Fixed flickering with frustrum culling at very small field of view

Author: ProjectPhysX

src/graphics.hpp

@@ -302,7 +302,7 @@ class Camera {
 		}
 	}
 	void input_X() {
-		fov = fmax(fov-1.0f, 1.0f);
+		fov = fmax(fov-1.0f, 1E-6f);
 		dis = 0.5f*(float)width/tan(fov*pif/360.0f);
 	}
 	void input_Y() {

src/kernel.cpp

@@ -823,10 +823,11 @@ string opencl_c_container() { return R( // ########################## begin of O
 	const float x_right  = !vr ? (float)( (int)def_screen_width/2-1) : ((float)( (int)def_screen_width/2-1)-(float)(def_screen_width/4u))*rtv;
 	const float y_top    = (float)(-(int)def_screen_height/2 );
 	const float y_bottom = (float)((int)def_screen_height/2-1);
-	float3 r00 = p0+normalize((float3)(x_left , y_top   , -dis)); // get 4 edge vectors of frustrum, get_camray(...) inlined and redundant parts eliminated
-	float3 r01 = p0+normalize((float3)(x_right, y_top   , -dis));
-	float3 r10 = p0+normalize((float3)(x_left , y_bottom, -dis));
-	float3 r11 = p0+normalize((float3)(x_right, y_bottom, -dis));
+	const float dis_clamped = fmin(dis, 1E4f); // avoid flickering at very small field of view
+	float3 r00 = p0+normalize((float3)(x_left , y_top   , -dis_clamped)); // get 4 edge vectors of frustrum, get_camray(...) inlined and redundant parts eliminated
+	float3 r01 = p0+normalize((float3)(x_right, y_top   , -dis_clamped));
+	float3 r10 = p0+normalize((float3)(x_left , y_bottom, -dis_clamped));
+	float3 r11 = p0+normalize((float3)(x_right, y_bottom, -dis_clamped));
 	r00 = Rx*r00.x+Ry*r00.y+Rz*r00.z+pos-camera_center; // reverse rotation and reverse transformation of r00
 	r01 = Rx*r01.x+Ry*r01.y+Rz*r01.z+pos-camera_center; // reverse rotation and reverse transformation of r01
 	r10 = Rx*r10.x+Ry*r10.y+Rz*r10.z+pos-camera_center; // reverse rotation and reverse transformation of r10

src/setup.cpp

@@ -717,7 +717,7 @@ void main_setup() { // benchmark; required extensions in defines.hpp: BENCHMARK,
 		if(x==0u||x==Nx-1u||y==0u||y==Ny-1u||z==Nz-1u) lbm.flags[n] = TYPE_E;
 	}); // ####################################################################### run simulation, export images and data ##########################################################################
 	lbm.graphics.visualization_modes = VIS_FLAG_SURFACE|VIS_Q_CRITERION;
-	lbm.graphics.set_camera_centered(20.0f, 30.0f, 1.0f, 1.648722f);
+	lbm.graphics.set_camera_centered(20.0f, 30.0f, 0.0f, 1.648722f);
 	lbm.run(0u); // initialize simulation
 #if defined(FP16S)
 	const string path = get_exe_path()+"FP16S/"+to_string(memory)+"MB/";