Creating a shadow with a Sprite and change its tint or use shader?

[daniel_herzog]

Hi all,

these days I was reading about shader, fragments and materials, I wanted to create a shader that changes the screen darker making it so it feels darker.

Now I did not really know how to do it with a shader, I could practice a bit with the examples I found here, which yeah made me realise I will have to read more into OpenGL to really create a Shader. I was reading into it but I did not found away to make a vect4 transparent.

So i decided to create a GO with a sprite and add a black rectangle as sprite and changed its color with like this:

sprite.set_constant("shadow#sprite", "tint", vmath.vector4(1, 1, 1, 0.2))

Is this a viable way for this effect?
How would you do a shader on a quad thats screen size to make it have that effect?

[selimanac]

I’m not sure if I fully understand what you’re trying to do, but there might be several ways to approach it. There’s a good (though possibly a bit old) tutorial on color grading:

Grading shader tutorial

Or if you want something like this:

publicexamples/examples/simple_lights at master · britzl/publicexamples

How to make Simple Lighting in Defold? Screen Space Light Maps! #gamedev #tutorial #indiedev

More complex with shadows:

GitHub - defold/sample-lights-and-shadows: Example of how to achieve pixel perfect shadows in...

[daniel_herzog]

This would describe it the best:

Shaders are a game-changer!

I would like to have a full screen shader like these which makes everything darker. Like if i would put a black sprite over everything and change its “tint” to an alpha value of 0.4. This gives me the same effect basicly.

[selimanac]

@daniel_herzog

I would like to have a full screen shader like these which makes everything darker. Like if i would put a black sprite over everything and change its “tint” to an alpha value of 0.4. This gives me the same effect basicly.

This is exactly what color grading does. You can combine it with the first shadow tutorial

[daniel_herzog]

Ok thank you. i will have a look into it!

[robotiger]

I think for this simple effect don’t need to borher with shaders… For full screen effect you can use a GUI node and play with its color property - it’s a vector4 with ‘w’ component as alpha (opacity).

Maybe you have solved it already but it can help someone else.

[daniel_herzog]

Thanks yeah the GUI approach seems good for that. I did make a Gameobject instead of a GUI object with the same result. But yeah GUI makes more sense since it always will cover all. the Gameobject i had to add to the player.

Thanks.