Fixes and proper tangent space

client/shaders/nodes_shader/opengl_fragment.glsl

@@ -44,6 +44,8 @@ uniform vec2 windowSize;
 uniform float fov;
 
 varying vec3 vNormal;
+varying vec3 vTangent;
+varying vec3 vBinormal; 
 varying vec3 vPosition;
 // World position in the visible world (i.e. relative to the cameraOffset.)
 // This can be used for many shader effects without loss of precision.
@@ -100,36 +102,6 @@ vec3 gnoise(vec3 p){
     );
 }
 
-float snoise(vec3 p)
-{
-	vec3 a = floor(p);
-	vec3 d = p - a;
-	d = d * d * (3.0 - 2.0 * d);
-
-	vec4 b = a.xxyy + vec4(0.0, 1.0, 0.0, 1.0);
-	vec4 k1 = perm(b.xyxy);
-	vec4 k2 = perm(k1.xyxy + b.zzww);
-
-	vec4 c = k2 + a.zzzz;
-	vec4 k3 = perm(c);
-	vec4 k4 = perm(c + 1.0);
-
-	vec4 o1 = fract(k3 * (1.0 / 41.0));
-	vec4 o2 = fract(k4 * (1.0 / 41.0));
-
-	vec4 o3 = o2 * d.z + o1 * (1.0 - d.z);
-	vec2 o4 = o3.yw * d.x + o3.xz * (1.0 - d.x);
-
-	return o4.y * d.y + o4.x * (1.0 - d.y);
-}
-
-vec3 hnoise(vec3 p) {
-	vec3 g = gnoise(p);
-	float s = snoise(p);
-	g *= 3.0 / (1.0 + exp(-16.0 * (s - 0.5))) - 1.5;
-	return g;
-}
-
 vec2 wave_noise(vec3 p, float off) {
 	return (gnoise(p + vec3(0.0, 0.0, off)) * 0.4 + gnoise(2.0 * p + vec3(0.0, off, off)) * 0.2 + gnoise(3.0 * p + vec3(0.0, off, off)) * 0.225 + gnoise(4.0 * p + vec3(-off, off, 0.0)) * 0.2).xz;
 }
@@ -457,13 +429,11 @@ vec3 getBumpMap(vec2 uv) {
 	float fx0y0 = texture2D(baseTexture, uv).r;
 	float fx1y0 = texture2D(baseTexture, uv + vec2(dr.x, 0.0)).r;
 	float fx0y1 = texture2D(baseTexture, uv + vec2(0.0, dr.y)).r;
+	// We get the gradient using partial derivatives
 	vec2 gradient = 0.1 * vec2((fx1y0 - fx0y0) / dr.x, (fx0y1 - fx0y0) / dr.y) + 0.05 * gnoise(vec3(2.0 * uv / texelSize0, 0.0)).xy;
-	// Compute a set of orthonormal basis vectors representing the node's surface plane.
-	vec3 orth1 = normalize(cross(vNormal, mix(vec3(0.0, -1.0, 0.0), vec3(0.0, 0.0, -1.0), step(0.9, abs(vNormal.y)))));
-	vec3 orth2 = normalize(cross(vNormal, orth1));
-	// The normal is computed using the partial derivatives along the texture space x and y axes. 
-	// These axes in world space are assumed to be parallel to the basis vectors we defined before.
-	return orth1 * gradient.x + orth2 * gradient.y;
+	vec3 tangent_space = normalize(vec3(gradient, 1.0));
+	// Convert tangent space information to real space
+	return -vTangent * tangent_space.x + vBinormal * tangent_space.y + vNormal * tangent_space.z;
 }
 #endif
 
@@ -501,10 +471,10 @@ void main(void)
 	// When applied to all blocks, these bump maps produce irritating Moiré effects.
 	// So we hide the bump maps when close up.
 	float moire_factor = abs(dot(vNormal, viewVec));
-	bump_normal *= mtsmoothstep(0.4 * moire_factor, 0.2 * moire_factor, length(eyeVec) * fov / windowSize.x);
-	fNormal = normalize(vNormal + bump_normal);
+	moire_factor = mtsmoothstep(0.4 * moire_factor, 0.2 * moire_factor, length(eyeVec) * fov / windowSize.x);
+	fNormal = normalize(mix(fNormal, bump_normal, moire_factor));
 	float adj_cosLight = max(1e-5, dot(fNormal, -v_LightDirection));
-#else 
+#else
 	float adj_cosLight = cosLight;
 #endif
 
