¿Cómo escribir graffiti, es decir, texto en una superficie poligonal en Graphics3D?

Aug 17 2020

¿Existe una manera relativamente fácil de colocar Texto [] en Polígono [] en Graphics3D? Por ejemplo, quiero que mi texto aparezca como si estuviera escrito en la "pared" gris claro de la imagen adjunta, de modo que permanezca fijo en la pared cuando se cambie el punto de vista.

Respuestas

5 TimLaska Aug 17 2020 at 10:17

Echaría un vistazo al video de Wolfram-U para gráficos 3D avanzados en Wolfram Language y descargaría el cuaderno. Mire la diapositiva 22 y la billboard3Dfunción, ya que adaptaré el código para incluir "graffiti" en las seis caras siguientes:

Clear[billboard3D];
billboard3D[s_, 
   width_, {x_, y_, z_}, {nx_, ny_, nz_}, {hx_, hy_, hz_}] :=
  Module[{img = Rasterize[s, "Image", Background -> None], height},
   height = width ImageAspectRatio[img];
   {
    FaceForm[White], EdgeForm[],
    Texture[ImageData[img]],
    GeometricTransformation[
     Polygon[{{-.5 width, .5 height, 0}, {.5 width, .5 height, 
        0}, {.5 width, -.5 height, 0}, {-.5 width, -.5 height, 0}}, 
      VertexTextureCoordinates -> {{0, 1}, {1, 1}, {1, 0}, {0, 0}}],
     Quiet@
      Composition[TranslationTransform[{x, y, z}], 
       RotationTransform[{{0, 1, 0}, {hx, hy, hz}}], 
       RotationTransform[{{0, 0, 1}, {nx, ny, nz}}]]]
    }
   ];

Framed[
 Graphics3D[{
   
   (* Add a Plot3D Object *)
   Plot3D[ 
     0.9 Exp[-9 ((x - 1/2)^2 + (y - 1/2)^2)], {x, 0, 1}, {y, 0, 1}, 
     PlotRange -> {0, 2}, ColorFunction -> "TemperatureMap", 
     PlotStyle -> Directive[Opacity[0.5], Red]][[1]],
   (* View frustum *)
   FaceForm[], EdgeForm[GrayLevel[.25]], Cuboid[],
   
   (* Camera *)
   FaceForm[GrayLevel[.25]], EdgeForm[], Specularity[White, 30],
   Cuboid[{.45, -1, .4}, {.55, -1.3, .6}],
   Cylinder[{{.475, -1.1, .65}, {.525, -1.1, .65}}, .05],
   Cylinder[{{.475, -1.2, .65}, {.525, -1.2, .65}}, .05],
   Cylinder[{{.5, -1, .5}, {.5, -.9, .5}}, .05],
   Cylinder[{{.5, -1.15, .5}, {.5, -.9, 0}}, .01],
   Cylinder[{{.5, -1.15, .5}, {.35, -1.3, 0}}, .01],
   Cylinder[{{.5, -1.15, .5}, {.65, -1.3, 0}}, .01],
   billboard3D[
    Style["ViewPoint", 24, Bold, 
     FontFamily -> "Courier"], .4, {.5, -1.15, .8}, {1, 0, 0}, {0, 0, 
     1}],
   
   (* View span *)
   GrayLevel[.25],
   With[{p = {.5, -.9, .5}}, 
    Line[{{p, {0, 0, 0}}, {p, {1, 0, 0}}, {p, {0, 0, 1}}, {p, {1, 0, 
        1}}}]],
   
   (* View angle *)
   Gray, Dashed,
   With[{p = {.5, -.9, .5}}, Line[{{p, {.5, 0, 1}, {.5, 0, 0}, p}}]],
   Arrowheads[{-.015, .015}], 
   Arrow[BezierCurve[{{.5, -.5, 
       0.28}, {.5, -.4, .5}, {.5, -.5, .72}}]],
   billboard3D[
    Style["ViewAngle", 24, Bold, 
     FontFamily -> "Courier"], .3, {.5, -.4, .45}, {1, 0, 0}, {0, 0, 
     1}],
   
   (* View vertical *)
   billboard3D[
    Style["ViewVertical", 24, Bold, 
     FontFamily -> "Courier"], .35, {.5, -.05, .75}, {1, 0, 
     0}, {0, -1, 0}],
   
   (* View center *)
   PointSize[Large], Point[{{.5, .5, .5}, {.5, 0, .5}}],
   Arrowheads[.015], Arrow[{{.5, .5, .5}, {.5, 0, .5}}],
   billboard3D[
    Style["ViewCenter", 24, Bold, 
     FontFamily -> "Courier"], .25, {.5, .25, .55}, {1, 0, 0}, {0, 0, 
     1}],
   
   (* View range *)
   Gray,
   Line[{{{1, 0, 0}, {1, 0, -.1}}, {{1, 1, 0}, {1, 1, -.1}}}],
   Arrowheads[{-.02, .02}], Arrow[{{1, 0, -0.05}, {1, 1, -.05}}],
   billboard3D[
    Style["ViewRange", 24, Bold, 
     FontFamily -> "Courier"], .4, {1.075, .5, -.1}, {1, 0, 0}, {0, 0,
      1}],
   
   (* View left wall *)
   billboard3D[
    Style["Left Wall", 24, Bold, FontFamily -> "Courier"], .35, {0, 
     0.5, .5}, {1, 0, 0}, {0, 0, 1}],
   
   (* View right wall *)
   billboard3D[
    Style["Right Wall", 24, Bold, FontFamily -> "Courier"], .35, {1, 
     0.5, .5}, {1, 0, 0}, {0, 0, 1}],
   
   (* View top wall *)
   billboard3D[
    Style["Top Wall", 24, Bold, FontFamily -> "Courier"], .35, {0.5, 
     0.5, 1}, {0, 0, 1}, {0, 1, 0}],
   
   (* View bottom wall *)
   billboard3D[
    Style["Bottom Wall", 24, Bold, 
     FontFamily -> "Courier"], .35, {0.5, 0.5, 0}, {0, 0, 1}, {0, 1, 
     0}],
   
   (* View front wall *)
   billboard3D[
    Style["Front Wall", 24, Bold, FontFamily -> "Courier"], .35, {0.5,
      0, 0.5}, {0, 0, 1}, {0, 0, 1}],
   
   (* View back wall *)
   billboard3D[
    Style["Back Wall", 24, Bold, FontFamily -> "Courier"], .35, {0.5, 
     1, 0.5}, {0, 0, 1}, {0, 0, 1}]
   
   },
  Boxed -> False, ImageSize -> 750, Lighting -> "Neutral",
  ViewPoint -> {5, -2, 1.5}
  ],
 FrameMargins -> 20, FrameStyle -> GrayLevel[.75]]