Scene Configuration

Before building any subsurface model or running simulations, the 3D scene must be properly framed: which geographical area does it cover, what is the reference altitude, what grid fineness is appropriate, and how should the view be oriented. These settings determine the precision of interpolations, the readability of cross-sections, and the overall calculation time. This page describes the available parameters and recommended values based on context.

Geographical Extent

The extent defines the volume encompassing the scene: a horizontal rectangle on the ground and a maximum depth. IsoFind offers several modes for determining this area.

Mode	Principle	Recommended Use
Automatic by samples	Bounding box of sampling points expanded by 10%	Initial draft on an existing dataset
Manual by coordinates	Direct entry of boundaries in lat/lon or local meters	Known regulatory perimeter, site boundary
Shapefile Import	Loads an extent from a GIS file	Projects already mapped in other software
Extent around point	Center point + radius in meters	Known point source, scene centered on it

The extent can be modified at any time without data loss. Samples located outside the new extent remain recorded but will no longer be displayed in the scene. No data is deleted during resizing.

An extent that is too wide makes plumes and anomalies hard to see in the overview. An extent that is too narrow clips the edges and skews interpolations at the boundaries. A practical rule of thumb is to take the bounding box of the samples and add a margin of 15 to 25% in each direction.

Reference Altitude

The vertical axis of the scene can be referenced in several ways depending on the nature of the project.

Reference	Convention	Use Case
Local Ground Level	Zero at ground level, positive depths downward	Flat industrial sites, shallow aquifers
MSL or Geoid	Zero at the official reference level, positive altitudes upward	Large watersheds, regional hydrogeology
Depth below Water Table	Zero at the water table (potentiometric surface)	Studies focused specifically on the saturated zone
Wellhead Datum	Zero at the top of the borehole, positive depths downward	Prospecting, borehole logging

Changing the reference mid-project requires a conversion of sample depths. IsoFind provides this operation, but be careful with samples imported without explicit depth data: they will not be converted. It is best to fix the reference once and for all at the beginning of the project.

Calculation Grid

Interpolations and simulations are performed on a regular 3D grid. Its resolution determines the spatial fineness of the results and the computational cost.

Resolution	Typical Cell Count	Use Case	Indicative Calculation Time
Coarse	50 x 50 x 20 = 50,000	Initial draft, visual exploration	A few seconds
Intermediate	100 x 100 x 40 = 400,000	Standard analysis, interpretations	10 to 60 seconds
Fine	200 x 200 x 80 = 3,200,000	Final reports, reference simulations	Several minutes
Custom	Manual entry	Specific cases, anisotropy	Variable

Resolution can differ on each axis. Typically, the vertical grid is finer than the horizontal one in hydrogeological contexts, as stratification is the direction of rapid variation.

Visual Markers

Several visual aids facilitate the reading of the scene and can be toggled independently.

Marker	Description	Default
XYZ Axes	Three colored arrows at the origin	Active
Ground Grid	Planar grid at the zero level	Active
Extent Box	Wireframe cube around the scene volume	Active
Compass Rose	North indicator in the corner	Active
Axis Graduations	Numerical labels on the edges	Active
Water Table	Semi-transparent plane at the potentiometric level	Hidden
Surface Topography	DEM rendered on the surface	Hidden

Orientation and Navigation

The scene is oriented by default with North in depth and East to the right. The user can lock the orientation or leave it free. Four presets are accessible with one click: Top View, North-South View, East-West View, and Isometric View.

Navigation follows standard conventions: Left click to orbit, scroll wheel to zoom, right click to pan. An auto-framing button repositions the camera on all samples or a selected area.

Vertical Exaggeration

In most geological contexts, the vertical variation of interest is very small compared to the horizontal extent: a few meters of depth for several hundred meters of extension. A natural representation "flattens" everything happening at depth. IsoFind offers an adjustable vertical exaggeration factor that stretches the Z-axis in the display without modifying the underlying data.

Vertical exaggeration is a visual tool. It makes cross-sections and plumes more readable but can give a false impression of strong anisotropy. The real scale must be noted in any publication derived from the scene. IsoFind systematically displays the exaggeration factor as an overlay in the scene.

Standard Initial Configuration Workflow

3D Visualization > Configuration > Extent Mode > Altitude Reference > Grid Resolution > Visual Markers > Save

The configuration is saved with the project and automatically restored upon the next opening. For a single project, multiple configuration presets can be saved (overview, focal source view, cross-section view) and recalled with one click.