Lights in AutoCAD 2007 - Part 1

I'm sure you have heard by now that AutoCAD 2007 has gotten a major overhaul in its 3D Modeling capabilities. These changes wouldn't make much difference if they didn't improve lighting, materials and rendering as well.  In this posting I take a look at some of the new lighting improvements at a very basic level.

AutoCAD 2007 supports 4 different types of light sources (5 if you are going to count default lighting).  The four different types of lights are Point, Spotlight, Distant and Sun light.  Point, Spotlight, and Distant lights were all available in previous releases of AutoCAD that supported rendering (all the way back to R13).  Point lights are lights that emit light in all directions, and are similar to a candle or a common household light bulb and as the light moves further away from the source it gets dimmer.  A spotlight, would be similar to a flash light as it emits in a specific direction and as the light gets further away from the source it gets dimmer.

1. Point light
2. Spotlight
3. Distant light

Distant lights are lights that emit light along a specified vector, but the light does not get dimmer the further away from the source that it gets.  A distant light would be similar to the sun, the angle and direction affects how the light is emitted.  Sunlight is really a specific distant light that allows you to control the time and day of the sun, and its position through longitudinal and latitudinal values.  All lights can be selected in the model using the Lights in Model palette or in some cases light with the point and spotlights can be selected and manipulated directly in the model using grips.

 

That is about all the time I have for now on lights, until next time.

Sincerely,
  Lee

Comments

[RBPrice]

It would have been a better article if the author had proof read it before publishing it.

Seen is not the same as scene. The phrase "distant lights are lights that shine in a specific distance" doesn't make sense.

Bob Price

[Lee Ambrosius]

Hello Bob,

Sometimes things make more sense at 1:00 AM in the morning than they do after one gets some actual sleep. The article has been tweaked and should read a little better, also at times I might rely a little too much on MS Word to find things when I start getting a little on the tired side of things. Have a nice day.

Sincerely,
Lee

[Paul Li]

Unfortunately, when Autodesk added Sun Light to AutoCAD 2007, they also took away previous AutoCAD Distant Light feature where the user can define multiple sun lights with them.

[aisling]

hi Can you explain how to turn off default lights in 2007

Thanks

Aisling

[Lee Ambrosius]

Default lighting can be turned on or off using the DEFAULTLIGHTING system variable. Enter DEFAULTLIGHTING at the command prompt and enter a value of 1 or 0 to turn default lighting on or off respectfully. You can also click the Viewport Lighting Mode toggle on the Lights control pnale found on the Dashboard.

[EDD]

I always use MText command when drafting and providing call outs. But everytime I wanted to edit the Mtext by double clicking the mouse, the In-place text editor does not show.

Thank you

[Lee Ambrosius]

Your issue sounds like it could be one of two things since I am not which release of AutoCAD you are using. The first is that the system variable PICKFIRST must be set to a value of 1. To change it, type in PICKFIRST at the command prompt and press ENTER. When prompted for the new value enter 1 and press ENTER.

The second and usually not the most likely is that you are using an older menu than the one that can with AutoCAD 2007 and 2008 that doesn’t define what command should execute when a MTEXT object is double-clicked. So in this case make sure that you are the appropriate action setup in the CUI editor by typing in CUI at the command prompt and press ENTER. Expand the Double-click Actions node and check the MTEXT object node to make sure it is using the DDEDIT command.

[ang]

quite an old article it is, but i wonder where is the part 2?? :D