Add cone angle control to particle emission ring shape

doc/classes/CPUParticles3D.xml

@@ -168,6 +168,10 @@
 		<member name="emission_ring_axis" type="Vector3" setter="set_emission_ring_axis" getter="get_emission_ring_axis">
 			The axis of the ring when using the emitter [constant EMISSION_SHAPE_RING].
 		</member>
+		<member name="emission_ring_cone_angle" type="float" setter="set_emission_ring_cone_angle" getter="get_emission_ring_cone_angle">
+			The angle of the cone when using the emitter [constant EMISSION_SHAPE_RING]. The default angle of 90 degrees results in a ring, while an angle of 0 degrees results in a cone. Intermediate values will result in a ring where one end is larger than the other.
+			[b]Note:[/b] Depending on [member emission_ring_height], the angle may be clamped if the ring's end is reached to form a perfect cone.
+		</member>
 		<member name="emission_ring_height" type="float" setter="set_emission_ring_height" getter="get_emission_ring_height">
 			The height of the ring when using the emitter [constant EMISSION_SHAPE_RING].
 		</member>

doc/classes/ParticleProcessMaterial.xml

@@ -207,6 +207,10 @@
 		<member name="emission_ring_axis" type="Vector3" setter="set_emission_ring_axis" getter="get_emission_ring_axis">
 			The axis of the ring when using the emitter [constant EMISSION_SHAPE_RING].
 		</member>
+		<member name="emission_ring_cone_angle" type="float" setter="set_emission_ring_cone_angle" getter="get_emission_ring_cone_angle">
+			The angle of the cone when using the emitter [constant EMISSION_SHAPE_RING]. The default angle of 90 degrees results in a ring, while an angle of 0 degrees results in a cone. Intermediate values will result in a ring where one end is larger than the other.
+			[b]Note:[/b] Depending on [member emission_ring_height], the angle may be clamped if the ring's end is reached to form a perfect cone.
+		</member>
 		<member name="emission_ring_height" type="float" setter="set_emission_ring_height" getter="get_emission_ring_height">
 			The height of the ring when using the emitter [constant EMISSION_SHAPE_RING].
 		</member>

scene/3d/cpu_particles_3d.cpp

@@ -448,6 +448,10 @@ void CPUParticles3D::set_emission_ring_inner_radius(real_t p_radius) {
 	emission_ring_inner_radius = p_radius;
 }
 
+void CPUParticles3D::set_emission_ring_cone_angle(real_t p_angle) {
+	emission_ring_cone_angle = p_angle;
+}
+
 void CPUParticles3D::set_scale_curve_x(Ref<Curve> p_scale_curve) {
 	scale_curve_x = p_scale_curve;
 }
@@ -501,6 +505,10 @@ real_t CPUParticles3D::get_emission_ring_inner_radius() const {
 	return emission_ring_inner_radius;
 }
 
