Stage 1: Apply "Heal geometry"
The ‘Heal geometry’ button initiates automated geometry correction depending on the settings in the ‘Shell Import Preferences’ > Shell surface orientation and ‘Heal Geometry’ Preferences section. Here the VE attempts to fix shell surface orientations as well as healing bad geometry by closing off open room/space/zone volumes.
Thus, before applying ‘Heal geometry’, it is recommended to check the ‘Shell Import Preferences’ dialog first. This can be done by clicking on the ‘Settings’ option within the ‘Quarantine’ dialog:
The ‘Shell Import Preferences’ dialog can also be accessed via Tools Preferences Shell Import tab.
Options available to the user are detailed below:
Shell surface orientation and ‘Heal Geometry’ Preferences
These fixing options are only applied geometry imported through method A (see Set VE shell import preferences) was successful.
The fixes applied to the geometry are as follows:
1. Attempt to fix shell surface orientation
2. Attempt to heal bad geometry by adding surfaces to close shell:
Image from the Virtual Environment: Shell Import Preferences – Healing & surface orientation options
1. Attempt to fix shell surface orientation
This option automatically flips surfaces that are incorrect orientated on import when selected. All surfaces should be oriented outwards from the room. Surface orientation can be checked visually within the ‘Quarantine’ dialog’s model tree using the right click and selecting ‘Show normals’.
We recommend to select at least “Attempt to fix shell surface orientations” as often BIM files do not consider this requirement. Failure to correct this can lead to inverse room volumes, additional unmatched edges and missing surface areas, floors and ceilings being identified incorrectly and their subsequent adjacencies being incorrect. Overall, this leads to incorrect construction assignments and Space Data, which in turn produces inaccurate thermal simulation results.
Image from the Virtual Environment: Quarantine dialogue – Show Surface Normals
2. Attempt to heal bad geometry by adding surfaces to close shell:
Selecting this option runs an initial healing on any bad geometry from imported files to close volumes off. The user has sub options that allows a limit to be set on the number of edges and surfaces to be included within this process.
The reason for this is, if a single space has a vast number of unmatched edges or surfaces then including such a space in your final model would have an impact on your overall simulation time.
For more complex models (e.g. spaces with curved walls), the maximum number of unmatched edges should be increased significantly. This increases the chance of successful import of such geometry, but consideration has to be given to the number of surfaces typically imported with such geometry. For example, if you have a single piece of geometry with 5000 surfaces, this will lead to increased simulation time.
Once the settings have been adjusted ‘Heal geometry’ can be applied.
Image from the Virtual Environment: Quarantine dialogue
