コード例 #1
0
SExp* Eval::addPairs(SExp* p, SExp* x,SExp* a)
{
	char sStr[1000];
	memset(sStr,0,1000);

	if (x->isNIL()==1 && p->isNIL()==1)
	  return a;
	if (x->isNIL()==1)
	{
		x->convertString(sStr);
		ErrorManager E;
		E.buildRunTimeErrors(ErrorManager::USER_ARG_NO_MATCH,sStr);
	}

	if (p->isNIL()==1)
	{
		p->convertString(sStr);
		ErrorManager E;
		E.buildRunTimeErrors(ErrorManager::USER_ARG_NO_MATCH,sStr);
	}

	SExp* s=new SExp();
	s->car=p->car;
	s->cdr=x->car;

	return 	addPairs(p->cdr,x->cdr,cons(s,a));
}
コード例 #2
0
void NestedBoxTestModel::setup(tgWorld& world)
{
    const double edge = 30.0;
    const double height = tgUtil::round(std::sqrt(3.0)/2 * edge);
    std::cout << "edge: " << edge << "; height: " << height << std::endl;

    // Create the tetrahedra
    tgStructure tetra;
    addNodes(tetra, edge, height);
    addPairs(tetra);

    // Move the first one so we can create a longer snake.
    // Or you could move the snake at the end, up to you. 
    tetra.move(btVector3(0.0, 2.0, 100.0));

    // Create our snake segments
    tgStructure snake;
    addSegments(snake, tetra, edge, m_segments);
    addMuscles(snake);

    // Create the build spec that uses tags to turn the structure into a real model
    // Note: This needs to be high enough or things fly apart...
    const double density = 4.2 / 3000.0; // kg / length^3 - see app for length
    const double radius = 0.5;
    const double h  = 0.5;
    const tgBox::Config rodConfig(radius, density);
    tgBuildSpec spec;
    spec.addBuilder("rod", new tgBoxInfo(rodConfig));
    
    tgSpringCableActuator::Config muscleConfig(1000, 10);
    //spec.addBuilder("muscle", new tgBasicActuatorInfo(muscleConfig));
    
    const tgSphere::Config sphereConfig(0.5, 0.5);
    spec.addBuilder("light", new tgSphereInfo(sphereConfig));
    
    const tgSphere::Config sphereConfig2(0.5, 2.5);
    spec.addBuilder("light", new tgSphereInfo(sphereConfig2));
    
    // Create your structureInfo
    tgStructureInfo structureInfo(snake, spec);
    // Use the structureInfo to build ourselves
    structureInfo.buildInto(*this, world);

    // We could now use tgCast::filter or similar to pull out the models (e.g. muscles)
    // that we want to control.    
    allMuscles = tgCast::filter<tgModel, tgSpringCableActuator> (getDescendants());
    mapMuscles(muscleMap, *this);

    trace(structureInfo, *this);

    // Actually setup the children
    tgModel::setup(world);
}
コード例 #3
0
// This is basically a manual setup of a model.
// There are things that do this for us (@todo: reference the things that do this for us)
void TetraSpineGoal::setup(tgWorld& world)
{
    const double edge = 3.8 * scaleFactor;
    const double height = tgUtil::round(std::sqrt(3.0)/2 * edge);
    std::cout << "edge: " << edge << "; height: " << height << std::endl;
	
    // Create the tetrahedra
    tgStructure tetra;
    addNodes(tetra, edge, height, scaleFactor);
    addPairs(tetra);

    // Move the first one so we can create a longer snake.
    // Or you could move the snake at the end, up to you. 
    tetra.move(btVector3(0.0, 8.0, 10.0));

    // Create our snake segments
    tgStructure snake;
    addSegments(snake, tetra, -2.30 * scaleFactor, m_segments);
    addMuscles(snake);

    // Create the build spec that uses tags to turn the structure into a real model
    // Note: This needs to be high enough or things fly apart...
    

