Add support for rim backlights

res/shaders/simple.frag

@@ -20,10 +20,12 @@ uniform mat4 MVnormal;
 // material
 uniform float opacity;
 uniform float shininess;
+uniform float backlight_strength;
 uniform float reflexiveness;
 uniform vec3 diffuse_color;
 uniform vec3 specular_color;
 uniform vec3 emissive_color;
+uniform vec3 backlight_color;
 
 uniform bool isIlluminated;
 uniform bool isTextured;
@@ -97,9 +99,7 @@ vec3 get_nnormal() {
     }
 }
 
-vec3 phong(vec3 basecolor) {
-    vec3 nnormal = get_nnormal(); // normalized normal
-
+vec3 phong(vec3 basecolor, vec3 nnormal) {
     vec3 diffuse_component  = vec3(0.0);
     vec3 specular_component = vec3(0.0);
 
@@ -139,16 +139,19 @@ vec3 phong(vec3 basecolor) {
 }
 
 void main() {
+    vec3 nnormal = get_nnormal(); // normalized normal
     vec4 c = vec4(vec3(1.0), opacity);
     if (isVertexColored)    c *= color;
     if (isTextured)         c *= texture(diffuseTexture, UV);
     if (isInverted)         c.rgb = 1 - c.rgb;
-    if (isIlluminated)      c.rgb = phong(c.rgb);
+    if (isIlluminated)      c.rgb = phong(c.rgb, nnormal);
     else {
         c.rgb *= diffuse_color;
         if (isReflectionMapped)
             c.rgb = reflection(c.rgb, normalize(normal));
     }
+    if (backlight_strength > 0.05)
+        c.rgb += backlight_color * clamp((dot(normalize(vertex), nnormal) + backlight_strength) / backlight_strength, 0, 1);
     //c.rgb = diffuse_color;
     //c.rgb = emissive_color;
     //c.rgb = specular_color;

src/renderlogic.cpp

@@ -190,8 +190,10 @@ void renderNode(SceneNode* node, Gloom::Shader* parent_shader, vector<NodeDistSh
                 u3fv (diffuse_color);
                 u3fv (emissive_color);
                 u3fv (specular_color);
+                u3fv (backlight_color);
                 u1f  (opacity);
                 u1f  (shininess);
+                u1f  (backlight_strength);
                 u1f  (reflexiveness);
                 u1f  (displacementCoefficient);
                 u1ui (isTextured);

src/scene.cpp

@@ -114,6 +114,7 @@ void init_scene(CommandLineOptions options) {
         //{12, Material().diffuse({1.0, 1.0, 1.0})},// License_Plate_Frame
         //{13, Material().diffuse({1.0, 1.0, 1.0})},// 
         });
+    carNode->setMaterial(Material().backlight(vec3(0.3), 0.3).backlight_only().no_texture_reset(), true);
     carNode->position = {500, 500, 100};
     carNode->scale *= 100;
     rootNode->children.push_back(carNode);

src/sceneGraph.cpp

@@ -66,6 +66,8 @@ void SceneNode::setMaterial(const Material& mat, bool recursive) {
 	if (!mat.ignore_emissive) emissive_color = mat.emissive_color;
 	if (!mat.ignore_specular) specular_color = mat.specular_color;
 	if (!mat.ignore_specular) shininess      = mat.shininess;
+	if (!mat.ignore_backlight)backlight_color= mat.backlight_color;
+	if (!mat.ignore_backlight)backlight_strength= mat.backlight_strength;
 	setTexture(
 		mat.diffuse_texture,
 		mat.normal_texture,

src/sceneGraph.hpp

@@ -71,10 +71,12 @@ struct SceneNode {
 	// textures and materials
 	float opacity = 1.0;
 	float shininess = 1.0; // specular power
+	float backlight_strength = 0.0;
 	float reflexiveness = 0.0; // 0 is no reflection, 1 is a mirror. Negative value will have it multiply with base instead
 	vec3 diffuse_color  = vec3(1.0);
 	vec3 emissive_color = vec3(0.5);
 	vec3 specular_color = vec3(0.2);
+	vec3 backlight_color = vec3(0.2);
 	vec2 uvOffset = vec2(0.0, 0.0); // specular power
 	uint diffuseTextureID;
 	uint normalTextureID;

