Fake shadow


I’m developing a helicopter game for android platform. As shadow casting makes the FPS going close to 0 for most of the android devices, I got the idea to simulate the helicopter shadow with a plane fitted with a transparent texture. The shadow is really needed so that the player can easily get an idea of his height above the ground.
So far, it works perfectly, but now, I would like to animate the shadow texture to match with the main rotor rotation speed (or at least give the feeling that the shadow is consistent with the rotor speed).

Up to now, I’m using a material based on “unshaded” for saving FPS…

What’s the best way to animate this kind of texture…

PS: I do not know anything in shaders, but I can learn fast if shader is the solution!

Thanks for your support

Take a look at the particle material, it uses a shader that loops over supparts of it, then you can use something similar in a own shader.

Depends on what the texture looks like, but I would just make the quad/plane that the texture is on rotate around the y axis at the same speed as the rotor.

Waow… It’s a bit more complex than I could imagine… I think I have to study more about shaders to get a better understanding of what is possible to do… I guess that bluring the image is also possible and that would look perfect…

Do you really need the shadow to be accurate?
Can’t you just have a blurry round shadow? That’s pretty common and it gives the impression of height you want

I do not need an extreme accuracy because I would like to blur it, but at least I want it to be animated to be consistent with the rotor motion… Fixed shadow can be acceptable for a fixed wing, but for a helicopter it looks strange!