For an animation project I'm working on, some vehicles with a warning light - these plastic ones with a rotating mirror inside which you can find on top of police cars, firefighter trucks (blue) or excavators and construction trucks (orange).
Some time ago I read a question (I am not sure if it was on stack exchange or somewhere else) where someone wanted to create glowing buttons. The answer which was given to him was something like "cycles is a physically-based renderer, so try to model like in the real world". So the solution for that was to model a button and put an object emitting light below.
With that answer in mind, I modeled the light as it looks like in the real world. A basic plastic casing with a separate transparent part (Glass BSDF), the mirror (Glossy BSDF) and a kind of light bulb (Emission). So far so good. The problem with that is, you need an unreasonable number of samples to make it look alright. You can have a look on my results below.
This example scene has only ~1500 verts and the same for the faces. The vehicles I made have up to 80k faces and there is also a landscape around.
My question is: Is there a better way (in terms of rendering time) to achieve the same or a similar effect?
Thanks in advance nioerd
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An image how the scene looks like with the changes suggested by pycoder (change the glass material of the bulb and the hull to a material which is only viewable for the camera)
I can't see any real difference between my first try and the suggestion by pycoder, except that there is no illumination from inside the hull. Even the time needed for rendering does not realy changed. Did i do something wrong?
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Added the model to download via blend-exchange.