Move code for looking_at to Basis

core/math/basis.cpp

@@ -1129,3 +1129,21 @@ void Basis::rotate_sh(real_t *p_values) {
 	p_values[7] = -d3;
 	p_values[8] = d4 * s_scale_dst4;
 }
+
+Basis Basis::looking_at(const Vector3 &p_target, const Vector3 &p_up) {
+#ifdef MATH_CHECKS
+	ERR_FAIL_COND_V_MSG(p_target.is_equal_approx(Vector3()), Basis(), "The target vector can't be zero.");
+	ERR_FAIL_COND_V_MSG(p_up.is_equal_approx(Vector3()), Basis(), "The up vector can't be zero.");
+#endif
+	Vector3 v_z = -p_target.normalized();
+	Vector3 v_x = p_up.cross(v_z);
+#ifdef MATH_CHECKS
+	ERR_FAIL_COND_V_MSG(v_x.is_equal_approx(Vector3()), Basis(), "The target vector and up vector can't be parallel to each other.");
+#endif
+	v_x.normalize();
+	Vector3 v_y = v_z.cross(v_x);
+
+	Basis basis;
+	basis.set(v_x, v_y, v_z);
+	return basis;
+}

core/math/basis.h

@@ -242,6 +242,8 @@ public:
 
 	operator Quaternion() const { return get_quaternion(); }
 
+	static Basis looking_at(const Vector3 &p_target, const Vector3 &p_up = Vector3(0, 1, 0));
+
 	Basis(const Quaternion &p_quaternion) { set_quaternion(p_quaternion); };
 	Basis(const Quaternion &p_quaternion, const Vector3 &p_scale) { set_quaternion_scale(p_quaternion, p_scale); }
 

core/math/transform_3d.cpp

@@ -71,40 +71,12 @@ void Transform3D::rotate_basis(const Vector3 &p_axis, real_t p_phi) {
 
 Transform3D Transform3D::looking_at(const Vector3 &p_target, const Vector3 &p_up) const {
 	Transform3D t = *this;
-	t.set_look_at(origin, p_target, p_up);
+	t.basis = Basis::looking_at(p_target - origin, p_up);
 	return t;
 }
 
 void Transform3D::set_look_at(const Vector3 &p_eye, const Vector3 &p_target, const Vector3 &p_up) {
-#ifdef MATH_CHECKS
-	ERR_FAIL_COND(p_eye == p_target);
-	ERR_FAIL_COND(p_up.length() == 0);
-#endif
-	// Reference: MESA source code
-	Vector3 v_x, v_y, v_z;
-
-	/* Make rotation matrix */
-
-	/* Z vector */
-	v_z = p_eye - p_target;
-
-	v_z.normalize();
-
-	v_y = p_up;
-
-	v_x = v_y.cross(v_z);
-#ifdef MATH_CHECKS
-	ERR_FAIL_COND(v_x.length() == 0);
-#endif
-
-	/* Recompute Y = Z cross X */
-	v_y = v_z.cross(v_x);
-
-	v_x.normalize();
-	v_y.normalize();
-
-	basis.set(v_x, v_y, v_z);
-
+	basis = Basis::looking_at(p_target - p_eye, p_up);
 	origin = p_eye;
 }
 

core/variant/variant_call.cpp

@@ -1728,6 +1728,7 @@ static void _register_variant_builtin_methods() {
 	bind_method(Basis, slerp, sarray("to", "weight"), varray());
 	bind_method(Basis, is_equal_approx, sarray("b"), varray());
 	bind_method(Basis, get_rotation_quaternion, sarray(), varray());
+	bind_static_method(Basis, looking_at, sarray("target", "up"), varray(Vector3(0, 1, 0)));
 
 	/* AABB */
 

doc/classes/Basis.xml

@@ -109,6 +109,15 @@
 				Returns [code]true[/code] if this basis and [code]b[/code] are approximately equal, by calling [code]is_equal_approx[/code] on each component.
 			</description>
 		</method>
+		<method name="looking_at" qualifiers="static">
+			<return type="Basis" />
+			<argument index="0" name="target" type="Vector3" />
+			<argument index="1" name="up" type="Vector3" default="Vector3(0, 1, 0)" />
+			<description>
+				Creates a Basis with a rotation such that the forward axis (-Z) points towards the [code]target[/code] position.
+				The up axis (+Y) points as close to the [code]up[/code] vector as possible while staying perpendicular to the forward axis. The resulting Basis is orthonormalized. The [code]target[/code] and [code]up[/code] vectors cannot be zero, and cannot be parallel to each other.
+			</description>
+		</method>
 		<method name="operator !=" qualifiers="operator">
 			<return type="bool" />
 			<argument index="0" name="right" type="Basis" />

