highlight negative values in SH debug files

libs/ibl/include/ibl/CubemapUtils.h

@@ -78,6 +78,8 @@ public:
     //! clamps image to acceptable range
     static void clamp(Image& src);
 
+    static void highlight(Image& src);
+
     //! Downsamples a cubemap by helf in x and y using a box filter
     static void downsampleCubemapLevelBoxFilter(utils::JobSystem& js, Cubemap& dst, const Cubemap& src);
 

libs/ibl/src/CubemapUtils.cpp

@@ -57,6 +57,19 @@ void CubemapUtils::clamp(Image& src) {
     }
 }
 
+void CubemapUtils::highlight(Image& src) {
+    const size_t width = src.getWidth();
+    const size_t height = src.getHeight();
+    for (size_t y=0 ; y<height ; ++y) {
+        for (size_t x = 0; x < width; ++x) {
+            float3& c = *static_cast<float3*>(src.getPixelRef(x, y));
+            if (min(c) < 0.0f) {
+                c = { 1, 0, 1 };
+            }
+        }
+    }
+}
+
 void CubemapUtils::equirectangularToCubemap(JobSystem& js, Cubemap& dst, const Image& src) {
     const size_t width = src.getWidth();
     const size_t height = src.getHeight();

tools/cmgen/src/cmgen.cpp

@@ -745,6 +745,7 @@ void sphericalHarmonics(utils::JobSystem& js, const utils::Path& iname, const Cu
                 std::string basename = iname.getNameWithoutExtension();
                 utils::Path filePath =
                         outputDir + (basename + "_sh" + (g_sh_irradiance ? "_i" : "_r") + ".hdr");
+                CubemapUtils::highlight(image);
                 saveImage(filePath, ImageEncoder::Format::HDR, image, "");
             }
 
@@ -755,6 +756,7 @@ void sphericalHarmonics(utils::JobSystem& js, const utils::Path& iname, const Cu
                 std::string basename = iname.getNameWithoutExtension();
                 utils::Path filePath =
                         outputDir + (basename + "_sh" + (!g_sh_irradiance ? "_i" : "_r") + ".hdr");
+                CubemapUtils::highlight(image);
                 saveImage(filePath, ImageEncoder::Format::HDR, image, "");
             }
         }