Do realtime refraction kinda.

1 files changed, 44 insertions, 1 deletions

diff --git a/resources/shaders/shader.vert b/resources/shaders/shader.vert
index 15e6833..90ebdf8 100755
--- a/resources/shaders/shader.vert
+++ b/resources/shaders/shader.vert
@@ -7,6 +7,8 @@ uniform mat4 proj;
 uniform mat4 view;
 uniform mat4 model;
 uniform mat4 inverseView;
+//uniform float width;
+//uniform float height; // TODO: Pass in width and height as uniform
 
 uniform mat3 inverseTransposeModel;
 
@@ -14,12 +16,53 @@ out vec3 normal_cameraSpace;
 out vec3 normal_worldSpace;
 out vec3 camera_worldSpace;
 out vec3 pos;
+out vec3 refrPos;
+out vec2 uv;
+
+vec3 getRefrPos() {
+    float depth = -1.f;
+    vec3 w_o = pos - camera_worldSpace;
+    float cos_theta_i = dot(-w_o, normal_worldSpace);
+    float n_i = 1;
+    float n_t = 1.33f;
+    float determinant = 1.f - (pow((n_i / n_t), 2.f) * (1.f - pow(cos_theta_i, 2.f)));
+
+    if (determinant >= 0) {
+        float cos_theta_t = sqrt(determinant);
+        vec3 w_t = (n_i / n_t) * w_o + ((n_i / n_t) * cos_theta_i - cos_theta_t) * normal_worldSpace;
+//        Ray reflectedRay(i.hit, w_t);
+//        float attenuation = (!entering && attenuateRefract) ? std::pow(M_E, (-(ray.o - i.hit).norm()) * mat.ior) : 1;
+//        L += traceRay(reflectedRay, scene, true, n_t, !is_in_refractor) * attenuation / threshold;
+        float dist = position.y - depth;
+        float depthScale = dist / w_t.y;
+        vec3 groundContactPoint = -(w_t * depthScale) + position;
+        return groundContactPoint;
+    } else {
+//        Eigen::Vector3f w_i = w_o - 2 * w_o.dot(intersectNormal) * incidenceNormal;
+//        Ray reflectedRay(i.hit, w_i);
+//        L += traceRay(reflectedRay, scene, true, current_ior, false) / threshold;
+        return vec3(0, 0, 0);
+    }
+}
 
 void main() {
+    float depth = -2.f;
+    float dist = position.y - depth;
+    float width = 81.f * 2.f;
+    float length = 81.f * 2.f;
+
     normal_cameraSpace = normalize(inverse(transpose(mat3(view))) * inverseTransposeModel * normal);
     camera_worldSpace = vec3(inverseView * vec4(0.f, 0.f, 0.f, 1.f));
     normal_worldSpace = normal;
-    pos = position;
+    pos = vec3(model * vec4(position, 1.f)); //vec3(model * vec4(objSpacePos, 1.f));
+//    pos = position;
+
+    float depthScale = dist / normal.y;
+    vec3 groundContactPoint = -(normal * depthScale) + position; // carries down to ground
+    groundContactPoint = vec3(model * vec4(position, 1));
+    uv = vec2((position.x + 81.f) / (162.f), groundContactPoint.z);
+//    uv = vec2(normal);
+    refrPos = getRefrPos();
 
     gl_Position = proj * view * model * vec4(position, 1);
 }