@@ -642,7 +612,7 @@ void main(void)
 	// Note: clarity = (1 - fogginess)
 	float clarity = clamp(fogShadingParameter
 		- fogShadingParameter * length(eyeVec) / fogDistance, 0.0, 1.0);
-		
+
 #ifdef ENABLE_TINTED_FOG
 	float fogColorMax = max(max(fogColor.r, fogColor.g), fogColor.b);
 	// Prevent zero division.

client/shaders/nodes_shader/opengl_vertex.glsl

@@ -7,6 +7,8 @@ uniform highp vec3 cameraOffset;
 uniform float animationTimer;
 
 varying vec3 vNormal;
+varying vec3 vTangent;
+varying vec3 vBinormal; 
 varying vec3 vPosition;
 // World position in the visible world (i.e. relative to the cameraOffset.)
 // This can be used for many shader effects without loss of precision.
@@ -209,6 +211,8 @@ void main(void)
 	normalPass = normalize((inVertexNormal+1)/2);
 #endif
 	vNormal = inVertexNormal;
+	vTangent = inVertexTangent.xyz;
+	vBinormal = inVertexBinormal.xyz;
 
 	// Calculate color.
 	vec4 color = inVertexColor;

client/shaders/second_stage/opengl_fragment.glsl

@@ -111,11 +111,6 @@ vec3 screen_space_dither(highp vec2 frag_coord) {
 }
 #endif
 
-float sFunction(float x, float a) {
-	x = 2.0 * x - 1.0;
-	return 0.5 * sign(x) * pow(abs(x), a) + 0.5;
-}
-
 void main(void)
 {
 	vec2 uv = varTexCoord.st;

client/shaders/volumetric_light/opengl_fragment.glsl

@@ -53,7 +53,7 @@ float sampleVolumetricLight(vec2 uv, vec3 lightVec, float rawDepth)
 	// We use the depth map to approximate the effect of depth on the light intensity.
 	// The exponent was chosen based on aesthetic preference.
 	// To make this phsyically accurate, the brightness here should scale linearly with depth,
-	// but this would make the godrays either too faint or too strong in many cases. 
+	// but this would make the godrays either too faint or too strong in many cases.
 	return result / samples * pow(texture2D(depthmap, uv).r, 128.0);
 #else
 	return result / samples;

irr/include/IMeshManipulator.h

@@ -42,6 +42,26 @@ public:
 	virtual void recalculateNormals(IMeshBuffer *buffer,
 			bool smooth = false, bool angleWeighted = false) const = 0;
 
+	//! Recalculates tangents, requires a tangent mesh
+		/** \param mesh Mesh on which the operation is performed.
+		\param recalculateNormals If the normals shall be recalculated, otherwise original normals of the mesh are used unchanged.
+		\param smooth If the normals shall be smoothed.
+		\param angleWeighted If the normals shall be smoothed in relation to their angles. More expensive, but also higher precision.
+		*/
+	virtual void recalculateTangents(IMesh* mesh,
+		bool recalculateNormals = false, bool smooth = false,
+		bool angleWeighted = false) const = 0;
+
+	//! Recalculates tangents, requires a tangent mesh buffer
+	/** \param buffer Meshbuffer on which the operation is performed.
+	\param recalculateNormals If the normals shall be recalculated, otherwise original normals of the buffer are used unchanged.
+	\param smooth If the normals shall be smoothed.
+	\param angleWeighted If the normals shall be smoothed in relation to their angles. More expensive, but also higher precision.
+	*/
+	virtual void recalculateTangents(IMeshBuffer* buffer,
+		bool recalculateNormals = false, bool smooth = false,
+		bool angleWeighted = false) const = 0;
+
 	//! Scales the actual mesh, not a scene node.
 	/** \param mesh Mesh on which the operation is performed.
 	\param factor Scale factor for each axis. */

irr/src/CMeshManipulator.cpp

@@ -80,6 +80,335 @@ void recalculateNormalsT(IMeshBuffer *buffer, bool smooth, bool angleWeighted)
 }
 }
 
