Star Dust Burst – Particles in Blender

Today we’ll be talking about particles in Blender. In this project I’ll be using the 2.90 version of Blender.

So, let’s get started. Here are the steps to follow:

Step 1 – Set the Render Engine and Create a UV Sphere

Let’s start by deleting the default cube and adding a UV Sphere (A). This is going to the star. In this tutorial we’ll be using the Cycles renderer because otherwise we wouldn’t be able to see the colors in the particles correctly. So, in the Render Properties tab (B) set the render engine to Cycles (C).

Step 2 – Add an Emission Material

Rename the UV Sphere ‘Star’ in the Outliner (A). In the Object menu select Shade Smooth (B). Then, in the Material Properties tab (C) set the shader type to Emission (D) and set the color to hex FF5E51 (E). To see how it looks, go to Rendered shading (F).

The star is going to be the emitter. It will emit the particles that will create the star dust.

Step 3 – Add an Ico Sphere

The star dust is going to consist of tiny ico spheres. So, let’s create an ico sphere (A) and without clicking anywhere else, let’s set its Subdivisions to 1 (B). This is because the geometry of a single dust grain should be as simple as possible. We’re going to use tens of thousands of such grains after all.

Step 4 – Scale Down the Grain of Dust

Move the ico sphere away from the star (G Y 15) and scale it down (S .15) (A). Rename the ico sphere ‘Dust’ in the Outliner.

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Step 5 – Move the Dust Grain to a New Collection

With Dust still selected hit M and then New to create a new collection. This is to keep the particle separate from the star. Name the collection Dust:

Step 6 – Add a Particle System

Select the emitter (A) and go to the Particle Properties tab (B). Hit the plus sign button (C) to create a new particle system, set the number of particles to 50,000 (D), Frame Start to 100 (E), End to 200 (F) and Lifetime to 100 (G). The particles are not going to be emitted from the very beginning of the animation, as you can see.

Step 7 – Select the Particle Object

We want the dust grains to be used as the particles. So, expand the Render section (A) in the Particle Properties tab and set Render As to Object (B). Then select Dust as the instance object (C):

Step 8 – Play the Animation with the Particles

Go to frame 1 if you’re not there and play the animation. After the first 100 frames the particles will appear and they will start falling down. This is because gravity pulls them down. This is not how we want it to work, though. We’re going to take care of it in a minute.

Step 9 – Animate the Emission Strength

Stop the animation and go back to frame 1 (A). Before we continue with the particles, let’s focus on the star for a while. During the first 100 frames, when there are no particles yet, the star will be getting ready for the burst of the star dust. We will make it change its emission intensity.

So, with the star selected, go to the Material Properties tab (B) and make sure Strength is set to 1 (C). Then hit the little diamond button (D) to insert a keyframe:

Step 10 – Add More Keyframes

We will need more keyframes, so insert some more at the following frames:

Here’s what it looks like in the Timeline:

Step 11 – Turn Off Gravity

Now, back to our particles. We don’t want to fall them down, so let’s turn off gravity. With the star selected go back to the Particle Properties tab (A) and under Field Weights (B) set Gravity to 0 (C):

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Step 12 – Randomize Particle Size

Let’s make the particles slightly bigger by setting Scale to .07 (A). Let’s also randomize their size so that they are not identical. You can do it by setting Scale Randomness to 1 (B):

Step 13 – Add Turbulence

We want the dust to swirl around the star, so let’s add some turbulence. Use the Shift + A shortcut to add Turbulence (A), which you will find under Force Field in the menu that pops up. Then, before clicking anywhere else, set its radius to 2 (B). If you now play the animation, they will be affected by the force field:

Step 14 – Make the Star Dust Swirl

With the Turbulence selected (A), go to the Physics Properties tab (B). Set Strength to 20 (C) and Flow to 5 (D). The Flow parameter will cause the particles to move in clusters, following one another, rather than individually in random directions:

Step 15 – Add an Emission Material to the Particles

Go to frame 227 (or any other near the end of the animation time). Select the Dust object in the Outliner (A) and switch to the Shading workspace (B). In the Shader editor below the 3D Viewport editor hit the New button to create a new material. Delete the Principled shader and add an Emission shader (C) instead. Plug it into the Output:

Step 16 – Add a Particle Info Input, a Math Converter and a ColorRamp Converter

Now we want the particles to change color as they travel away from the star surface and cool down. So, when they leave the surface of the star they should be light yellow, then they should change to red and finally to blue. Don’t worry if it doesn’t sound realistic to you, it’s not supposed to be scientifically accurate.

