Add environment light intensity in GLSL

libraries/pbrlib/genglsl/lib/mx_microfacet_specular.glsl

@@ -495,7 +495,7 @@ vec3 mx_latlong_map_lookup(vec3 dir, mat4 transform, float lod, sampler2D envSam
 {
     vec3 envDir = normalize((transform * vec4(dir,0.0)).xyz);
     vec2 uv = mx_latlong_projection(envDir);
-    return textureLod(envSampler, uv, lod).rgb;
+    return textureLod(envSampler, uv, lod).rgb * $envLightIntensity;
 }
 
 // Return the mip level with the appropriate coverage for a filtered importance sample.

resources/Lights/environment_map.mtlx

@@ -46,7 +46,12 @@
       <input name="filtertype" type="string" value="linear" />
     </image>
 
+    <multiply name="envImageAdjusted" type="color3">
+      <input name="in1" type="color3" nodename="envImage" />
+      <input name="in2" type="float" value="1.0" />
+    </multiply>
+
     <!-- Return the resulting color -->
-    <output name="out" type="color3" nodename="envImage" />
+    <output name="out" type="color3" nodename="envImageAdjusted" />
   </nodegraph>
 </materialx>

source/MaterialXGenShader/HwShaderGenerator.cpp

@@ -77,6 +77,7 @@ const string T_ENV_RADIANCE                   = "$envRadiance";
 const string T_ENV_RADIANCE_MIPS              = "$envRadianceMips";
 const string T_ENV_RADIANCE_SAMPLES           = "$envRadianceSamples";
 const string T_ENV_IRRADIANCE                 = "$envIrradiance";
+const string T_ENV_LIGHT_INTENSITY            = "$envLightIntensity";
 const string T_ENV_PREFILTER_MIP              = "$envPrefilterMip";
 const string T_REFRACTION_TWO_SIDED           = "$refractionTwoSided";
 const string T_ALBEDO_TABLE                   = "$albedoTable";
@@ -132,6 +133,7 @@ const string ENV_RADIANCE                     = "u_envRadiance";
 const string ENV_RADIANCE_MIPS                = "u_envRadianceMips";
 const string ENV_RADIANCE_SAMPLES             = "u_envRadianceSamples";
 const string ENV_IRRADIANCE                   = "u_envIrradiance";
+const string ENV_LIGHT_INTENSITY              = "u_envLightIntensity";
 const string ENV_PREFILTER_MIP                = "u_envPrefilterMip";
 const string REFRACTION_TWO_SIDED             = "u_refractionTwoSided";
 const string ALBEDO_TABLE                     = "u_albedoTable";
@@ -233,6 +235,7 @@ HwShaderGenerator::HwShaderGenerator(SyntaxPtr syntax) :
     _tokenSubstitutions[HW::T_ENV_RADIANCE_MIPS] = HW::ENV_RADIANCE_MIPS;
     _tokenSubstitutions[HW::T_ENV_RADIANCE_SAMPLES] = HW::ENV_RADIANCE_SAMPLES;
     _tokenSubstitutions[HW::T_ENV_IRRADIANCE] = HW::ENV_IRRADIANCE;
+    _tokenSubstitutions[HW::T_ENV_LIGHT_INTENSITY] = HW::ENV_LIGHT_INTENSITY;
     _tokenSubstitutions[HW::T_REFRACTION_TWO_SIDED] = HW::REFRACTION_TWO_SIDED;
     _tokenSubstitutions[HW::T_ALBEDO_TABLE] = HW::ALBEDO_TABLE;
     _tokenSubstitutions[HW::T_ALBEDO_TABLE_SIZE] = HW::ALBEDO_TABLE_SIZE;
@@ -366,6 +369,7 @@ ShaderPtr HwShaderGenerator::createShader(const string& name, ElementPtr element
         const Matrix44 yRotationPI = Matrix44::createScale(Vector3(-1, 1, -1));
         psPrivateUniforms->add(Type::MATRIX44, HW::T_ENV_MATRIX, Value::createValue(yRotationPI));
         psPrivateUniforms->add(Type::FILENAME, HW::T_ENV_RADIANCE);
+        psPrivateUniforms->add(Type::FLOAT, HW::T_ENV_LIGHT_INTENSITY, Value::createValue(1.0f));
         psPrivateUniforms->add(Type::INTEGER, HW::T_ENV_RADIANCE_MIPS, Value::createValue<int>(1));
         psPrivateUniforms->add(Type::INTEGER, HW::T_ENV_RADIANCE_SAMPLES, Value::createValue<int>(16));
         psPrivateUniforms->add(Type::FILENAME, HW::T_ENV_IRRADIANCE);
@@ -384,6 +388,7 @@ ShaderPtr HwShaderGenerator::createShader(const string& name, ElementPtr element
     if (context.getOptions().hwWriteEnvPrefilter)
     {
         psPrivateUniforms->add(Type::FILENAME, HW::T_ENV_RADIANCE);
+        psPrivateUniforms->add(Type::FLOAT, HW::T_ENV_LIGHT_INTENSITY, Value::createValue(1.0f));
         psPrivateUniforms->add(Type::INTEGER, HW::T_ENV_PREFILTER_MIP, Value::createValue<int>(1));
         const Matrix44 yRotationPI = Matrix44::createScale(Vector3(-1, 1, -1));
         psPrivateUniforms->add(Type::MATRIX44, HW::T_ENV_MATRIX, Value::createValue(yRotationPI));

