Step 4: Adding foam and a rotating light to my lighthouse

Step 4: Adding foam and a rotating light to my lighthouse


Ok folks, I am becoming more in tune with Blender. It is complex, the interface is terrible… but man can I do things with it :)

Today I will show you how I:

  • added foam (simple),
  • added a ray of light coming from the lighthouse lamp (annoying)
  • made the light rotate (dammit!)


Foam is simply a variable on the ocean modifier that I used on the plane. Yep – that’s it. You can see a little check-box on the modifier panel below. How easy!

ocean settings

Volumetric light from the lighthouse lamp

OK – I’m being a show-off to those of you unfamiliar with techy type term. Volumetric light just means that you can see the rays. You know, like on those really cool days when rays of light drop down like columns between gaps in the clouds.

My dim dark secret is that this took me forever to work out, and heaps of YouTube tutorials later I finally smacked my head and went “Doh!”.

Fact 1 – should you decide to place a light in a cylinder, make sure that the cylinder is actually transparent! Yes, I’m officially a thick-head.

Fact 2 – (less embarrassing), you need to make sure that the atmosphere has some density to make these cones or columns of light appear. So go to the World settings and do the following:


It’s the Volume Scatter at the bottom, with a density of 0.005 that I found worked best for me.

Now here is a little tip. When I first rendered this I got a really grainy output:


This had me stumped. Without the light and the atmospheric density it looked good. Add light and suddenly I got this. Erk!

The answer is on the bottom right hand side of the screen shot. There is a variable group called Samples. See it? The Render defaults to 16. Nope – that’s no good. You need to crank it up. Here it is at 200.


Heaps better.

Rotating the lighthouse lamp

It took me two hours to figure out something that took about 30 seconds to actually do!!!

Now obviously this is an animation, so I used the frame-thingy at the bottom (yes, frame-thingy is a technical term… um…).


So if you look at the ruler-thingy (another technical term) at the bottom of the frame-thingy you can see the progression of frames. I have this set to 24 frames per second elsewhere in Blender (standard) and so my animation has 250 frames as you can see here. With my cursor set to Frame one, my lighthouse lamp object selected, I right click on the rotation Z field and select insert Keyframes.


I make sure it is set to 0.


Next I move along the frames on the ruler-thingy to the final frame and set this Z value to 360 (as in a full circle) and add it as a keyframe with a right click. So, if at the beginning of the animation the lamp has a rotating value of 0 degrees and at the end it has a rotating value of 360 degrees (and you have set keyframes at each point) the computer will figure out how far the light should be rotated for each frame in-between.

Yep – that’s it folks.

And the result of all this is:

It’s actually about 7 seconds played twice (hence a little bump in the middle).

So I am very excited with myself :)

Hope some of you got something out of this :)











  1. Impressive. Especially the use of the frame thingy and ruler thingy. I don’t use Blender and likely never will, but I utterly comprehend the how the **** does it work. Thanks to the gods whose names are youtube and google, you got there.


    1. Yes, I intend to become the thingy-master. I just hope I don’t overwhelm people with my technical jargon :) I know what you mean about Google and Youtube. I would not be able to do any of this without them. And I felt like giving up so many times. So many of the videos I watched where I just found myself going “huh?”. Mind you, I’m sure I am not any clearer than them. LOL. Thanks for reading and commenting :)


  2. I got left behind after the first sentence. Struggled through though and eventually reached the end enveloped in a dense fog. Enjoyed the read whilst blundering through after retracing the steps a few times.


    1. Thanks for struggling through and taking the time to comment ☺ One of the aims of my blog was to demonstrate that ordinary people (with enough patience and determination) can conquer computer graphics and create marvelous things. Alas as i continue on my own journey of discovery i get further away from that target audience Hopefully my own struggle with the technical aspects of this endeavor are visible ☺ Thanks for reading ☺


  3. Neat! Would you happen to know if the ocean shape can be exported as an OBJ?


    1. I’ll try that tonight ☺ (am eating my breakfast before going to work at the moment)


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