm currently part the way to isolating the windows in this building by color range/threshold. I'm happy to keep the emissive areas as is, but have been unsuccessful in making the black areas invisible, to bring back to the original original texture.
Node Setup Attached Below.

You need to connect something to the "fac" of the mix shader

Yeah use mix shader to mix your normal shader with transparent shader and in fac input plug in your black and white mask you just made. The black areas will use one mix shader input and the white areas will use the other.


text:
Little nobs when displacing the UV from a texture
I followed this tut: https://www.youtube.com/watch?v=McALCOr39rY&t=324s
To convert my shader noise displacement to a texture and then displace it with the dispose modifier.
Works great. The only thing is that I get these little nobs or nipples on both poles of the spheres ( I am using a sphere)  in the viewport I also see the UVs quite dramatically. I had to increase subdivision to 6 and I still saw the UVs ( at level 6 my RAM was directly full (64GB)
Does anyone know how I can get rid of the nipples and visible UVS? I need to print it with a surface as smooth as possible.
Best

Could you provide your Blender file using https://blend-exchange.com/ ? Otherwise it is pure guess about what is going wrong...

oh yes, sorry, new to this. is there a different website to upload to where you don't have to transfer the whole IP to the site?


text:
Issue with Blender Spiral Curve
I am a beginner at blender/3d modeling and I am trying to create a 3d model of an asian scroll. I've tried my best to draw the issue I'm having with the Blender Archemedian Curve Spiral.

I am trying to replicate the effect of rolling up a scroll. A long piece of paper with wood attached to the end of it. When I roll up my scroll I want the effects of the spiral starting small and gradually growing as it gets more rotations/layers. However, I am having the issue of the spiral starting at max(?) diameter, and proceeding to fill in the inside as it gets more rotations/layers.
First rotation:

Second rotation:

If I try to spiral from the center, I get the intended growing layer look, but experience a clipping error where it cuts through the paper.
First Rotation:

Second Rotation:

I think the main part to get what you want is to make sure the spiral keeps its start radius and the end radius has to grow with the number of rotations.
The width increase has to be a constant value per rotation, not per curve length or anything, so that the distance between each layer stays constant even though the circumference of each layer increases.
To do that, I would animate the value for the rotation, multiply this with the chosen distance and add it to the start radius:

If you now animate the rotation value, the spiral grows outwards while keeping the layer "thickness":

And now to get the illusion as if the core of the spiral was rotating while the spiral is growing, the spiral has to overall rotate, exactly 2*pi or tau (which you can enter directly to get the value) into a Math node set to Multiply which you can then use for Rotation in a Transform Geometry node:

And the result:

So far, so good. To have the endpoint of the spiral at the top of the viewport, I rotate everything 90° on Z with a second Transform Geometry node. I also want the spiral to be "supplied" from somewhere, so I instance a Bézier curve on the endpoint of the spiral. If I set the Start to (0, 0, 0) it will be placed exactly on the spiral's endpoint. I then realize the curve instance to set the position of the outer endpoint to a fixed position so that it doesn't move with the growing spiral.

This is as a basic idea how you could do that. Maybe someone has an even easier method to do it.
You can then convert the curve into a mesh to give it some width as if it was a sheet of paper, put something in the center and give it the same rotation as the spiral so you have something to "hold" the paper. Maybe extrude it for some thickness etc. and in the end it could look something like this:

Thank you very much for the multi step instructions to explain every portion of the animation. This was very informative as a beginner.


text:
Add extra texture coordinates to object for a game
I use Blender to create an object for my game. The game have dynamic textures applied to the object and I need more than one texture coordinate. In the game engine, I can have the normal texture coordinate, and add the additional texture coordinates 2 to 8.
Type.TexCoord
Type.TexCoord1
...
Type.TexCoord8

Can I just copy the UV texture coordinate that I created in blender, in UV mapping, and use it as TexCoord1, TexCoord2, TexCoord3, etc., to TexCoord8?
Currently, I load the mesh and just copy the texture buffer 7 times. But, can I just export the object with 8 texture coordinates?

Hello. Theoretically nowadays in Blender you can have an infinite number of UV maps by using generic attributes on the mesh. I don't really understand the question though, and I feel like it doesn't really concern Blender itself but rather the way texture maps are dealt with in your target engine.

Maybe I didn't explain it well. I create tex coordinates in UV mapping in Blender. If I then export the mesh, there is one set of texture coordinates with the model. I want to have the same tex coordinates copied 7 times and have it also exported with the model in Blender. But maybe my question is silly, and I should do this in my game engine.


text:
Having issues with Geo Nodes Dependency Cycle
Having the curve modifiers not working properly with geo nodes.
The coloured objects are dictating where the objects are to be placed along the "PCG" curve
I want to have a curve modifier on the placement objects so that if I change the curve, these objects will follow along.
However it seems that only 1 curve modifier is working at a given time.
The objects do follow the curve but nothing gets displayed.
eg. in the 2nd picture, only the purple object has the curve modifier, and it works as expected.
but in the 3rd picture, both the purple and red objects have the same modifier, but only 1 of the instanced objects is being displayed.
I get the error
"Can't access object's geometry because it's not evaluated yet. This can happen when there is a dependency cycle"
I would like to not have to apply the curve modifier

Can you tell us what message you have in the console about cyclic dependencies, if any ? (see here if you are using Windows OS : https://blender.stackexchange.com/questions/23147/how-do-i-get-the-console-on-windows). Could you provide your Blender file using https://blend-exchange.com/ ?

My guess would be to attach the GN modifier to the default Cube e.g., and to input the PCG curve as "external" object, using an Object Info node to recover the curve geometry. This way, the curve will be at the root of a tree with two independent branches, one carrying the Curve modifier, the other carrying the GN modifier, without circular dependency.


text:
There is a difference between the image output on the program screen and the final rendered image
When rendering in Blender,
When comparing the image output on the program screen with the final rendered image, the color saturation of the rendered image is too high
I'm wondering what modifications can I make to reduce the difference between the expected render image and the final image.

This file link was posted on January 11th and is valid until January 13th.

though there are ways to go about doing it, i would usually use a color correction node in the compositor

it's generally the opposite, the render is duller, could you please share a part of your file (just the walls and lights for example)? https://pasteall.org/blend/

My guess is you have a blue light hidden / disabled in viewport, but not disabled in render.

compositing maybe?

if u share your blend file, we can check it out, else we can just guess

I checked it now. i have uploaded the file to thank you for your request. You can go to the link and download it. If you have any problems, please let me know. I can also send you by email.

Hi,I just rendered the image right now and both the viewport preview and the render look the same. What's the problem, then?

I also just accidentally saved and reopened the file and was puzzled.
Randomly change the color of the cube wall object at random (eg pink), save it again, close it, and open it again, and it is saved as a bright blue color.
It seems that the material color initially set (probably bright sky blue at that time) does not change.

I solved it! The problem seems to be that the object (cube wall) has an error with the sky blue material. If you release the face connected to the material, delete it, and set it to a new material, it will render normally. Thank you for your interest.

The object has no problem with the material - the material itself has the problem, see my answer.

