#!F-adobe-helvetica-medium-r-normal--18* #!N #!N #!Rtextmap Texture Mapping #!N #!N #!N If the machine on which Data Explorer is running supports OpenGL or GL, then texture mapping is available using hardware rendering. Texture mapping is the process of mapping an image (a field with 2-dimensional positions, quad connections, and colors) onto a geometry field with 2-dimensional connections and, typically, 3-dimensional positions (e.g., a color image mapped onto a rubbersheeted height field). The advantage of texture mapping over the use of Map, for example, is that the resulting image may have much greater resolution than the height map. #!N #!N The geometry field must have 2-D connections (triangles or quads) and must also have a component, with the name "uv," that is dependent on positions and provides the mapping between the image and the positions of the geometry field. This component consists of 2-vectors. The origin of the image will be mapped to the uv value [0 0], and the opposite corner to the uv value [1 1]. #!N #!N The texture map is the image to be mapped onto the geometry field. One requirement of the image (imposed by the hardware) is that the number of pixels in each dimension must be a power of 2 greater than or equal to 32. The two dimensions do not have to be the same size. The texture map should be attached to the geometry field as an attribute, with the attribute name "texture," which can be done with the Options module. A texture-mapped image can be retrieved from the Display window using ReadImageWindow and then written to a file using WriteImage. #!N #!N #!T,1,216,356,641 #!F-adobe-times-bold-r-normal--18* #!N TAB Attribute Name TAB Value TAB Description #!EF #!N TAB texture TAB a texture map TAB specifies a texture map #!N #!N Components #!N #!N The #!F-adobe-times-bold-r-normal--18* object #!EF input must have a "colors," "front colors," or "back colors" component. #!N #!N Script Language Examples #!N #!I0 #!N #!F-adobe-times-medium-r-normal--18* #!N #!N #!I30 #!N 1. This example renders two views of the object and displays them in two separate windows, as specified by the #!F-adobe-times-bold-r-normal--18* where #!EF parameter. #!CForestGreen #!N #!N #!F-adobe-courier-bold-r-normal--18* #!N electrondensity = Import("/usr/lpp/dx/samples/data/watermolecule"); #!N isosurface = Isosurface(electrondensity, 0.3); #!N camera1 = AutoCamera(isosurface, "front", resolution=300); #!N camera2 = AutoCamera(isosurface, "top", resolution=300); #!N image1 = Render(isosurface, camera1); #!N image2 = Render(isosurface, camera2); #!N Display(image1,where="X, localhost:0, view from front"); #!N Display(image2,where="X, localhost:0, view from top"); #!EF #!N #!N #!EC #!N #!I30 #!N 2. This example sets the rendering mode to "hardware" with the approximation method of "dots." #!CForestGreen #!N #!N #!F-adobe-courier-bold-r-normal--18* #!N electrondensity = Import("/usr/lpp/dx/samples/data/watermolecule"); #!N isosurface = Isosurface(electrondensity, 0.3); #!N from = Direction(65, 5, 10); #!N camera = AutoCamera(isosurface, from); #!N isosurface=Options(isosurface, "rendering mode", "hardware", #!N "rendering approximation", "dots"); #!N Display(isosurface,camera); #!EF #!N #!N #!EC #!N #!I0 #!N #!EF #!N #!N #!N Example Visual Programs #!CForestGreen #!N #!N #!F-adobe-courier-bold-r-normal--18* #!N MovingCamera.net #!N PlotLine.net #!N PlotTwoLines.net #!N ReadImage.net #!N #!N ScaleScreen.net #!N #!N TextureMapOpenGL.net #!N UsingCompute.net #!N UsingMorph.net #!EF #!N #!N #!EC #!N #!N See Also #!N #!N #!Larrange,dxall768 h Arrange #!EL , #!Lcollect,dxall788 h Collect #!EL , #!Lfilter,dxall849 h Filter #!EL , #!Limage,dxall860 h Image #!EL , #!Lrender,dxall923 h Render #!EL , #!Lreduce,dxall918 h Reduce #!EL , #!Lrefine,dxall919 h Refine #!EL , #!Lscalscr,dxall935 h ScaleScreen #!EL , #!Lnormals,dxall897 h Normals #!EL , #!Lfacenor,dxall847 h FaceNormals #!EL , #!Lsupwind,dxall961 h SuperviseWindow #!EL , #!Lsupstat,dxall958 h SuperviseState #!EL , #!Lreadimw,dxall916 h ReadImageWindow #!EL , #!Loptions,dxall898 h Options #!EL #!N #!N #!N #!F-adobe-times-medium-i-normal--18* Next Topic #!EF #!N #!N #!Ldivcurl,dxall827 h DivCurl #!EL #!N #!F-adobe-times-medium-i-normal--18* #!N
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