    // Params for In Won
    const double radius  = 0.635 * scaleFactor / 10.0;
    const double sphereRadius  = 0.635 * scaleFactor / (10.0);
    const double density = 2.0 *.0201 / (pow(radius, 2) * M_PI * edge); // Mass divided by volume... should there be a way to set this automatically??
    const double friction = 0.5;
    const tgRod::Config rodConfig(radius, density, friction);
    tgBuildSpec spec;
    spec.addBuilder("rod", new tgRodInfo(rodConfig));
    
    // 1000 is so the units below can be in grams
    const double sphereVolume1 = 1000.0 * 4.0 / 3.0 * M_PI * pow(sphereRadius, 3);
    const double sphereVolume2 = 1000.0 * 4.0 / 3.0 * M_PI * pow(sphereRadius, 3);
    
    const double baseCornerMidD = 180.0 / sphereVolume1;
    const tgSphere::Config baseCornerMidConfig(sphereRadius, baseCornerMidD, friction);
    spec.addBuilder("base", new tgSphereInfo(baseCornerMidConfig));

    const double tipCornerMidD = 120.0 / sphereVolume1;
    const tgSphere::Config tipCornerMidConfig(sphereRadius, tipCornerMidD, friction);
    spec.addBuilder("tip", new tgSphereInfo(tipCornerMidConfig));
    
    const double PCBD = 70.0 / sphereVolume2;
    const tgSphere::Config PCB_1_Config(radius, PCBD, friction);
    spec.addBuilder("PCB", new tgSphereInfo(PCB_1_Config));
    
    
        const double elasticity = 1000.0;
    const double damping = 10.0;
    const double pretension = 0.0;
    const bool   history = false;
    const double maxTens = 7000.0;
    const double maxSpeed = 12.0;

    const double mRad = 1.0;
    const double motorFriction = 10.0;
    const double motorInertia = 1.0;
    const bool backDrivable = false;
    
    tgKinematicActuator::Config motorConfig(elasticity, damping, pretension,
                                            mRad, motorFriction, motorInertia, backDrivable,
                                            history, maxTens, maxSpeed);
    
    spec.addBuilder("muscle", new tgKinematicContactCableInfo(motorConfig));

    // Create your structureInfo
    tgStructureInfo structureInfo(snake, spec);

    // Use the structureInfo to build ourselves
    structureInfo.buildInto(*this, world);

    // We could now use tgCast::filter or similar to pull out the models (e.g. muscles)
    // that we want to control.    
    m_allMuscles = this->find<tgSpringCableActuator> ("muscle");
    m_allSegments = this->find<tgModel> ("segment");
    mapMuscles(m_muscleMap, *this);
    
    //addMarkers(snake, *this);
    
    #if (0)
    trace(structureInfo, *this);
    #endif
    
    // Actually setup the children
    BaseSpineModelGoal::setup(world);
}
コード例 #4
0
void RibModelMixedContact::setup(tgWorld& world)
{
    double v_size = 3.0;
    
    // Create the spinal processes
    tgStructure vertebrae;
    addNodes(vertebrae, v_size);
    addPairs(vertebrae);

    // Move the first one so we can create a longer snake.
    // Or you could move the snake at the end, up to you. 
    vertebrae.move(btVector3(0.0, 2 * v_size, v_size * m_segments));
    
    // Create ribs and add them to the vertebrae
    double majorAxis  = 6.0;
    double minorAxis  = 4.0;
    double startTheta = M_PI / 2.0;
    double endTheta   = 5.0 * M_PI / 4.0;
    size_t segs       = 15;
    
    tgStructure ribs;
    ellipseNodes(ribs, majorAxis, minorAxis, startTheta, endTheta, segs);
    makePairs(ribs);
    
    #if (0) // Attempt at compliant rib attachments
    ribs.move(btVector3(v_size / 3.0, 2 * v_size - minorAxis, v_size * m_segments));
    #else
    ribs.move(btVector3(0.0, 2 * v_size - minorAxis -.3, v_size * m_segments));
    #endif
    // Create our snake segments
    tgStructure snake;
    addSegments(snake, vertebrae, ribs, v_size, m_segments);
    
    snake.move(btVector3(0.0, majorAxis, 0.0));
    
    addMuscles(snake);

