Implements #151 alternate minimums

Loops over other possible surfaces during render.

applications/reconstruct/src/dibr.cu

@@ -418,6 +418,10 @@ __device__ inline float warpMin(float e) {
 	const int x = (blockIdx.x*blockDim.x + threadIdx.x) / WARP_SIZE;
 	const int y = blockIdx.y*blockDim.y + threadIdx.y;
 
+	float clusterBase = params.camera.m_sensorDepthWorldMin;
+
+	while (clusterBase < params.camera.m_sensorDepthWorldMax) {
+
 	const int lane = tid % WARP_SIZE;
 	if (lane == 0) {
 		minimum[warp] = 100000000;
@@ -428,6 +432,8 @@ __device__ inline float warpMin(float e) {
 	__syncwarp();
 
 	// Search for a valid minimum neighbour
+	// TODO: Should this really be minimum or the median of a depth cluster?
+	// cluster median seems very hard to calculate...
 	for (int i=lane; i<NEIGHBOR_WINDOW; i+=WARP_SIZE) {
 		const int u = (i % (2*NEIGHBOR_RADIUS_2+1)) - NEIGHBOR_RADIUS_2;
 		const int v = (i / (2*NEIGHBOR_RADIUS_2+1)) - NEIGHBOR_RADIUS_2;
@@ -435,7 +441,7 @@ __device__ inline float warpMin(float e) {
 		const float3 camPos = params.camera.kinectDepthToSkeleton(x, y, point.z);
 
 		// If it is close enough...
-		if (point.z > params.camera.m_sensorDepthWorldMin && point.z < params.camera.m_sensorDepthWorldMax && length(point - camPos) <= 0.02f) {
+		if (point.z > clusterBase && point.z < params.camera.m_sensorDepthWorldMax && length(point - camPos) <= SPATIAL_SMOOTHING) {
 			atomicMin(&minimum[warp], point.z*1000.0f);
 		}
 	}
@@ -457,7 +463,7 @@ __device__ inline float warpMin(float e) {
 		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...
-		if (point.z > params.camera.m_sensorDepthWorldMin && point.z < params.camera.m_sensorDepthWorldMax && length(point - minPos) <= 0.02f) {
+		if (point.z > params.camera.m_sensorDepthWorldMin && point.z < params.camera.m_sensorDepthWorldMax && length(point - minPos) <= SPATIAL_SMOOTHING) {
 			// Append to neighbour list
 			//unsigned int idx = atomicInc(&nidx[warp], MAX_NEIGHBORS_2-1);
 			unsigned int idx = atomicAdd(&nidx[warp], 1);
@@ -517,6 +523,12 @@ __device__ inline float warpMin(float e) {
 			//depth(cx,cy) = bestdepth * 1000.0f;
 		}
 	}
+
+	if (maxenergy >= 0.1f) return;
+
+	clusterBase = minDepth + SPATIAL_SMOOTHING;
+
+	};
 }
 
 // ===== Pass 2 and 3 : Attribute contributions ================================