doc/classes/Node3D.xml

@@ -113,8 +113,9 @@
 			<argument index="0" name="target" type="Vector3" />
 			<argument index="1" name="up" type="Vector3" default="Vector3(0, 1, 0)" />
 			<description>
-				Rotates itself so that the local -Z axis points towards the [code]target[/code] position.
-				The transform will first be rotated around the given [code]up[/code] vector, and then fully aligned to the target by a further rotation around an axis perpendicular to both the [code]target[/code] and [code]up[/code] vectors.
+				Rotates the node so that the local forward axis (-Z) points toward the [code]target[/code] position.
+				The local up axis (+Y) points as close to the [code]up[/code] vector as possible while staying perpendicular to the local forward axis. The resulting transform is orthogonal, and the scale is preserved. Non-uniform scaling may not work correctly.
+				The [code]target[/code] position cannot be the same as the node's position, the [code]up[/code] vector cannot be zero, and the direction from the node's position to the [code]target[/code] vector cannot be parallel to the [code]up[/code] vector.
 				Operations take place in global space.
 			</description>
 		</method>
@@ -124,7 +125,7 @@
 			<argument index="1" name="target" type="Vector3" />
 			<argument index="2" name="up" type="Vector3" default="Vector3(0, 1, 0)" />
 			<description>
-				Moves the node to the specified [code]position[/code], and then rotates itself to point toward the [code]target[/code] as per [method look_at]. Operations take place in global space.
+				Moves the node to the specified [code]position[/code], and then rotates the node to point toward the [code]target[/code] as per [method look_at]. Operations take place in global space.
 			</description>
 		</method>
 		<method name="orthonormalize">

doc/classes/Transform3D.xml

@@ -79,9 +79,8 @@
 			<argument index="0" name="target" type="Vector3" />
 			<argument index="1" name="up" type="Vector3" default="Vector3(0, 1, 0)" />
 			<description>
-				Returns a copy of the transform rotated such that its -Z axis points towards the [code]target[/code] position.
-				The transform will first be rotated around the given [code]up[/code] vector, and then fully aligned to the target by a further rotation around an axis perpendicular to both the [code]target[/code] and [code]up[/code] vectors.
-				Operations take place in global space.
+				Returns a copy of the transform rotated such that the forward axis (-Z) points towards the [code]target[/code] position.
+				The up axis (+Y) points as close to the [code]up[/code] vector as possible while staying perpendicular to the forward axis. The resulting transform is orthonormalized. The existing rotation, scale, and skew information from the original transform is discarded. The [code]target[/code] and [code]up[/code] vectors cannot be zero, cannot be parallel to each other, and are defined in global/parent space.
 			</description>
 		</method>
 		<method name="operator !=" qualifiers="operator">

editor/plugins/skeleton_3d_editor_plugin.cpp

@@ -397,7 +397,7 @@ PhysicalBone3D *Skeleton3DEditor::create_physical_bone(int bone_id, int bone_chi
 	bone_shape->set_transform(capsule_transform);
 
 	Transform3D body_transform;
-	body_transform.set_look_at(Vector3(0, 0, 0), child_rest.origin);
+	body_transform.basis = Basis::looking_at(child_rest.origin);
 	body_transform.origin = body_transform.basis.xform(Vector3(0, 0, -half_height));
 
 	Transform3D joint_transform;

scene/3d/node_3d.cpp

@@ -673,19 +673,17 @@ void Node3D::set_identity() {
 }
 
 void Node3D::look_at(const Vector3 &p_target, const Vector3 &p_up) {
-	Vector3 origin(get_global_transform().origin);
+	Vector3 origin = get_global_transform().origin;
 	look_at_from_position(origin, p_target, p_up);
 }
 
 void Node3D::look_at_from_position(const Vector3 &p_pos, const Vector3 &p_target, const Vector3 &p_up) {
-	ERR_FAIL_COND_MSG(p_pos == p_target, "Node origin and target are in the same position, look_at() failed.");
-	ERR_FAIL_COND_MSG(p_up.cross(p_target - p_pos) == Vector3(), "Up vector and direction between node origin and target are aligned, look_at() failed.");
+	ERR_FAIL_COND_MSG(p_pos.is_equal_approx(p_target), "Node origin and target are in the same position, look_at() failed.");
+	ERR_FAIL_COND_MSG(p_up.is_equal_approx(Vector3()), "The up vector can't be zero, look_at() failed.");
+	ERR_FAIL_COND_MSG(p_up.cross(p_target - p_pos).is_equal_approx(Vector3()), "Up vector and direction between node origin and target are aligned, look_at() failed.");
 