+namespace
+{
+	void calculateTangents(
+		core::vector3df& normal,
+		core::vector3df& tangent,
+		core::vector3df& binormal,
+		const core::vector3df& vt1, const core::vector3df& vt2, const core::vector3df& vt3, // vertices
+		const core::vector2df& tc1, const core::vector2df& tc2, const core::vector2df& tc3) // texture coords
+	{
+		// choose one of them:
+		//#define USE_NVIDIA_GLH_VERSION // use version used by nvidia in glh headers
+#define USE_IRR_VERSION
+
+#ifdef USE_IRR_VERSION
+
+		core::vector3df v1 = vt1 - vt2;
+		core::vector3df v2 = vt3 - vt1;
+		normal = v2.crossProduct(v1);
+		normal.normalize();
+
+		// binormal
+
+		f32 deltaX1 = tc1.X - tc2.X;
+		f32 deltaX2 = tc3.X - tc1.X;
+		binormal = (v1 * deltaX2) - (v2 * deltaX1);
+		binormal.normalize();
+
+		// tangent
+
+		f32 deltaY1 = tc1.Y - tc2.Y;
+		f32 deltaY2 = tc3.Y - tc1.Y;
+		tangent = (v1 * deltaY2) - (v2 * deltaY1);
+		tangent.normalize();
+
+		// adjust
+
+		core::vector3df txb = tangent.crossProduct(binormal);
+		if (txb.dotProduct(normal) < 0.0f)
+		{
+			tangent *= -1.0f;
+			binormal *= -1.0f;
+		}
+
+#endif // USE_IRR_VERSION
+
+#ifdef USE_NVIDIA_GLH_VERSION
+
+		tangent.set(0, 0, 0);
+		binormal.set(0, 0, 0);
+
+		core::vector3df v1(vt2.X - vt1.X, tc2.X - tc1.X, tc2.Y - tc1.Y);
+		core::vector3df v2(vt3.X - vt1.X, tc3.X - tc1.X, tc3.Y - tc1.Y);
+
+		core::vector3df txb = v1.crossProduct(v2);
+		if (!core::iszero(txb.X))
+		{
+			tangent.X = -txb.Y / txb.X;
+			binormal.X = -txb.Z / txb.X;
+		}
+
+		v1.X = vt2.Y - vt1.Y;
+		v2.X = vt3.Y - vt1.Y;
+		txb = v1.crossProduct(v2);
+
+		if (!core::iszero(txb.X))
+		{
+			tangent.Y = -txb.Y / txb.X;
+			binormal.Y = -txb.Z / txb.X;
+		}
+
+		v1.X = vt2.Z - vt1.Z;
+		v2.X = vt3.Z - vt1.Z;
+		txb = v1.crossProduct(v2);
+
+		if (!core::iszero(txb.X))
+		{
+			tangent.Z = -txb.Y / txb.X;
+			binormal.Z = -txb.Z / txb.X;
+		}
+
+		tangent.normalize();
+		binormal.normalize();
+
+		normal = tangent.crossProduct(binormal);
+		normal.normalize();
+
+		binormal = tangent.crossProduct(normal);
+		binormal.normalize();
+
+		core::plane3d<f32> pl(vt1, vt2, vt3);
+
+		if (normal.dotProduct(pl.Normal) < 0.0f)
+			normal *= -1.0f;
+
+#endif // USE_NVIDIA_GLH_VERSION
+	}
+
+
+	//! Recalculates tangents for a tangent mesh buffer
+	template <typename T>
+	void recalculateTangentsT(IMeshBuffer* buffer, bool recalculateNormals, bool smooth, bool angleWeighted)
+	{
+		if (!buffer || (buffer->getVertexType() != video::EVT_TANGENTS))
+			return;
+
+		const u32 vtxCnt = buffer->getVertexCount();
+		const u32 idxCnt = buffer->getIndexCount();
+
+		T* idx = reinterpret_cast<T*>(buffer->getIndices());
+		video::S3DVertexTangents* v =
+			(video::S3DVertexTangents*)buffer->getVertices();
+
+		if (smooth)
+		{
+			u32 i;
+
+			for (i = 0; i != vtxCnt; ++i)
+			{
+				if (recalculateNormals)
+					v[i].Normal.set(0.f, 0.f, 0.f);
+				v[i].Tangent.set(0.f, 0.f, 0.f);
+				v[i].Binormal.set(0.f, 0.f, 0.f);
+			}
+
+			//Each vertex gets the sum of the tangents and binormals from the faces around it
+			for (i = 0; i < idxCnt; i += 3)
