Sun and Shadows

Various improvements to sun lighting have been introduced. The first of these improvements is in the azimuth and zenith of the sun's path throughout the day. Previously, the sun traveled along a path parallel to the world, leading to poor shading of block surfaces at nearly all times of the day. This directly led to poor visuals at noon, due to the apparent lack of shadows present. BetterRTX offsets the azimuth and zenith to avoid any situations where the sun is directly overhead. This is achieved through a matrix rotation of the directionToSun variable made available through the view buffer. The rotation is optionally invertible as it is used to change the direction of the sun's texture.

float3 rotateBySunAngle(float3 dir, bool inverse = false)
{
	float a = inverse ? -SUN_ZENITH : SUN_ZENITH;
	float b = inverse ? -SUN_AZIMUTH : SUN_AZIMUTH;
	matrix<float, 3, 3> zenith =
	{
		1.0, 0.0,     0.0,
		0.0, cos(a), -sin(a),
		0.0, sin(a),  cos(a),
	};
	matrix<float, 3, 3> azimuth =
	{
		 cos(b), 0.0,  sin(b),
		 0.0,    1.0,  0.0,
		-sin(b), 0.0,  cos(b),
	};
	return inverse ? mul(zenith, mul(azimuth, dir)) : mul(azimuth, mul(zenith, dir));
}

Sun shadow clarity has also been heavily improved, through both reducing the sun's sampling radius and improving shadow filtering behaviors.