-	Transform3D lookat;
-	lookat.origin = p_pos;
-
-	Vector3 original_scale(get_scale());
-	lookat = lookat.looking_at(p_target, p_up);
+	Transform3D lookat = Transform3D(Basis::looking_at(p_target - p_pos, p_up), p_pos);
+	Vector3 original_scale = get_scale();
 	set_global_transform(lookat);
 	set_scale(original_scale);
 }

servers/rendering/renderer_rd/renderer_scene_sky_rd.cpp

@@ -1177,12 +1177,11 @@ void RendererSceneSkyRD::update(RendererSceneEnvironmentRD *p_env, const CameraM
 			RD::DrawListID cubemap_draw_list;
 
 			for (int i = 0; i < 6; i++) {
-				Transform3D local_view;
-				local_view.set_look_at(Vector3(0, 0, 0), view_normals[i], view_up[i]);
+				Basis local_view = Basis::looking_at(view_normals[i], view_up[i]);
 				RID texture_uniform_set = sky->get_textures(storage, SKY_TEXTURE_SET_CUBEMAP_QUARTER_RES, sky_shader.default_shader_rd);
 
 				cubemap_draw_list = RD::get_singleton()->draw_list_begin(sky->reflection.layers[0].mipmaps[2].framebuffers[i], RD::INITIAL_ACTION_KEEP, RD::FINAL_ACTION_READ, RD::INITIAL_ACTION_KEEP, RD::FINAL_ACTION_DISCARD);
-				_render_sky(cubemap_draw_list, p_time, sky->reflection.layers[0].mipmaps[2].framebuffers[i], pipeline, material->uniform_set, texture_uniform_set, 1, &cm, local_view.basis, multiplier, p_transform.origin);
+				_render_sky(cubemap_draw_list, p_time, sky->reflection.layers[0].mipmaps[2].framebuffers[i], pipeline, material->uniform_set, texture_uniform_set, 1, &cm, local_view, multiplier, p_transform.origin);
 				RD::get_singleton()->draw_list_end();
 			}
 		}
@@ -1195,12 +1194,11 @@ void RendererSceneSkyRD::update(RendererSceneEnvironmentRD *p_env, const CameraM
 			RD::DrawListID cubemap_draw_list;
 
 			for (int i = 0; i < 6; i++) {
-				Transform3D local_view;
-				local_view.set_look_at(Vector3(0, 0, 0), view_normals[i], view_up[i]);
+				Basis local_view = Basis::looking_at(view_normals[i], view_up[i]);
 				RID texture_uniform_set = sky->get_textures(storage, SKY_TEXTURE_SET_CUBEMAP_HALF_RES, sky_shader.default_shader_rd);
 
 				cubemap_draw_list = RD::get_singleton()->draw_list_begin(sky->reflection.layers[0].mipmaps[1].framebuffers[i], RD::INITIAL_ACTION_KEEP, RD::FINAL_ACTION_READ, RD::INITIAL_ACTION_KEEP, RD::FINAL_ACTION_DISCARD);
-				_render_sky(cubemap_draw_list, p_time, sky->reflection.layers[0].mipmaps[1].framebuffers[i], pipeline, material->uniform_set, texture_uniform_set, 1, &cm, local_view.basis, multiplier, p_transform.origin);
+				_render_sky(cubemap_draw_list, p_time, sky->reflection.layers[0].mipmaps[1].framebuffers[i], pipeline, material->uniform_set, texture_uniform_set, 1, &cm, local_view, multiplier, p_transform.origin);
 				RD::get_singleton()->draw_list_end();
 			}
 		}
@@ -1209,12 +1207,11 @@ void RendererSceneSkyRD::update(RendererSceneEnvironmentRD *p_env, const CameraM
 		PipelineCacheRD *pipeline = &shader_data->pipelines[SKY_VERSION_CUBEMAP];
 
 		for (int i = 0; i < 6; i++) {
-			Transform3D local_view;
-			local_view.set_look_at(Vector3(0, 0, 0), view_normals[i], view_up[i]);
+			Basis local_view = Basis::looking_at(view_normals[i], view_up[i]);
 			RID texture_uniform_set = sky->get_textures(storage, SKY_TEXTURE_SET_CUBEMAP, sky_shader.default_shader_rd);
 
 			cubemap_draw_list = RD::get_singleton()->draw_list_begin(sky->reflection.layers[0].mipmaps[0].framebuffers[i], RD::INITIAL_ACTION_KEEP, RD::FINAL_ACTION_READ, RD::INITIAL_ACTION_KEEP, RD::FINAL_ACTION_DISCARD);
-			_render_sky(cubemap_draw_list, p_time, sky->reflection.layers[0].mipmaps[0].framebuffers[i], pipeline, material->uniform_set, texture_uniform_set, 1, &cm, local_view.basis, multiplier, p_transform.origin);
+			_render_sky(cubemap_draw_list, p_time, sky->reflection.layers[0].mipmaps[0].framebuffers[i], pipeline, material->uniform_set, texture_uniform_set, 1, &cm, local_view, multiplier, p_transform.origin);
 			RD::get_singleton()->draw_list_end();
 		}
 

tests/test_render.cpp

@@ -184,7 +184,7 @@ public:
 		light = vs->instance_create2(lightaux, scenario);
 		Transform3D lla;
 		//lla.set_look_at(Vector3(),Vector3(1, -1, 1));
-		lla.set_look_at(Vector3(), Vector3(0.0, -0.836026, -0.548690));
+		lla.basis = Basis::looking_at(Vector3(0.0, -0.836026, -0.548690));
 
 		vs->instance_set_transform(light, lla);