+real_t CPUParticles3D::get_emission_ring_cone_angle() const {
+	return emission_ring_cone_angle;
+}
+
 CPUParticles3D::EmissionShape CPUParticles3D::get_emission_shape() const {
 	return emission_shape;
 }
@@ -878,8 +886,14 @@ void CPUParticles3D::_particles_process(double p_delta) {
 					}
 				} break;
 				case EMISSION_SHAPE_RING: {
+					real_t radius_clamped = MAX(0.001, emission_ring_radius);
+					real_t top_radius = MAX(radius_clamped - Math::tan(Math::deg_to_rad(90.0 - emission_ring_cone_angle)) * emission_ring_height, 0.0);
+					real_t y_pos = Math::randf();
+					real_t skew = MAX(MIN(radius_clamped, top_radius) / MAX(radius_clamped, top_radius), 0.5);
+					y_pos = radius_clamped < top_radius ? Math::pow(y_pos, skew) : 1.0 - Math::pow(y_pos, skew);
 					real_t ring_random_angle = Math::randf() * Math_TAU;
-					real_t ring_random_radius = Math::sqrt(Math::randf() * (emission_ring_radius * emission_ring_radius - emission_ring_inner_radius * emission_ring_inner_radius) + emission_ring_inner_radius * emission_ring_inner_radius);
+					real_t ring_random_radius = Math::sqrt(Math::randf() * (radius_clamped * radius_clamped - emission_ring_inner_radius * emission_ring_inner_radius) + emission_ring_inner_radius * emission_ring_inner_radius);
+					ring_random_radius = Math::lerp(ring_random_radius, ring_random_radius * (top_radius / radius_clamped), y_pos);
 					Vector3 axis = emission_ring_axis == Vector3(0.0, 0.0, 0.0) ? Vector3(0.0, 0.0, 1.0) : emission_ring_axis.normalized();
 					Vector3 ortho_axis;
 					if (axis.abs() == Vector3(1.0, 0.0, 0.0)) {
@@ -890,7 +904,7 @@ void CPUParticles3D::_particles_process(double p_delta) {
 					ortho_axis = ortho_axis.normalized();
 					ortho_axis.rotate(axis, ring_random_angle);
 					ortho_axis = ortho_axis.normalized();
-					p.transform.origin = ortho_axis * ring_random_radius + (Math::randf() * emission_ring_height - emission_ring_height / 2.0) * axis;
+					p.transform.origin = ortho_axis * ring_random_radius + (y_pos * emission_ring_height - emission_ring_height / 2.0) * axis;
 				} break;
 				case EMISSION_SHAPE_MAX: { // Max value for validity check.
 					break;
@@ -1550,6 +1564,9 @@ void CPUParticles3D::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("set_emission_ring_inner_radius", "inner_radius"), &CPUParticles3D::set_emission_ring_inner_radius);
 	ClassDB::bind_method(D_METHOD("get_emission_ring_inner_radius"), &CPUParticles3D::get_emission_ring_inner_radius);
 
+	ClassDB::bind_method(D_METHOD("set_emission_ring_cone_angle", "cone_angle"), &CPUParticles3D::set_emission_ring_cone_angle);
+	ClassDB::bind_method(D_METHOD("get_emission_ring_cone_angle"), &CPUParticles3D::get_emission_ring_cone_angle);
+
 	ClassDB::bind_method(D_METHOD("get_gravity"), &CPUParticles3D::get_gravity);
 	ClassDB::bind_method(D_METHOD("set_gravity", "accel_vec"), &CPUParticles3D::set_gravity);
 
@@ -1577,9 +1594,10 @@ void CPUParticles3D::_bind_methods() {
 	ADD_PROPERTY(PropertyInfo(Variant::PACKED_VECTOR3_ARRAY, "emission_normals"), "set_emission_normals", "get_emission_normals");
 	ADD_PROPERTY(PropertyInfo(Variant::PACKED_COLOR_ARRAY, "emission_colors"), "set_emission_colors", "get_emission_colors");
 	ADD_PROPERTY(PropertyInfo(Variant::VECTOR3, "emission_ring_axis"), "set_emission_ring_axis", "get_emission_ring_axis");
-	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "emission_ring_height"), "set_emission_ring_height", "get_emission_ring_height");
-	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "emission_ring_radius"), "set_emission_ring_radius", "get_emission_ring_radius");
-	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "emission_ring_inner_radius"), "set_emission_ring_inner_radius", "get_emission_ring_inner_radius");
+	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "emission_ring_height", PROPERTY_HINT_RANGE, "0,1000,0.01,or_greater"), "set_emission_ring_height", "get_emission_ring_height");
+	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "emission_ring_radius", PROPERTY_HINT_RANGE, "0,1000,0.01,or_greater"), "set_emission_ring_radius", "get_emission_ring_radius");
+	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "emission_ring_inner_radius", PROPERTY_HINT_RANGE, "0,1000,0.01,or_greater"), "set_emission_ring_inner_radius", "get_emission_ring_inner_radius");
+	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "emission_ring_cone_angle", PROPERTY_HINT_RANGE, "0,90,0.01,degrees"), "set_emission_ring_cone_angle", "get_emission_ring_cone_angle");
 	ADD_GROUP("Particle Flags", "particle_flag_");
 	ADD_PROPERTYI(PropertyInfo(Variant::BOOL, "particle_flag_align_y"), "set_particle_flag", "get_particle_flag", PARTICLE_FLAG_ALIGN_Y_TO_VELOCITY);
 	ADD_PROPERTYI(PropertyInfo(Variant::BOOL, "particle_flag_rotate_y"), "set_particle_flag", "get_particle_flag", PARTICLE_FLAG_ROTATE_Y);
@@ -1716,6 +1734,7 @@ CPUParticles3D::CPUParticles3D() {
 	set_emission_ring_height(1);
 	set_emission_ring_radius(1);
 	set_emission_ring_inner_radius(0);
+	set_emission_ring_cone_angle(90);
 
