Merge branch 'PanosK92:master' into linux

Author: josejl1987

.github/images/world_selection_4.png

@@ -78,6 +78,17 @@ struct FrameBufferData
     float cloud_shadows;
     float padding3;
     float padding4;
+
+    // vr stereo - right eye matrices (left eye uses the primary matrices above)
+    matrix view_right;
+    matrix projection_right;
+    matrix view_projection_right;
+    matrix view_projection_inverted_right;
+    matrix view_projection_previous_right;
+    uint   is_multiview;
+    uint   padding_mv0;
+    uint   padding_mv1;
+    uint   padding_mv2;
 };
 
 // push constant buffer - carries per-draw and per-pass data

data/shaders/common_resources.hlsl

@@ -392,6 +392,16 @@ struct Light
         return tex2.SampleLevel(samplers[sampler_bilinear_clamp_border], atlas_uv, 0).r;
     }
 
+    // computes the roughness widening for area lights so that the specular
+    // highlight spreads to match the light's angular extent instead of
+    // collapsing into a point-like peak (Karis 2013)
+    float compute_area_roughness_modification(float roughness_alpha, float distance)
+    {
+        float area_size  = max(area_width, area_height) * 0.5f;
+        float solid_angle = saturate(area_size / (2.0f * max(distance, 0.01f)));
+        return saturate(roughness_alpha + solid_angle / (2.0f * roughness_alpha + solid_angle));
+    }
+
     void Build(uint index, Surface surface)
     {
         LightParameters light            = light_parameters[index];

data/shaders/common_structs.hlsl

@@ -110,6 +110,7 @@ gbuffer_vertex main_ds(HsConstantDataOutput input, float3 bary_coords : SV_Domai
     vertex.uv_misc.xy        = barycentric(patch[0].uv_misc.xy, patch[1].uv_misc.xy, patch[2].uv_misc.xy, bary_coords);
     vertex.uv_misc.z         = barycentric(patch[0].uv_misc.z, patch[1].uv_misc.z, patch[2].uv_misc.z, bary_coords);
     vertex.uv_misc.w         = patch[0].uv_misc.w; // instance_id is constant per patch
+    vertex.view_id           = patch[0].view_id;    // view_id is constant per patch
 
     // reconstruct world positions from interpolated clip
     float clip_w             = vertex.position.w;
@@ -150,9 +151,11 @@ gbuffer_vertex main_ds(HsConstantDataOutput input, float3 bary_coords : SV_Domai
         }
     }
 
-    // write final clip space
-    vertex.position          = mul(float4(position, 1.0f), buffer_frame.view_projection);
-    vertex.position_previous = mul(float4(position_previous, 1.0f), buffer_frame.view_projection_previous);
+    // write final clip space (select per-eye matrices for multiview stereo)
+    matrix vp      = (buffer_frame.is_multiview && vertex.view_id == 1) ? buffer_frame.view_projection_right          : buffer_frame.view_projection;
+    matrix vp_prev = (buffer_frame.is_multiview && vertex.view_id == 1) ? buffer_frame.view_projection_previous_right : buffer_frame.view_projection_previous;
+    vertex.position          = mul(float4(position, 1.0f), vp);
+    vertex.position_previous = mul(float4(position_previous, 1.0f), vp_prev);
 
     return vertex;
 }

data/shaders/common_tessellation.hlsl

@@ -70,6 +70,7 @@ struct gbuffer_vertex
     float4 uv_misc           : TEXCOORD;  // xy = uv, z = height_percent, w = instance_id - packed together to reduced the interpolators (shader registers) the gpu needs to track
     float width_percent      : TEXCOORD2; // temp, will remove
     nointerpolation uint material_index : TEXCOORD3; // for indirect draws, material index passed from vs
+    nointerpolation uint view_id        : TEXCOORD4; // multiview eye index (0 = left, 1 = right)
 };
 
 float4x4 compose_instance_transform(min16float instance_position_x, min16float instance_position_y, min16float instance_position_z, uint instance_normal_oct, uint instance_yaw, uint instance_scale)
@@ -396,10 +397,16 @@ gbuffer_vertex transform_to_world_space(Vertex_PosUvNorTan input, uint instance_
     return vertex;
 }
 
-gbuffer_vertex transform_to_clip_space(gbuffer_vertex vertex, float3 position, float3 position_previous)
+gbuffer_vertex transform_to_clip_space(gbuffer_vertex vertex, float3 position, float3 position_previous, uint view_id = 0)
 {
-    vertex.position          = mul(float4(position, 1.0f), buffer_frame.view_projection);
-    vertex.position_previous = mul(float4(position_previous, 1.0f), buffer_frame.view_projection_previous);
+    vertex.view_id = view_id;
+
+    // select per-eye matrices when rendering in multiview stereo
+    matrix vp      = (buffer_frame.is_multiview && view_id == 1) ? buffer_frame.view_projection_right           : buffer_frame.view_projection;
+    matrix vp_prev = (buffer_frame.is_multiview && view_id == 1) ? buffer_frame.view_projection_previous_right  : buffer_frame.view_projection_previous;
+
+    vertex.position          = mul(float4(position, 1.0f), vp);
+    vertex.position_previous = mul(float4(position_previous, 1.0f), vp_prev);
 
     return vertex;
 }

data/shaders/common_vertex_processing.hlsl

@@ -45,6 +45,7 @@ gbuffer_vertex main_vs(Vertex_PosUvNorTan input, uint instance_id : SV_InstanceI
     float3 position_world_previous = 0.0f;
     gbuffer_vertex vertex          = transform_to_world_space(input, instance_id, _draw.transform, position_world, position_world_previous);
     vertex.material_index          = _draw.material_index;
+    vertex.view_id                 = 0;
     vertex.position                = mul(float4(position_world, 1.0f), light.transform[index_array]);
 
     return vertex;

data/shaders/depth_light.hlsl

@@ -25,12 +25,12 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 //=================================
 