    // Create the build spec that uses tags to turn the structure into a real model
    // Note: This needs to be high enough or things fly apart...
    const double density = 4.2 / 300.0;
    const double radius  = 0.5;
    const double friction = 0.5; // Default is 0.5
    const double rollFriction  = 0.5; // Default is 0.0
    const double restitution  = 0.0; // Default
    
    const tgRod::Config rodConfig(radius, density, friction, rollFriction, restitution);
    tgBuildSpec spec;
    spec.addBuilder("rod", new tgRodInfo(rodConfig));  
    
    const double elasticity = 500.0;
    const double elasticityAct = 1000.0;
    const double damping = 5.0;
    const double dampingAct = 10.0;
    const double pretension = 0.0;
    const bool	 history = true;
    const double maxTens = 1000.0;
    const double maxTensAct = 7000.0;
    const double maxSpeed = 100.0;
    const double maxSpeedAct = 24.0;
    
    const double mRad = 1.0;
    const double motorFriction = 10.0;
    const double motorInertia = 1.0; 
    const bool backDrivable = false;
    

    #if (0) //Replacing with tgKinematicActuator, leaving option to turn it off. 9/9/15.
    tgKinematicActuator::Config muscleConfig(elasticity, damping, pretension,
                                            mRad, motorFriction, motorInertia, backDrivable,
                                            history, maxTens, maxSpeed);
    spec.addBuilder("muscle", new tgKinematicContactCableInfo(muscleConfig));

    tgKinematicActuator::Config muscleConfigAct(elasticityAct, dampingAct, pretension,
						mRad, motorFriction, motorInertia, backDrivable,
                                                history, maxTensAct, maxSpeedAct);
    spec.addBuilder("muscleAct", new tgKinematicContactCableInfo(muscleConfigAct));
    #else
    tgSpringCableActuator::Config muscleConfig(elasticity, damping, pretension, history);
    spec.addBuilder("muscle", new tgBasicContactCableInfo(muscleConfig));
    /// @todo acceleration constraint was removed on 12/10/14 Replace with tgKinematicActuator as appropreate
    tgSpringCableActuator::Config muscleConfigAct(elasticityAct, dampingAct, pretension, history, 7000, 24);
    spec.addBuilder("muscleAct", new tgBasicContactCableInfo(muscleConfigAct));
    #endif
    
    #if (0) // Compliant Rib Attachments
    const double stiffness = 1000;
    const double damping = .01 * stiffness;
    
    tgSpringCableActuator::Config muscleConfig1(stiffness, damping, -M_PI / 2.0);
    tgSpringCableActuator::Config muscleConfig2(stiffness, damping, M_PI / 2.0);
    tgSpringCableActuator::Config muscleConfig3(stiffness, damping, M_PI);
    tgSpringCableActuator::Config muscleConfig4(stiffness, damping, 0);
    
    spec.addBuilder("multiMuscle", new tgBasicActuatorInfo(muscleConfig1));
    spec.addBuilder("multiMuscle", new tgBasicActuatorInfo(muscleConfig2));
    spec.addBuilder("multiMuscle", new tgBasicActuatorInfo(muscleConfig3));
    spec.addBuilder("multiMuscle", new tgBasicActuatorInfo(muscleConfig4));
    #endif
    // Create your structureInfo
    tgStructureInfo structureInfo(snake, spec);

    // Use the structureInfo to build ourselves
    structureInfo.buildInto(*this, world);

    // We could now use tgCast::filter or similar to pull out the models (e.g. muscles)
    // that we want to control.    
    m_allMuscles = find<tgSpringCableActuator> ("muscleAct");
    m_allSegments = find<tgModel> ("segment");

