message: Change initial camera translation.
  Many models were loading behind the camera.  This seems to set a better
  initial translation.
diff: @@ -25,15 +25,17 @@ ArcballCamera::ArcballCamera(const ospcommon::math::box3f &worldBounds,
  translation(ospcommon::math::one),
  rotation(ospcommon::math::one)
  {
  - ospcommon::math::vec3f diag = worldBounds.size();
  - zoomSpeed = ospcommon::math::max(length(diag) / 150.0, 0.001);
  - diag =
  - ospcommon::math::max(diag, ospcommon::math::vec3f(0.3f * length(diag)));
  + float diag = length(worldBounds.size());
  + zoomSpeed = ospcommon::math::max(diag / 150.0, 0.001);
  +
  + // This works well enough for the models I'm testing
  + if (diag < 1)
  + diag = 1.f/diag;
  centerTranslation =
  ospcommon::math::AffineSpace3f::translate(-worldBounds.center());
  translation = ospcommon::math::AffineSpace3f::translate(
  - ospcommon::math::vec3f(0, 0, length(diag)));
  + ospcommon::math::vec3f(0, 0, diag));
  updateCamera();
  }
  