 	set_gravity(Vector3(0, -9.8, 0));
 

scene/3d/cpu_particles_3d.h

@@ -178,6 +178,7 @@ private:
 	real_t emission_ring_height = 0.0;
 	real_t emission_ring_radius = 0.0;
 	real_t emission_ring_inner_radius = 0.0;
+	real_t emission_ring_cone_angle = 0.0;
 
 	Ref<Curve> scale_curve_x;
 	Ref<Curve> scale_curve_y;
@@ -282,6 +283,7 @@ public:
 	void set_emission_ring_height(real_t p_height);
 	void set_emission_ring_radius(real_t p_radius);
 	void set_emission_ring_inner_radius(real_t p_radius);
+	void set_emission_ring_cone_angle(real_t p_angle);
 	void set_scale_curve_x(Ref<Curve> p_scale_curve);
 	void set_scale_curve_y(Ref<Curve> p_scale_curve);
 	void set_scale_curve_z(Ref<Curve> p_scale_curve);
@@ -297,6 +299,7 @@ public:
 	real_t get_emission_ring_height() const;
 	real_t get_emission_ring_radius() const;
 	real_t get_emission_ring_inner_radius() const;
+	real_t get_emission_ring_cone_angle() const;
 	Ref<Curve> get_scale_curve_x() const;
 	Ref<Curve> get_scale_curve_y() const;
 	Ref<Curve> get_scale_curve_z() const;

scene/resources/particle_process_material.cpp

@@ -110,6 +110,7 @@ void ParticleProcessMaterial::init_shaders() {
 	shader_names->emission_ring_height = "emission_ring_height";
 	shader_names->emission_ring_radius = "emission_ring_radius";
 	shader_names->emission_ring_inner_radius = "emission_ring_inner_radius";
+	shader_names->emission_ring_cone_angle = "emission_ring_cone_angle";
 	shader_names->emission_shape_offset = "emission_shape_offset";
 	shader_names->emission_shape_scale = "emission_shape_scale";
 
