add support for skeletal animation

Sandbox/assets/models/Plane1m.obj

@@ -0,0 +1,17 @@
+# Blender v2.80 (sub 75) OBJ File: 'Plane1m.blend'
+# www.blender.org
+mtllib Plane1m.mtl
+o Plane
+v -0.500000 0.000000 0.500000
+v 0.500000 0.000000 0.500000
+v -0.500000 0.000000 -0.500000
+v 0.500000 0.000000 -0.500000
+vt 1.000000 0.000000
+vt 0.000000 1.000000
+vt 0.000000 0.000000
+vt 1.000000 1.000000
+vn 0.0000 1.0000 0.0000
+usemtl None
+s off
+f 2/1/1 3/2/1 1/3/1
+f 2/1/1 4/4/1 3/2/1

Sandbox/assets/shaders/Grid.glsl

@@ -0,0 +1,50 @@
+// Simple Texture Shader
+
+#type vertex
+#version 430
+
+layout(location = 0) in vec3 a_Position;
+layout(location = 4) in vec2 a_TexCoord;
+
+uniform mat4 u_MVP;
+
+out vec2 v_TexCoord;
+
+void main()
+{
+    vec4 position = u_MVP * vec4(a_Position, 1.0);
+    gl_Position = position;
+
+    v_TexCoord = a_TexCoord;
+}
+
+#type fragment
+#version 430
+
+layout(location = 0) out vec4 color;
+
+uniform sampler2D u_Texture;
+uniform float u_Scale;
+uniform float u_Res;
+
+in vec2 v_TexCoord;
+
+/*void main()
+{
+	color = texture(u_Texture, v_TexCoord * 8.0);
+}*/
+
+float grid(vec2 st, float res)
+{
+    vec2 grid = fract(st);
+    return step(res, grid.x) * step(res, grid.y);
+}
+
+void main()
+{
+    float scale = u_Scale;
+    float resolution = u_Res;
+
+    float x = grid(v_TexCoord * scale, resolution);
+    color = vec4(vec3(0.2), 0.5) * (1.0 - x);
+}

Sandbox/assets/shaders/simplepbr.glsl

@@ -18,25 +18,41 @@ layout(location = 2) in vec3 a_Tangent;
 layout(location = 3) in vec3 a_Binormal;
 layout(location = 4) in vec2 a_TexCoord;
 
+layout(location = 5) in ivec4 a_BoneIndices;
+layout(location = 6) in vec4 a_BoneWeights;
+
 uniform mat4 u_ViewProjectionMatrix;
 uniform mat4 u_ModelMatrix;
 
+const int MAX_BONES = 100;
+uniform mat4 u_BoneTransforms[100];
+
 out VertexOutput
 {
 	vec3 WorldPosition;
     vec3 Normal;
 	vec2 TexCoord;
 	mat3 WorldNormals;
+	vec3 Binormal;
 } vs_Output;
 
 void main()
 {
-	vs_Output.WorldPosition = vec3(mat4(u_ModelMatrix) * vec4(a_Position, 1.0));
-    vs_Output.Normal = a_Normal;
+	mat4 boneTransform = u_BoneTransforms[a_BoneIndices[0]] * a_BoneWeights[0];
+	boneTransform += u_BoneTransforms[a_BoneIndices[1]] * a_BoneWeights[1];
+	boneTransform += u_BoneTransforms[a_BoneIndices[2]] * a_BoneWeights[2];
+	boneTransform += u_BoneTransforms[a_BoneIndices[3]] * a_BoneWeights[3];
+
+	vec4 localPosition = boneTransform * vec4(a_Position, 1.0);
+
+	vs_Output.WorldPosition = vec3(u_ModelMatrix * boneTransform * vec4(a_Position, 1.0));
+	vs_Output.Normal = mat3(boneTransform) * a_Normal;
 	vs_Output.TexCoord = vec2(a_TexCoord.x, 1.0 - a_TexCoord.y);
 	vs_Output.WorldNormals = mat3(u_ModelMatrix) * mat3(a_Tangent, a_Binormal, a_Normal);
+	vs_Output.Binormal = mat3(boneTransform) * a_Binormal;
 
-	gl_Position = u_ViewProjectionMatrix * u_ModelMatrix * vec4(a_Position, 1.0);
+	//gl_Position = u_ViewProjectionMatrix * u_ModelMatrix * vec4(a_Position, 1.0);
+	gl_Position = u_ViewProjectionMatrix * u_ModelMatrix * localPosition;
 }
 
 #type fragment
@@ -62,6 +78,7 @@ in VertexOutput
     vec3 Normal;
 	vec2 TexCoord;
 	mat3 WorldNormals;
+	vec3 Binormal;
 } vs_Input;
 
 layout(location=0) out vec4 color;