+			{
+				// if this triangle is degenerate, skip it!
+				if (v[idx[i + 0]].Pos == v[idx[i + 1]].Pos ||
+					v[idx[i + 0]].Pos == v[idx[i + 2]].Pos ||
+					v[idx[i + 1]].Pos == v[idx[i + 2]].Pos
+					/*||
+					v[idx[i+0]].TCoords == v[idx[i+1]].TCoords ||
+					v[idx[i+0]].TCoords == v[idx[i+2]].TCoords ||
+					v[idx[i+1]].TCoords == v[idx[i+2]].TCoords */
+					)
+					continue;
+
+				//Angle-weighted normals look better, but are slightly more CPU intensive to calculate
+				core::vector3df weight(1.f, 1.f, 1.f);
+				if (angleWeighted)
+					weight = irr::scene::getAngleWeight(v[i + 0].Pos, v[i + 1].Pos, v[i + 2].Pos);	// writing irr::scene:: necessary for borland
+				core::vector3df localNormal;
+				core::vector3df localTangent;
+				core::vector3df localBinormal;
+
+				calculateTangents(
+					localNormal,
+					localTangent,
+					localBinormal,
+					v[idx[i + 0]].Pos,
+					v[idx[i + 1]].Pos,
+					v[idx[i + 2]].Pos,
+					v[idx[i + 0]].TCoords,
+					v[idx[i + 1]].TCoords,
+					v[idx[i + 2]].TCoords);
+
+				if (recalculateNormals)
+					v[idx[i + 0]].Normal += localNormal * weight.X;
+				v[idx[i + 0]].Tangent += localTangent * weight.X;
+				v[idx[i + 0]].Binormal += localBinormal * weight.X;
+
+				calculateTangents(
+					localNormal,
+					localTangent,
+					localBinormal,
+					v[idx[i + 1]].Pos,
+					v[idx[i + 2]].Pos,
+					v[idx[i + 0]].Pos,
+					v[idx[i + 1]].TCoords,
+					v[idx[i + 2]].TCoords,
+					v[idx[i + 0]].TCoords);
+
+				if (recalculateNormals)
+					v[idx[i + 1]].Normal += localNormal * weight.Y;
+				v[idx[i + 1]].Tangent += localTangent * weight.Y;
+				v[idx[i + 1]].Binormal += localBinormal * weight.Y;
+
+				calculateTangents(
+					localNormal,
+					localTangent,
+					localBinormal,
+					v[idx[i + 2]].Pos,
+					v[idx[i + 0]].Pos,
+					v[idx[i + 1]].Pos,
+					v[idx[i + 2]].TCoords,
+					v[idx[i + 0]].TCoords,
+					v[idx[i + 1]].TCoords);
+
+				if (recalculateNormals)
+					v[idx[i + 2]].Normal += localNormal * weight.Z;
+				v[idx[i + 2]].Tangent += localTangent * weight.Z;
+				v[idx[i + 2]].Binormal += localBinormal * weight.Z;
+			}
+
+			// Normalize the tangents and binormals
+			if (recalculateNormals)
+			{
+				for (i = 0; i != vtxCnt; ++i)
+					v[i].Normal.normalize();
+			}
+			for (i = 0; i != vtxCnt; ++i)
+			{
+				v[i].Tangent.normalize();
+				v[i].Binormal.normalize();
+			}
+		}
+		else
+		{
+			core::vector3df localNormal;
+			for (u32 i = 0; i < idxCnt; i += 3)
+			{
+				calculateTangents(
+					localNormal,
+					v[idx[i + 0]].Tangent,
+					v[idx[i + 0]].Binormal,
+					v[idx[i + 0]].Pos,
+					v[idx[i + 1]].Pos,
+					v[idx[i + 2]].Pos,
+					v[idx[i + 0]].TCoords,
+					v[idx[i + 1]].TCoords,
+					v[idx[i + 2]].TCoords);
+				if (recalculateNormals)
+					v[idx[i + 0]].Normal = localNormal;
+
+				calculateTangents(
+					localNormal,
+					v[idx[i + 1]].Tangent,
+					v[idx[i + 1]].Binormal,
+					v[idx[i + 1]].Pos,
+					v[idx[i + 2]].Pos,
+					v[idx[i + 0]].Pos,
+					v[idx[i + 1]].TCoords,
+					v[idx[i + 2]].TCoords,
