# Blender 3D: Noob to Pro/Billboard Animation

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Billboard
visualization of particles - and especially their animation - is one of
the more arcane concepts in Blender. We\'re going to shed some light on
this. Billboard visualization is extremely powerful, everything that can
be done with a halo can also be done with a billboard. But billboards
are real objects, they are seen by raytracing, they appear behind
transparent objects, they may have an arbitrary form and receive light
and shadows. They are a bit more difficult to set up and take more
render time and resources.

*Billboards* are aligned square planes. If you move an aligned billboard
in a circle around an object, the billboards always faces the center of
the object. The size of the billboard is set with the Size of the
particle.

Texturing billboards is done by using uv coordinates that are generated
automatically for them.

-   The main thing to understand is that if the object doesn\'t have any
    UV Layers, you need to create at least one in the objects Editing
    buttons for any of these to work (**Img. 1a**).
-   Moreover, material should be set to UV coordinates in the Map Input
    panel (**Img. 1b**).

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framed\|**Image 1a:** UV coordinates for Billboard
textures

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framed\|**Image 1b:** UV coordinates as *Map
Input*

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## Splitting a texture

framed\|**Image 2a:** Billboard settings and texture for UV
split
The simplest thing we can do is to give every billboard its own fraction
of an image texture. We\'re going to use a simple image (**Img. 2a**,
right hand side) and split this in four parts (*UV Split* = 2,
horizontally and vertically).

-   Create the UV coordinates (simply click on *New* next to *UV
    Texture* in the *Mesh* panel).
-   Create a particle system.
-   Activate *Billboard* visualization.
-   Set *UV Split* to 2.
-   *Offset: Random* to randomly choose one of the images sections. None
    would give only the first of the four fields, so all billboards
    would be red, linear would first use red, then blue, then white and
    then yellow repeatedly.
-   Set *UV Channel* to *Split*. This creates the necessary UV
    coordinates, that are stored in the UV layer. If you use another UV
    channel, you need a second (or third) UV layer to store the
    coordinates (see below for an example).
-   Fill in the field *UV* with the name of the coordinate set (here
    \"UVTex\").

!**Image 2b:** UV Split for
Billboards{width="400"}

-   Now create a material for the particle emitter.
-   Add a texture if not there already.
-   Set *Map Input* to *UV*. If you only have one active *UV* layer this
    is used by default, but if you want to continue this tutorial you
    have to fill in the name of the UV set also (i.e. \"UVTex\").
-   Load the texture as Image texture.

Now every billboard gets a random section of the texture (see
**Img. 2b**). 

## Animating Alpha in relative particle time

framed\|**Image 3a:** Using an UV layer for time
animation
Now we\'re going to combine the texture split effect with an animation
of the billboard alpha. This is done in relative particle
time,
i.e. in the lifetime of each particle.

Billboard time is setup completely different than particle time.

-   Create a new UV layer (the second one). Name it \"UVTex.Blend\".
    Naming is not important here as long as it is unique.
-   Select the UV channel *Time-Index (X-Y)* in the *Visualization*
    panel of the particle system. Fill in the name of the newly created
    UV layer \"UVTex.Blend\". This creates an additional set of UV
    coordinates in this UV layer.

Now both UV layers with different UV coordinates will be used. The
material settings:

-   Activate *RayTransp* and *TraShadow*.
-   Add a second texture to your material.
-   *Map Input* also *UV*, but now use the UV layer \"UVTex.Blend\".
-   *Map To:*
    -   *Invert Alpha* and *Invert Spec*
    -   *No RGB* (since we\'re going to use a colorband texture)
    -   *DVar* = 0 to set Alpha to zero where the colorband is black.

This is one of the possible combinations for using a texture to make a
material transparent (**Img. 3b**), there are several other methods that
work as well.

framed\|none\|**Image 3b:** Material for the *Alpha* animation. This is
already the finished preview with the
texture.

**The texture is really the most important thing here.**

-   Use a linear *Blend* texture.
-   Activate *Colorband* for full control.

-   Adjust the colorband to your liking.

I\'ve mapped the texture so, that \"white\" means full opacity, black
full transparency. framed\|none\|**Image 3c:** Texture to control the
animation
time.

See this animation for the result of the
combined textures.

## Animating billboard color

!**Image 4a:** Animating Billboard color.
Animation{width="150"}
I will show here a second example for animating with a billboard
texture, because this is so important. We\'re going to change the color
during the lifetime of the billboard, but you can animate every property
that way that can be influenced by a texture. Additionally you can
animate the material itself, this is done in absolute time for
billboards. So you can mix relative and absolute time animations.

-   Open a new file.
-   Remove the cube and add a plane.
-   Add an UV layer to the plane
-   Add a particle system with *Billboard* visualization and *UV
    Channel* Time-Index. Fill in the name of the UV layer.

The particle life time is 50 frames.

-   Add a material to your plane.
    -   Basis color *Yellow*.
-   Use a linear blend texture. If you would use a color band here, you
    could create an even more colorful animation.
    -   *Map Input* UV
    -   Fill in the name of the UV layer.
    -   *Map To* *Col*. I\'ve used a dark blue color here.

Now the linear blend texture sets the amount of blue color that is mixed
to the basis color of the material.

-   At the left hand side the blend texture has a value of 0, so zero
    blue is mixed to the base color in the first frame of the particle
    lifetime.
-   At the right hand side the blend texture has a value of 1, so 100%
    blue is mixed to the base color in the last frame of the particle
    lifetime.

## Changing the starting color of a billboard

framed\|**Image 4b:** Flipped XY for the blend
texture
If you flip the Blend texture, you get a different effect. Now every
Billboard gets another starting color, but keeps that color during it\'s
lifetime.

Have I mentioned that you may use multiple textures on a billboard,
combining all effects?