src/utilities/material.cpp

@@ -12,6 +12,7 @@ Material Material::apply(const Material& other) const {
 	if (!other.ignore_diffuse)  out.ignore_diffuse  = false;
 	if (!other.ignore_emissive) out.ignore_emissive = false;
 	if (!other.ignore_specular) out.ignore_specular = false;
+	if (!other.ignore_backlight)out.ignore_backlight= false;
 	if (!other.texture_reset)   out.texture_reset   = true;
 	
 	if (other.texture_reset || other.diffuse_texture)      out.diffuse_texture      = other.diffuse_texture;
@@ -40,6 +41,12 @@ Material Material::emissive(glm::vec3 color) const {
 	out.emissive_color = color;
 	return out;
 }
+Material Material::backlight(glm::vec3 color, float strength) const {
+	Material out(*this);
+	out.backlight_color = color;
+	out.backlight_strength = strength;
+	return out;
+}
 Material Material::textured(PNGImage* diffuse) const {
 	Material out(*this);
 	out.diffuse_texture = diffuse;
@@ -76,6 +83,7 @@ Material Material::no_colors() const {
 	out.ignore_diffuse = true;
 	out.ignore_emissive = true;
 	out.ignore_specular = true;
+	out.ignore_backlight = true;
 	return out;
 }
 Material Material::no_diffuse() const {
@@ -93,12 +101,20 @@ Material Material::no_specular() const {
 	out.ignore_specular = true;
 	return out;
 }
+Material Material::no_backlight() const {
+	Material out(*this);
+	out.ignore_backlight = true;
+	return out;
+}
 Material Material::diffuse_only() const {
-	return this->no_emissive().no_specular();
+	return this->no_emissive().no_specular().no_backlight();
 }
 Material Material::emissive_only() const {
-	return this->no_diffuse().no_specular();
+	return this->no_diffuse().no_specular().no_backlight();
 }
 Material Material::specular_only() const {
-	return this->no_diffuse().no_emissive();
+	return this->no_diffuse().no_emissive().no_backlight();
+}
+Material Material::backlight_only() const {
+	return this->no_diffuse().no_emissive().no_specular();
 }

src/utilities/material.hpp

@@ -7,9 +7,11 @@ struct Material {
 	float opacity = 1.0;
 	float shininess = 1; // specular
 	float reflexiveness = 0;
+	float backlight_strength = 0;
 	glm::vec3 diffuse_color  = glm::vec3(1.0);
 	glm::vec3 emissive_color = glm::vec3(0.5);
 	glm::vec3 specular_color = glm::vec3(0.2);
+	glm::vec3 backlight_color= glm::vec3(0.0);
 	PNGImage* diffuse_texture      = nullptr;
 	PNGImage* normal_texture       = nullptr;
 	PNGImage* displacement_texture = nullptr;
@@ -18,6 +20,7 @@ struct Material {
 	bool ignore_diffuse  = false;
 	bool ignore_emissive = false;
 	bool ignore_specular = false;
+	bool ignore_backlight= false;
 	bool texture_reset = true;
 	
 	Material apply(const Material& other) const;
@@ -25,6 +28,7 @@ struct Material {
 	Material diffuse(glm::vec3 color) const;
 	Material specular(glm::vec3 color, float shininess) const;
 	Material emissive(glm::vec3 color) const;
+	Material backlight(glm::vec3 color, float strength) const;
 	Material textured(PNGImage* diffuse) const;
 	Material normal_mapped(PNGImage* normal) const;
 	Material diffuse_mapped(PNGImage* diffuse) const;
@@ -37,7 +41,9 @@ struct Material {
 	Material no_diffuse() const;
 	Material no_emissive() const;
 	Material no_specular() const;
-	Material diffuse_only() const; // and not the other two
-	Material emissive_only() const; // and not the other two
-	Material specular_only() const; // and not the other two
+	Material no_backlight() const;
+	Material diffuse_only() const; // and not the other three
+	Material emissive_only() const; // and not the other three
+	Material specular_only() const; // and not the other three
+	Material backlight_only() const; // and not the other three
 };