+					v[idx[i + 0]].TCoords);
+				if (recalculateNormals)
+					v[idx[i + 1]].Normal = localNormal;
+
+				calculateTangents(
+					localNormal,
+					v[idx[i + 2]].Tangent,
+					v[idx[i + 2]].Binormal,
+					v[idx[i + 2]].Pos,
+					v[idx[i + 0]].Pos,
+					v[idx[i + 1]].Pos,
+					v[idx[i + 2]].TCoords,
+					v[idx[i + 0]].TCoords,
+					v[idx[i + 1]].TCoords);
+				if (recalculateNormals)
+					v[idx[i + 2]].Normal = localNormal;
+			}
+		}
+	}
+}
+
+
+//! Recalculates tangents for a tangent mesh buffer
+void CMeshManipulator::recalculateTangents(IMeshBuffer* buffer, bool recalculateNormals, bool smooth, bool angleWeighted) const
+{
+	if (buffer && (buffer->getVertexType() == video::EVT_TANGENTS))
+	{
+		if (buffer->getIndexType() == video::EIT_16BIT)
+			recalculateTangentsT<u16>(buffer, recalculateNormals, smooth, angleWeighted);
+		else
+			recalculateTangentsT<u32>(buffer, recalculateNormals, smooth, angleWeighted);
+	}
+}
+
+
+//! Recalculates tangents for all tangent mesh buffers
+void CMeshManipulator::recalculateTangents(IMesh* mesh, bool recalculateNormals, bool smooth, bool angleWeighted) const
+{
+	if (!mesh)
+		return;
+
+	const u32 meshBufferCount = mesh->getMeshBufferCount();
+	for (u32 b = 0; b < meshBufferCount; ++b)
+	{
+		recalculateTangents(mesh->getMeshBuffer(b), recalculateNormals, smooth, angleWeighted);
+	}
+}
+
+
+namespace
+{
+	//! Creates a planar texture mapping on the meshbuffer
+	template<typename T>
+	void makePlanarTextureMappingT(scene::IMeshBuffer* buffer, f32 resolution)
+	{
+		u32 idxcnt = buffer->getIndexCount();
+		T* idx = reinterpret_cast<T*>(buffer->getIndices());
+
+		for (u32 i = 0; i < idxcnt; i += 3)
+		{
+			core::plane3df p(buffer->getPosition(idx[i + 0]), buffer->getPosition(idx[i + 1]), buffer->getPosition(idx[i + 2]));
+			p.Normal.X = fabsf(p.Normal.X);
+			p.Normal.Y = fabsf(p.Normal.Y);
+			p.Normal.Z = fabsf(p.Normal.Z);
+			// calculate planar mapping worldspace coordinates
+
+			if (p.Normal.X > p.Normal.Y && p.Normal.X > p.Normal.Z)
+			{
+				for (u32 o = 0; o != 3; ++o)
+				{
+					buffer->getTCoords(idx[i + o]).X = buffer->getPosition(idx[i + o]).Y * resolution;
+					buffer->getTCoords(idx[i + o]).Y = buffer->getPosition(idx[i + o]).Z * resolution;
+				}
+			}
+			else
+				if (p.Normal.Y > p.Normal.X && p.Normal.Y > p.Normal.Z)
+				{
+					for (u32 o = 0; o != 3; ++o)
+					{
+						buffer->getTCoords(idx[i + o]).X = buffer->getPosition(idx[i + o]).X * resolution;
+						buffer->getTCoords(idx[i + o]).Y = buffer->getPosition(idx[i + o]).Z * resolution;
+					}
+				}
+				else
+				{
+					for (u32 o = 0; o != 3; ++o)
+					{
+						buffer->getTCoords(idx[i + o]).X = buffer->getPosition(idx[i + o]).X * resolution;
+						buffer->getTCoords(idx[i + o]).Y = buffer->getPosition(idx[i + o]).Y * resolution;
+					}
+				}
+		}
+	}
+}
+
 //! Recalculates all normals of the mesh buffer.
 /** \param buffer: Mesh buffer on which the operation is performed. */
 void CMeshManipulator::recalculateNormals(IMeshBuffer *buffer, bool smooth, bool angleWeighted) const