    #if (0)
    trace(structureInfo, *this);
    #endif
   
    // Actually setup the children
    BaseSpineModelLearning::setup(world);
}
コード例 #5
0
ファイル: cntGlue.c プロジェクト: davidhoover/kent
int main(int argc, char *argv[])
{
struct hash *bacHash;
char line[1024];
int lineCount;
char *words[256];
int wordCount;
int fileIx;
char *fileName;
FILE *f;

if (argc < 2)
    usage();
bacHash = newHash(16);

for (fileIx = 1; fileIx < argc; ++fileIx)
    {
    fileName = argv[fileIx];
    uglyf("Processing %s\n", fileName);
    f = mustOpen(fileName, "r");
    lineCount = 0;
    while (fgets(line, sizeof(line), f))
        {
        ++lineCount;
        wordCount = chopLine(line, words);
        if (wordCount == ArraySize(words))
            errAbort("Too many words line %d of %s\n", lineCount, fileName);
        if (wordCount != 0)
            {
            char *bacName;
            int cIx;
            struct contigTrack *ctList = NULL, *ct;
            struct bacTrack *bt;
            struct hashEl *hel;

            /* Check line syntax and parse it. */
            if (!sameString(words[1], "glues"))
                errAbort("Bad format line %d of %s\n", lineCount, fileName);
            bacName = words[2];
            for (cIx = 4; cIx < wordCount; cIx += 5)
                {
                char *parts[3];
                int partCount;

                AllocVar(ct);
                ct->ix = atoi(words[cIx]);
                ct->strand = words[cIx+1][0];
                ct->dir = words[cIx+2][0];
                partCount = chopString(words[cIx+3], "(-)", parts, ArraySize(parts));
                if (partCount != 2)
                    errAbort("Bad format line %d of %s\n", lineCount, fileName);
                ct->start = atoi(parts[0]);
                ct->end = atoi(parts[1]);
                ct->cookedScore = atof(words[cIx+4]);
                slAddHead(&ctList, ct);                
                }
            slSort(&ctList, cmpContigTrack);
        
            /* Lookup bacTrack and make it if new. */
            hel = hashLookup(bacHash, bacName);
            if (hel == NULL)
                {
                AllocVar(bt);
                hel = hashAdd(bacHash, bacName, bt);
                bt->name = hel->name;
                slAddHead(&bacList, bt);
                }
            else
                {
                bt = hel->val;
                }
            
            /* Process pairs into bacTrack. */
            addPairs(bt, ctList);
            slFreeList(&ctList);
            }
        }
    fclose(f);
    }
slSort(&bacList, cmpBacTrack);

printStats();
return 0;
}
コード例 #6
0
// This is basically a manual setup of a model.
// There are things that do this for us (@todo: reference the things that do this for us)
void TetraSpineStaticModel_hf::setup(tgWorld& world)
{
    const double edge = 38;
    const double height = tgUtil::round(std::sqrt(3.0)/2 * edge);
    std::cout << "edge: " << edge << "; height: " << height << std::endl;

    // Create the tetrahedra
    tgStructure tetra;
    addNodes(tetra, edge, height);
    addPairs(tetra);

    // Move the first one so we can create a longer snake.
    // Or you could move the snake at the end, up to you.
    tetra.move(btVector3(0.0, 2.0, 100.0));

    // Create our snake segments
    tgStructure snake;
    addSegments(snake, tetra, edge, m_segments);
    addMuscles(snake);

    // Create the build spec that uses tags to turn the structure into a real model
    // Note: This needs to be high enough or things fly apart...


    // Params for In Won
    const double oldDensity = .00311;
    const double radius  = 0.635 / 2.0;
    const double density = 0.0201 / (pow(radius, 2) * M_PI * edge); // Mass divided by volume... should there be a way to set this automatically??
    const double friction = 0.15;
    const tgRod::Config rodConfig(radius, density, friction);
    tgBuildSpec spec;
    spec.addBuilder("rod", new tgRodInfo(rodConfig));

