Method UpdateLocalT

GTE/Graphics/IKController.cpp:280–343

}

bool IKController::Joint::UpdateLocalT(int32_t axis, std::vector<Goal> const& goals)
{
    Vector3<float> U = GetAxis(axis);
    float numer = 0.0f;
    float denom = 0.0f;
    float oldNorm = 0.0f;
    for (auto g : goalIndices)
    {
        auto const& goal = goals[g];
        Vector3<float> GmE = goal.GetTargetPosition() - goal.GetEffectorPosition();
        oldNorm += Dot(GmE, GmE);
        numer += goal.weight * Dot(U, GmE);
        denom += goal.weight;
    }

    if (denom == 0.0f)
    {
        return false;
    }

    // Desired distance to translate along axis(i).
    float t = numer / denom;

    // Clamp to range.
    Vector3<float> trn = object->localTransform.GetTranslation();
    float desired = trn[axis] + t;
    if (desired > minTranslation[axis])
    {
        if (desired < maxTranslation[axis])
        {
            trn[axis] = desired;
        }
        else
        {
            t = maxTranslation[axis] - trn[axis];
            trn[axis] = maxTranslation[axis];
        }
    }
    else
    {
        t = minTranslation[axis] - trn[axis];
        trn[axis] = minTranslation[axis];
    }

    // Test whether step should be taken.
    float newNorm = 0.0f;
    Vector3<float> step = t * U;
    for (auto g : goalIndices)
    {
        auto const& goal = goals[g];
        Vector3<float> newE = goal.GetEffectorPosition() + step;
        Vector3<float> diff = goal.GetTargetPosition() - newE;
        newNorm += Dot(diff, diff);
    }
    if (newNorm >= oldNorm)
    {
        // Translation does not get effector closer to goal.
        return false;