irr/src/CMeshManipulator.h

@@ -29,6 +29,12 @@ public:
 	\param smooth: Whether to use smoothed normals. */
 	void recalculateNormals(IMeshBuffer *buffer, bool smooth = false, bool angleWeighted = false) const override;
 
+	//! Recalculates tangents, requires a tangent mesh buffer
+	virtual void recalculateTangents(IMeshBuffer* buffer, bool recalculateNormals = false, bool smooth = false, bool angleWeighted = false) const _IRR_OVERRIDE_;
+
+	//! Recalculates tangents, requires a tangent mesh
+	virtual void recalculateTangents(IMesh* mesh, bool recalculateNormals = false, bool smooth = false, bool angleWeighted = false) const _IRR_OVERRIDE_;
+
 	//! Clones a static IMesh into a modifiable SMesh.
 	SMesh *createMeshCopy(scene::IMesh *mesh) const override;
 

src/client/mapblock_mesh.cpp

@@ -40,10 +40,11 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 	MeshMakeData
 */
 
-MeshMakeData::MeshMakeData(const NodeDefManager *ndef, u16 side_length, bool use_shaders):
+MeshMakeData::MeshMakeData(const NodeDefManager *ndef, u16 side_length, bool use_shaders, bool use_tangent_vertices):
 	side_length(side_length),
 	nodedef(ndef),
-	m_use_shaders(use_shaders)
+	m_use_shaders(use_shaders),
+	m_use_tangent_vertices(use_tangent_vertices)
 {}
 
 void MeshMakeData::fillBlockDataBegin(const v3s16 &blockpos)
@@ -617,6 +618,7 @@ MapBlockMesh::MapBlockMesh(Client *client, MeshMakeData *data, v3s16 camera_offs
 	for (auto &m : m_mesh)
 		m = make_irr<scene::SMesh>();
 	m_enable_shaders = data->m_use_shaders;
+	m_use_tangent_vertices = data->m_use_tangent_vertices;
 
 	auto mesh_grid = client->getMeshGrid();
 	v3s16 bp = data->m_blockpos;
@@ -752,27 +754,44 @@ MapBlockMesh::MapBlockMesh(Client *client, MeshMakeData *data, v3s16 camera_offs
 				p.layer.applyMaterialOptions(material);
 			}
 