    // 1000 is so the units below can be in grams
    const double sphereVolume = 1000.0 * 4.0 / 3.0 * M_PI * pow(radius, 3);

    const double baseCornerFrontD = 140.0 / sphereVolume;
    const tgSphere::Config baseCornerFrontConfig(radius, baseCornerFrontD, friction);
    spec.addBuilder("num0 base", new tgSphereInfo(baseCornerFrontConfig));

    const double baseCornerMidD = 180.0 / sphereVolume;
    const tgSphere::Config baseCornerMidConfig(radius, baseCornerMidD, friction);
    spec.addBuilder("num1 base", new tgSphereInfo(baseCornerMidConfig));

    const double baseCornerRearD = 100.0 / sphereVolume;
    const tgSphere::Config baseCornerRearConfig(radius, baseCornerRearD, friction);
    spec.addBuilder("num2 base", new tgSphereInfo(baseCornerRearConfig));

    const double tipCornerFrontD = 40.0 / sphereVolume;
    const tgSphere::Config tipCornerFrontConfig(radius, tipCornerFrontD, friction);
    spec.addBuilder("num0 tip", new tgSphereInfo(tipCornerFrontConfig));

    const double tipCornerMidD = 120.0 / sphereVolume;
    const tgSphere::Config tipCornerMidConfig(radius, tipCornerMidD, friction);
    spec.addBuilder("num1 tip", new tgSphereInfo(tipCornerMidConfig));
    spec.addBuilder("num2 tip", new tgSphereInfo(tipCornerMidConfig));

    const double PCBD = 70.0 / sphereVolume;
    const tgSphere::Config PCB_1_Config(radius, PCBD, friction);
    spec.addBuilder("PCB num0", new tgSphereInfo(PCB_1_Config));
    spec.addBuilder("PCB num1", new tgSphereInfo(PCB_1_Config));

    const double PCB2D = 95.0 / sphereVolume;
    const tgSphere::Config PCB_2_Config(radius, PCB2D, friction);
    spec.addBuilder("PCB num2", new tgSphereInfo(PCB_2_Config));

    // Two different string configs
    /// @todo acceleration constraint was removed on 12/10/14 Replace with tgKinematicActuator as appropreate
    tgSpringCableActuator::Config muscleConfig(229.16, 20, 2000.0, true, 5000, 7.0, 1.0, 1.0);
    tgSpringCableActuator::Config muscleConfig2(229.16, 20, 700.0, true, 5000, 7.0, 1.0, 1.0);
    spec.addBuilder("top muscle", new tgBasicActuatorInfo(muscleConfig));
    spec.addBuilder("left muscle", new tgBasicActuatorInfo(muscleConfig2));
    spec.addBuilder("right muscle", new tgBasicActuatorInfo(muscleConfig2));

    // Create your structureInfo
    tgStructureInfo structureInfo(snake, spec);

    // Use the structureInfo to build ourselves
    structureInfo.buildInto(*this, world);

    // We could now use tgCast::filter or similar to pull out the models (e.g. muscles)
    // that we want to control.
    m_allMuscles = this->find<tgSpringCableActuator> ("muscle");
    m_allSegments = this->find<tgModel> ("segment");
    mapMuscles(m_muscleMap, *this);

    addMarkers(snake, *this);

#if (0)
    trace(structureInfo, *this);
#endif

    // Actually setup the children
    BaseSpineModelLearning::setup(world);
}
コード例 #7
0
SExp* Eval::apply(SExp* f, SExp* x, SExp* a,Tree* d)
{
	char sStr[1000];

	memset(sStr,0,1000);

	if(f->isAtom==0)
	{
		f->convertString(sStr);
		ErrorManager E;
		E.buildRunTimeErrors(ErrorManager::NON_ATOMIC_FUNC,sStr);
	}

	if(f->value[0]=='\0')
	{
		f->convertString(sStr);
		ErrorManager E;
		E.buildRunTimeErrors(ErrorManager::F_VALUE_NULL,sStr);
	}

	if(strcmp(f->value,"NULL")==0)
	{
		if(x->car==NULL)
		{
			x->convertString(sStr);
			ErrorManager E;
			E.buildRunTimeErrors(ErrorManager::ARGUMENT_NO_MATCH,sStr);
		}
		else
			return isNull(x->car);
	}