Your material has a keyframe at frame 1 on the RGB color, that's why it always gets reset. Even if you change values and they are displayed correctly in the viewport without setting a new keyframe, Blender resets the values to the keyframed ones before render and upon re-opening of course.


text:
Exporting model to FBX with specific materials and animations for Spark AR studio
I wanted to create a mask for Instagram so I created a model of a character inside a mesh. This character has a face rig that can be animated with textures. It has an upper face with eyes and a bottom face with the mouth, each with a UV. I tried to export it as an .fbx, but these textures don't seem to work then.
Here are nodes for one part of the face (I used mapping to change tiles on one texture image)

Also I have multiple animations for this model made with Action Editor (they were made into NLA Tracks I think, I've never done multiple animations in one file before) and they also don't seem to work as I intended when exported. I exported with baked animations (key all bones, NLA strips, all actions, force start). The mesh and the character are different armatures.
Can someone explain to me what I'm doing wrong? Maybe there is another file extension I can export with that can preserve these animations? I'm fairly new to Blender.

https://blender.stackexchange.com/questions/57531/fbx-export-why-there-are-no-materials-or-textures

You can only follow the instructions on the target platform's site. Technically, 3/4 of this question is about Spark AR because it is the target platform.
Your automatic reaction to any incompatibility should be to check if the target platform has designed a Blender add on.
As for that add on question:
1)Maybe you know this, but Spark AR has an addon for Blender called the SPARK AR toolkit, download the zip, open preferences, and install it. If it doesn't work on the current Blender version, you may have to try a previous stable one.
https://sparkar.facebook.com/ar-studio/learn/articles/creating-and-prepping-assets/toolkit-for-blender

2)read the optimization guidelines and set up your export accordingly, they have a lot of advice:
https://sparkar.facebook.com/ar-studio/learn/articles/fundamentals/technical-guidelines#optimizing-3d-objects
No worries, you will be able to bring in a mesh with textures.
Unfortunately the remaining problems are Spark AR Studio issues.  You may need an Animation Patch to loop an animation properly in Spark AR studio.  Reference their site for information on this.
Final notes: The Spark AR toolkit does not export FBX and the type of FBX preferred by Spark AR is picky:
FBX 2014/2015 (binary and ASCII versions)


text:
Blender donut - geo node sprinkles not on top of icing
I am following the Blender 3.0 beginners tutorial on geometry nodes and i am following the tutorial exactly as is in the video only when he selects Reset children in the collection info node the sprinkles stick to the donut whilst my sprinkles sort of orbit around the donut.

Does anybody know whats wrong with it as i am completely lost at the moment
Blend file

looks like you didn't apply a scale maybe? if it doesn't help, please provide blend file

@Chris i applied all scales beforehand, here is the blend file

In the Collection Information Node you need to switch from Original to Relative.  You also need to enable Reset Children
Also, you must have created the sprinkles in edit mode.  Open the Sprinkles collection, select all of the sprinkles, right click and select Set Origin to geometry:

I tried it and the sprinkles just moved up a bit, it still looks the same as in the pic

@nikola ah, you needed to do three things.  see updated answer.

That did it! thank you so much :) why did it not work before?

You're welcome.  Maybe it didn't work before because you only tried one thing at a time, resetting between tries, but you had three problems?


text:
Turning snake scale object into seamless texture and displacement map?
How would you turn this snake scale object with Array modifier into usable seamless texture in order to unwrap a snake model.

Made it work, with one more hiccup of "bald" spots:

Create the scale object with Array modifier, then render a displacement map image in EXR.

Then, make a material with the Image Texture node and Displacement node.

Then Append the material into the actual snake body object.

you could bake the normal of the first object and project it on the surface of your second object? Choose Unwrap > Cylinder Projection or Follow Active Quads

Not really sure how to go about baking the normals... Is there a link you could provide?

maybe check this tuto? https://www.youtube.com/watch?v=Kg0wIBIpGG0

https://www.youtube.com/watch?v=arvhK4tvYuY&t=104s&ab_channel=DefaultCube Made it work with this really clever video.

baking the normals is much easier imho


text:
How do I do Texturing and Shading with this Spider-Man PS4 Model?
Hello all I have been getting back into Blender after a few years, and I've been trying to texture and shade this Spider-Man model I found online.

While I think I am getting it down I have a few questions on how to properly shade it using the textures/images provided to me.
'
If anyone can help, I don't know what to do with some of the textures and materials, I know what to do with the normal maps (labeled _n) and the gloss maps. (labeled _g)
But I don't know what to do with the rest of the files and I would like to learn. Any help would be appreciated thank you!

This is my current node setup with the images/textures/maps I have applied so far.
https://sketchfab.com/3d-models/peter-parker-spider-man-into-the-spider-verse-2ee34540c9f149ed9d09e3bd96b703e3
This is the link to download I want to get all the textures and maps applied in the proper locations to match as close as possible to the movie and game.
Here are some examples:

And for reference here is what I have so far:
cycles:

Eevee:

don't forget to switch the normal map image texture node from Color Space > sRGB to Non-Color


text:
Smooth STL not working
New to blender and not sure what I am doing wrong no matter what I do I can not get my stls completely smooth in blender.
I have tried shade smooth, subdivision and nothing seems to get rid of triangles on the model

try to go into the Data panel > Geometry Data > Clear Custom Split Normals Data?

You are referring to smooth shading, yes? Can you show a screenshot, please?

It smooths in blender when I export it for 3d printing it still looks rough. i am not sure how to add a screenshot

hav eyou tried what i suggest?

Yes I did it looks smooth then when I export it and open it in slicer it is still rough looking

Smooth shading is just a way how something is displayed. Really smooth surfaces need a lot of geometry - if your object is too low poly, it will never be really smooth. And I'm quite sure the slicer software does not use any smooth shading, so it does not make the mesh appear smoother than it is.


text:
Gothic Pointed Arch Window
I have a problem that I don't know how to make the following window as good as possible. I have watched tutorial videos which have not helped me as a whole. I've tried drawing the window in LibreCAD, but when I try to follow the lines I drew, they don't look the way I want them to look in the original image.
I would like your help on how to model this window as easily as possible in Blender? What modifiers should I use or what method should I use? And what is the best modifier/method in modelling gothic architectures.
The most problematic part was:

creating the arch,
creating the three circle in the larger circle. (without cutting each other) and adding the arch also.

https://blender.stackexchange.com/questions/56344/reducing-internal-faces-generated-by-extensive-curve-extrusion


text:
UV editor all purple (Solid mode viewport is set to texture not color)
I have the situation as in the title. My queston was closed before suggesting that my viewport might be set to color in solid mode. It isn't. But What I did notice is that no matter what object I select, in the UV editor I see the same texture name with a solid purple color. I've changed around the texture of teh selected part, and I still only see this option selected (at around top left/middle of the screenshot). Thanks if you have any suggestions.

Do not ask questions twice! And I've already told you what is going on there in the comments the last time you asked this.

I don't know what to do based on that.

Still no need to ask the question again. And there is nothing wrong in your scene, you just have to select a different texture in the material if you want to see it in this Solid mode. If you do not understand what I explain in my linked answer there which explains in detail what the different options are and how Blender decides which texture to show, there is nothing more I can tell you. If you can't make it work in this shading mode, switch to Material Preview or Rendered. If you don't know how to even do that, please try to learn the basics of using the 3D Viewport.

