# Making a radio wave/transmission waves

I've been researching for a while now and I can't seem to find any way to make radio or transmission waves in blender.

I'm looking for an effect sort of like this, but coming from a point in the animation. I am using Cycles and I am trying to create an internet of things animation, but it is very hard to portray what is happening without waves.

I have already tried to use a particle system, but was unable to achieve this effect. Maybe something like this would work but I'm not sure how to do it without the plane still being there. I also don't have after effects so that isn't really an option for me.

Any help of ways to make waves or to portray them would be greatly appreciated! Thanks!

• What was the issue when you used the particle system? Commented Nov 17, 2016 at 18:25
• I couldn't figure out how to make the spheres I was using go outward in an expanding type fashion. Also I was unable to make the particles come out in waves at the same height. Commented Nov 17, 2016 at 18:34
• Do you, by any chance, have an image sequence of the waves coming out of the tower? Commented Nov 17, 2016 at 18:50
• I don't have an image sequence, but I could certainly make one if this is a good way to do it. Would a GIF work or does it have to be separate images? Commented Nov 17, 2016 at 18:53

I don't think particles are the way to go for this effect

If you are just looking for a 2D style animation you can easily do this with bezier curves and shapekyes or the offset property.

Just add a circle to your scene, duplicate it a few times (as many as desired) and scale them up a constant scale factor so they dist the same from each other.

Join them all into a single curve with Ctrl+J. Don't forget to apply the scale and reset all vertex radius into $1$ so they have the same weight.

Make all vertex handles type Free, then erase all segments leaving only a quarter circle. Rotate it $45º$ about the center and exit Edit Mode

Make a duplicate of your waves object for reference and make sure you add one additional wave outside the last one, again with the correct distance for snapping.

Now create two new shapekeys , one base and one for editing. In the editing one, scale all segments one by one so they reach exactly the one immediately after it with a bigger radius. Make sure you scale with pivot on the 3D Cursor (period key .) and that the cursor is correctly placed at the center of the wave emission.

Animate the effect by keyframing the Factor property of your shapekeys with the i key, then make sure the animation curve handle is set to vector in the Graph Editor so the animation is smooth and without discontinuities.

Now add bevels and materials as desired

If you want a similar effect but with a 3D appearance and volumetric shape, then replace the bezier curves by 3D mesh spheres.

Bonus point if add a material with a gradient from color to transparent so the curves fade in and out at the ends.

EDIT

I just found out a much easier way to achieve this, animate the Offset curve property instead, saves the trouble with all the shapekeys and scaling with references. Just create the concentric circles and join them together as before, but then just keyframe the Modification > Offset property instead.

Here is a bonus image with a possible node setup for the material. Add the gradient to transparency if you want it to fade away

• Every time I try and click <kbd>I</kbd> while hovered over my shape keys, it always tells me that the property cannot be animated. Any idea why? Commented Nov 17, 2016 at 20:18
• You have to animated by keyframing the Value property, bellow the list not the Shapekey itself. Commented Nov 18, 2016 at 2:00
• Actually I just found out a much easier way to achieve this animating the Offset curve property instead, updated answer above. Commented Nov 18, 2016 at 2:07
• Nice solution! Could you explain a little more why you used the mapping node with these scaling values? and what I'm really curious about: does these values affect render times? - can a normal or fresnel node work as well? Commented Nov 18, 2016 at 8:43
• The scaling value is used only to make the gradient match the size of my object in scene units. It is just an absolute value in Blender scene units, and will depend entirely on how big you built your object. Should have absolutely no effect in render times. Normal or Fresnel nodes would only work if the object had any 3D shape, in my case it is a flat 2D surface so no, it would not work here. In anyway those would not be able to make this fade to black effect at the edges since the gradient would be more curvature based, not position based. Commented Nov 18, 2016 at 14:42

I just finished with the particle implementation:

The trick is to use a texture for the animation of each particle:

I also added a simple material to demonstrate a way to fade out the rings over the particle's lifetime.

Here is the finished blend:

I was able to solve this using a particle system.

First, you need to add a UV sphere into your scene, go into edit mode, and delete all faces except for the center layer. The easiest way to do this is from the inside of the circle. Select all then shift click all the middle layer. It should look like an extruded circle once you have deleted the faces.

Then, delete the faces that you don't want to be emitting waves from.

You then need to create a new particle system. Set the start frame to whenever you want it to start and set the end frame to the frame after.

Set the amount of particles to 30. You can change this in order to change the 'density' of your waves.

Change the 'Emit From' setting to 'verts', and uncheck random.

Set the normal value to whatever you want the speed of your wave to be.

Create an object that will be emitted as the wave. I used a cube.

Under the 'Render' tab, uncheck emitter, and select object. Select the object you want to use. Set the size to whatever you want.

Under the 'Field Weights' tab, set gravity to 0.

Repeat this process with mutiple particle systems spaced a few frames apart to get a radio wave effect.

• Did you have any issues with my answer? It uses a particle system to get what your question said. Commented Nov 17, 2016 at 22:33
• @pycoder no, your answer is fine. I was also trying to come up with a solution and when I thought of it and it worked, I put it here. Commented Nov 18, 2016 at 2:03