Implements #146 upsampling option

applications/reconstruct/src/dibr.cu

@@ -67,7 +67,10 @@ __device__ inline bool isStable(const float3 &previous, const float3 &estimate,
 	if (camPos.z < params.camera.m_sensorDepthWorldMin) return;
 	if (camPos.z > params.camera.m_sensorDepthWorldMax) return;
 
-	const int upsample = min(UPSAMPLE_MAX-2, int((2.0f*r) * params.camera.fx / camPos.z))+2;
+	// TODO: Don't upsample so much that only minimum depth makes it through
+	// Consider also using some SDF style approach to accumulate and smooth a
+	// depth value between points
+	const int upsample = min(UPSAMPLE_MAX-2, int(0.01 * params.camera.fx / camPos.z))+3;
 	const float interval = 1.0f / float(upsample / 2);
 
             
@@ -94,6 +97,35 @@ __device__ inline bool isStable(const float3 &previous, const float3 &estimate,
 	}
 }
 
+/*
+ * Pass 1: Directly render each camera into virtual view but with no upsampling
+ * for sparse points.
+ */
+ __global__ void dibr_merge_kernel(TextureObject<int> depth, int cam, SplatParams params) {
+	const ftl::voxhash::DepthCameraCUDA &camera = c_cameras[cam];
+
+	const int x = blockIdx.x*blockDim.x + threadIdx.x;
+	const int y = blockIdx.y*blockDim.y + threadIdx.y;
+
+	const float3 worldPos = make_float3(tex2D<float4>(camera.points, x, y));
+	if (worldPos.x == MINF) return;
+
+    // Find the virtual screen position of current point
+	const float3 camPos = params.m_viewMatrix * worldPos;
+	if (camPos.z < params.camera.m_sensorDepthWorldMin) return;
+	if (camPos.z > params.camera.m_sensorDepthWorldMax) return;
+
+	const float d = camPos.z;
+
+	const uint2 screenPos = params.camera.cameraToKinectScreen(camPos);
+	const unsigned int cx = screenPos.x;
+	const unsigned int cy = screenPos.y;
+	if (d > params.camera.m_sensorDepthWorldMin && d < params.camera.m_sensorDepthWorldMax && cx < depth.width() && cy < depth.height()) {
+		// Transform estimated point to virtual cam space and output z
+		atomicMin(&depth(cx,cy), d * 1000.0f);
+	}
+}
+
 // ===== PASS 2 : Splat Visible Surface ========================================
 
 /*
@@ -406,6 +438,7 @@ __global__ void OLD_dibr_visibility_kernel(TextureObject<int> depth, int cam, Sp
 		const float3 point = params.camera.kinectDepthToSkeleton(x+u, y+v, float(point_in.tex2D(x+u, y+v)) / 1000.0f);
 
 		// If it is close enough...
+		// TODO: We don't have camPos so distance if this pixel takes on same depth
 		if (length(point - camPos) <= SPATIAL_SMOOTHING) {
 			// Append to neighbour list
 			unsigned int idx = atomicInc(&nidx[warp], MAX_NEIGHBORS_2-1);
@@ -625,20 +658,33 @@ void ftl::cuda::dibr(const TextureObject<int> &depth_out,
 
 	int i=3;
 	// Pass 1, gather and upsample depth maps
-	for (int i=0; i<numcams; ++i)
-		dibr_merge_upsample_kernel<<<sgridSize, sblockSize, 0, stream>>>(tmp_depth, i, params);
+	if (params.m_flags & ftl::render::kNoUpsampling) {
+		for (int i=0; i<numcams; ++i)
+			dibr_merge_kernel<<<gridSize, blockSize, 0, stream>>>(tmp_depth, i, params);
+	} else {
+		for (int i=0; i<numcams; ++i)
+			dibr_merge_upsample_kernel<<<sgridSize, sblockSize, 0, stream>>>(tmp_depth, i, params);
+	}
 
+	if (params.m_flags & ftl::render::kNoSplatting) {
+		// Pass 3, accumulate all point contributions to pixels
+		for (int i=0; i<numcams; ++i)
+        	dibr_attribute_contrib_kernel<<<sgridSize, sblockSize, 0, stream>>>(tmp_depth, tmp_colour, normal_out, confidence_out, i, params);
+	} else {
+		// Pass 2
+		dibr_visibility_principal_kernel2<<<sgridSize, sblockSize, 0, stream>>>(tmp_depth, depth_out, params);
+
+		// Pass 3, accumulate all point contributions to pixels
+		for (int i=0; i<numcams; ++i)
+        	dibr_attribute_contrib_kernel<<<sgridSize, sblockSize, 0, stream>>>(depth_out, tmp_colour, normal_out, confidence_out, i, params);
+	}
 	// Pass 2
-	dibr_visibility_principal_kernel2<<<sgridSize, sblockSize, 0, stream>>>(tmp_depth, depth_out, params);
+	//dibr_visibility_principal_kernel2<<<sgridSize, sblockSize, 0, stream>>>(tmp_depth, depth_out, params);
 
     // Pass 2, merge a depth map from each camera.
 	//for (int i=0; i<numcams; ++i)
     //    dibr_visibility_principal_kernel<<<sgridSize, sblockSize, 0, stream>>>(depth_out, i, params);
 
-    // Pass 3, accumulate all point contributions to pixels
-    for (int i=0; i<numcams; ++i)
-        dibr_attribute_contrib_kernel<<<sgridSize, sblockSize, 0, stream>>>(depth_out, tmp_colour, normal_out, confidence_out, i, params);
-
     // Pass 4, normalise contributions
     dibr_normalise_kernel<<<gridSize, blockSize, 0, stream>>>(tmp_colour, colour_out, normal_out, confidence_out);