...and for the UV Editor on the left: the screenshot shows you have opened the dropdown menu where you can choose an image to be displayed. If you don't want to see the normal map, why don't you just simply select a different image - preferably one without the suffix "normal" if you don't want to see a purple image?


text:
Texture Bake Comes Out Blobby
I'm trying to bake some high poly grass meshes (image 1 below) into a transparent albedo texture & normal map to then use as alpha cards in game development. The square plane behind the tufts of grass is what I'm using as the bake plane.
The problem is, whenever I bake, each grass blade comes out as a blob with no definition (image 2 is the bake result). It's like somebody used a thick brush in MS Paint & traced over each blade. The normal map also comes out blobby. I spent hours playing around with the settings, and researching on the internet, but nothing seems to work.
The only thing that comes a bit closer to giving the correct results is increasing the resolution of the texture, which makes the disgusting looking blobs thinner.
I'm using old hardware, which makes the GPU cycles greyed out in the render settings, forcing me to use CPU. Could this be the reason?
If the solution is obvious and the problem is due to something really stupid I'm doing, just go easy on me, I'm fairly new to blender lol

I somehow missed the very obvious Margin parameter in the bake settings, which happened to be the culprit.
Setting the Margin to 0 pixels removed the awful padding.


text:
How to obtain a solid model from a complex shell geometry?
I am trying to create a solid out from a complex mesh of a car. I have a mesh which is paper thin and my 3D printer is unable to read it, so I would like it to have 3mm walls all over like a real shell.
The idea is to print it (resin) and adapt it onto a RC CHASSI.
I have already tried "solidify", but the model is deformed as soon as I reach 0.5mm.
Also tried to extrude every internal surface each by each but the outcome was hollow walls (unfilled), so the model is also colapsing while printing (too thin).
Any help would be much appreciated.
Thanks.

Hello I don't think that there's any magic trick, you need to either use Solidify modifier or Extrude Faces Along Normals but in both cases you'll need to make sure that no faces are intersecting

Thanks for answering. I did extrude faces of all internal areas to increase thickness of the walls, however it was all hollow. Do you know how to extrude but filling in the geometry created?

it means that your topology is not correct, maybe share a piece of your object?

how can I send you the file?

read the instructions here: https://blend-exchange.com/ only share a part of your object


text:
How do i export a file to open into my slice program
After i have smoothed out a file and save it stl when i reopen it in a slicer program it shows its still low poly looking. I have watched videos but i just can't figure it out.

How did you "smooth out" the file? Setting it to Shade Smooth is just a display method, it is not actually making the object smoother or high poly.


text:
Auto Rig Pro - Attach the Kilt/Skirt Rig to an existing Custom Character Rig and get a good result
I'm in the process of rigging a character in Blender. The rig is custom-made from scratch, as I followed Dikko's character rigging tutorial series for most of it.
My character has a skirt, and the skirt doesn't have a very robust rig, so I decided to use the Auto Rig Pro add-on to attach the built-in kilt/skirt rig to my Character Rig.
Since my character doesn't use the Auto Rig Pro Human Rig, I decided to spawn in an Empty Rig instead so I can add a Skirt rig to attach to my character.

Then I join the empty ARP rig with my custom character rig, it says I'll have to update, so I did.

Once that's done, I add the Kilt setup from the Limbs menu. It's much smaller than the character though, so I just scale it up in Edit Mode

After that I align the bones to the skirt and then I select "Match To Rig" and parent the Skirt to the new Bones.

Now, here comes that part that I'm especially having difficulty with. The process of adding Collision to the Skirt.
I click on "Edit Reference Bones" and choose the Limb Options, and assign the Leg Bones that the skirt will Collide With.

In ARP, when you attach the Kilt to an ARP Human Rig, there would be these Sliders for the Kilt Bones, where you can control the collision and there would also be Secondary Bones for more adjustment options.

But on MY Empty with Kilt Rig joined with Custom Character Rig, these don't show up, why is that? That's the difficulty I'm having here.

Is there a way for me to add Auto Rig Pro's Skirt Rig to a Custom Character Rig without using the ARP Human Rig?


text:
How to restrict a part of an object getting painted while texturing in blender
For example if I am painting a plane I only want its certain specified part to be painted. I tried using a box to cover the area which is not to be painted and when i start painting, the whole area gets painted. So I want to how paint only a certain specified area.

Enable the ''Face selection masking for painting'' option.

Masking using 'Face selection masking for painting' option.

Enable the Face selection masking for painting option. Press A to display the grid and select faces you want to paint using RMB.

Masking using painted stencil.

In Uv/Image Editor add a new image, change its name and set its color to white.

Paint the areas where you want your texture to appear with a black color (create a mask). Save an image. Your mask is ready.

In Slots bookmark of a Tool Shelf check the Mask checkbox, choose the UV map you want to use (the one with the painted stencil displayed). Then select your painted mask image (click on an image icon under the Stencil Image). If you want to inverse the mask click on the b&w square under the Visualisation.

Add a new material and a texture (an image) you want to paint on. Now when you paint in a Texture Paint mode your brush strokes'll apear only in a black areas of your mask.

Your idea will work when I want to restrict certain faces which is not to be painted but how to restrict certain area within a face.

Please see my updated answer. Hope this is what you're looking for :).


text:
When you're running a modal operator, how to you know when the user has clicked on a button displayed in the 3dviewport?
I'm writing a modal operator that needs to keep track of mouse movement and mouse clicks.  A side effect of this is that it makes any panels or workspace tools completely inoperable.  Since my operator is getting first dibs on any mouse events, all the buttons and other controls in the layover panels are being ignored.  I also cannot pass through these events, since I do not know if any given mouse event has occurred within one of the overlaid controls or is in the main part of the viewport.  Is there any any way to make sure that if the user clicks on a button, the signal is sent to that button first?

Your modal handler needs to return {'PASS_THROUGH'} for any event it doesn't handle.  Here's an example modal event handler that does that:
    def modal(self, context, event):
        v3d = context.space_data
        rv3d = v3d.region_3d

        if event.type == 'MOUSEMOVE':
            mouse_pos = Vector((event.mouse_x, event.mouse_y, 0.0))
            mouse_move = self._initial_mouse - mouse_pos
            self.offset = mouse_move * 0.02
            self.execute(context)
            context.area.header_text_set("Offset %.4f %.4f %.4f" % tuple(self.offset))

        elif event.type == 'LEFTMOUSE':
            context.area.header_text_set(None)
            return {'FINISHED'}

        elif event.type in {'RIGHTMOUSE', 'ESC'}:
            v3d = context.space_data
            rv3d = v3d.region_3d
            rv3d.view_location = self._initial_location
            context.area.header_text_set(None)
            return {'CANCELLED'}

        elif event.type in {'WHEELUPMOUSE', 'WHEELDOWNMOUSE'}:
            return {'PASS_THROUGH'}

        return {'RUNNING_MODAL'}

This is a very simple example that only deals with mouse events, not keyboard or others. You'll have to organize your own tests for whatever you want, but the example should give you a guide.  The example is taken from this tutorial. It might be worth your time to watch the tutorial as well.
Your handler should recognize a specific event to trigger completing.  This one uses Left Mouse click.  Return {'FINISHED'} in that case.
Your handler should recognize a specific event to trigger cancelling.  This one uses typing Esc while holding the right mouse button. Return {'CANCELLED'} in that case.
Your handler should pass through any events it doesn't want to handle..  This one ignores the third (wheel) mouse button. Return {'PASS_THROUGH'} in that case.
Implicit in this example is that in cases that your handler doesn't explicitly handle or ignore it should do whatever it wants with the event and return {'RUNNING_MODAL'} to continue running as a modal event.  Don't fall off the end of the function without returning one of these things. This one is just throwing "handled" events away. A useful modal might do some work between the if statement and the final return.

