[OpendTect_Users] 2D viewers in OpendTect and screenshot tips

[Arnaud Huck]

Dear OpendTect users,

Following the last discussion I would to gather for you some tips you 
may not know.

First of all despite OpendTect being a native 3D environment, it does 
contain an increasing number of 2D viewers that are gradually introduced 
for 3 years now. Let me summarize them:

- All attributes displayed on vertical sections (inline, crossline, 
random line, 2D line) can be posted in a 2D viewer from their 
right-click menu, in wiggles or colour display. The 2D viewer is 
attached to the corresponding tree element and gets its positioning, 
data and colour scheme from it (although that later can be changed in 
the 2D viewer).  You can have one 2D viewer for each tree item, with up 
to 2 attributes per viewer, 1 of display type wiggle and the other one 
of display type VD (colour).
- The prestack gathers displayed in the 3D scene can also be posted in a 
2D viewer from their right-click menu.
- The surfaces (Z values or grids) can be posted in a 2D viewer that 
will always be north oriented, from their right-click menu.
- The synthetic-to-seismic tie module is of course natively a 2D viewer. 
Please note that the synthetics and composites traces can be saved in 
volumes for display in the 3D window (on top of another attribute). Also 
the wavelet manager enables to display wavelets in time, frequency and 
phase domains, or the display of multiple wavelets overlaid in the time 
domain (merge utility). Well logs also have their own 2D viewer in the 
right click menu of the wells loaded in the scene.
- Several attributes have 2D analysis windows: Gapped deconvolution 
(auto-correlation window), spectral decomposition (Time-Frequency panels)
- Several plugins have their own 2D viewer: The well correlation panel 
is a new plugin that allows to display seismic data, horizons and well 
logs in a single 2D window. Also the VMB has vertical and horizontal 
velocity analysis panel with gather and semblance display. The CCB 
plugin has a 2D panel showing the filtered seismic data in the 
structural or flattened domain. Finally the SSB/SCI plugins have 2D 
parameter analysis windows where the impact of the operator can be 
displayed on vertical sections while tuning the design parameters.

Some viewers listed above do not actually do more than displaying data. 
However the main 2D viewers (the first of the list and the well 
correlation panel) actually are working areas. You can pick faults and 
horizons in a 2D manner solely in these windows, without doing any 
picking in the 3D scene (but the viewer itself must be started from the 
3D scene). This picking mode has been enabled in OD4.0 for the Kingdom 
addicts and the workflow has been made fully independent in OpendTect 
4.2: The 2D viewer features a tree where new elements can be added for 
picking. Note that horizons picked on a coarse 2D setup will need to be 
gridded in the 3D scene after the 2D interpretation. Nevertheless you 
will NOT benefit from the 3D tracking engine by interpreting horizons in 
2D: In volume tracking mode you can much more easily create full 
horizons from a few well-placed seeds. Also the 2D interpretation does 
not integrate the benefits of the new tracking mode that utilizes 
SteeringCubes instead of seismic amplitudes for getting very quickly 
several horizons using the Dip-steering and HorizonCube plugins.


Now let me provide you some tips for reproducible screenshots:

1) First of all select the data to display: Use the "position" function 
in the right-click menu of your element to specify the inline, 
crossline, time ranges.
2) Choose if you want a screenshot in the 3D scene (a) or in a 2D viewer (b)
2a) 3D scene: Optionally add gridlines, toggle on or off the 
perspective, post the colorbar in the scene and axis annotations, toggle 
on or off the survey box annotations, choose the right camera angle or 
the shortcuts "View inline", "View crossline"., ... Most important: 
Switch the resolution of your vertical section to "Highest" to avoid 
blocky displays (right-click menu of the tree item).
2b) Post the data in the 2D viewer. The window will be filled by data 
(you can send the tree outside the 2D viewer) according to the ranges 
specified in (1). Thus resizing the window will directly affect the 
aspect ratio of the screenshot.
3) For both screenshots from 2D and 3D displays: When using the 
integrated snapshot tool you may toggle off "Lock aspect ratio". 
Increasing the vertical size for the same horizontal size (or the 
opposite) will then directly stretch the data to the right size. Note 
that this screenshot tool accesses the data directly and enables you to 
make very large resolution pictures unlike with an external tool that is 
limited to your screen resolution.

Finally the post would not be complete without mentioning the PDF3D 
plugin that largely decreases the number of screenshots to make since it 
can post the content of an entire 3D scene into an interactive PDF 
document where one can change the camera position and zoom level at will.

Best regards,
Arnaud Huck.

-- 
-- Senior Geoscientist
-- dGB Earth Sciences
-- Nijverheidstraat 11-2, 7511 JM Enschede, The Netherlands
-- mailto: arnaud.huck at dgbes.com, http://www.dgbes.com
-- Tel: +31 53 4315155 , Fax: +31 53 4315104