subtle paper texture for depth sense comfort

Assets/backbox.hlsl

@@ -2,16 +2,23 @@
 
 //--name = dofdev/backbox
 //--color:color = 1, 1, 1, 1
+//--tex_scale   = 1
+//--diffuse     = white
 
 float4       color;
+float        tex_scale;
+Texture2D    diffuse   : register(t0);
+SamplerState diffuse_s : register(s0);
 
 struct vsIn {
 	float4 pos  : SV_Position;
 	float3 norm : NORMAL0;
+	float2 uv   : TEXCOORD0;
 	// float4 col  : COLOR0;
 };
 struct psIn {
 	float4 pos   : SV_POSITION;
+	float2 uv    : TEXCOORD0;
 	float4 color : COLOR0;
 	float3 normal : NORMAL0;
 	float3 world_pos : WORLD;
@@ -35,16 +42,19 @@ psIn vs(vsIn input, uint id : SV_InstanceID) {
 	// flip input normals to treat backfaces like normal
 	o.normal = normalize(mul(-input.norm, (float3x3)sk_inst[id].world));
 
+	o.uv    = input.uv * tex_scale;
 	o.color = color * sk_inst[id].color;
 
 	return o;
 }
 float4 ps(psIn input) : SV_TARGET {
+  float4 col = diffuse.Sample(diffuse_s, input.uv);
+
 	float3 view_dir = normalize(input.world_pos - input.cam_pos);
 
 	// Fresnel effect calculation
 	float fresnel = 1.0 - saturate(dot(-view_dir, input.normal));
 	fresnel = pow(fresnel, 5.0); // Adjust power for different falloff rates
 	float value = 0.5;
-	return float4(fresnel * input.color.rgb * value, input.color.a);
+	return lerp(col, float4(1), 0.666) * float4(fresnel * input.color.rgb * value, input.color.a);
 }

Assets/unlit.hlsl

@@ -40,7 +40,7 @@ psIn vs(vsIn input, uint id : SV_InstanceID) {
 float4 ps(psIn input) : SV_TARGET {
 	float4 col = diffuse.Sample(diffuse_s, input.uv);
 
-	col = col * input.color;
+	col = lerp(col, float4(1), 0.666) * input.color;
 
 	return col;
 }

src/Arts.cs

@@ -14,6 +14,7 @@ static class Arts
     static Material mat_backbox = new Material("backbox.hlsl");
     static Material mat_justcolor = new Material("justcolor.hlsl");
 
+    static Tex tex_box = Tex.FromFile("paper.jpg");
     static Quat food_ori = Quat.Identity;
 
     static XYZi last_headpos = new(0, 0, 0);
@@ -31,6 +32,9 @@ static class Arts
             }
         }
 
+        // mat_mono.SetTexture("diffuse", tex_mono);
+        mat_box.SetTexture("diffuse", tex_box);
+        mat_backbox.SetTexture("diffuse", tex_box);
 
         mat_backbox.FaceCull = Cull.Front;
         mat_backbox.Transparency = Transparency.Add;