source/MaterialXGenShader/HwShaderGenerator.h

@@ -71,6 +71,7 @@ Uniform variables :
     $envMatrix                          u_envMatrix                         mat4       Rotation matrix for the environment.
     $envIrradiance                      u_envIrradiance                     sampler2D  Sampler for the texture used for diffuse environment lighting.
     $envRadiance                        u_envRadiance                       sampler2D  Sampler for the texture used for specular environment lighting.
+    $envLightIntensity                  u_envLightIntensity                 float      Linear multiplier for environment lighting
     $envRadianceMips                    u_envRadianceMips                   int        Number of mipmaps used on the specular environment texture.
     $envRadianceSamples                 u_envRadianceSamples                int        Samples to use if Filtered Importance Sampling is used for specular environment lighting.
 
@@ -126,6 +127,7 @@ extern MX_GENSHADER_API const string T_ENV_RADIANCE;
 extern MX_GENSHADER_API const string T_ENV_RADIANCE_MIPS;
 extern MX_GENSHADER_API const string T_ENV_RADIANCE_SAMPLES;
 extern MX_GENSHADER_API const string T_ENV_IRRADIANCE;
+extern MX_GENSHADER_API const string T_ENV_LIGHT_INTENSITY;
 extern MX_GENSHADER_API const string T_ENV_PREFILTER_MIP;
 extern MX_GENSHADER_API const string T_REFRACTION_TWO_SIDED;
 extern MX_GENSHADER_API const string T_ALBEDO_TABLE;
@@ -183,6 +185,7 @@ extern MX_GENSHADER_API const string ENV_RADIANCE;
 extern MX_GENSHADER_API const string ENV_RADIANCE_MIPS;
 extern MX_GENSHADER_API const string ENV_RADIANCE_SAMPLES;
 extern MX_GENSHADER_API const string ENV_IRRADIANCE;
+extern MX_GENSHADER_API const string ENV_LIGHT_INTENSITY;
 extern MX_GENSHADER_API const string ENV_PREFILTER_MIP;
 extern MX_GENSHADER_API const string REFRACTION_TWO_SIDED;
 extern MX_GENSHADER_API const string ALBEDO_TABLE;

source/MaterialXRender/LightHandler.h

@@ -38,6 +38,7 @@ class MX_RENDER_API LightHandler
         _directLighting(true),
         _indirectLighting(true),
         _usePrefilteredMap(false),
+        _envLightIntensity(1.0f),
         _envSampleCount(DEFAULT_ENV_SAMPLE_COUNT),
         _refractionTwoSided(false)
     {
@@ -150,6 +151,18 @@ class MX_RENDER_API LightHandler
         return _envSampleCount;
     }
 
