1vpSeti(3) Library Functions Manual vpSeti(3)
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6 vpSeti, vpSetd - set the value of an option
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9 #include <volpack.h>
10 vpResult
12 vpSeti(vpc, option, value)
13 vpContext *vpc;
14 int option;
15 int value;
16 vpResult
18 vpSetd(vpc, option, value)
19 vpContext *vpc;
20 int option;
21 double value;
22
24 vpc VolPack context from vpCreateContext.
25 option Constant that specifies the option to be set.
27 value New value for the option.
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31 These functions are used to set the values of integer- or double-valued
32 options in a rendering context. The following list summarizes the
33 integer-valued options that can be set with vpSeti:
34 VP_CONCAT_MODE
36 Choose whether transformation matrices are premultiplied or
37 postmultiplied. If value is VP_CONCAT_LEFT then matrices are
38 premultiplied. If value is VP_CONCAT_RIGHT then matrices are
39 postmultiplied. Default: VP_CONCAT_RIGHT.
40 VP_DEPTH_CUE_SIZE_HINT
42 Set the suggested number of entries in the depth cueing lookup
43 table. See vpSetDepthCueing(3). Default: none
44 VP_INT_WIDTH_HINT
46 Set the suggested width (in pixels) of the intermediate image
47 work buffer. See vpRenderRawVolume(3). Default: none
48 VP_INT_HEIGHT_HINT
50 Set the suggested height (in pixels) of the intermediate image
51 work buffer. See vpRenderRawVolume(3). Default: none
52 VP_SHADOW_LIGHT
54 Get the current shadow light (see vpSetShadowLookupShader(3)).
55 Legal values are VP_LIGHT0, VP_LIGHT1, ..., VP_LIGHT5. Default:
56 VP_LIGHT0
57 VP_SHADOW_WIDTH_HINT
59 Set the suggested width (in pixels) of the shadow buffer (see
60 vpSetShadowLookupShader(3)). Default: none
61 VP_SHADOW_HEIGHT_HINT
63 Set the suggested height (in pixels) of the shadow buffer (see
64 vpSetShadowLookupShader(3)). Default: none
65 VP_SHADOW_BIAS
67 Set the current shadow bias value (see vpSetShadowLookup‐
68 Shader(3)). The value is an integral distance in units of vox‐
69 els. Default: 4
70 VP_AXIS_OVERRIDE
72 Force the rendering routine to composite along a particular
73 principle viewing axis, regardless of the current viewing direc‐
74 tion. Legal values are VP_X_AXIS, VP_Y_AXIS or VP_Z_AXIS. Set
75 the value to VP_NO_AXIS to let VolPack choose the optimal axis
76 automatically (the default). This option is normally used only
77 for debugging.
78 VP_TRACE_SHADOW_K
80 When pixel tracing is enabled (see vpTracePixel(3)) and shadows
81 are enabled (the VP_SHADOW option to vpEnable(3)), this option
82 is used to choose one shadow buffer pixel to trace. The value
83 must be a voxel slice number. The shadow buffer pixel that gets
84 traced is the shadow pixel that affects the traced image pixel
85 at the indicated slice.
86 The following list summarizes the double-valued options that can be set
88 with vpSetd:
89 VP_DEPTH_CUE_QUANTIZATION
91 Set the difference in depth between two adjacent entries in the
92 depth cueing lookup table (see vpSetDepthCueing(3)). Must be
93 greater than 0.0 and less than 1.0. Default: 1/255
94 VP_MAX_RAY_OPACITY
96 Set the maximum opacity threshold. During rendering, when a
97 pixel's opacity reaches this threshold no more voxels are com‐
98 posited into the pixel. To maximize performance, the value
99 should be as low as possible without adversely affecting image
100 quality. Must be in the range 0.0-1.0 (1.0 is the default and
101 0.95 is the suggested value). Default: 1.0
102 VP_MIN_VOXEL_OPACITY
104 Set the minimum opacity threshold. During classification, if a
105 voxel's opacity is less than or equal to this threshold then the
106 voxel is discarded before rendering. To maximize performance,
107 the value should be as high as possible without adversely
108 affecting image quality. Must be in the range 0.0-1.0 (0.0 is
109 the default and 0.05 is the suggested value). Default: 0.0
110
112 The normal return value is VP_OK. The following error return values
113 are possible:
114 VPERROR_BAD_OPTION
116 The option argument is invalid.
117 VPERROR_BAD_VALUE
119 The value argument is invalid or out of range.
120
122 VolPack(3), vpCreateContext(3), vpGeti(3)
123VolPack vpSeti(3)