Creating Pylons and Wires Using Ropes
A Wire Attached to Pylons
This example shows how to create a wire using a rope body and attach it to pylons. A tutorial teaching how to reproduce the same scene in UnigineEditor can be found here.
In the AppWorldLogic.h file, define smart pointers for the objects of our scene.
// AppWorldLogic.h
#include <UnigineObjects.h>
/* .. */
class AppWorldLogic : public Unigine::WorldLogic {
public:
/* .. */
private:
Unigine::ObjectDummyPtr dummy1;
Unigine::ObjectDummyPtr dummy2;
Unigine::ObjectMeshDynamicPtr pylon1;
Unigine::ObjectMeshDynamicPtr pylon2;
Unigine::ObjectMeshDynamicPtr rope;
Unigine::PlayerSpectatorPtr player;
};
Insert the following code into the AppWorldLogic.cpp file.
Unchanged methods of the AppWorldLogic class are not listed here, so leave them as they are.
/* .. */
#include "UnigineGame.h"
#include "UniginePrimitives.h"
#include "UnigineObjects.h"
using namespace Unigine;
using namespace Math;
/* .. */
/// function, creating a named pylon with a specified radius and height at pos
ObjectMeshDynamicPtr create_pylon(char *name, float radius, float length, const vec3& pos)
{
// creating a cylinder dynamic mesh
ObjectMeshDynamicPtr OM = Primitives::createCylinder(radius, length, 1, 6);
// setting parameters
OM->setWorldTransform(Mat4(translate(pos)));
OM->setMaterialParameterFloat4("albedo_color", vec4(0.1f, 0.1f, 0.0f, 1.0f), 0);
OM->setName(name);
return OM;
}
/// function, creating a named dummy body of a specified size at pos
ObjectDummyPtr createBodyDummy(char *name, const vec3& size, const vec3& pos)
{
// creating a dummy object
ObjectDummyPtr OMD = ObjectDummy::create();
// setting parameters
OMD->setWorldTransform(Mat4(translate(pos)));
OMD->setName(name);
//assigning a dummy body to the dummy object and adding a box shape to it
BodyDummy::create(OMD);
OMD->getBody()->addShape(ShapeBox::create(size), translate(0.0f, 0.0f, 0.0f));
return OMD;
}
/// function, creating a named rope with specified parameters at pos
ObjectMeshDynamicPtr createBodyRope(char *name, float radius, float length, int segments, int slices, const Mat4& tm)
{
// creating a cylinder dynamic mesh
ObjectMeshDynamicPtr OMD = Primitives::createCylinder(radius, length, segments, slices);
// setting parameters
OMD->setWorldTransform(tm);
OMD->setMaterialParameterFloat4("albedo_color", vec4(0.5f, 0.5f, 0.0f, 1.0f), 0);
OMD->setName(name);
//assigning a rope body to the dynamic mesh object and setting rope parameters
BodyRopePtr body = BodyRope::create(OMD);
body->setMass(1.0f);
body->setRadius(0.25f);
body->setFriction(0.5f);
body->setRestitution(0.05f);
body->setRigidity(0.05f);
body->setLinearStretch(0.5f);
return OMD;
}
/* .. */
int AppWorldLogic::init() {
// setting up player
player = PlayerSpectator::create();
player->setPosition(Vec3(0.0f, -23.401f, 15.5f));
player->setDirection(vec3(0.0f, 1.0f, -0.4f), vec3(0.0f, 0.0f, -1.0f));
Game::setPlayer(player);
// creating dummy objects to attach a rope to and placing them on the top of each pylon
dummy1 = createBodyDummy("fixpoint1", vec3(0.5f, 0.5f, 0.5f), vec3(-12.0f, 0.0f, 15.0f));
dummy2 = createBodyDummy("fixpoint2", vec3(0.5f, 0.5f, 0.5f), vec3(12.0f, 0.0f, 15.0f));
// creating pylons
pylon1 = create_pylon("Pylon1", 0.3f, 17, vec3(-12.2f, 0.0f, 7.0f));
pylon2 = create_pylon("Pylon2", 0.3f, 17, vec3(12.2f, 0.0f, 7.0f));
// creating a rope
rope = createBodyRope("MyRope", 0.05f, 24, 96, 6, Mat4(translate(0.0f, 0.0f, 15.0f)*rotateY(-90.0f)));
// creating 2 particles joints to attach the rope to dummy bodies
JointParticles::create(dummy1->getBody(), rope->getBody(), dummy1->getPosition(), vec3(0.55f));
JointParticles::create(dummy2->getBody(), rope->getBody(), dummy2->getPosition(), vec3(0.55f));
return 1;
}
/* .. */
Last update:
2023-06-23
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