@@ -269,6 +270,7 @@ void ParticleProcessMaterial::_update_shader() {
 			code += "uniform float " + shader_names->emission_ring_height + ";\n";
 			code += "uniform float " + shader_names->emission_ring_radius + ";\n";
 			code += "uniform float " + shader_names->emission_ring_inner_radius + ";\n";
+			code += "uniform float " + shader_names->emission_ring_cone_angle + ";\n";
 		} break;
 		case EMISSION_SHAPE_MAX: { // Max value for validity check.
 			break;
@@ -643,8 +645,14 @@ void ParticleProcessMaterial::_update_shader() {
 		code += "		pos = texelFetch(emission_texture_points, emission_tex_ofs, 0).xyz;\n";
 	}
 	if (emission_shape == EMISSION_SHAPE_RING) {
+		code += "		float radius_clamped = max(0.001, emission_ring_radius);\n";
+		code += "		float top_radius = max(radius_clamped - tan(radians(90.0 - emission_ring_cone_angle)) * emission_ring_height, 0.0);\n";
+		code += "		float y_pos = rand_from_seed(alt_seed);\n";
+		code += "		float skew = max(min(radius_clamped, top_radius) / max(radius_clamped, top_radius), 0.5);\n";
+		code += "		y_pos = radius_clamped < top_radius ? pow(y_pos, skew) : 1.0 - pow(y_pos, skew);\n";
 		code += "		float ring_spawn_angle = rand_from_seed(alt_seed) * 2.0 * pi;\n";
-		code += "		float ring_random_radius = sqrt(rand_from_seed(alt_seed) * (emission_ring_radius * emission_ring_radius - emission_ring_inner_radius * emission_ring_inner_radius) + emission_ring_inner_radius * emission_ring_inner_radius);\n";
+		code += "		float ring_random_radius = sqrt(rand_from_seed(alt_seed) * (radius_clamped * radius_clamped - emission_ring_inner_radius * emission_ring_inner_radius) + emission_ring_inner_radius * emission_ring_inner_radius);\n";
+		code += "		ring_random_radius = mix(ring_random_radius, ring_random_radius * (top_radius / radius_clamped), y_pos);\n";
 		code += "		vec3 axis = emission_ring_axis == vec3(0.0) ? vec3(0.0, 0.0, 1.0) : normalize(emission_ring_axis);\n";
 		code += "		vec3 ortho_axis = vec3(0.0);\n";
 		code += "		if (abs(axis) == vec3(1.0, 0.0, 0.0)) {\n";
@@ -662,7 +670,7 @@ void ParticleProcessMaterial::_update_shader() {
 		code += "			vec3(axis.z * axis.x * oc - axis.y * s, axis.z * axis.y * oc + axis.x * s, c + axis.z * axis.z * oc)\n";
 		code += "			) * ortho_axis;\n";
 		code += "		ortho_axis = normalize(ortho_axis);\n";
-		code += "		pos = ortho_axis * ring_random_radius + (rand_from_seed(alt_seed) * emission_ring_height - emission_ring_height / 2.0) * axis;\n";
+		code += "		pos = ortho_axis * ring_random_radius + (y_pos * emission_ring_height - emission_ring_height / 2.0) * axis;\n";
 	}
 	code += "	}\n";
 	code += "	return pos * emission_shape_scale + emission_shape_offset;\n";
@@ -1615,6 +1623,11 @@ void ParticleProcessMaterial::set_emission_ring_inner_radius(real_t p_radius) {
 	RenderingServer::get_singleton()->material_set_param(_get_material(), shader_names->emission_ring_inner_radius, p_radius);
 }
 
+void ParticleProcessMaterial::set_emission_ring_cone_angle(real_t p_angle) {
+	emission_ring_cone_angle = p_angle;
+	RenderingServer::get_singleton()->material_set_param(_get_material(), shader_names->emission_ring_cone_angle, p_angle);
+}
+
 void ParticleProcessMaterial::set_inherit_velocity_ratio(double p_ratio) {
 	inherit_emitter_velocity_ratio = p_ratio;
 	RenderingServer::get_singleton()->material_set_param(_get_material(), shader_names->inherit_emitter_velocity_ratio, p_ratio);
@@ -1664,6 +1677,10 @@ real_t ParticleProcessMaterial::get_emission_ring_inner_radius() const {
 	return emission_ring_inner_radius;
 }
 
+real_t ParticleProcessMaterial::get_emission_ring_cone_angle() const {
+	return emission_ring_cone_angle;
+}
+
 void ParticleProcessMaterial::set_emission_shape_offset(const Vector3 &p_emission_shape_offset) {
 	emission_shape_offset = p_emission_shape_offset;
 	RenderingServer::get_singleton()->material_set_param(_get_material(), shader_names->emission_shape_offset, p_emission_shape_offset);
@@ -2015,6 +2032,9 @@ void ParticleProcessMaterial::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("set_emission_ring_inner_radius", "inner_radius"), &ParticleProcessMaterial::set_emission_ring_inner_radius);
 	ClassDB::bind_method(D_METHOD("get_emission_ring_inner_radius"), &ParticleProcessMaterial::get_emission_ring_inner_radius);
 
+	ClassDB::bind_method(D_METHOD("set_emission_ring_cone_angle", "cone_angle"), &ParticleProcessMaterial::set_emission_ring_cone_angle);
+	ClassDB::bind_method(D_METHOD("get_emission_ring_cone_angle"), &ParticleProcessMaterial::get_emission_ring_cone_angle);
+
 	ClassDB::bind_method(D_METHOD("set_emission_shape_offset", "emission_shape_offset"), &ParticleProcessMaterial::set_emission_shape_offset);
 	ClassDB::bind_method(D_METHOD("get_emission_shape_offset"), &ParticleProcessMaterial::get_emission_shape_offset);
 
