Blender Stack Exchange
Blender Stack Exchange

Questions tagged [drivers]

Blender drivers are a way to control values of properties by means of a function, or a mathematical expression. Use this tag for questions about Blender drivers.

The Blender manual describes drivers thusly:

Drivers are a way to control values of properties by means of a function, or a mathematical expression.

Effectively, drivers consist of:

  • A driver configuration that specifies zero, one, or more input values using other properties or object transformation channels, and combines them using a predefined mathematical function or a custom Python expression.

  • An animation F-Curve that maps the output of the driver configuration to the final value to apply to the driven property.

898 questions
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How can a blender driver python script access scene properties like FPS?

I would like to be able to access properties of the current scene such as render.fps, frame_start, and frame_end from within a python driver script. I have some data that is defined in terms of seconds, and I'd like the drivers consuming that data…
Mutant Bob
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Why can't I "Copy a Data Path"?

I'm sorry this question won't be very clear but i really can't understand why i can't "Copy Data Path". I can't even select him although i correctly paste data before. What could be wrong??
Fuboski
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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 Dope Sheet is later on, but for now, I wondered…
Cubit
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How can I get a random number that is constant per object in a driver?

I would like a driver that gives different result when duplicating the object but stays constant on frame update, transformations, etc... noise.random gets updated on frame change. I thought about using the object Id…
matali
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Drive Objects Rotation depending on state of other objects sin and cos value

I started to get into Drives. I want one cube(green) to rotate 90° whenever the other cube(red) is doing it's last 90° turn on the way to the full 360°. Now i've come up with following Logic depending on the red cubes rotation(rot). [when sin(rot)<0…
Järv
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How can I use a driver for multiple objects?

I made this little easy animation where a barrier opens automatically, if the car is near enough. I realized it with a distance driver. Link: https://youtu.be/s78ClbPBHNM Now I would like to add another car, where the barrier should open too. Is…
Chris
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How to update the dependencies of a driver via python script?

i need to be able to update the dependencies of my drivers via script, does anyone knows how to? thank you very much in advance! my script works on changing the values of the drivers , but sometimes i may need to update import bpy import random #…
Francesco Shanigawe Kobane
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adding a delay for a driver

I have a driver on a keyshape which is controlled by an object moving in the scene. I would like to add a 5 frame delay so the keyshape changes are delayed by X frames. I am using scripted expression currently it has (var+2.73)*.1 so if its possible…
ToxsickcitY
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How do I make a driver alway move forward even if the source moves backwards?

How do I make a "driver" that works like this? If I move object1 +X forward, then object 2 +X going forward, but if I move object1 -X backwards, also object2 +X going forward.
Norbert Farkas
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Get object data for previous frame in driver?

In blender drivers, you can access a property value on the current frame through a var. How can a value on a past/previous frame be accessed?
GiantCowFilms
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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 trying to apply a driver to the Y Location of a…
Dan Bennett
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How can I set a Shape Key value to be a driver's variable?

I want a Shape Key's value to be driven by another shape key. But I don't know how to add a shape key value as a variable into a driver. I've selected single property and tried with Object or Mesh types. Do I need to select another one?
Antonio Buch
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what "hashtag variables" are allowed as driver values?

I've found some people mention that almost any blender value can have the magic value "#frame" to use the current frame number as the value. for example, change an object's X location to '#frame/100" and it will rapidly fly away when walking through…
ThorSummoner
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Beginner issue with getting a Driver to refer to "self" so I can link it to many objects

I'm trying to get an object to scale with its distance to another object, so I can then link the driver to the rest of the 639 objects in the collection. I need it to somehow refer to itself, rather than explicitly selecting the object, so that…
Stage
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How to set up a driver to change value from zero to one every frame

I want to figure out how to set up up drivers that alternate from zero to one every frame. Id also love to know how to do it if i wanted to alternate every 4 frames or possibly value 1 for 4 frames and value 0 for 2 frames or so. These are the types…
Abdarahman Asif
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