The problem here is that I need to know the locations of the various buttons and overlays before I can know if I need to pass the events through.  So if I've created a panel which is accessible through the N menu, I am unable to use it while my operator is running because my operator gets passed the events before the panel controls do.


text:
Is there a way to hide the masking lines when using Texture Paint with masking enabled?
I'm getting into painting textures onto my models using Blender's texture paint.  I like that Blender provides the 'face selection masking' button that lets me mask out faces that I don't want to accidentally paint.  However, when enabled this feature outlines all the selected faces with bold white lines - making it really difficult to see the results of my painting.  Is there a way to hide this overlay?

im not sure , but select the faces you dont want to paint and press "H" , and if you want to unhide them press alt - H

To hide texture borders, I had to disable mipmaps in Blender menu "File" -> "User settings" -> "System". I am not sure if you had the same problem but it may help other people.

As far as I know there is no such option, which disables the white lines.
In Weight Paint Mode you have an option to display vertices instead of edges, but in Texture Paint Mode there is no option like this.

I think that using the Clipping Border Tool may be a good solution for you. Press ALT+B and drag a mouse to select the portion of the model which you want to be visible.

You can rotate selected portion, and paint on it precisely. And the most important is, there are no lines that may disturb you :).

Well, just download the latest Blender.
Hiding the masked texture painting lines was one of its features:
Blender 2.73 Release Notes


text:
Managing noise in a night scene
I've been trying to get a pretty noise free image from this scene for a while. And nothing seems to be working.
I've been trying to use 3000 samples, then rendering different noise seeds and composite them together, but the base images are to noisy to even use this.
I've never really had this much noise before, and I'm not sure what's wrong with it. It already takes around 5-6 hours for me to render it at 3k samples (Laptop, so I cant use GPU rendering). Any help?
I've attached my render settings as well if it helps.

Here's a link to a bigger version of the photo if it's not large enough
https://www.dropbox.com/s/r3swgloty4rt2ef/1430608690119.jpg?dl=0
Someone on another forum suggested I use Luxrender instead, but I'd rather save myself the time in learning a completely new renderer and converting everything.

Does this image have anything to do with GTA Vice City? Because it reminds me of it...

Its Ocean Beach from VC, so yeah.


text:
Wrap spiral curve around complex object
How can I get a spiral curve to wrap around an object in blender?
More importantly, an object with some degree of complexity.
I've been using the shrinkwrap modifier with varying degrees of success.
In the example, I can get a spiral to wrap around simple shapes pretty well.
But in the second example, as soon as introduce different angles to the wrapped object, the spiral messes up completely.
Also in the second example is the type of curve/spiral I'm using.
I've tried all three different types of spiral, but none gives any better result than the other.
Any ideas?

Use the Curve Modifier to slide your Spiral Curve along a Bezier Curve
With the Add Curve: Extra Objects add-on enabled, Add a spiral object by pressing ShiftACurve > Spirals.

In the Operator Panel customize the spiral's shape.

Set your Curve settings as you want them.
Add a Bezier Curve. (ShiftACurve > Bezier)
Use the Curve Modifier on the spiral object to make it follow the Bezier Curve object. Set the Axis correctly (usually it will be Z). Enable the third and fourth modifier options, to Display Modifier in Edit Mode (makes it easier to see what you're doing) and Apply on Spline (makes for a nicer curve shape).

Make sure their Object Origins are at the same point, and that both objects have the same rotation (to avoid confusion). If you need to slide the spirals position along the Bezier Curve, Select All (A) and Grab (G) the spiral object and move it in Edit Mode.

You can also scale the spiral along Z to stretch, or X,Y to fatten it.

Above: Scaling with the 3D Cursor as the Pivot Point, to fit the spiral to the Bezier Curve.

Definitely more in depth than I had expected, but a great answer nonetheless.
The thought of using another curve to modify the direction of the curve is something that went right over my head.
I found myself trying to manually go in and rotate the vertexes, which was pretty time consuming.
Thanks a lot, I appreciate it.

No worries. I can imagine nudging around the curve points was tedious. Glad this will be a solution for you. :-)


text:
What is the differance between Linking and Appending an external blend?
What is the differance between Linked and Appended data from external .blend files?

The difference is simple.
Link: Link copies the object from the blend file, much like Alt-D does for meshes. When it is pulled in, the mesh/material whatever cannot be edited in the file. Changes in the original file will cross apply to it every where. This is useful for production assets which need to be the same in ever shot.
Append:
The object will be copied into the new file, there will be no link, much like importing an .obj or .fbx

Appended data is just copied into a blend file.
Linked data will continue to update if the original data is updated. For example, if you link a red material from blend 1 into blend 2 the material will appear red. If you then update the original material in blend 1 to be blue (and then save blend 1) the material will also appear to be blue in blend 2 (once blend 2 is reloaded).
Linking allows organisation when creating complex scenes. Instead of modelling many props, rigging characters, and then animating in a single file, which might become complex, you can split your project into separate files and then link them together to render.


text:
Blender 2.7 Background image not working
I've watched a video on background images, and I can only see the background image that I add in the camera view. I can't see it in any other view.
How do I fix this?

Make sure you are in ortho view (numpad 5) and viewing along a specific axis (e.g. numpad 1 for front view).


text:
RegionView3D from Region object and vice versa
How do I get a RegionView3D object from a Region object?
I'm working on an operator in the quad view of the 3D view and I need to determine which region the user clicked in and the relative position to that specific region

I've tried event.mouse_region_x and y but those are relative to the original region that the operator was ran in
I've also tried using the ctx object provided to the operator's modal function as well as bpy.context but both seem to be frozen on the original place the operator was ran in?
Current solution is to check all areas in bpy.context.screen.areas, find the one clicked in and then find the region in that area. This means I now have a region but I can't get the RegionView3D from it. This is because RegionView3D is accessed from a Space object and that doesn't have any actual positional information on the screen.

