In order to represent three dimension complex stratigraphic objects including faults

disappearances

outcrops and other phenomena

we have to face the difficult problems in the process of spatial partition or calculating intersection lines of curved surfaces in building 3D strata model

either based on surface elements

or based on volume elements

or based on hybrid elements. But these methods in building 3D complex strata models usually failed

because of complex topological relationships of the strata

source data error and computer accuracy etc. It is a good idea to resolve these problems by using level set methods. Level sets are implicit functions of surfaces or hypersurfaces

which can represent complex geological bodies and implement a series of topological operations such as union

intersection

difference etc. In building 3D strata model

after interpolating geological interfaces

these interfaces are transformed into level sets

and the complex topological operations based on level sets are applied to building the 3D strata model. After building the 3D strata model

the interfaces of engineering activities represented by level sets

are inserted into the 3D strata model; and the 3D engineering activities strata model is built by the complex topological operations based on level sets. Then the geological interfaces or the interfaces of engineering activities are extracted by marching cube algorithm to constructing a NMTINF-BR 3D strata model or a NMTINF-BR 3D engineering activities strata model which is suitable for real-time visualization and numerical simulation (such as finite elements).