 #ifdef INDIRECT_DRAW
-gbuffer_vertex main_vs(uint vertex_id : SV_VertexID, uint instance_id : SV_InstanceID, [[vk::builtin("DrawIndex")]] uint draw_id : DRAW_INDEX)
+gbuffer_vertex main_vs(uint vertex_id : SV_VertexID, uint instance_id : SV_InstanceID, [[vk::builtin("DrawIndex")]] uint draw_id : DRAW_INDEX, uint view_id : SV_ViewID)
 {
     _draw = indirect_draw_data_out[draw_id];
     Vertex_PosUvNorTan input = pull_vertex(vertex_id);
 #else
-gbuffer_vertex main_vs(Vertex_PosUvNorTan input, uint instance_id : SV_InstanceID)
+gbuffer_vertex main_vs(Vertex_PosUvNorTan input, uint instance_id : SV_InstanceID, uint view_id : SV_ViewID)
 {
     _draw = draw_data[buffer_pass.draw_index];
 #endif
@@ -39,7 +39,7 @@ gbuffer_vertex main_vs(Vertex_PosUvNorTan input, uint instance_id : SV_InstanceI
     float3 position_world_previous = 0.0f;
     gbuffer_vertex vertex          = transform_to_world_space(input, instance_id, _draw.transform, position_world, position_world_previous);
     vertex.material_index          = _draw.material_index;
-    return transform_to_clip_space(vertex, position_world, position_world_previous);
+    return transform_to_clip_space(vertex, position_world, position_world_previous, view_id);
 }
 
 void main_ps(gbuffer_vertex vertex)

data/shaders/depth_prepass.hlsl

@@ -112,12 +112,12 @@ float3 compute_flower_color(float height_percent, uint instance_id)
 }
 
 #ifdef INDIRECT_DRAW
-gbuffer_vertex main_vs(uint vertex_id : SV_VertexID, uint instance_id : SV_InstanceID, [[vk::builtin("DrawIndex")]] uint draw_id : DRAW_INDEX)
+gbuffer_vertex main_vs(uint vertex_id : SV_VertexID, uint instance_id : SV_InstanceID, [[vk::builtin("DrawIndex")]] uint draw_id : DRAW_INDEX, uint view_id : SV_ViewID)
 {
     _draw = indirect_draw_data_out[draw_id];
     Vertex_PosUvNorTan input = pull_vertex(vertex_id);
 #else
-gbuffer_vertex main_vs(Vertex_PosUvNorTan input, uint instance_id : SV_InstanceID)
+gbuffer_vertex main_vs(Vertex_PosUvNorTan input, uint instance_id : SV_InstanceID, uint view_id : SV_ViewID)
 {
     _draw = draw_data[buffer_pass.draw_index];
 #endif
@@ -126,7 +126,7 @@ gbuffer_vertex main_vs(Vertex_PosUvNorTan input, uint instance_id : SV_InstanceI
     float3 position_world_previous = 0.0f;
     gbuffer_vertex vertex          = transform_to_world_space(input, instance_id, _draw.transform, position_world, position_world_previous);
     vertex.material_index          = _draw.material_index;
-    return transform_to_clip_space(vertex, position_world, position_world_previous);
+    return transform_to_clip_space(vertex, position_world, position_world_previous, view_id);
 }
 
 gbuffer main_ps(gbuffer_vertex vertex, bool is_front_face : SV_IsFrontFace)

data/shaders/g_buffer.hlsl

@@ -200,6 +200,16 @@ void main_cs(uint3 thread_id : SV_DispatchThreadID)
             AngularInfo angular_info;
             angular_info.Build(light, surface);
 
+            // for area lights, widen the specular distribution to match the light's angular
+            // extent - this prevents the highlight from collapsing into a concentrated point
+            float original_roughness       = surface.roughness;
+            float original_roughness_alpha = surface.roughness_alpha;
+            if (light.is_area())
+            {
+                surface.roughness_alpha = light.compute_area_roughness_modification(surface.roughness_alpha, light.distance_to_pixel);
+                surface.roughness       = sqrt(surface.roughness_alpha);
+            }
+
             // compute specular brdf lobes
             {
                 // main specular lobe (anisotropic or isotropic)
@@ -230,6 +240,10 @@ void main_cs(uint3 thread_id : SV_DispatchThreadID)
                     L_subsurface += subsurface_scattering(surface, light, angular_info);
                 }
             }
+
+            // restore original roughness so other lights aren't affected
+            surface.roughness       = original_roughness;
+            surface.roughness_alpha = original_roughness_alpha;
 
             // compute diffuse brdf term
             L_diffuse_term += BRDF_Diffuse(surface, angular_info);