Improvements in the handling of properties in GOCAD++

@inproceedings{DeBaunRM1995a,
 abstract = { As the application of GOCAD++ to the modeling of reservoir properties increases, the need for more sophisticated and flexible handling of properties has become evident. GOCAD allows properties to be associated with objects of many different types. For efficiency, the way these property values are handled internally differs substantially between many of these types. To solve this problem, a number of improvements in the handling of property data have been implemented to allow these properties to be handled in a uniform way. • A uniform means of doing basie inquiries and manipulations such as adding, removing, and renarning properties on all objects that carry property information. Objects which can support having multiple properties associated with them have a property database associated with them. This allows for a uniform means of handling property information on the objects, even when the underlying implementation of the propertiès on the objects may be quite different. These objects include point sets, surfaces, tetrahedral solids, voxets, stratigraphie grids, and wells. • Sharing of colormap, scale, statistical, and other information between properties on different objects. Properties on objects have a property class associated with them. This property class can be shared by rnany different properties on the sarne or different objects. For example, we rnay have a porosity trace in several wells, a stratigraphic grid with several porosity estimates, and a voxet with sorne of these estimates interpolated to a uniform grid. If each of these property instances shares the sarne property class, they will autornatically share colormap and scaling information, and each of thern will be queried if the statistieal distribution of the property values is required. This, for example, allows values of the same physieal quantity to be viewed using the same color scale on different objects. • A uniform method of interpolating spatial properties from one object to another, of supplying prol?erty data to a cornrnand, and of supplying statistieal information about the property values. . Improvements in the handling of properties in Gocad++ 1 Once aproperty is computed on one object, we may want to transfer its values to another dissimilar object. This operation generally involves resampling and interpolation of the data. For example, porosity values computed on a stratigraphie grid may have to be resampled to a uniform voxet grid for output to another package. Since the number of possible transfers goes up as the square of the number of objects types, writing separate data interpolation and transfer between each type of object for each type of data transfer would be time-consuming and error-prone. Instead, we have adopted a client-server approach to the problem. Objects know which types of interpolation they can perform on their properties. For example, a voxet can interpolate the value of a property at any point in 3D space within its cage. A surface in general cannot interpolate values in 3D space, but can interpolate values along lines. That is, given a line, the surface can interpolate the property value at the intersection of the surface with that line. Thus a voxet has an associated point property server and a surface has an associated line property server. On the other hand, both a voxet and a surface can supply statistical information about its property values, so both have an associated statistical property server. Similar associations can be made on the client side. With this arrangement, an object can supply interpolated property values to another object without having to know the specifics of the receiving object. Similarly, an object can request interpolated property values from another object without knowing the specifics of that object. With this approach we can move properties between any pair of objects for which the type of interpolation makes sense, and who have the appropriate servers and clients. Currently, several types of servers and clients defined. Pointwise volumetric servers and clients transfer data defined in a region of 3D space. Line and vertical servers and clients transfer data along lines in 3D space. Discrete servers and clients can transfer data as a discrete set of values at associated points. Statistieal servers are used by the property class to request statistical information about the property values. },
 author = { DeBaun, David },
 booktitle = { 11th gOcad Meeting },
 month = { "june" },
 publisher = { ASGA },
 title = { Improvements in the handling of properties in GOCAD++ },
 year = { 1995 }
}