Questions tagged [drivers]

Questions related to drivers. Drivers are used to control one property with another. Drivers can also use python expressions to give even more possibilities, e.g. *#frame/2* will give the current frame divided by two.

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25
votes
1answer
4k views

Possible to control a Driver from a Group Node input slider?

Sometimes I create Material Groups to be used as appendable reusable assets. Unfortunately sometimes parameters I want to control using a Group Node's slider are not available for routing to a Group ...
4
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2answers
11k views

What does 'Autorun disabled' statement mean?

Could someone explain me what does this statement mean and what option should I click when it pops up?
14
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3answers
11k views

How can I make a plane always look at camera? [duplicate]

How can I make a plane always look at camera? Like in old videogames, like Doom or Wolfenstein, this kind of software used static images that always looked at the camera, is this possible to make on ...
6
votes
2answers
1k views

I want to mix Cycles shaders based on self shadow

I have a sphere (world) that I want to reveal the night lights on. I can use a normal node and manually rotate the DOT product, then I use this as a factor mix between Day time shader and Night time ...
3
votes
1answer
1k views

How to create a PyDriver in blender 2.7

I've heard of PyDrivers where you can put python code into a driver, & I'm wondering, how would you do that in blender 2.7x without resorting to a lower blender version? Here's what I'd like to ...
4
votes
4answers
540 views

Drive shape key based on relative camera orientation?

Let's say (for the sake of simplicity) that this cube with two blue sides is my character... and the shape key in question raises a few vertices on top. Whenever the camera views either Blue side, I'...
8
votes
2answers
5k views

How do I stick an object to another objects vertex?

I just created a plane and added a wave modifier to it, to simply make it look like something fluid. Now, I have an Object that I want to place on the surface of this fluid plane. But how do I do that?...
6
votes
1answer
3k views

Is it possible to put an if statement into the scripted expression of a driver?

If the y location of a certain object is greater than 0, I want to add a fixed amount to another object's driven channel. How do I achieve that?
5
votes
1answer
2k views

Is there a caveat to using drivers on node properties?

So, it seems to be a trivial matter to use a different seed on each frame (it looks nicer in animations). I.e. type "#frame" into the seed value and viola! You now have a driver. In fact, if I turn on ...
12
votes
2answers
360 views

How can I rig a cylinder so that when it's rotated its end cap will not penetrate the floor?

I have a default Blender cylinder positioned upright atop a ground plane: How can I rig the cylinder so that can be animated to wiggle/jitter (perhaps procedurally with noise f-curve modifiers on two ...
3
votes
4answers
2k views

Possible to use object speed/acceleration as driver variable?

If I have an animated moving object, is it possible to get its speed and/or acceleration vector into a driver variable? Some ideas I've thought of and haven't worked out: Obviously differentiating ...
4
votes
1answer
463 views

Rotate a Cube on a Plane Using Drivers

This is a simplified example which I wish to apply to a more complicated animation situation. I have a cube, that is 1x1x1 in size, origin at the centre and is located at (0,0,0). It sits atop a ...
2
votes
1answer
1k views

How to correctly drive a normal node with lamp rotation?

I'm trying to use drivers to allow a lamp rotation to dictate the direction of my normal node. The problem seems to be that the sun can rotate from 0-360 degrees, but the driver has a limit of 0-90 ...
6
votes
1answer
1k views

Relative reference to object property in material driver?

Is it possible to get a value such as the dimensions (object.dimensions) of an object in the material node editor, without referencing a specific object? In other ...
1
vote
2answers
1k views

How Can I modify drivers properties via python in blender?

how can I modify properties, for example adding variables, changing their type and targets in a driver on an object all via python, so that I can loop that on multiple objects?
2
votes
1answer
2k views

Get length of Bezier curve with python? (For driver)

Is there a way to get the length of a Bezier curve in Python such that I can use it in a driver?
2
votes
0answers
191 views

Use self and the slow python expression

In putting together an answer to Changing Multiple Influences Simultaneously I came across the Slow python script warning in the drivers editor Using a set up as outlined here driving a pose bone's ...
12
votes
3answers
3k views

How would I change a Cycles material's color using the scale of the object instance it's applied to?

Basically I have a field of spheres that are a bunch of different sizes that use the same material and I want them to be a different color based on their size. I'm using a volumetric shader, so each ...
5
votes
1answer
1k views

Python script to print tooltip value when mouse is over a property

I want to get the tooltip value of a property when the mouse is over it (after pressing a shortcut), like the X location of an object or another value that can be animated in the scene. In specific, ...
16
votes
2answers
3k views

how to copy drivers to multiple Objects?

I want to copy one driver to all selected objects at once, but the "copy to selected" function copies solely the current value of driver, and not the driver itself. Is there a possibility to copy ...
7
votes
1answer
336 views

Can drivers span more than one line?

Is it possible to write Multi-line drivers? As I understand it, drivers just assign the given statement to a variable, so you couldn't have _expressions (which don't evaluate to anything) in there. Is ...
5
votes
1answer
423 views

How to access data related to individual particles?

I would like to create simple drivers to manipulate individual data points for things like Particles and Array Modifiers. Just as an example, when I create a particle system, if I create a driver for ...
9
votes
1answer
324 views

Essentially, what are drivers?

Okay, so I'm a relatively new user of Blender. I've delved into most of Blender already, including the Graph Editor and F-curves, but not the Dope Sheet or Drivers. I'm planning to get into what the ...
5
votes
1answer
3k views

Bake driver to keyframes

Can you bake the animation created from a driver to keyframes?
4
votes
2answers
782 views

Driver on material not updating

Sorry for the noise... My previous question was answered, and I've fixed what I was doing wrong; but only so far as to allow me to phrase a new question, as my original problem still exists. :/ I am ...
3
votes
1answer
135 views

How to write drivers to be copied and pasted between objects' modifiers?