A RegionView3D is actually a space, the access path is bpy.context.screen.areas[#].spaces.active.region_3d (area being of type VIEW_3D), or in case of quadview mode, ... spaces.active.region_quadviews[#].
There are no direct references from a region to a RegionView3D.
It's possible to find the right quadview region and its space, here's a (modal timer) example:
import bpy
import math

def get_view_orientation(space, quadview):

    if quadview.view_perspective == 'CAMERA':
        view_orientation = "Camera Persp"

    else:
        r = lambda x: round(x, 2)
        view_rot = quadview.view_matrix.to_euler()

        orientation_dict = {(0.0, 0.0, 0.0) : 'TOP',
                            (r(math.pi), 0.0, 0.0) : 'BOTTOM',
                            (r(-math.pi/2), 0.0, 0.0) : 'FRONT',
                            (r(math.pi/2), 0.0, r(-math.pi)) : 'BACK',
                            (r(-math.pi/2), r(math.pi/2), 0.0) : 'LEFT',
                            (r(-math.pi/2), r(-math.pi/2), 0.0) : 'RIGHT'}

        view_orientation =  orientation_dict.get(tuple(map(r, view_rot)), 'USER').capitalize()
        view_orientation += " " + quadview.view_perspective.capitalize()

    if space.local_view is not None:
        view_orientation += " (Local)"

    return view_orientation

def get_quadview_index(context, x, y):
    for area in context.screen.areas:
        if area.type != 'VIEW_3D':
            continue
        if len(area.spaces.active.region_quadviews) == 0:
            return
        i = -1
        for region in area.regions:
            if region.type == 'WINDOW':
                i += 1
                if (x >= region.x and
                    y >= region.y and
                    x < region.width + region.x and
                    y < region.height + region.y):

                    return (area.spaces.active, i)
    return (None, None)

class ModalTimerOperator(bpy.types.Operator):
    """Operator which runs its self from a timer"""
    bl_idname = "wm.modal_timer_operator"
    bl_label = "Modal Timer Operator"

    _timer = None

    def modal(self, context, event):
        if event.type in {'RIGHTMOUSE', 'ESC'}:
            return self.cancel(context)

        if event.type == 'TIMER':
            space, i = get_quadview_index(context, event.mouse_x, event.mouse_y)
            if space is not None:
                quadview = space.region_quadviews[i]
                print(get_view_orientation(space, quadview))

        return {'PASS_THROUGH'}

    def execute(self, context):
        wm = context.window_manager
        self._timer = wm.event_timer_add(0.5, context.window)
        wm.modal_handler_add(self)
        return {'RUNNING_MODAL'}

    def cancel(self, context):
        wm = context.window_manager
        wm.event_timer_remove(self._timer)
        return {'FINISHED'}

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

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

if __name__ == "__main__":
    register()

    # test call
    bpy.ops.wm.modal_timer_operator()

Is it safe to assume that in area.regions will have regions in the same order every time? Same with spaces.active.region_quadviews? Because then that simplifies things a lot

I believe they are. You may wanna check the code that many all 4 regions available to python. Here's the related bug report: https://developer.blender.org/T39028

It doesn't actually seem possible.
Using this other topic "Getting the active region" as sort of a jumping off point, you'll have to go through and compare all the regions positions to the indices of the quadviews list (having to assume that quadviews is a fixed list where 0 is Front, 1 is Top, etc.)
Couldn't come up with a better way to sort these but here it is
#+-------------------------------------+
#| reg 1  (TOP/XY)  | reg 3 (USER/USR) |
#|------------------+------------------|
#| reg 0 (FRONT/XZ) | reg 2 (RIGHT/YZ) |
#+-------------------------------------+
#First find reg 0
minReg = None
for reg in ctx.area.regions:
    if reg.type != "WINDOW":
        continue
    if not minReg:
        minReg = reg
        continue
    if reg.x <= minReg.x and reg.y <= minReg.y:
        minReg = reg

#Place all the other regions with respect to reg 0
regions = [None, None, None, None]
regions[0] = minReg
for reg in ctx.area.regions:
    if reg.type != "WINDOW" or reg == regions[0]:
        continue
    if reg.x > regions[0].x and reg.y > regions[0].y:
        regions[3] = reg
    elif reg.x > regions[0].x:
        regions[2] = reg
    elif reg.y > regions[0].y:
        regions[1] = reg

#Make the dictionary
self.viewDict = {
    "XY" : (ctx.space_data.region_quadviews[0], regions[0])
    "XZ" : (ctx.space_data.region_quadviews[1], regions[1])
    "YZ" : (ctx.space_data.region_quadviews[2], regions[2])
    "USER" : (ctx.space_data.region_quadviews[3], regions[3])
}


text:
Blender connected proportional edit in UV/Image editor not working
I'm trying to proportionally edit some vertices using the connected mode in the UV/Image editor. According to the Blender manual on proportional editting, I should be able to edit vertices that are both close (in spatial coordinates) while simultaneously ignoring those that are far away topographically.
This is not what happens though. It seems as though it edits the vertices with normal proportional edit, ignoring the fact that some of the vertices are far away topographically.
Here's a picture

Is this the expected behavior for this tool or am I just doing it wrong?

Are those 2 disconnected meshes ? It isn't seen there, but the meshes have to be not connected by any vertex.

They are connected yes. But according to the manual This means that you can proportionally edit the vertices in a finger of a hand without affecting the other fingers. While the other vertices are physically close (in 3D space), they are far away following the topological edge connections of the mesh. this leads me to think they can still be connected

They can be connected; however for absolute moving lock of any geometry it should be unconnected. Try working with simple proportional edit and change influence radius; you should see the difference between the modes.

@MrZak Changing the radius doesn't give me the transform I want unfortunately because I still want the large radius, just not affect the vertices on the other side of the gap. Maybe they're just too close topographically as well because I compared using both simple proportional and connected proportional and they affect the vertices that are farther away just the same amount. So I don't really know what's going on.

Unfortunately proportional editing in the UV editor works differently to the 3Dview. In the 3Dview connected proportional editing will only move vertices that are directly attached to the selected vertices that you are moving. In the UV editor all points that are indirectly connected are influenced by proportional editing.
A possible solution is to select only the vertices you want to move (in the 3Dview), the unselected vertices will not be visible in the UV editor and will not be moved when you move the nearby points. Note that this can tear apart neighbouring faces at the edge of the selection.

This is what I ended up doing to get the result I wanted even if it was a bit more of a pain. Thanks for answering the question too.

you can try temporarily pinning some vertices in the UV map with  Shift-P

I was looking for something like this! Thanks


text:
Set active blender area/region in headless python module
I compiled Blender as python module to be able to do unit testing of a plugin I'm working on. The issue is that bpy.context.area and other context values do not seem to populate so I can't run operators that require a specific area (like bpy.ops.screen.region_quadviews()).
How do I set the active area and region in Blender?

Related

If your running in headless mode then there are no screen regions to work with. Maybe setup two testing steps, one without gui and one with.

@sambler The regions exist, you can explore them in bpy.data.screen.areas and further. There's just no way to set any sort of active one. I've tried using cursor_warp to place the "cursor" over them, as well as some other ones that talk about "cycling the context" but nothing seems to work. There might be a new function in 2.79 that handles it that I'm rebuilding to test out

As has been quoted from a blender developer "when in background mode there is no window or opengl context" for any screen region to exist in, that is what leads to no screen regions being available, even though the properties exist, that doesn't mean there is any valid data that can be used.