	if(strcmp(f->value,"ATOM")==0)
	{
		if(x->car==NULL)
		{
			x->convertString(sStr);
			ErrorManager E;
			E.buildRunTimeErrors(ErrorManager::ARGUMENT_NO_MATCH,sStr);
		}
		else
			return atom(x->car);
	}

	if(strcmp(f->value,"INT")==0)
	{
		if(x->car==NULL)
		{
			x->convertString(sStr);
			ErrorManager E;
			E.buildRunTimeErrors(ErrorManager::ARGUMENT_NO_MATCH,sStr);
		}
		else
			return Int(x->car);
	}

	if(strcmp(f->value,"CAR")==0)
	{
		if(x->car==NULL)
		{
			x->convertString(sStr);
			ErrorManager E;
			E.buildRunTimeErrors(ErrorManager::ARGUMENT_NO_MATCH,sStr);
		}
		else
			return car(x->car);
	}

	if(strcmp(f->value,"CDR")==0)
	{
		if(x->car==NULL)
		{
			x->convertString(sStr);
			ErrorManager E;
			E.buildRunTimeErrors(ErrorManager::ARGUMENT_NO_MATCH,sStr);
		}
		else
			return cdr(x->car);
	}

	if(strcmp(f->value,"EQ")==0)
	{
		if(x->car==NULL || x->cdr->car==NULL)
		{
			x->convertString(sStr);
			ErrorManager E;
			E.buildRunTimeErrors(ErrorManager::ARGUMENT_NO_MATCH,sStr);

		}
		else
			return eq(x->car,x->cdr->car);
	}

	if(strcmp(f->value,"CONS")==0)
	{
		if(x->car==NULL || x->cdr->car==NULL)
		{
			x->convertString(sStr);
			ErrorManager E;
			E.buildRunTimeErrors(ErrorManager::ARGUMENT_NO_MATCH,sStr);
		}
		else
			return cons(x->car,x->cdr->car);
	}

	if(strcmp(f->value,"PLUS")==0)
	{
		if(x->car==NULL || x->cdr->car==NULL)
		{
			x->convertString(sStr);
			ErrorManager E;
			E.buildRunTimeErrors(ErrorManager::ARGUMENT_NO_MATCH,sStr);
		}
		else
			return plus(x->car,x->cdr->car);
	}

	if(strcmp(f->value,"MINUS")==0)
	{
		if(x->car==NULL || x->cdr->car==NULL)
		{
			x->convertString(sStr);
			ErrorManager E;
			E.buildRunTimeErrors(ErrorManager::ARGUMENT_NO_MATCH,sStr);
		}
		else
			return minus(x->car,x->cdr->car);
	}

	if(strcmp(f->value,"TIMES")==0)
	{
		if(x->car==NULL || x->cdr->car==NULL)
		{
			x->convertString(sStr);
			ErrorManager E;
			E.buildRunTimeErrors(ErrorManager::ARGUMENT_NO_MATCH,sStr);
		}
		else
			return times(x->car,x->cdr->car);
	}


	if(strcmp(f->value,"QUOTIENT")==0)
	{
		if(x->car==NULL || x->cdr->car==NULL)
		{
			x->convertString(sStr);
			ErrorManager E;
			E.buildRunTimeErrors(ErrorManager::ARGUMENT_NO_MATCH,sStr);
		}
		else
			return quotient(x->car,x->cdr->car);
	}

	if(strcmp(f->value,"REMAINDER")==0)
	{
		if(x->car==NULL || x->cdr->car==NULL)
		{
			x->convertString(sStr);
			ErrorManager E;
			E.buildRunTimeErrors(ErrorManager::ARGUMENT_NO_MATCH,sStr);

