diff --git a/examples/environment/src/main.rs b/examples/environment/src/main.rs
index e24e5d91..fb006268 100644
--- a/examples/environment/src/main.rs
+++ b/examples/environment/src/main.rs
@@ -72,6 +72,7 @@ pub async fn run() {
 
     // main loop
     let mut color = [1.0; 4];
+    let mut show_debug = false;
     window.render_loop(move |mut frame_input| {
         let mut panel_width = 0.0;
         gui.update(
@@ -83,6 +84,7 @@ pub async fn run() {
                 use three_d::egui::*;
                 Panel::left("side_panel").show_inside(ui, |ui| {
                     ui.heading("Debug Panel");
+                    ui.checkbox(&mut show_debug, "Show debug");
 
                     ui.label("Material");
                     ui.add(Slider::new(&mut model.material.metallic, 0.0..=1.0).text("Metallic"));
@@ -186,6 +188,79 @@ pub async fn run() {
             .write(|| gui.render())
             .unwrap();
 
+        if show_debug {
+            let secondary_viewport = Viewport {
+                x: viewport.x,
+                y: viewport.y,
+                width: (200.0 * frame_input.device_pixel_ratio) as u32,
+                height: (100.0 * frame_input.device_pixel_ratio) as u32,
+            };
+            camera.set_viewport(secondary_viewport);
+            frame_input.screen().apply_screen_effect(
+                &CopyEffect::default(),
+                &camera,
+                &[],
+                Some(ColorTexture::CubeMap {
+                    texture: skybox.texture(),
+                    sides: &[],
+                }),
+                None,
+            );
+
+            let secondary_viewport = Viewport {
+                x: viewport.x,
+                y: viewport.y + (100.0 * frame_input.device_pixel_ratio) as i32,
+                width: (200.0 * frame_input.device_pixel_ratio) as u32,
+                height: (100.0 * frame_input.device_pixel_ratio) as u32,
+            };
+            camera.set_viewport(secondary_viewport);
+            frame_input.screen().apply_screen_effect(
+                &CopyEffect::default(),
+                &camera,
+                &[],
+                Some(ColorTexture::CubeMap {
+                    texture: &light.environment.as_ref().unwrap().prefilter_map,
+                    sides: &[],
+                }),
+                None,
+            );
+
+            let secondary_viewport = Viewport {
+                x: viewport.x,
+                y: viewport.y + (200.0 * frame_input.device_pixel_ratio) as i32,
+                width: (200.0 * frame_input.device_pixel_ratio) as u32,
+                height: (100.0 * frame_input.device_pixel_ratio) as u32,
+            };
+            camera.set_viewport(secondary_viewport);
+            frame_input.screen().apply_screen_effect(
+                &CopyEffect::default(),
+                &camera,
+                &[],
+                Some(ColorTexture::CubeMap {
+                    texture: &light.environment.as_ref().unwrap().irradiance_map,
+                    sides: &[],
+                }),
+                None,
+            );
+
+            let secondary_viewport = Viewport {
+                x: viewport.x,
+                y: viewport.y + (300.0 * frame_input.device_pixel_ratio) as i32,
+                width: (200.0 * frame_input.device_pixel_ratio) as u32,
+                height: (200.0 * frame_input.device_pixel_ratio) as u32,
+            };
+            camera.set_viewport(secondary_viewport);
+            frame_input.screen().apply_screen_effect(
+                &CopyEffect::default(),
+                &camera,
+                &[],
+                Some(ColorTexture::Single(
+                    &light.environment.as_ref().unwrap().brdf_map,
+                )),
+                None,
+            );
+        }
+
         FrameOutput::default()
     });
 }
diff --git a/src/core/texture.rs b/src/core/texture.rs
index c8c17c8f..2f9365b2 100644
--- a/src/core/texture.rs
+++ b/src/core/texture.rs
@@ -137,7 +137,21 @@ impl ColorTexture<'_> {
                     return texture(colorMap, vec3(uv, colorLayers[index]));
                 }"
             .to_owned(),
-            Self::CubeMap { .. } => todo!(),
+            // Equirectangular projection
+            // SOURCE: https://stackoverflow.com/a/57544913
+            Self::CubeMap { .. } => "
+                #define PI 3.1415926
+                uniform samplerCube cubeMap;
+                vec4 sample_color(vec2 uv) {
+                    float phi=uv.s*PI*2;
+                    float theta=(uv.t-0.5)*PI;
+
+                    vec3 dir = vec3(cos(phi)*cos(theta),sin(theta),sin(phi)*cos(theta));
+
+                    return texture(cubeMap, dir);
+                }
+            "
+            .to_owned(),
         }
     }
 
@@ -148,9 +162,7 @@ impl ColorTexture<'_> {
         match self {
             Self::Single { .. } => 1u16 << 3,
             Self::Array { .. } => 10u16 << 3,
-            Self::CubeMap { .. } => {
-                todo!()
-            }
+            Self::CubeMap { .. } => 100u16 << 3,
         }
     }
 
@@ -169,7 +181,7 @@ impl ColorTexture<'_> {
                 program.use_uniform_array("colorLayers", &la);
                 program.use_texture_array("colorMap", texture);
             }
-            Self::CubeMap { .. } => todo!(),
+            Self::CubeMap { texture, .. } => program.use_texture_cube("cubeMap", texture),
         }
     }
 }