working 6-stage fragments

shaders/frag4.glsl

@@ -0,0 +1,19 @@
+#version 460
+
+uniform float iTime;
+uniform vec2 iResolution;
+
+uniform sampler2D frame4;
+uniform sampler2D frame6;
+
+in vec2 vUV;
+layout(location = 6) out vec3 fragColor;
+
+// FX B
+// ---------
+// IN: 4 / 6
+// OUT: 6
+
+void main() {
+    fragColor = texture(frame4, vUV).xyz;
+}