Method Update

GTE/Samples/Physics/BouncingBall/DeformableBall.cpp:154–208

}

void DeformableBall::Update(float time)
{
    uint32_t const numVertices = mMesh->GetVertexBuffer()->GetNumElements();
    Vertex* vertices = mMesh->GetVertexBuffer()->Get<Vertex>();
    uint32_t const numTriangles = mMesh->GetIndexBuffer()->GetNumElements() / 3;
    uint32_t const* indices = mMesh->GetIndexBuffer()->Get<uint32_t>();

    Vector3<float> zero = Vector3<float>::Zero();
    std::fill(mNormal.begin(), mNormal.end(), zero);
    std::fill(mMean.begin(), mMean.end(), zero);

    for (uint32_t i = 0; i < numTriangles; ++i)
    {
        int32_t i0 = *indices++;
        int32_t i1 = *indices++;
        int32_t i2 = *indices++;

        Vector3<float> v0 = vertices[i0].position;
        Vector3<float> v1 = vertices[i1].position;
        Vector3<float> v2 = vertices[i2].position;

        Vector3<float> edge1 = v1 - v0;
        Vector3<float> edge2 = v2 - v0;
        Vector3<float> normal = Cross(edge1, edge2);

        mNormal[i0] += normal;
        mNormal[i1] += normal;
        mNormal[i2] += normal;

        mMean[i0] += v1 + v2;
        mMean[i1] += v2 + v0;
        mMean[i2] += v0 + v1;
    }

    for (uint32_t i = 0; i < numVertices; ++i)
    {
        Normalize(mNormal[i]);
        mMean[i] /= static_cast<float>(mNeighborCount[i]);
    }

    for (uint32_t i = 0; i < numVertices; ++i)
    {
        Vector3<float> position = vertices[i].position;
        if (VertexInfluenced(i, time, position))
        {
            Vector3<float> localDiff = mMean[i] - position;
            Vector3<float> surfaceNormal = Dot(localDiff, mNormal[i]) * mNormal[i];
            Vector3<float> tangent = localDiff - surfaceNormal;
            float tWeight = GetTangentWeight(i, time, position);
            float nWeight = GetNormalWeight(i, time, position);
            position += tWeight * tangent + nWeight * mNormal[i];
            vertices[i].position = position;
        }
    }
}

bool DeformableBall::DoSimulationStep(float realTime)
{