The image to the left shows the actor properties window. This can be brought up by right clicking on an actor and selecting properties, by presseing the actor properties button on the menubar or pressing F4

The Level properties window is the same except shows the properties for the current level and is displayed by pressing F6

Bring up the surfaces window by pressing F5 or right clicking on the surface and choosing properties.
NEW IN 425! The texture pack and name is now displayed at the top of the properties dialog box

The first tab shows various tick boxes for properties for the selected surface.

• Invisible - The surface cannot be seen
• Masked - The surface contains 'blank' bits, e.g. a grate or a fence effect
• Translucent - The surface is see-through, e.g. water or glass
• Force View Zone - don't know
• Modulated - not sure
• Fake Backdrop - select this is this surface is to show the sky
• Two Sided - the texture will show on both sides of the surface (pointless for brushes, but useful for sheets
• U-Pan - the texture moves horizantally
• V-Pan - the texture moves vertically. To get a texture panning the other way, flip it.
• High Shadow Detail - The detail of the shadow.
• Low Shadow Detail - For large outdoor areas you can choose High and Low to give Super Low.
• No Smooth -
• Special Poly - something special no doubt
• Small Wavy - a ripple like effect
• Dirty Shadows -
• Bright Corners - The surface is lit evenly
• Special Lit - Only lit by lights with bSpecialLit set to true
• No Bounds Reject - No idea
• Unlit - the texture is unlit, and remains at its full brightness.
• Portal - this surface is a portal. Usually you would use Add Special Brush to add a portal sheet or brush, and not set this manually
• Mirror - makes it a mirror, this plus translucent makes it a reflective texture (e.g. marble)