RegionPlot3D[(x+y+z≤3/2),{x,0,2},{y,0,2},{z,0,2},PlotPoints->150]

RegionPlot3D[(x+y≤y+z≤z+x≤0.7)&&(x+y+z≤3/2),{x,0,2},{y,0,2},{z,0,2},PlotPoints->150]

RegionPlot3D[(x+y≤y+z≤0.7≤z+x≤1.3)&&(x+y+z≤3/2),{x,0,1},{y,0,1},{z,0,1},PlotPoints->150]

RegionPlot3D[(x+y≤0.7≤y+z≤z+x≤1.3)&&(x+y+z≤3/2),{x,0,1.5},{y,0,1.5},{z,0,1.5},PlotPoints->150]

RegionPlot3D[(0.7≤x+y≤y+z≤z+x≤1.3)&&(x+y+z≤3/2),{x,0,1.5},{y,0,1.5},{z,0,1.5},PlotPoints->150]

RegionPlot3D[(x+y≤y+z≤0.7≤1.3≤z+x)&&(x+y+z≤3/2),{x,0,1.0},{y,0,1.0},{z,0,1.0},PlotPoints->350]

RegionPlot3D[(x+y≤0.7≤y+z≤1.3≤z+x)&&(x+y+z≤3/2),{x,0,1.5},{y,0,1.5},{z,0,1.5},PlotPoints->150]

RegionPlot3D[(x+y≤0.7≤1.3≤y+z≤z+x)&&(x+y+z≤3/2),{x,0,1.5},{y,0,1.5},{z,0,1.5},PlotPoints->150]

RegionPlot3D[(0.7≤x+y≤y+z≤1.3≤z+x)&&(x+y+z≤3/2),{x,0,1.5},{y,0,1.5},{z,0,1.5},PlotPoints->150]

RegionPlot3D[(0.7≤x+y≤y+z≤1.3≤z+x)&&(x+y+z≤3/2),{x,0.5,1.0},{y,0,0.5},{z,0.5,1.0},PlotPoints->150]

RegionPlot3D[(0.7≤x+y≤1.3≤y+z≤z+x)&&(x+y+z≤3/2),{x,0,1.5},{y,0,1.5},{z,0,1.5},PlotPoints->150]

RegionPlot3D[(y≤x&&x+y≤0.7&&x+y+z≤3/2),{x,0,1.5},{y,0,1.5},{z,0,1.5},PlotPoints->150]

RegionPlot3D[(x+y≤y+z≤z+x≤0.7)&&(y≤x&&x+y≤0.7&&x+y+z≤3/2),{x,0,1.5},{y,0,1.5},{z,0,1.5},PlotPoints->150]

RegionPlot3D[(y+z≤z+x≤x+y≤0.7)&&(y≤x&&x+y≤0.7&&x+y+z≤3/2),{x,0,1.5},{y,0,1.5},{z,0,1.5},PlotPoints->150]

RegionPlot3D[(z+y≤y+x≤z+x≤0.7)&&(y≤x&&x+y≤0.7&&x+y+z≤3/2),{x,0,1.5},{y,0,1.5},{z,0,1.5},PlotPoints->150]

RegionPlot3D[(x+y≤y+z≤0.7≤z+x≤1.3)&&(y≤x&&x+y≤0.7&&x+y+z≤3/2),{x,0,1.5},{y,0,1.5},{z,0,1.5},PlotPoints->150]

RegionPlot3D[(z+y≤y+x≤0.7≤z+x≤1.3)&&(y≤x&&x+y≤0.7&&x+y+z≤3/2),{x,0,1.5},{y,0,1.5},{z,0,1.5},PlotPoints->150]

RegionPlot3D[(x+y≤0.7≤y+z≤z+x≤1.3)&&(y≤x&&x+y≤0.7&&x+y+z≤3/2),{x,0,1.5},{y,0,1.5},{z,0,1.5},PlotPoints->150]

RegionPlot3D[(x+y≤y+z≤0.7≤1.3≤z+x)&&(y≤x&&x+y≤0.7&&x+y+z≤3/2),{x,0,1.5},{y,0,1.5},{z,0,1.5},PlotPoints->150]

RegionPlot3D[(z+y≤y+x≤0.7≤1.3≤z+x)&&(y≤x&&x+y≤0.7&&x+y+z≤3/2),{x,0,1.5},{y,0,1.5},{z,0,1.5},PlotPoints->150]

RegionPlot3D[(x+y≤0.7≤y+z≤1.3≤z+x)&&(y≤x&&x+y≤0.7&&x+y+z≤3/2),{x,0,1.5},{y,0,1.5},{z,0,1.5},PlotPoints->150]

RegionPlot3D[(x+y≤0.7≤1.3≤y+z≤z+x)&&(y≤x&&x+y≤0.7&&x+y+z≤3/2),{x,0,1.5},{y,0,1.5},{z,0,1.5},PlotPoints->150]

RegionPlot3D[(y≤x&&x+y≥1.3&&x+y+z≤3/2),{x,0,1.5},{y,0,1.5},{z,0,1.5},PlotPoints->150]

RegionPlot3D[(y+z≤z+x≤0.7≤1.3≤x+y)&&(y≤x&&x+y≥1.3&&x+y+z≤3/2),{x,0,1.5},{y,0,1.5},{z,0,1.5},PlotPoints->150]

RegionPlot3D[(y+z≤0.7≤z+x≤1.3≤x+y)&&(y≤x&&x+y≥1.3&&x+y+z≤3/2),{x,0,1.5},{y,0,1.5},{z,0,1.5},PlotPoints->150]

RegionPlot3D[(y+z≤0.7≤1.3≤z+x≤x+y)&&(y≤x&&x+y≥1.3&&x+y+z≤3/2),{x,0,1.5},{y,0,1.5},{z,0,1.5},PlotPoints->150]

RegionPlot3D[(y+z≤0.7≤1.3≤x+y≤z+x)&&(y≤x&&x+y≥1.3&&x+y+z≤3/2),{x,0,1.5},{y,0,1.5},{z,0,1.5},PlotPoints->150]

RegionPlot3D[(0.7≤y+z≤z+x≤1.3≤x+y)&&(y≤x&&x+y≥1.3&&x+y+z≤3/2),{x,0,1.5},{y,0,1.5},{z,0,1.5},PlotPoints->150]