Fix Decals broken in Terra

Docs/src/manual/Ogre3.0.Changes.md

@@ -48,6 +48,12 @@ Default material BRDF settings have changed in 3.0; thus materials will look dif
 
 See [PBR / PBS Changes in 3.0](@ref PBSChangesIn30) to how make them look like they did in 2.3 and what these changes mean.
 
+## Hlms Shader piece changes
+
+The piece block `LoadNormalData` got split into `LoadGeomNormalData` & `LoadNormalData` in order to support Decals in Terra.
+
+If you were overriding `LoadNormalData` in a custom piece, make sure to account for the new `LoadGeomNormalData`.
+
 ## Move to C++11 and general cleanup
 
 Lots of dead \& long-deprecated code was removed.

Samples/2.0/Tutorials/Tutorial_Terrain/src/Terra/Hlms/OgreHlmsTerra.cpp

@@ -783,6 +783,7 @@ namespace Ogre
         outLibraryFoldersPaths.push_back( "Hlms/Pbs/Any/Atmosphere" );
 #endif
         outLibraryFoldersPaths.push_back( "Hlms/Pbs/Any/Main" );
+        outLibraryFoldersPaths.push_back( "Hlms/Pbs/" + shaderSyntax );
         outLibraryFoldersPaths.push_back( "Hlms/Terra/Any" );
 
         // Fill the data folder path

Samples/Media/Hlms/Pbs/Any/ForwardPlus_DecalsCubemaps_piece_ps.any

@@ -69,17 +69,15 @@
 		float3 absLocalPos = abs( localPos.xyz );
 		bool isOutsideDecal = absLocalPos.x > 0.5f || absLocalPos.y > 0.5f || absLocalPos.z > 0.5f;
 
-		//Mask away objects looking away from the decal. Please note that inPs.normal is not unit-length
-		//and is before any TBN for normal mapping. In other words it's the geometric normal
-		//geomNormal is not available because it gets decalred after decals run
+		//Mask away objects looking away from the decal.
 		//We assume invWorldView is orthogonal, thus the transpose = inverse, hance invWorldView1.xyz
 		//works as the decal's direction
 		//
 		//Use a smooth fade to avoid flickering due to floating point precision when the normal
 		//and the decal are perpendicular to each other. (tolerance set to 0.0002)
 		midf3 decalDir = normalize( midf3_c( invWorldView1.xyz ) );
-		//isOutsideDecal = dot( decalDir.xyz, inPs.normal.xyz ) <= 0.0 ? true : isOutsideDecal;
-		midf normalAway = saturate( (dot( decalDir.xyz, inPs.normal.xyz ) + _h( 0.0002 ) ) / _h( 0.0002 ) );
+		//isOutsideDecal = dot( decalDir.xyz, pixelData.geomNormal.xyz ) <= 0.0 ? true : isOutsideDecal;
+		midf normalAway = saturate( (dot( decalDir.xyz, pixelData.geomNormal.xyz ) + _h( 0.0002 ) ) / _h( 0.0002 ) );
 		normalAway = isOutsideDecal ? _h( 0.0f ) : normalAway;
 
 		midf decalMask = normalAway;

Samples/Media/Hlms/Pbs/Any/Main/800.PixelShader_piece_ps.any

@@ -371,11 +371,12 @@
 		@piece( two_sided_flip_normal )* (gl_FrontFacing ? 1.0 : -1.0)@end
 	@end
 @end
+@piece( LoadGeomNormalData )
+	// Geometric normal
+	pixelData.geomNormal = normalize( inPs.normal ) @insertpiece( two_sided_flip_normal );
+@end
 @piece( LoadNormalData )
-	@property( !normal_map )
-		// Geometric normal
-		pixelData.normal = normalize( inPs.normal ) @insertpiece( two_sided_flip_normal );
-	@else
+	@property( normal_map )
 		//Normal mapping.
 		pixelData.geomNormal = normalize( inPs.normal ) @insertpiece( two_sided_flip_normal );
 		midf3 vTangent		= normalize( inPs.tangent );
@@ -791,6 +792,10 @@
 		pixelData.specular.xyz	= float3( 0.0f, 0.0f, 0.0f );
 @end
 
+		@property( !hlms_use_prepass )
+			@insertpiece( LoadGeomNormalData )
+		@end
+
 		@insertpiece( forwardPlusDoDecals )
 
 		@property( !hlms_use_prepass )

Samples/Media/Hlms/Terra/Any/800.PixelShader_piece_ps.any

@@ -182,6 +182,7 @@
 	@end
 @end
 
+@undefpiece( LoadGeomNormalData )
 @undefpiece( LoadNormalData )
 @piece( LoadNormalData )
 	// Geometric normal
@@ -227,6 +228,7 @@
 	@insertpiece( LoadDetailWeights )
 
 	@property( !hlms_use_prepass )
+		@insertpiece( LoadGeomNormalData )
 		@insertpiece( LoadNormalData )
 		@insertpiece( SampleAndApplyDetailNormalMaps@property( detail_triplanar_normal )Triplanar@end )
 	@end