		}
		else
			return remainder(x->car,x->cdr->car);
	}

	if(strcmp(f->value,"GREATER")==0)
	{
		if(x->car==NULL || x->cdr->car==NULL)
		{
			x->convertString(sStr);
			ErrorManager E;
			E.buildRunTimeErrors(ErrorManager::ARGUMENT_NO_MATCH,sStr);
		}
		else
			return greater(x->car,x->cdr->car);
	}

	if(strcmp(f->value,"LESS")==0)
	{
		if(x->car==NULL || x->cdr->car==NULL)
		{
			x->convertString(sStr);
			ErrorManager E;
			E.buildRunTimeErrors(ErrorManager::ARGUMENT_NO_MATCH,sStr);
		}
		else
			return less(x->car,x->cdr->car);
	}

	SExp* body = getFunc(f, d)->cdr;
	if(body!=NULL){}
	else
		return NULL;

	SExp* SE = addPairs(getFunc(f, d)->car, x, a);
	if(SE!=NULL){

	}else
		return NULL;

	return eval(body,SE,d);
}
コード例 #8
0
/***************************************
 * The primary functions., called from other classes.
 **************************************/
void VerticalSpineModel::setup(tgWorld& world)
{
    // debugging output: edge and height length
    //std::cout << "edge: " << c.edge << "; height: " << c.height << std::endl;
    
    // Create the first fixed snake segment
    // @todo move these hard-coded parameters into config
    tgStructure tetraB;
    addNodes(tetraB, c.edge, c.height);
    addPairsB(tetraB);
    tetraB.move(btVector3(0.0, 2, 0));
    
    // Create our snake segments
    tgStructure snake;
    
    // add 1st child to snake
    tgStructure* const tB = new tgStructure(tetraB);
    snake.addChild(tB);
    tB->addTags(tgString("segment", 1));
    
    // Create the first non-fixed tetrahedra
    tgStructure tetra;
    addNodes(tetra, c.edge, c.height);
    addPairs(tetra);
    
    // Move the first tetrahedra
    // @todo move these hard-coded parameters into config
    tetra.move(btVector3(0.0, -6, 0));
    
    // add rest of segments using original tetra configuration
    addSegments(snake, tetra, c.edge, m_segments);
    
    addMuscles(snake);

    // Create the build spec that uses tags to turn the structure into a real model
    // Note: This needs to be high enough or things fly apart...
    
    // length of inner strut = 12.25 cm
    // m = 1 kg
    // volume of 1 rod = 9.62 cm^3
    // total volume = 38.48 cm^3
    //const double density = 1/38.48; = 0.026 // kg / length^3 - see app for length
    const tgRod::Config rodConfigA(c.radius, c.densityA, c.friction, 
				  c.rollFriction, c.restitution);
    const tgRod::Config rodConfigB(c.radius, c.densityB, c.friction, 
				  c.rollFriction, c.restitution);
    //holder
    const tgRod::Config rodConfigHA(0.1, c.densityA, c.friction,
				    c.rollFriction, c.restitution);
    const tgRod::Config rodConfigHB(0.1, c.densityB, c.friction,
				    c.rollFriction, c.restitution);
    tgBuildSpec spec;
    spec.addBuilder("rod", new tgRodInfo(rodConfigA));
    spec.addBuilder("rodB", new tgRodInfo(rodConfigB));


    // set muscle (string) parameters
    // @todo replace acceleration constraint with tgKinematicActuator if needed...
    tgSpringCableActuator::Config muscleConfig(c.stiffness, c.damping, c.pretension,
					 c.hist, c.maxTens, c.targetVelocity);
    spec.addBuilder("muscle", new tgBasicActuatorInfo(muscleConfig));

    
    // Create your structureInfo
    tgStructureInfo structureInfo(snake, spec);
    // Use the structureInfo to build ourselves
    structureInfo.buildInto(*this, world);

    // We could now use tgCast::filter or similar to pull out the models (e.g. muscles)
    // that we want to control.    
    allMuscles = tgCast::filter<tgModel, tgSpringCableActuator> (getDescendants());
    mapMuscles(muscleMap, *this, m_segments);

    //trace(structureInfo, *this);

    // Actually setup the children
    notifySetup();
    tgModel::setup(world);
}