Hmm, I think that I might just be able to get away with faking a context and passing it to my class like you've provided in the link. I think that's the only way to go for now


text:
Determine if a Python file is running in Blender?
My add-on needs to run both inside and outside of Blender (I have unit tests that I run with a headless version of Blender to make sure everything continues to work).
How do I determine in my __init__.py file if my package is being loaded and ran in Blender versus being loaded in just normal Python?
What I've tried:

globals() does not seem to contain anything useful to check at least in a loaded Python file. It has quite a few things in the Python console as well as when running a file from the TextEditor in Blender.
sys.modules[__name__].__addon_enabled__ does not seem to work
try: import bpy work for my case as I have a module in my environment called bpy (headless Blender)

My workaround for now is that for my unit tests there's an environment variable set to tell it that's it shouldn't try to do normal Blender registration.

What about sys.argv ?

Damn, that's a clever idea... I'll have to try that.

IS_RUNNING_IN_BLENDER: bool = not hasattr(__builtins__, 'print')
Blender's __builtins__ dict doesn't contain print, so you can check for its presence and assume that the file is running in Blender if print is not present, and running outside of Blender if print is present.

This is False in my copy of Blender (4.2, Linux).

edit: This answer will not work since Blender 2.91 because the meaning of sys.executable changed, see https://developer.blender.org/rB04c5471ceefb41c9e49bf7c86f07e9e7b8426bb3.

I found an example of this on the "Blender as a python module" wiki: https://github.com/TylerGubala/blenderpy/wiki/Caveat---Importing-Addons#development-of-new-gui-addons
Their suggestion is to test os.path.basename(sys.executable) for a prefix of "blender" vs "python", eg.
in_blender = os.path.basename(sys.executable or '').lower().startswith('blender')

(Testing sys.executable is a little better than sys.argv[0]. A script with a shebang line called like ./blender-script.py will have a sys.argv[0] of "./blender_script.py" (giving a false positive), while its sys.executable will still be the path to the python interpreter.)
Another idea is to test that sys.executable is the same as bpy.app.binary_path
try:
    import bpy
    in_blender = (sys.executable == bpy.app.binary_path)
except ModuleNotFoundError:
    in_blender = False

Wouldn't os.path.samefile(sys.executable, bpy.app.binary_path) been more robust again file system?


text:
How to model this car hood?
I recently started to model a car and can't get past the hood :P
I tried many things, ended up with this (not finished, I'm aware of ngons...)
I'm aware that the topology is not right, it has a bad flow and so on.
So I ask you for advice on how to model such non-traditional hood.

My reference

Thank you in advance!

sorry but Imho this is not a modeling course support forum... I feel that topology should be learned in other ways, and not through a blender related q&a site...

Probably the best way, would be to trace the curves of the hood, and then fill it in. You should probably go to BlenderArtists.org to get help there.

@DalekMaker Yes I realized that already... Thank you for your time

After many hours of trial and error, I somehow figured it out myself :

however, I'm always opened to your suggestions :)


text:
Car modeling technique
I have been using blender for a few years now and I decided to model a detailed car to improve my skills in modeling, texturing, shading, lighting etc. However, for some reason, it seems like very daunting task for me. There are so many ways to get it wrong, that I don't know where to start.
My question is: What is/are a good - proven method/s to model a detailed (smooth) base shape of the car (something like this) for further detailing?
The one that I want to model is Dodge Challenger 1971
Thank you!

you might find this post interesting: difference-between-hard-surface-and-organic-models

Common workflow for this task is a quad oriented "vertex by vertex" modeling upon a blueprint base followed by Subdivision Surface modifier. You can see an example in this video: https://www.youtube.com/watch?v=sxGjhzV_Qkk

http://wiki.polycount.com/wiki/Subdivision_Surface_Modeling

@Jerryno thanks for that link! Valuable resource


text:
What are the system requirements for working with heavy/complex scene in Blender?
Is it possible to create a scene like kung fu panda with more that 5 characters, environment, simulation, vfx, lighting ...etc.

It's a bit hard to give a cold hard and exact hardware estimate as a "requirement" for making this scene. Aside from having enough RAM (which isn't easily determined either, depends on many many factors), and being able to run blender at all, you could technically make this on pretty much any hardware. What hardware you want to work with is what matters, and that can only be answered by you..

This question if about peoples opinions and what they know . There is no exact answer.

I recommend having a GPU that supports the Blender Cycles Engine. It saves you a lot of time. But be careful some GPUs aren't supported, that's why I had to buy a new one. But as @NuclearBoofluff said, this question is a bit to vast.

what about if let's say i have a laptop with an additional external VGA... would it possible? @Marten Zander...

Of course it is possible, the minimum for rendering/composting this type of scene in less than 20 hours is and Nvidia GTX 650+ and either intel i5 or i7. But, your question was a bit vague so I don't really know what you mean. I hoped this answer helped though. :)

Thanks for your reply. I am having (Intel® Xeon® Processor E5-2690, 8 core)*2, ( 64 gb ram) (nvidia gtx 780 ti)*2, I am trying to re-create this scene as a sequence to check that how much can blender handle. I heard that blender can't handle heavy scene and it will crash.

There are no requirements. Even a Windows XP can create this, it will just take a long time to make. Probably another you might want is a good fan. The computer would burn out if you don't have one. I think this podcast might help. http://www.blenderguru.com/podcasts/ep53-harddrive-wonder-theres-lesson/

It can also depend on whether you are using GPU or CPU rendering.  With GPU rendering, you are limited to the amount of RAM in your video cards.  So if the entire scene cannot fit into the GPU's memory, then you will be limited to CPU rendering.


text:
The file not showing up on Movie Clip Editor?

My file just refuses to show up on the Movie Clip Editor workflow. I'm sure it must be something simple, but I don't know what it is.

It was the start frame not set to where the playhead was.


text:
Clothing falls off model?
I am following along with an online tutorial to try and make a shirt, but instead of adhering to the 3d model, it falls right off and does not work.

The comments are not the place for sharing information essential to answer the question. These should be edited into the question body itself

While files, images, and external videos or links may be helpful additions they should not be the only way to obtain information about your issue. Don't make understanding your question rely on downloading a file, watching a video or visiting an external site. Use the builtin tools to upload images or gifs, along with thoroughly explaining the problem in written form so it can be indexed and searched for thus helping future visitors with similar issues.

Activate Sewing
In the Cloth's Shape section, you didn't activate the Sewing option to enable the strings to be pulled.


text:
How can I make my skirt with riffles?

I am trying to re-create a skirt with ruffles like the grey one above with the blue shirt, I have already run a cloth simulation, but I cannot get the shape to look right on my version of the skirt.
Everything looks very flat because I am only using two subdivided planes.

The cloth is folded on the top and then stitched together.

I've never tried the cloth simulation myself, but from what I've seen in tutorials, I don't believe achieving that skirt with a sim is impossible. Of course I could be wrong, tho.

Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer.

