This tutorial shows how to create an Illumination Analysis over an OMNI 3D Ray Model. This is
a very quick method for identifying areas of your target which may present illumination
problems. Shot and Receiver elevations are used and curved rays are traced through the 3D
velocity model.
Working with this Tutorial
Set parameters as described or shown in pictures. As you work, use OMNI 3D’s Popup Help to
see explanations of all available parameters. Hover your cursor over a parameter or click the
question mark in the upper right of a dialog and then click the parameter for Popup Help.
If you are new to OMNI 3D, please see the “Basic Land” and “Land: Script and Fold” tutorials
before you use this tutorial. In this advanced tutorial it is assumed that you can:
Start OMNI 3D
Create a project
Find and use menus in the Project Tree
Use Pop-Up Help in OMNI 3D’s menus and dialogs
Use right-click menus in the View tabs
Modify Color scales
Create a survey
Create a script
Create an analysis
Use analysis style settings to display bin Overlays and Offset/Azimuth limited fold
Go to Help | Local Resources | Load Tutorial Solutions and open the Workshop Analyses
folder. The folder contains both the input data for this exercise and the completed solution
project. (Please see the end of this tutorial for information about working with the solution
project.)
To complete this tutorial you will need these input files:
...\Tutorial\Workshop Analyses\Illumination - 3D Ray Example-Data\Survey For
Illum.osd
...\Tutorial\Workshop Analyses\Illumination - 3D Ray Example-Data\Topography.xyz
...\Tutorial\Workshop Analyses\Illumination - 3D Ray Example-Data\Illumination.r3d
Note: This tutorial was written to accompany the OMNI 3D V10 release. Just before the release
a new Auto-Finish button was added to the wizard dialogs. This can be used when you want to
recalculate an analysis. Adjust only the parameters you want to change and press Auto-Finish.
Preparation
Double-click the OMNI 3D icon on your
Desktop to start the program. When
OMNI 3D opens, go to File on the OMNI
3D Menu Bar and select New. Create a
directory for your project and name it
“Illumination Target”. The result is a
database file (Illumination Target.odb)
and a corresponding folder (Illumination
Target-files).
Specify the Projection for this project.
Right-click on the Project Tree folder
titled "Surveys" and select Add Existing
Survey | OMNI 3D Design Format.
Browse for and add Survey For
Illum.osd.
This analysis requires elevations for shot and
receivers. Right-click on the name of the
survey (Survey For Illum.osd) and select
Attributes | Set from XYZ File. First you will
specify the attribute you want to set.
All OMNI 3D surveys automatically have an
"Elevation" attribute. Additional attributes
may be created in the Shot Style or Receiver
Style dialogs. Confirm that Elevation is
selected for Shots and press Next. Do the
same for Receivers.
Create an Illumination Analysis
Right-click on the name of the script in the Project Tree
(Field Layout-Pattern 6×56) and select Create New
Analysis. Under OMNI 3D Workshop Module, choose
Illumination - Ray-traced fold over a complex model.
Calculate 3D Ray Model Illumination
The 3D Ray Model Illumination is a full 3D curved ray
tracing method. Shot and Receiver elevations are used.
This analysis is very fast.
Rays are curved through the velocity model described in
the 3D Ray Model. An illumination point is identified for
each shot and receiver pair. The illumination point is
refined based on topography, structure and velocity to
find the shortest time path. The result is that sometimes
no reflection points are found for deep synclines or steep
structures.
Choose to calculate Fold AND Points.
The Fold ONLY option can be useful
when you have a large survey to
calculate or you need to save time and
disk space.
Select Ray 3DModel for the
Calculation Method.
(For Illumination calculated over a
Target Model please see the Illumination
- Target tutorial.)
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