Multi-Z surfaces
Multi-Z surfaces - contains multi-valued (TIN / faulted) surfaces that can carry several Z values per XY location.
Surfaces are organised under Time and Depth domain nodes and are handled in the same way as faults: each surface has a check box in the Data manager that controls its visibility and expands into separate nodes for the triangulated mesh and for the picked sticks, one surface at a time is the active surface used for picking and editing, and colour and other visual settings match those used for faults.
The entry for a surface in the Data manager is drawn in the colour assigned to that surface with Set color, or with Colorize when a group of surfaces is given distinct colours, so the same surface is easy to recognise in the location map, the 3D view and on seismic sections. The entry follows the colour as soon as it is changed, and a surface with no colour assigned keeps its default appearance. Only the surface entry itself carries the colour, not its Surface and Sticks nodes.
Right mouse button on the icon allows to:
- Create new
- Export all to RESQML EPC
- Clear
- Colorize
- Sort by name
- Add folder
Right mouse button on a surface additionally allows to:
- Export to GOCAD TSurf
- Set color
- Rename
- Remove
- Convert to depth / time
- Convert to regular map
- Recreate surface
- Clear sticks
- Mesh optimization
Import into a Multi-Z surface (Import from GOCAD TSurf, Import from RESQML EPC) is offered on the Time / Depth domain sub-node.
Displaying and editing surfaces
- Tick a surface's check box in the Data manager to display it. A checked surface is projected onto inline, crossline and arbitrary-line seismic sections (in both time and depth), and drawn in the location map view and in the 3D view of its own domain: a surface under Time appears only in a time 3D view, a surface under Depth only in a depth 3D view. Picked sticks are drawn in 3D under the same rule. The check box on the surface shows or hides it as a whole, while the check boxes on its Surface and Sticks nodes control the triangulated mesh and the individual sticks separately.
- Select a surface to make it the active surface. The active surface is the target for interactive stick picking on seismic sections, exactly as for faults.
- Build the surface by adding sticks on a seismic section, use Clear sticks to remove them and Recreate surface to rebuild the triangulated mesh from the current sticks. Sticks are joined by their position on the surface, not by the order in which they were picked, so sections can be picked in any order and an earlier inline or crossline can be revisited without creating a long connection across the surface; a stick picked in the opposite direction is reversed automatically so that the mesh does not twist.
Sticks under a Multi-Z surface
Every Multi-Z surface can be expanded in the Data manager: it contains a Surface node for the triangulated mesh, and a surface that was built by picking also has a Sticks node that lists every picked stick by name (Stick 1, Stick 2, and so on). The sticks are listed one after another and are not grouped by inline, crossline or slice; the current stick of the active surface is shown in bold.
Each of these nodes has its own check box, so the mesh and every individual stick can be shown or hidden separately. Sticks are also a separate entry in Visual Settings: All Multi-Z sticks on seismic sections and the location map, and Multi-Z sticks 3D next to Multi-Z surfaces 3D time / Multi-Z surfaces 3D in the 3D views.
- Select a stick to make its surface the active surface and that stick the current one for picking.
- Right mouse button on a stick allows to Rename or Remove it. Removing a stick rebuilds the surface from the remaining sticks; the surface itself is kept.
- Drag sticks onto another Multi-Z surface in the Data manager to move them - a single stick, a multiple selection, or the whole Sticks node. The sticks keep their names, and both the source and the destination surface are rebuilt. A move is accepted only between surfaces of the same domain: time to time and depth to depth.
Convert surfaces between time and depth
A selected velocity model is required to convert a Multi-Z surface between the time and depth domains.
Right-click a surface in the Data manager and choose Convert to depth for a surface under Time, or Convert to time for a surface under Depth. The command is disabled when no velocity model is selected.
Conversion adds a copy of the surface under the opposite domain node, keeping the source surface's name and colour; if that name is already taken, a numeric suffix is added. The original surface remains unchanged.
For a surface built from picked sticks, the sticks are converted and the mesh is rebuilt from them, so the copy stays editable in the new domain. Parts of the surface that fall outside the velocity model coverage are left out of the copy, and a message is shown if no part of the surface can be converted.
See Also