Accelerating the pace of engineering and science

# MATLAB

## Volume Visualization

This example shows several methods for visualizing volumes.

Set Up the Figure

Set the figure to use a dark background and to preserve this dark background when creating screenshots with PRINT.

```figNumber=figure;
colordef(figNumber,'black');
set(gcf,'InvertHardcopy','off')
```

Isosurface of MRI Data

```cla
D = squeeze(D);
[x, y, z, D] = subvolume(D, [nan nan nan nan nan 4]);
p = patch(isosurface(x,y,z,D, 5), 'FaceColor', 'red', 'EdgeColor', 'none');
patch(isocaps(x,y,z,D, 5), 'FaceColor', 'interp', 'EdgeColor', 'none');
isonormals(x,y,z,D,p);
view(3)
daspect([1 1 .4])
colormap(gray(100))
camva(9)
box on
camlight(40, 40)
camlight(-20,-10)
lighting gouraud
```

Coneplot of Wind Data

```cla
[cx, cy, cz] = meshgrid(linspace(71,134,10),linspace(18,59,10),3:4:15);
daspect([1 1 1])
h = coneplot(x,y,z,u,v,w,cx,cy,cz,y,3);
set(h,'EdgeColor', 'none')
colormap(hsv)
box on
axis tight
camproj perspective
camva(35)
campos([175 10 85])
camtarget([105 40 0])
camlight left
lighting gouraud
```

Streamlines of Wind Data

```cla
[sx, sy, sz] = meshgrid(80, 20:10:50, 0:5:15);
h = streamline(x,y,z,u,v,w,sx,sy,sz);
set(h, 'Color', 'cyan')
daspect([1 1 1])
box on
camproj perspective
camva(32)
axis tight
campos([175 10 85])
camtarget([105 40 0])
camlight left
lighting gouraud
```

Streamtubes of Wind Data

STREAMTUBE is useful for visualizing divergence of a vector field.

```cla
[sx, sy, sz] = meshgrid(80, [20 30 40], [5 10]);
daspect([1,1,1])
h = streamtube(x,y,z,u,v,w,sx,sy,sz);
set(h,'facecolor','cyan','edgecolor','none')
box on
camproj perspective
axis([70 138 17 60 2.5 16])
axis tight
camva(28)
campos([175 10 95])
camtarget([105 40 0])
camlight left
lighting gouraud
```

Streamribbons of Wind Data

STREAMRIBBON is useful for visualizing curl of a vector field.

```cla
[sx, sy, sz] = meshgrid(80, [20 30 40], [5 10]);
daspect([1,1,1])
h = streamribbon(x,y,z,u,v,w,sx,sy,sz);
set(h,'facecolor','cyan','edgecolor','none')
box on
camproj perspective
axis([70 138 17 60 2.5 16])
axis tight
camva(28)
campos([175 10 85])
camtarget([105 40 0])
camlight left
lighting gouraud
```

Isosurface, Isocaps, Coneplot, and Streamlines of Wind Data

```cla
spd = sqrt(u.*u + v.*v + w.*w);
p = patch(isosurface(x,y,z,spd, 40));
isonormals(x,y,z,spd, p)
set(p, 'FaceColor', 'red', 'EdgeColor', 'none');
p2 = patch(isocaps(x,y,z,spd, 40));
set(p2, 'FaceColor', 'interp', 'EdgeColor', 'none')
daspect([1 1 1])
[f, verts] = reducepatch(isosurface(x,y,z,spd, 30), .2);
h = coneplot(x,y,z,u,v,w,verts(:,1),verts(:,2),verts(:,3),2);
set(h, 'FaceColor', 'cyan', 'EdgeColor', 'none')
[sx, sy, sz] = meshgrid(80, 20:10:50, 0:5:15);
h2 = streamline(x,y,z,u,v,w,sx,sy,sz);
set(h2, 'Color', [.4 1 .4])
colormap(jet)
box on
axis tight
camproj perspective
camva(34)
campos([165 -20 65])
camtarget([100 40 -5])
camlight left
lighting gouraud
```