To create a smoke effect in your rendering, you need to turn on the Smoke option in your rendering settings before rendering the view.
To create a smoke effect:
Select View
> 3DTrueView > 3DTrueView Options, or click the 3DTrueView
Options button on the 3DTrueView toolbar.
In the Program Settings dialog, select the Rendering tab.
In the Effects area, check the Enable check box.
Enable the Smoke radio button.
In the Density edit box, specify the desired thickness of the smoke. The higher the percentage, the thicker the smoke.
Click OK.