Method GetGeometry

Source/Engine/Physics/Colliders/SplineCollider.cpp:163–313

}

void SplineCollider::GetGeometry(CollisionShape& collision)
{
    // Reset bounds
    _box = BoundingBox(_transform.Translation);
    BoundingSphere::FromBox(_box, _sphere);
    const float minSize = 0.001f;
    collision.SetSphere(minSize);

    // Skip if sth is missing
    if (!_spline || !IsActiveInHierarchy() || _spline->GetSplinePointsCount() < 2 || !CollisionData || !CollisionData->IsLoaded())
        return;
    PROFILE_CPU();

    // Extract collision geometry
    // TODO: cache memory allocation for dynamic colliders
    Array<Float3> collisionVertices;
    Array<int32> collisionIndices;
    CollisionData->ExtractGeometry(collisionVertices, collisionIndices);
    if (collisionIndices.IsEmpty())
        return;

    // Apply local mesh transformation
    if (!_preTransform.IsIdentity())
    {
        for (int32 i = 0; i < collisionVertices.Count(); i++)
            collisionVertices[i] = _preTransform.LocalToWorld(collisionVertices[i]);
    }

    // Find collision geometry local bounds
    BoundingBox localModelBounds;
    localModelBounds.Minimum = localModelBounds.Maximum = collisionVertices[0];
    for (int32 i = 1; i < collisionVertices.Count(); i++)
    {
        Vector3 v = collisionVertices[i];
        localModelBounds.Minimum = Vector3::Min(localModelBounds.Minimum, v);
        localModelBounds.Maximum = Vector3::Max(localModelBounds.Maximum, v);
    }
    auto localModelBoundsSize = localModelBounds.GetSize();

    // Deform geometry over the spline
    const auto& keyframes = _spline->Curve.GetKeyframes();
    const int32 segments = keyframes.Count() - 1;
    _vertexBuffer.Resize(collisionVertices.Count() * segments);
    _indexBuffer.Resize(collisionIndices.Count() * segments);
    const Transform splineTransform = _spline->GetTransform();
    const Transform colliderTransform = GetTransform();
    Transform curveTransform, leftTangent, rightTangent;
    for (int32 segment = 0; segment < segments; segment++)
    {
        // Setup for the spline segment
        auto offsetVertices = segment * collisionVertices.Count();
        auto offsetIndices = segment * collisionIndices.Count();
        const auto& start = keyframes[segment];
        const auto& end = keyframes[segment + 1];
        const float tangentScale = (end.Time - start.Time) / 3.0f;
        AnimationUtils::GetTangent(start.Value, start.TangentOut, tangentScale, leftTangent);
        AnimationUtils::GetTangent(end.Value, end.TangentIn, tangentScale, rightTangent);