Merge branch 'feature/222/meshmerge' into 'master'

Implements #222 simple mesh merge

Closes #222

See merge request nicolas.pope/ftl!154

components/renderers/cpp/src/splatter_cuda.hpp

@@ -21,6 +21,13 @@ namespace cuda {
 		ftl::cuda::TextureObject<short2> &screen,
 		const ftl::render::SplatParams &params,
 		cudaStream_t stream);
+
+	void mesh_blender(
+		ftl::cuda::TextureObject<int> &depth_in,
+		ftl::cuda::TextureObject<int> &depth_out,
+		const ftl::rgbd::Camera &camera,
+		float alpha,
+		cudaStream_t stream);
 	
 	void dibr_merge(
 		ftl::cuda::TextureObject<float4> &points,

components/renderers/cpp/src/tri_render.cpp

@@ -292,8 +292,17 @@ void Triangular::_dibr(cudaStream_t stream) {
 
 void Triangular::_mesh(cudaStream_t stream) {
 	cv::cuda::Stream cvstream = cv::cuda::StreamAccessor::wrapStream(stream);
-	temp_.get<GpuMat>(Channel::Depth2).setTo(cv::Scalar(0x7FFFFFFF), cvstream);
 
+	bool do_blend = value("mesh_blend", true);
+	float blend_alpha = value("blend_alpha", 0.02f);
+	if (do_blend) {
+		temp_.get<GpuMat>(Channel::Depth).setTo(cv::Scalar(0x7FFFFFFF), cvstream);
+		temp_.get<GpuMat>(Channel::Depth2).setTo(cv::Scalar(0x7FFFFFFF), cvstream);
+	} else {
+		temp_.get<GpuMat>(Channel::Depth2).setTo(cv::Scalar(0x7FFFFFFF), cvstream);
+	}
+
+	// For each source depth map
 	for (size_t i=0; i < scene_->frames.size(); ++i) {
 		auto &f = scene_->frames[i];
 		auto *s = scene_->sources[i];
@@ -305,6 +314,7 @@ void Triangular::_mesh(cudaStream_t stream) {
 
 		auto pose = MatrixConversion::toCUDA(s->getPose().cast<float>());
 
+		// Calculate and save virtual view screen position of each source pixel
 		ftl::cuda::screen_coord(
 			f.createTexture<float>(Channel::Depth),
 			f.createTexture<float>(Channel::Depth2, Format<float>(f.get<GpuMat>(Channel::Depth).size())),
@@ -312,14 +322,29 @@ void Triangular::_mesh(cudaStream_t stream) {
 			params_, pose, s->parameters(), stream
 		);
 
+		// Must reset depth channel if blending
+		if (do_blend) {
+			temp_.get<GpuMat>(Channel::Depth).setTo(cv::Scalar(0x7FFFFFFF), cvstream);
+		}
+
+		// Decide on and render triangles around each point
 		ftl::cuda::triangle_render1(
 			f.getTexture<float>(Channel::Depth2),
-			temp_.createTexture<int>(Channel::Depth2),
+			temp_.createTexture<int>((do_blend) ? Channel::Depth : Channel::Depth2),
 			f.getTexture<short2>(Channel::Screen),
 			params_, stream
 		);
 
-		//LOG(INFO) << "DIBR DONE";
+		if (do_blend) {
+			// Blend this sources mesh with previous meshes
+			ftl::cuda::mesh_blender(
+				temp_.getTexture<int>(Channel::Depth),
+				temp_.createTexture<int>(Channel::Depth2),
+				params_.camera,
+				blend_alpha,
+				stream
+			);
+		}
 	}
 }
 

components/renderers/cpp/src/triangle_render.cu

@@ -3,6 +3,8 @@
 #include <ftl/rgbd/camera.hpp>
 #include <ftl/cuda_common.hpp>
 
+#include <ftl/cuda/weighting.hpp>
+
 using ftl::rgbd::Camera;
 using ftl::cuda::TextureObject;
 using ftl::render::SplatParams;
@@ -162,3 +164,39 @@ void ftl::cuda::triangle_render1(TextureObject<float> &depth_in, TextureObject<i
 	triangle_render_1_kernel<-1,-1><<<gridSize, blockSize, 0, stream>>>(depth_in, depth_out, screen, params);
     cudaSafeCall( cudaGetLastError() );
 }
+
+// ==== BLENDER ========
+
+/*
+ * Merge two depth maps together
+ */
+ __global__ void mesh_blender_kernel(
+        TextureObject<int> depth_in,
+		TextureObject<int> depth_out,
+		ftl::rgbd::Camera camera,
+		float alpha) {
+	const int x = blockIdx.x*blockDim.x + threadIdx.x;
+	const int y = blockIdx.y*blockDim.y + threadIdx.y;
+
+    if (x < 0 || x >= depth_in.width() || y < 0 || y >= depth_in.height()) return;
+
+	int a = depth_in.tex2D(x,y);
+	int b = depth_out.tex2D(x,y);
+
+	float mindepth = (float)min(a,b) / 100000.0f;
+	float maxdepth = (float)max(a,b) / 100000.0f;
+	float weight = ftl::cuda::weighting(maxdepth-mindepth, alpha);
+
+	//depth_out(x,y) = (int)(((float)mindepth + (float)maxdepth*weight) / (1.0f + weight) * 100000.0f);
+
+	float depth = (mindepth + maxdepth*weight) / (1.0f + weight);
+	depth_out(x,y) = (int)(depth * 100000.0f);
+}
+
+void ftl::cuda::mesh_blender(TextureObject<int> &depth_in, TextureObject<int> &depth_out, const ftl::rgbd::Camera &camera, float alpha, cudaStream_t stream) {
+    const dim3 gridSize((depth_in.width() + T_PER_BLOCK - 1)/T_PER_BLOCK, (depth_in.height() + T_PER_BLOCK - 1)/T_PER_BLOCK);
+    const dim3 blockSize(T_PER_BLOCK, T_PER_BLOCK);
+
+	mesh_blender_kernel<<<gridSize, blockSize, 0, stream>>>(depth_in, depth_out, camera, alpha);
+    cudaSafeCall( cudaGetLastError() );
+}