@@ -2096,9 +2116,10 @@ void ParticleProcessMaterial::_bind_methods() {
 	ADD_PROPERTY(PropertyInfo(Variant::OBJECT, "emission_color_texture", PROPERTY_HINT_RESOURCE_TYPE, "Texture2D"), "set_emission_color_texture", "get_emission_color_texture");
 	ADD_PROPERTY(PropertyInfo(Variant::INT, "emission_point_count", PROPERTY_HINT_RANGE, "0,1000000,1"), "set_emission_point_count", "get_emission_point_count");
 	ADD_PROPERTY(PropertyInfo(Variant::VECTOR3, "emission_ring_axis"), "set_emission_ring_axis", "get_emission_ring_axis");
-	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "emission_ring_height"), "set_emission_ring_height", "get_emission_ring_height");
-	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "emission_ring_radius"), "set_emission_ring_radius", "get_emission_ring_radius");
-	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "emission_ring_inner_radius"), "set_emission_ring_inner_radius", "get_emission_ring_inner_radius");
+	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "emission_ring_height", PROPERTY_HINT_RANGE, "0,1000,0.01,or_greater"), "set_emission_ring_height", "get_emission_ring_height");
+	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "emission_ring_radius", PROPERTY_HINT_RANGE, "0,1000,0.01,or_greater"), "set_emission_ring_radius", "get_emission_ring_radius");
+	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "emission_ring_inner_radius", PROPERTY_HINT_RANGE, "0,1000,0.01,or_greater"), "set_emission_ring_inner_radius", "get_emission_ring_inner_radius");
+	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "emission_ring_cone_angle", PROPERTY_HINT_RANGE, "0,90,0.01,degrees"), "set_emission_ring_cone_angle", "get_emission_ring_cone_angle");
 	ADD_SUBGROUP("Angle", "");
 	ADD_MIN_MAX_PROPERTY("angle", "-720,720,0.1,or_less,or_greater,degrees", PARAM_ANGLE);
 	ADD_PROPERTYI(PropertyInfo(Variant::OBJECT, "angle_curve", PROPERTY_HINT_RESOURCE_TYPE, "CurveTexture"), "set_param_texture", "get_param_texture", PARAM_ANGLE);
@@ -2276,6 +2297,7 @@ ParticleProcessMaterial::ParticleProcessMaterial() :
 	set_emission_ring_height(1);
 	set_emission_ring_radius(1);
 	set_emission_ring_inner_radius(0);
+	set_emission_ring_cone_angle(90);
 	set_emission_shape_offset(Vector3(0.0, 0.0, 0.0));
 	set_emission_shape_scale(Vector3(1.0, 1.0, 1.0));
 

scene/resources/particle_process_material.h

@@ -259,6 +259,7 @@ private:
 		StringName emission_ring_height;
 		StringName emission_ring_radius;
 		StringName emission_ring_inner_radius;
+		StringName emission_ring_cone_angle;
 		StringName emission_shape_offset;
 		StringName emission_shape_scale;
 
@@ -325,6 +326,7 @@ private:
 	real_t emission_ring_height = 0.0f;
 	real_t emission_ring_radius = 0.0f;
 	real_t emission_ring_inner_radius = 0.0f;
+	real_t emission_ring_cone_angle = 0.0f;
 	int emission_point_count = 1;
 	Vector3 emission_shape_offset;
 	Vector3 emission_shape_scale;
@@ -417,6 +419,7 @@ public:
 	void set_emission_ring_height(real_t p_height);
 	void set_emission_ring_radius(real_t p_radius);
 	void set_emission_ring_inner_radius(real_t p_radius);
+	void set_emission_ring_cone_angle(real_t p_angle);
 	void set_emission_point_count(int p_count);
 
 	EmissionShape get_emission_shape() const;
@@ -429,6 +432,7 @@ public:
 	real_t get_emission_ring_height() const;
 	real_t get_emission_ring_radius() const;
 	real_t get_emission_ring_inner_radius() const;
+	real_t get_emission_ring_cone_angle() const;
 	int get_emission_point_count() const;
 
 	void set_turbulence_enabled(bool p_turbulence_enabled);