You could try it this way:
Create a cone:

Create a vertex group, that will be the cloth pin group:

Give it 2 shapekeys, select the second one and scale one vertical edge out of several (make it a bit heterogeneous):

Give your object a Cloth simulation, choose the group as pin group, choose Cotton presets for example, increase the Quality Steps, the Vertex Mass, increase the Collisions Quality to 4, enable Self Collisions. Then keyframe the second shapekey from 0 to 1:

You can add fake folds with a Bump node and a Noise Texture that you stretch on Z.


text:
Mesh follows parented armature correctly, but only half way
I have a vertex group that I've weight painted to follow the rotation of a deformation bone.  As I rotate the bone, the mesh follows the rotation correctly, but the vertices with a value of 1.0 only appear to be moving at 50% of the bone's rotation, and the vertices at lower weights even less.
The deformation bone's Y axis is rotated 140 degrees off of the global axis, and it pivots on its local X axis.  This might explain the problem, but I don't know the solution.

if they move only 50% it means that they are also part of another vertex group with an equivalent weight of 1

I think moonboots is right: the vertices have been accidentally assigned to two groups in entirety, so they are averaging between the two respective bones.

Yes, that solved my problem.  Noobie mistake!


text:
Alternating black and white material for text characters
I am trying to add a alternating black and white material to the face of the text. The text has to stay editable and can not be made a mesh. I would like it to alternate from back and white on each character randomly at first and slowly end up with all of them being white.
I have used the wave texture node and the invert node which kind of of works but each character is not totally white or black.

That would be hard to do in the node editor without some typesetting constraints.  Either each letter should be the same width or spaced differently and then some math should be able to handle it.

Hello and welcome. Please use a title that reflects the content of the question. It should be succinct, unique and identifying, and summarize what the issue is so that users can at a glance broadly understand what your post is about before opening it. Use the [edit] link below your post and avoid any emojis salutations or extraneous text not essential to the question. Remember, your title is the first thing potential visitors will see, and will weight heavily on their decision to open your question, which will directly affect the number of answers you might get.

If rendering in Cycles, with simple, flat text, this is relatively easy to do.  You can use a geometry/random from island as a lookup on a noise texture:

Here, I'm combining a random-per-island with a value node driven by #frame.  If I'd like to bias this over time to some particular value, I can keyframe the "greater than" threshold.  If that threshold is 0, all letters will be white.  If it is 1, all letters will be black.
I've also shown here why the letters need to be flat for this to work.  Once we use extrusion (or bevel) on our letters, they have geometry with new islands, leading to different random values.  Note that even with flat letters, the dot of an i, for example, would be a different island, and thus potentially a different color, from the rest of the i.
If we need this to work in Eevee, or with text with geometry, it's not so hard; we just have to turn it into an actual mesh object so that we can weld vertices and UV map it, then use any of a number of techniques to get a unique identifier for each letter:

We'll start by using "convert to" operation to convert the text to a mesh object.  Then we'll enter edit on it and merge all vertices by distance (distance 0).  Then we'll UV map it, with a simple project from view.  Finally, here, I select all UV coordinates and scale, about individual origins, to 0.  Now, each letter has a constant, unique UV coordinate that I can use to create letter-wide random numbers.
Consider the "i" problem mentioned above.  Doing what i just mentioned will give us a different color for the dot of the i and the rest of it.  But if we want these to have the same color, all we need to do is give them the same UV coordinate.  We can select the UV coordinates for the whole i and scale to 0 in median, instead of individual origins, to give it that.

I'm not sure if this is possible to do with shader nodes alone. But this is as close as I could get.

Thank you for this. I will try it!

This makes some letters highlighted partially https://i.imgur.com/Hgjnj4i.png


text:
Weight Paint Mode: Hidden faces keep unhiding
I'm new to weight painting in Blender.
One thing continues to drive me nuts, when I try to hide disconnected parts of the mesh in Weight Paint mode, they keep re-appearing the moment I start painting.
Is this expected behavior and I'm doing something wrong? Is it a bug?

Maybe as an alternative, instead of hiding the object, you can disable it in viewport and then turn it back on when you need it. See if that still causes the bug. https://blender.stackexchange.com/questions/126941/shortcut-for-disable-object-in-the-viewport-dov-blender-2-8 I also suggest reporting this bug! https://www.youtube.com/watch?v=JTD0OJq_rF4

I found a workaround that fixes the problem. If you separate the mesh that is having the issue into it's own separate object and join it back to the original mesh then the problem seems to disappear all together.


text:
UV maps resetting on its own
I am having an issue with UV mapping ( Blender 2.83, needed for an export plugin) I have never encountered before in years of working with Blender.
I unwrap a portion of a mesh, set the map where I want it, and move on to the next section.   What is happening now, though, is a section that was mapped previously (in same cases, only a few moments) is resetting to a jumbled mess.
I have tried exporting the UV map before moving to a new section, closed Blender and restarted, reloaded the mesh, loaded an earlier version of it, keeps happening. I have been using Blender since 2.4x and never had this happened before.

hello, could you plese share your file (only the object with your problem)? https://pasteall.org/blend/

Ultimately, I fixed it by by deleting the UV maps, splitting the object into smaller parts and mapping each one, then recombing them.
Still not sure what actually went wrong though....


text:
Textures not appearing on autodesk models when I import them
I'm bit of noob when it comes to blender so I was wondering why when I import .fbx models into blender the textures do not appear even when I select the texture option?

Did you check for errors?

I've just reimported it now and blender isn't displaying any errors.

Hmm . . . No textures, no errors, rather odd. I found a diferent question on here that had a similar issue, but it didn't have an answer. One thought, do you have to select some option to bundle textures on the application that exports the fbx file?

I've just been mssing around with the model and it appears that when I choose to view the model in render mode it dispalys the texture.

Cool! So this is actually not an issue then?

It should also display in solid or material view. You just didn't use a diffuse tex.

@VinceScalia Note that textures won't be displayed in solid view by default, you'll need to enable Textured solid in 3D view > Properties region (N).

@gandalf3 sorry, I meant to write textured.


text:
Face behavior not equal after loop cut
I've been using blender for a while now - mainly just messing around. So all things being equal - this is a beginners question. (I tried searching, but only found the standard loop cut and slide questions)
If you take the default cube, and use loop-cuts to split it @ 50% (so all your faces are slit into 4 equal ones). Then if you grab a vertex in the middle of those 4 faces and move it perpendicular to the face (creating a pointed face) - why do some of the adjoining faces come out different than the others?
Either one of the two is OK with me, but i dislike that all equal faces do not have the same behavior.
Maybe someone can shed some light on this for me?

This is because you have created non-planar faces.
A non-planar face is a face with vertices which are not aligned in a plane in any direction.
Under the hood everything is represented in triangles (at least for drawing purposes), so blender must decide how to cut the quads. It can cut them two different ways:

Which way is used appears to be decided more or less at random.
To avoid this undefined behavior, you can split non-planar faces manually to match what you want (J works well for this). You can also press 3D view > Header > Clean up > Split non-planar faces to automatically split all non-planar faces automatically:

And the answer is that simple ... thank you very much!


text:
How to extrude surface keeping face angles
I have a simple object with two opposite faces at different angles. I'd like to extrude the connecting face such that the resulting extrusion follows both angles.
I would call this an extrude slide if I were to put a name to it, because it's similar to an edge slide. This scenario happens all the time, but I just can't find a simple way to do it.
What is the easiest way to do this?
My current model:

Normal Extrusion (not ideal):

Ideal Extrusion:

I don't think that is possible, at all. In your case it seems trivial to guess which edges to move along, but in more complex geometries how would Blender determine what faces to taper along?

