“Yeah It’s on. ”
前言
用GLSL实现了简单的linear fog. exp fog ect.待后续加入…
正文
首先vert shader 计算出每个点到视点距离，我是在视图坐标系下计算的:
uniform int useFog;
out float vs_fs_distance;
if(useFog == 1)
{
vec4 mvPosition = view_matrix * model_matrix * position;
vs_fs_distance = sqrt(mvPosition.x * mvPosition.x + mvPosition.y * mvPosition.y + mvPosition.z * mvPosition.z);
}
然后frag shader 根据距离计算出雾的权重对目标颜色和雾颜色进行线性插值:
uniform int useFog;
uniform int fogType;
uniform vec3 fogColor;
uniform float fogStart;
uniform float fogEnd;
in float vs_fs_distance;
if(useFog == 1)
{
// linear fog
if(fogType == 0)
{
vec4 _fogColor = vec4(fogColor, 1.0);
float fog = (vs_fs_distance - fogStart)/fogEnd;
fog = clamp(fog, 0.0, 1.0);
fColor = mix(fColor, _fogColor, fog);
}
}
对比效果如下:
具体代码在此
