Calculating skybox in shader for world objects?

Hello guys,

I'm trying to create a vertical fog effect with 2-color gradient skybox. The current implementation is based on calculating the world position of a fragment and lerping its color to a fog color. It isn't good enough since I need this effect to work with the gradient skybox. So basically I need to render a skybox in world shader. Is there any efficient way to calculate the color of the skybox for the specific fragment to achieve the smooth color blending?

Current implementation:


Need something like that (edited in Photoshop)

 

Sure, especially if your skybox is as simple as a two color gradient. You just need to write a custom shader that does the same calculations as your skybox shader (which is likely a lerp based on the normalized world space view direction vector's Y) and use that for the fog color.

Are you using a custom shader already, or a built in shader with the shadows turned off?

 

Woah, thanks! View direction worked perfectly. Yes, I'm using a custom shader for this.

 

Hey, any code examples or tutorials how to achieve this effect? I am searching the whole internet...