Blender doesn't need to determine which faces to taper along, it could just taper along all of them. If you select the face and hit {G}{G}, you can slide the entire face backwards along the normals. This would just be the opposite; I don't think it's unreasonable.

Actually I found a workaround, will post as answer below.

As far as I know it can't be done with extrusion directly, but it can be approximated using the Move Along Normals operator.
Select the desired face and press G,G (G key twice) to initiate the Move Along Normals operator.
Move your face "backwards" towards the existing geometry so it slides along existing edges and Blender picks up the correct directions. Once along the desired edges, while moving, press C to unclamp movement.
Once unclamped you can now freely move "forward" towards opposite direction, while still keeping the alignment of the previous geometry.

The downsides of this method are that you won't be able to move in absolute distances in Blender units, only in percentage increments, and there won't be an edge left at the original position, if you did want to keep one there.

Brilliant! This is exactly what I was looking for. The {C} for clamp I had never heard about anywhere. Thank you

Tip: Some operators have additional options while running, check the 3D view header during transform for additional hot keys. This option along with some others is listed there.

@DuarteFarrajotaRamos i can't perform an edit that is only 4 characters, so please consider changing the following little thing: "...press C to _un_clamp movement. Once _un_clamped you can now (...)". Clamped is the default state, hitting "C" unclamps the movement

@yann that is right, misread that detail. Its fixed now, thanks for the warning


text:
Bevelling a curve with object
I've googled and also searched the answers here but couldn't find my problem so here goes:
I know how to bevel a curve using another object and when I try it with a normal circle it's fine. But I'm trying to use this flat oval shape to bevel a larger curve of the same shape and it's not following the curve at the correct rotation. I've tried everything, rotating the bevel object, clicking random options in the object data menu.. I can't seem to budge it from looking how it is in the screenshot. In the screenshot you can see the curve I've failed to bevel correctly and also the bevel object in the bottom right.
Basically, I want the flat part of the oval to be above and below the curve, not on the sides as it is. I hope that makes sense. Anyone know what I need to do?

If you want to change the rotation of the bevel, you need to rotate the bevel object in Edit mode.

Enter edit mode for the small oval that is the bevel object.
Select all the curve points and rotate by 90 degrees (I can't tell which axis from the screenshot).

Perfect! Thank you for the extremely fast answer. (I'll mark it as the answer as soon as the countdown timer lets me) :)

authors: Михаил Степанов


text:
Glossy materials not rendering correctly
I'm new to blender (and 3D modelling) so please use dummy terms if you answer!
I have applied 3 materials one each to 3 different objects and only 1 renders the same as the material preview. I've attached a screenshot to show you what I mean. The silver material should be on the top ball and the brass material should be on the cylinder holding the ball up. I've no idea why it's not working when the copper material on the spiral wire worked. I'm using cycles render if that helps?

You have no enviroment to reflect. That is why it is so dull.
Add envrimonet map or model some eviroment.

Related: http://blender.stackexchange.com/q/15683/599 and http://blender.stackexchange.com/q/23111/599

@JozefCulen feel free to add an answer based on your comment. It would be helpful to future users.

You need something to reflect.
Currently you have white plane on the ground and grey sky. That is exactly what your material reflects.
You need to add enviroment map or sky texture.


text:
Swap two curves in the editor graph
I am wondering if possible to swap two curves in editor graphs? or to modify a curve to be constant =0 (no motion)?

For the latter you can select the curve and then press S (scale) Y (y axis) 0

Add limit modifier with MAX_Y and MIN_Y set to 0


text:
NLA and animation properties
I am watching a tuto on NLA doing on blender 2.66. I have the 2.72 version. I can not found the complete  properties  of animation in the NLA window (image2) as in the 2.66 version (image1).

Click the pushdown action button (icon with the double down arrows):

After that the Action Strip settings become available in the Properties

This is documented in the Docs Creating Action Strips


text:
Cycles is not using the materials created by MakeHuman
I am using a blender and  MakeHuman .mhx file to model some persons moved in a scene and captured by a fisheye lens camera.
I model a person with clothes on MakeHuman and I load it in blender in mode Cycles Render (because fihseye lens work only in Cycles Render). When I render I get a person without clothes and a lot of noise caused by the light (see image1). But in Blender Render I get the person with clothes (see image 2).

I'm guessing that the Make Human importer sets up a Blender Internal Material based on the Material that's in the file you imported.  This is not automatic yet for Cycles rendering yet.
First you have to go to the Materials Tab and click the 'Use Nodes' button.
Now you can up the Node Editor and add an Image Texture.  Next, plug the Texture's Color output into the the Shader node's Color input.

Thanks, in my case ,it is an armature, so there is no material and in the texture there is no node button.

armatures never render. They aren't supposed to. I think you may be confused...

What @MarcClintDion says is makehuman exports blender internal materials which have to be recreated (manually by you) in cycles. As a second opinion I confirm (hope that makes sense in English) that.

first enable all layers ("~" key), and find the body model (it's attached to the armature, so in the outliner window it's inside the armature). next play with materials for body and its parts (eyes, hair, eyelashes, eyebrows, genitals, etc). you're to setup all needed materials to cycle style. a little tip - use "F" button (it's next to material name) to add fake user to all of your old and new materials to prevent losing them on file save.
there are a lot of tutorials how to use textures in cycles, transparent ones as well (you'll need it for hair, eyelashes, etc). happy blending!

now there is a simpler way. just use mhx2 importer from makehuman. when importing it to scene with cycles render selected it automatically creates all the cycles materials!

Please see the comment by Mechanic.
In the latest blender release, use the mhx2 importer but you must first select the Cycles Render before importing the mhx2 file!


text:
Mix two materials in the Blender Internal Materials Nodes
I studying the node in the Blender internal (not Cycles render). In an exercice, I want to mix two materials. I create a sphere, I apply the first material with a texture and it is going. In the second task, I create an other materials without texture and I need to mix the two materials using the Mix node. The problem is Mix does not exist in the shaders node and exist in the compositing nodes or texture nodes. In addition, I can't show at the same time the nodes corresponding to the two materials in the
shaders node? How can I Mix the two materials. I am using this tutorial tuto blender

since the material nodes output is Color type you can mix them using the RGB_Mix node :


text:
Coordinate of each part of body in .mhx
I am imported a *.mhx file in blender to do a walk animation. I remark that each control FK/IK has a seperate coordinate system. However, I need to get the coordinate of each part of model (feet,..) in the world coordinate system (master).
For example here , the z coordinate of  the foot is negative but in the master coordinate system it will be positive. I need that to get the long of the stride for example and to check the position of feet on the ground.

As this is a custom shape, the real bone can be somewhere else than the shape you see.

@Bithur I did not understand what do you mean?

a custom shape is a representation of the bone, not the bone itself. The shape's position is not the real bone's position, it's placed here for conveniance. go in armature settings and uncheck the "shapes" display to see the real bone.


text:
How to select a graph in graph editor
I am doing an animation and in graph editor i need to interpolate some graphs. I select the graph point by point but it is not comfortable. Is there any shortcuts to select the graph?

To select a single "curve" in the graph editor, select a point and hover over it and hit L to select all the points, hit A. To select an area of points, hit B and use the box select tool.