+    /// Set the environment light intensity.
+    void setEnvLightIntensity(const float intensity)
+    {
+        _envLightIntensity = intensity;
+    }
+
+    /// Return the environment light intensity.
+    float getEnvLightIntensity()
+    {
+        return _envLightIntensity;
+    }
+
     /// Set the two-sided refraction property.
     void setRefractionTwoSided(bool enable)
     {
@@ -246,6 +259,7 @@ class MX_RENDER_API LightHandler
     ImagePtr _envRadianceMap;
     ImagePtr _envPrefilteredMap;
     ImagePtr _envIrradianceMap;
+    float _envLightIntensity;
     int _envSampleCount;
 
     bool _refractionTwoSided;

source/MaterialXRenderGlsl/GlslProgram.cpp

@@ -578,6 +578,7 @@ void GlslProgram::bindLighting(LightHandlerPtr lightHandler, ImageHandlerPtr ima
     Matrix44 envRotation = Matrix44::createRotationY(PI) * lightHandler->getLightTransform().getTranspose();
     bindUniform(HW::ENV_MATRIX, Value::createValue(envRotation), false);
     bindUniform(HW::ENV_RADIANCE_SAMPLES, Value::createValue(lightHandler->getEnvSampleCount()), false);
+    bindUniform(HW::ENV_LIGHT_INTENSITY, Value::createValue(lightHandler->getEnvLightIntensity()), false);
     ImagePtr envRadiance = nullptr;
     if (lightHandler->getIndirectLighting())
     {

source/MaterialXRenderMsl/MslPipelineStateObject.mm

@@ -706,6 +706,7 @@ int GetStrideOfMetalType(MTLDataType type)
     Matrix44 envRotation = Matrix44::createRotationY(PI) * lightHandler->getLightTransform().getTranspose();
     bindUniform(HW::ENV_MATRIX, Value::createValue(envRotation), false);
     bindUniform(HW::ENV_RADIANCE_SAMPLES, Value::createValue(lightHandler->getEnvSampleCount()), false);
+    bindUniform(HW::ENV_LIGHT_INTENSITY, Value::createValue(lightHandler->getEnvLightIntensity()), false);
     ImageMap envLights =
     {
         { HW::ENV_RADIANCE, lightHandler->getEnvRadianceMap() },

source/MaterialXView/RenderPipelineGL.cpp

@@ -370,6 +370,9 @@ void GLRenderPipeline::renderFrame(void*, int shadowMapSize, const char* dirLigh
                 float longitudeOffset = (lightRotation / 360.0f) + 0.5f;
                 envMaterial->modifyUniform("longitude/in2", mx::Value::createValue(longitudeOffset));
 
+                // Apply light intensity to the environment shader.
+                envMaterial->modifyUniform("envImageAdjusted/in2", mx::Value::createValue(lightHandler->getEnvLightIntensity()));
+
                 // Render the environment mesh.
                 glDepthMask(GL_FALSE);
                 envMaterial->bindShader();

source/MaterialXView/Viewer.cpp

@@ -172,6 +172,7 @@ Viewer::Viewer(const std::string& materialFilename,
     _userCameraEnabled(true),
     _userTranslationActive(false),
     _lightRotation(0.0f),
+    _intensityMultiplier(1.0f),
     _normalizeEnvironment(false),
     _splitDirectLight(false),
     _generateReferenceIrradiance(false),
@@ -817,6 +818,22 @@ void Viewer::createAdvancedSettings(Widget* parent)
     });
     lightRotationBox->set_editable(true);
 
+    Widget* envLightIntensityRow = new Widget(advancedPopup);
+    envLightIntensityRow->set_layout(new ng::BoxLayout(ng::Orientation::Horizontal));
+    mx::UIProperties intensityUI;
+    intensityUI.uiSoftMin = mx::Value::createValue(0.0f);
+    intensityUI.uiSoftMax = mx::Value::createValue(10.0f);
+    intensityUI.uiStep = mx::Value::createValue(0.1f);
+
+    ng::FloatBox<float>* envIntensity = createFloatWidget(envLightIntensityRow, "Light Intensity:",
+        _intensityMultiplier, &intensityUI, [this](float value)
+    {
+        _intensityMultiplier = value;
+        _lightHandler->setEnvLightIntensity(_intensityMultiplier);
+    });
+    envIntensity->set_value(1.0);
+    envIntensity->set_editable(true);
+
     ng::Label* shadowingLabel = new ng::Label(advancedPopup, "Shadowing Options");
     shadowingLabel->set_font_size(20);
     shadowingLabel->set_font("sans-bold");

source/MaterialXView/Viewer.h

@@ -355,6 +355,7 @@ class Viewer : public ng::Screen
     mx::FilePath _lightRigFilename;
     mx::DocumentPtr _lightRigDoc;
     float _lightRotation;
+    float _intensityMultiplier;
 
     // Light processing options
     bool _normalizeEnvironment;