Bulk update nvpro-samples 05/17/21

Changing license from BSD-3 to Apache2

ray_tracing_specialization/shaders/wavefront.glsl

@@ -0,0 +1,77 @@
+/*
+ * Copyright (c) 2019-2021, NVIDIA CORPORATION.  All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-FileCopyrightText: Copyright (c) 2019-2021 NVIDIA CORPORATION
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+struct Vertex
+{
+  vec3 pos;
+  vec3 nrm;
+  vec3 color;
+  vec2 texCoord;
+};
+
+struct WaveFrontMaterial
+{
+  vec3  ambient;
+  vec3  diffuse;
+  vec3  specular;
+  vec3  transmittance;
+  vec3  emission;
+  float shininess;
+  float ior;       // index of refraction
+  float dissolve;  // 1 == opaque; 0 == fully transparent
+  int   illum;     // illumination model (see http://www.fileformat.info/format/material/)
+  int   textureId;
+};
+
+struct sceneDesc
+{
+  int  objId;
+  int  txtOffset;
+  mat4 transfo;
+  mat4 transfoIT;
+};
+
+
+vec3 computeDiffuse(WaveFrontMaterial mat, vec3 lightDir, vec3 normal)
+{
+  // Lambertian
+  float dotNL = max(dot(normal, lightDir), 0.0);
+  vec3  c     = mat.diffuse * dotNL;
+  if(mat.illum >= 1)
+    c += mat.ambient;
+  return c;
+}
+
+vec3 computeSpecular(WaveFrontMaterial mat, vec3 viewDir, vec3 lightDir, vec3 normal)
+{
+  if(mat.illum < 2)
+    return vec3(0);
+
+  // Compute specular only if not in shadow
+  const float kPi        = 3.14159265;
+  const float kShininess = max(mat.shininess, 4.0);
+
+  // Specular
+  const float kEnergyConservation = (2.0 + kShininess) / (2.0 * kPi);
+  vec3        V                   = normalize(-viewDir);
+  vec3        R                   = reflect(-lightDir, normal);
+  float       specular            = kEnergyConservation * pow(max(dot(V, R), 0.0), kShininess);
+
+  return vec3(mat.specular * specular);
+}