Repository: godotengine/godot
File: modules/jolt_physics/objects/jolt_soft_body_3d.cpp (C++)

Code before:
	JPH::SoftBodyVertex &physics_vertex = physics_vertices[physics_index];

	physics_vertex.mVelocity += to_jolt(p_impulse) * physics_vertex.mInvMass;

	wake_up();
}

void JoltSoftBody3D::apply_vertex_force(int p_index, const Vector3 &p_force) {
	ERR_FAIL_COND_MSG(!in_space(), vformat("Failed to apply force to '%s'. Doing so without a physics space is not supported when using Jolt Physics. If this relates to a node, try adding the node to a scene tree first.", to_string()));

	apply_vertex_impulse(p_index, p_force * space->get_last_step());
}

void JoltSoftBody3D::apply_central_impulse(const Vector3 &p_impulse) {
	ERR_FAIL_COND_MSG(!in_space(), vformat("Failed to apply central impulse to '%s'. Doing so without a physics space is not supported when using Jolt Physics. If this relates to a node, try adding the node to a scene tree first.", to_string()));
	ERR_FAIL_NULL(shared);

	JoltWritableBody3D body = space->write_body(jolt_id);
	ERR_FAIL_COND(body.is_invalid());

	JPH::SoftBodyMotionProperties &motion_properties = static_cast<JPH::SoftBodyMotionProperties &>(*body->GetMotionPropertiesUnchecked());
	JPH::Array<JPH::SoftBodyVertex> &physics_vertices = motion_properties.GetVertices();

	const int mesh_vertex_count = shared->mesh_to_physics.size();

	const JPH::Vec3 impulse = to_jolt(p_impulse) / mesh_vertex_count;

	for (JPH::SoftBodyVertex &physics_vertex : physics_vertices) {
		if (physics_vertex.mInvMass > 0.0f) {
			physics_vertex.mVelocity += impulse * physics_vertex.mInvMass;
		}
	}

	wake_up();
}

void JoltSoftBody3D::apply_central_force(const Vector3 &p_force) {
	ERR_FAIL_COND_MSG(!in_space(), vformat("Failed to apply central force to '%s'. Doing so without a physics space is not supported when using Jolt Physics. If this relates to a node, try adding the node to a scene tree first.", to_string()));
	ERR_FAIL_NULL(shared);

	JPH::BodyInterface &body_iface = space->get_body_iface();

	body_iface.AddForce(jolt_id, to_jolt(p_force), JPH::EActivation::Activate);
}

void JoltSoftBody3D::set_is_sleeping(bool p_enabled) {
	if (!in_space()) {
		return;
	}

	JPH::BodyInterface &body_iface = space->get_body_iface();

Review comment (refactor):
Found the problem. The mesh contains many duplicate vertices, so we were not dividing by the correct number with the new loop:

```suggestion
	const JPH::Vec3 impulse = to_jolt(p_impulse) / physics_vertices.size();
```

Code after:

	JPH::BodyInterface &body_iface = space->get_body_iface();

	body_iface.AddForce(jolt_body->GetID(), to_jolt(p_force), JPH::EActivation::Activate);
}

void JoltSoftBody3D::set_is_sleeping(bool p_enabled) {
	if (!in_space()) {
		return;
	}

	JPH::BodyInterface &body_iface = space->get_body_iface();

	if (p_enabled) {
		body_iface.DeactivateBody(jolt_body->GetID());
	} else {
		body_iface.ActivateBody(jolt_body->GetID());
	}
}

bool JoltSoftBody3D::is_sleep_allowed() const {
	if (!in_space()) {
		return jolt_settings->mAllowSleeping;
	} else {
		return jolt_body->GetAllowSleeping();
	}
}

void JoltSoftBody3D::set_is_sleep_allowed(bool p_enabled) {
	if (!in_space()) {
		jolt_settings->mAllowSleeping = p_enabled;
	} else {
		jolt_body->SetAllowSleeping(p_enabled);
	}
}

void JoltSoftBody3D::set_simulation_precision(int p_precision) {
	if (unlikely(simulation_precision == p_precision)) {
		return;
	}

	simulation_precision = MAX(p_precision, 0);

	_simulation_precision_changed();
}

void JoltSoftBody3D::set_mass(float p_mass) {
	if (unlikely(mass == p_mass)) {
		return;
	}