diff --git a/doc/FAQ b/doc/FAQ index 539a921493809ecc59581ca5cf73a30e04db3e4c..eed1e8fe4cec45a63e4f0a8268daf584fd816367 100644 --- a/doc/FAQ +++ b/doc/FAQ @@ -1,4 +1,4 @@ -$Id: FAQ,v 1.59 2005-04-04 18:40:13 geuzaine Exp $ +$Id: FAQ,v 1.60 2005-05-12 15:43:12 geuzaine Exp $ This is the Gmsh FAQ @@ -137,6 +137,39 @@ problem: strategic locations in your geo files (e.g. before the creation of line loops, etc.). +* 4.3 How can I display only selected parts of my model? + +By using 'Tool->Visibility': + +- In the 'Browser' tab, you can select which group of entities to show +(several entities can be selected at once by dragging the mouse or by +holding the Ctrl and Shift keys while clicking). There are three main +modes: 'Elementary', in which the numbers in the list correspond to +elementary geometrical entities; 'Physical', in which the numbers in +the list correspond to physical entities; and 'Partitions', in which +the numbers in the list correspond to indices of mesh partitions (for +multi-domain meshes read from "new" .msh files). If 'Geometry+Mesh' is +selected, the selection applies to both the geometrical entities and +their associated meshes; if 'Mesh' is selected, the selection applies +only to the mesh; if 'Geometry' is selected, the selection applies +only to the geometry. If the 'Recursive' option is set, selecting an +entity implies that all the entities that are used to construct it +(all the "boundaries") are selected too, recursively. For example, if +'Recursive' is set, selecting a surface will automatically select its +boundary curves, as well as the boundaries of these curves (i.e., +points). If 'Recursive' is not set, only the surface (the dashed +cross) would be shown. + +- In the 'Numeric Input' tab, you can choose to show or hide any +entity or mesh element by giving its number. You can also use the "*" +character to select all the entities/elements at once. For example, to +show only the mesh element 13245 in the mesh, you would enter "*" in +the 'Element' input field and click on 'Hide' (this will hide all the +mesh elements); and then enter "13245" in the 'Element' input field +and click on 'Show' (this will show the element 13245). To show other +element, you would just enter another number in the input field, click +on 'Show', etc. + ******************************************************************** Section 5: Mesh module @@ -235,6 +268,25 @@ Lines, Physical Surfaces and Physical Volumes): see the reference manual as well as the tutorials (in particular 'tutorial/t1.geo') for a detailed description and some examples. +* 5.12 How can I display only the mesh associated with selected +geometrical entities? + +See question 4.3. + +* 5.13 How can I "explore" a mesh (for example, to see inside a +complex structure)? + +You can use 'Tools->Clipping Planes' to extract the region of +interest. You can define up to 6 clipping planes in Gmsh (i.e., enough +to define a "cube" inside your model) and each plane can clip either +the geometry, the mesh, the post-processing views, or any combination +of the above. The clipping planes are defined using the four +coeficients A,B,C,D of the equation A*x+B*y+C*y+D=0, which can be +adjusted interactively by dragging the mouse in the input +fields. There is also one additional clipping plane available for +"cutting" only the mesh (by keeping entire elements), in +'Tools->Options->Mesh->Cut Plane'. + ******************************************************************** Section 6: Solver module @@ -407,3 +459,13 @@ Also note that if all the views are based on the same grid, Gmsh can combine the separate views into a multi-time-step view by using the 'View->Combine->Time Steps' menu, or by using the '-combine' command line option. + +* 7.14 How can I see "inside" a complicated post-processing view? + +See question 5.13. + +When viewing 3D salar fields, you can also modify the colormap +('Tools->Options->View->Map') to make the iso-surfaces "transparent": +either by holding 'Ctrl' while dragging the mouse to draw the alpha +channel by hand, or by using the 'a', 'Ctrl+a', 'p' and 'Ctrl+p' +keyboard shortcuts.