Fix quaternion slerp in camera paths

NVlabs · Jan 31, 2024 · f45655b · f45655b
1 parent be449a7
commit f45655b
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Showing 4 changed files with 11 additions and 6 deletions.
diff --git a/dependencies/tiny-cuda-nn b/dependencies/tiny-cuda-nn
diff --git a/include/neural-graphics-primitives/camera_path.h b/include/neural-graphics-primitives/camera_path.h
@@ -40,7 +40,7 @@ struct CameraKeyframe {
 	int glow_mode;
 	float glow_y_cutoff;
 	mat4x3 m() const {
-		auto rot = to_mat3(normalize(quat(R)));
+		auto rot = to_mat3(normalize(R));
 		return mat4x3(rot[0], rot[1], rot[2], T);
 	}
 

diff --git a/include/neural-graphics-primitives/common_device.cuh b/include/neural-graphics-primitives/common_device.cuh
@@ -656,8 +656,7 @@ inline NGP_HOST_DEVICE mat4x3 camera_slerp(const mat4x3& a, const mat4x3& b, flo
 
 inline NGP_HOST_DEVICE mat4x3 get_xform_given_rolling_shutter(const TrainingXForm& training_xform, const vec4& rolling_shutter, const vec2& uv, float motionblur_time) {
 	float pixel_t = rolling_shutter.x + rolling_shutter.y * uv.x + rolling_shutter.z * uv.y + rolling_shutter.w * motionblur_time;
-	return camera_log_lerp(training_xform.start, training_xform.end, pixel_t);
-	// return camera_slerp(training_xform.start, training_xform.end, pixel_t);
+	return camera_slerp(training_xform.start, training_xform.end, pixel_t);
 }
 
 inline NGP_HOST_DEVICE void apply_quilting(uint32_t* x, uint32_t* y, const ivec2& resolution, vec3& parallax_shift, const ivec2& quilting_dims) {

diff --git a/src/camera_path.cu b/src/camera_path.cu
@@ -38,7 +38,7 @@ CameraKeyframe lerp(const CameraKeyframe& p0, const CameraKeyframe& p1, float t,
 	}
 
 	return {
-		slerp(p0.R, R1, t),
+		normalize(slerp(p0.R, R1, t)),
 		p0.T + (p1.T - p0.T) * t,
 		p0.slice + (p1.slice - p0.slice) * t,
 		p0.scale + (p1.scale - p0.scale) * t,
@@ -50,6 +50,12 @@ CameraKeyframe lerp(const CameraKeyframe& p0, const CameraKeyframe& p1, float t,
 	};
 }
 
+CameraKeyframe normalize(const CameraKeyframe& p0) {
+	CameraKeyframe result = p0;
+	result.R = normalize(result.R);
+	return result;
+}
+
 CameraKeyframe spline(float t, const CameraKeyframe& p0, const CameraKeyframe& p1, const CameraKeyframe& p2, const CameraKeyframe& p3) {
 	if (0) {
 		// catmull rom spline
@@ -67,7 +73,7 @@ CameraKeyframe spline(float t, const CameraKeyframe& p0, const CameraKeyframe& p
 		float b = (3.f*ttt-6.f*tt+4.f)*(1.f/6.f);
 		float c = (-3.f*ttt+3.f*tt+3.f*t+1.f)*(1.f/6.f);
 		float d = ttt*(1.f/6.f);
-		return p0 * a + p1 * b + p2 * c + p3 * d;
+		return normalize(p0 * a + p1 * b + p2 * c + p3 * d);
 	}
 }