Switch to Rendered shading (A) if you haven’t done so yet. Add three more nodes, a Particle Info node from the Input menu (B), a Math node from the Converter menu (C) and a ColorRamp node from the Converter menu. Go ahead and add these three nodes. Connect Particle Info’s Age and Lifetime to Math’s Values and select the Divide operation (E). This will divide the age of a particle by its lifetime so that we know what percentage of its lifetime the particle has already traveled. Connect Math’s Value to the ColorRamp’s Fac. We’ll discuss the ColorRamp in a minute. Then connect ColorRamp’s Color to Emission’s Color and set the latter’s Strength to 15 (F):

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Step 17 – Play with the ColorRamp

The ColorRamp is the node that will take care of the colors of the particles. The color on the left will be applied to the particles that are new, the color on the right to the older ones. To see how it works, move the left slider to about the middle of the width (A). This way the border between new and old particles lies in the middle, so they are considered new for the first half of their lives and old afterward. You can see that they are black when they leave the surface of the star and then, more or less halfway their journey, they turn to white:

Step 18 – Set the Start Color

As you remember, the particles should be light yellow when they leave the star, then they should turn to red and finally, near the end of their journey, they should turn to blue. Let’s set the start color first and take care of the other two in a minute.

So, to set the first color, click on the left slider to select it and then click on the black area below. You can now see a color pick dialog where you can choose a color. Set the color to hex F8FF7D, which is a shade of yellow (A). Now you can see that the particles near the star are yellowish (B):

Step 19 – Set the End Color

Now select the right slider (A) and move it slightly to the left, so that the particles don’t turn blue at the very end of their lives, but a little earlier. Repeat the steps above and set the color to hex 2F39FF, which is a shade of blue. Now you can see that the particles farther away from the star are blue (B):

Step 20 – Add the Middle Color

To add another color we need another slider. Click on the plus sign to add one and make sure it’s between the two other ones. Set its color to hex CC3A42, which is a shade of red:

Step 21 – Adjust the Particle Colors

Now, depending on what effects we want to achieve, we can move the sliders and experiment. I want the particles to be yellow for a relatively short period of time, then transition through red to blue. You can set the positions of the sliders by selecting them one by one and typing in exact values. So, I set the position of the first slider to 300, the second to 400 and the third to 700. I like the effect, but if you don’t, you can try other positions or even other colors. Here’s what I got:

Step 22 – Set the World Color to Black

It will look even better if we set the background color to black. You can do it in the World Properties tab (A) by setting Color to black (B):

Step 23 – Align Camera to View

We’re done with the material. Go back to the Layout workspace and zoom out slightly so that you can see the star from a distance. If you like how it looks, align the camera to view by selecting going to the View menu, then Align View and selecting Align Active Camera to View. Alternatively you can use the Ctrl + Alt + Num0 shortcut:

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Step 24 – Hide the Original Ico Sphere

In the image above you can see the original ico sphere that we’re using for the particles. It’s on the left of the star. We don’t want to see it, so let’s turn off its visibility. In the Outliner, next to each object you can see a little eye icon. You can use it toggle the visibility of each object on and off. But the object will still be visible in the render. To prevent it from being visible in the render, click on the Filter drop-down (A) and click on the Disable in Renders button (shown below). Then the two icons, the eye (for visibility in the viewport) and the camera (for visibility in the render) will be visible in the Outliner. Turn them both off (B).

And here’s how you can find the Disable in Renders button. Just click on the Filter drop-down (A) and it’s the button with the camera icon near the top (B):

Step 25 – Set the Focal Point of the Camera

Now we’ll turn on the depth of field and set the camera’s focal point. So, objects near the focal point will look sharp and objects farther away from it will look blurrier. First, hit 0 on your numpad to go into camera view and select the camera in the Outliner (A). Then go to the Object Data Properties tab (B) and check Depth of Field (C). Under Focus Object select the Star (D) and under Aperture set F-Stop to 2 (E). Now the star and the dust that is near the star will be sharper than the dust which is farther away:

Step 26 – Render Settings

We’re almost ready to render. Just a few more settings. Go to the Render Properties tab (A) and set Device to GPU (B). If you don’t have a GPU, you can use CPU. Then, under Sampling, set Render to 256 (C):

Step 27 – Make a Test Render

Before we render the animation, let’s make a quick test render. Go to the Render menu and select Render Image. If you like the image that is rendered, you’re good to go. Close the image.

Step 28 – Output Settings

Before you render the animation, there are still some settings in the Output Properties tab (A). First of all, select a folder where you want to save your animation (B). Then set File Format to FFmpeg video (C) and under Encoding set Container to MPEG-4 (D):

Step 29 – Render the Animation

Now you can render your animation. Go to the Render menu and hit Render Animation. It will take a bit longer because we’re using Cycles and not Eevee, but it shouldn’t be too long. After the render has finished, play the animation, watch and enjoy.