I have assigned a script-expression driver to a field in a modifier. The expression is a function of properties of the object to which the modifier is assigned, extracted as Single Property variables. ...
2
votes
1answer
289 views

Animating a rolling square wheel effect

I basically want the effect shown in the linked gif, like a cube that roles on the floor and doesn't clip the surface as it moves forward, like a rotating square wheel I can do the automatic rotation ...
1
vote
2answers
850 views

How to set driver distance max and min influence?

I have drivers set up between two Empties as an experiment (before I move on to more complex endeavors), and I want the scale of one Empty to be controlled by the distance between it and the other ...
4
votes
2answers
610 views

controlling speed of an action by driver or scripting

I'm scripting some crowd animation. I was searching about a way to control action speed by a driver or keys. Is there is some attribute for action speed that can be controlled? Something I can access ...
3
votes
1answer
208 views

add driver to Scene.current_frame?

Is it possible to add driver to Scene.current_frame so that one scene's current frame can drive other scene's? If not is there a way to link them continuously? ...
2
votes
2answers
336 views

Which operations are expecting input in radians and which in degrees?

Triggered by this question (unfortunately the OP didn't elaborate on the context), I'm puzzled now: which operations are done in radians and which in degrees? In the 3d window all navigation is in ...
2
votes
2answers
10k views

Blender 2.8 Beta: OpenGL 3.3 Error?

Before I start, YES, I have done my own research - I know how annoying a repeat question is. Yet each answer is so specific to others... When I tried the beta 2.8 64 bit, it says "Blender requires a ...
6
votes
2answers
5k views

Adding Other types of Custom Properties

I'm starting to use the amazing, yet simple to use Blender Drivers: I'm looking for a way to add other Types of Custom Properties than the default floats. For instance: Color, Vector, String, ...
4
votes
1answer
3k views

How to put together a driver with python

I'm trying to write a script to create the beginnings of a music visualizer but I'm having a hard time creating drivers to do it. My basic game plan is this: Calculate frequencies and step sizes For ...
9
votes
1answer
9k views

Python auto-execution disabled error [duplicate]

I'm getting this error often, and I'm fairly new to blender and I'm not sure if this is the same thing as the Auto-run disabled issue, but I can't finish my project with this error in the way. It ...
5
votes
1answer
2k views

Other possible expressions like #frame

I have learned a few minutes ago that you can type # into a numbutton to create a driver. So far the only value I know is frame. While this works nicely, it's still a bit limiting. What are the other ...
4
votes
1answer
763 views

add driver for a shapekey via python?

how can i add a driver for a shapekey via python? shape_keys.animation_data.driver_button_add(True) or ...
4
votes
1answer
240 views

Driver based on Render Layer

I want to drive a property in a Cycles material based on the current Render Layer or Scene being rendered. Is there any such property? If not, is this something that could be made as an addon, or is ...
4
votes
2answers
1k views

How to get a property value not in current frame?

I'm trying to make a driver which gets a property value not in current frame, but frame+2 for example. How I can do that?
4
votes
4answers
2k views

How do I create a driver with a random value and apply that driver to multiple objects?

I have a few rocks in my scene. Lets say the scene is in space and I want to add some random rotation to the rocks. Since there are a few of them, I don#t want to go to every rocks properties and ...
3
votes
2answers
2k views

Setting sun direction on sky texture with an empty

I am trying to control the direction of the sun on sky texture with an empty, I set the direction of the sun controllable by the rotation of the empty with drivers, each axis corresponding to the XYZ ...
2
votes
1answer
582 views

How to make an animated survey graph?

I try to make an animated graph like the one below (the value changes according to the post's lenght). I need about ten poles to be animated. I suppose that using drivers may be a good solution, but I ...
2
votes
1answer
51 views

What is the “standard 3-rig setup”?

The comment on this ticket states that lagging from cyclic constraints can be solved be using the 'the standard "3-rig" setup'. What is the specific setup this is referring to? Is it still considered ...
2
votes
2answers
994 views

How can I add drivers for custom properties?

Suppose that obj is a object. If I want to add a driver for its scale X, I can do d = obj.driver_add("scale", 0).driver but ...
2
votes
1answer
664 views

How to drive shape keys based on the angle between two bones?

My character rig needs shape key correctives when it makes certain poses (eg. lifting the arms, the shoulders need to be corrected with a shape key so they don't lose volume). I know you use a driver ...
2
votes
2answers
840 views

Making a shape key with a value that is the average of other shape keys

I have an object called "Template" and it has several shape keys, one of which is called "Speaking". Another is called "[AVERAGE]", which I want to be the value of the average of all its other shape ...
1
vote
1answer
319 views

Script not running as Handler or in Driver

Edit: DOWNLOAD DEMO BLEND FILE I am running into a weird issue that I have solved in the past but can't seem to figure out now. I have a material node keyframed in Blender Internal, and ...
1
vote
1answer
861 views

Simplest way to drive a pose bone's global location

When you drive a pose bone's location, you're actually driving its local, rather than global location (I guess that's true for any location, but still worth mentioning). I've been trying to find the ...
1
vote
1answer
91 views

Getting bpy.ops.anim.copy_driver_button() working

I am trying to copy the following driver in the Shape Keys section under Properties/Data: Look at the image below When I right click it and go to copy driver it works, and it shows the command to be ...
0
votes
1answer
503 views

How to get a list of Drivers used in certain bone

I would like to know how to get a list of drivers used in a certain bone. like how many and what type and what kind of variables it's using. I know I need to use bpy.context.object.animation_data....