-			scene::SMeshBuffer *buf = new scene::SMeshBuffer();
-			buf->Material = material;
-			if (p.layer.isTransparent()) {
-				buf->append(&p.vertices[0], p.vertices.size(), nullptr, 0);
-
-				MeshTriangle t;
-				t.buffer = buf;
-				m_transparent_triangles.reserve(p.indices.size() / 3);
-				for (u32 i = 0; i < p.indices.size(); i += 3) {
-					t.p1 = p.indices[i];
-					t.p2 = p.indices[i + 1];
-					t.p3 = p.indices[i + 2];
-					t.updateAttributes();
-					m_transparent_triangles.push_back(t);
-				}
-			} else {
-				buf->append(&p.vertices[0], p.vertices.size(),
+			if (m_use_tangent_vertices && !p.layer.isTransparent()) {
+				scene::SMeshBufferTangents* buf = new scene::SMeshBufferTangents();
+				buf->Material = material;
+				std::vector<video::S3DVertexTangents> vertices;
+				vertices.reserve(p.vertices.size());
+				for (video::S3DVertex &v : p.vertices)
+					vertices.push_back(video::S3DVertexTangents(v.Pos, v.Normal, v.Color, v.TCoords));
+				buf->append(&vertices[0], vertices.size(),
 					&p.indices[0], p.indices.size());
+				buf->recalculateBoundingBox();
+				scene::IMeshManipulator* meshmanip =
+					client->getSceneManager()->getMeshManipulator();
+				meshmanip->recalculateTangents(buf);
+				mesh->addMeshBuffer(buf);
+				buf->drop();
+			} else {
+				scene::SMeshBuffer *buf = new scene::SMeshBuffer();
+				buf->Material = material;
+				if (p.layer.isTransparent()) {
+					buf->append(&p.vertices[0], p.vertices.size(), nullptr, 0);
+
+					MeshTriangle t;
+					t.buffer = buf;
+					m_transparent_triangles.reserve(p.indices.size() / 3);
+					for (u32 i = 0; i < p.indices.size(); i += 3) {
+						t.p1 = p.indices[i];
+						t.p2 = p.indices[i + 1];
+						t.p3 = p.indices[i + 2];
+						t.updateAttributes();
+						m_transparent_triangles.push_back(t);
+					}
+				} else {
+					buf->append(&p.vertices[0], p.vertices.size(),
+						&p.indices[0], p.indices.size());
+				}
+				mesh->addMeshBuffer(buf);
+				buf->drop();
 			}
-			mesh->addMeshBuffer(buf);
-			buf->drop();
 		}
 
 		if (mesh) {

src/client/mapblock_mesh.h

@@ -51,8 +51,9 @@ struct MeshMakeData
 
 	const NodeDefManager *nodedef;
 	bool m_use_shaders;
+	bool m_use_tangent_vertices;
 
-	MeshMakeData(const NodeDefManager *ndef, u16 side_length, bool use_shaders);
+	MeshMakeData(const NodeDefManager *ndef, u16 side_length, bool use_shaders, bool use_tangent_vertices = false);
 
 	/*
 		Copy block data manually (to allow optimizations by the caller)
@@ -251,6 +252,7 @@ private:
 	v3f m_bounding_sphere_center;
 
 	bool m_enable_shaders;
+	bool m_use_tangent_vertices;
 
 	// Must animate() be called before rendering?
 	bool m_has_animation;

src/client/mesh_generator_thread.cpp

@@ -55,6 +55,7 @@ MeshUpdateQueue::MeshUpdateQueue(Client *client):
 	m_client(client)
 {
 	m_cache_enable_shaders = g_settings->getBool("enable_shaders");
+	m_cache_use_tangent_vertices = m_cache_enable_shaders && g_settings->getBool("enable_bumpmaps");
 	m_cache_smooth_lighting = g_settings->getBool("smooth_lighting");
 }
 
@@ -192,7 +193,7 @@ void MeshUpdateQueue::done(v3s16 pos)
 void MeshUpdateQueue::fillDataFromMapBlocks(QueuedMeshUpdate *q)
 {
 	auto mesh_grid = m_client->getMeshGrid();
-	MeshMakeData *data = new MeshMakeData(m_client->ndef(), MAP_BLOCKSIZE * mesh_grid.cell_size, m_cache_enable_shaders);
+	MeshMakeData *data = new MeshMakeData(m_client->ndef(), MAP_BLOCKSIZE * mesh_grid.cell_size, m_cache_enable_shaders, m_cache_use_tangent_vertices);
 	q->data = data;
 
 	data->fillBlockDataBegin(q->p);

src/client/mesh_generator_thread.h

@@ -86,6 +86,7 @@ private:
 
 	// TODO: Add callback to update these when g_settings changes
 	bool m_cache_enable_shaders;
+	bool m_cache_use_tangent_vertices;
 	bool m_cache_smooth_lighting;
 
 	void fillDataFromMapBlocks(QueuedMeshUpdate *q);

src/lighting.h

@@ -68,7 +68,7 @@ struct Vignette {
  * Colors in ASL CDL follow the following equation:
  *
  * out = pow(in * slope + offset, power)
- * 
+ *
  */
 struct ColorDecisionList {
 	core::vector3df slope{1.2, 1.0, 0.8};