Make clouds use specific upscale filter, break cloud render over walls

shader/upscale/cloud.vert

@@ -0,0 +1,7 @@
+#version 450 core
+layout (std140, binding = 2) uniform PosTex { vec4 posTex[3]; };
+out vec2 vTexPos;
+void main() {
+  gl_Position = vec4(posTex[gl_VertexID].xy,0,1);
+  vTexPos = posTex[gl_VertexID].zw ;
+}