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A time for reflection

Posted by Tyson Kartchner, Learning Guru

No, not the "deep meaning of life" kind of reflections -- I'm talking about the kind of reflection you'd see in a mirror. More specifically, the kind you might see when looking across a pool or lake. Here's a quick and easy way to simulate reflections in SketchUp:

You'll need a few things to create this illusion, starting with a body of water. In SketchUp terms, that means a surface you can paint with a transparent material. Make sure that you also have a ground surface for your objects to sit on.


  1. Take the objects in your scene that need reflections and copy them straight up in the blue direction:
  2. Select the objects with the Select tool.
  3. Press M to switch to the Move tool, start moving them, then press the Up or Down Arrow key on your keyboard to lock yourself in the up/down direction.
  4. While still moving your objects, press the Ctrl key (Option on a Mac) to make a copy of the objects you're moving.
  5. Drop the copies in space somewhere above the originals.
Next, mirror the copies with the Scale tool and move them to their correct locations:


  1. With the objects still selected, press S to switch to the Scale tool.
  2. Drag the top, center scaling grip down (see the image, above), "squashing" the objects until they are "inside out". Continue scaling until you see -1 in the Value Control Box (in the lower-left corner of your modeling window). Now the copies are mirrored.
  3. Select the copies and move them straight down so they are directly under their original counterparts.
  • Finally, paint the water surface with a transparent material. You mirrored the objects below the ground plane to create the illusion of a reflection. Orbit around to get the full effect.



    Extra credit: If you want to take this technique even farther, try this:

    Create a large surface (larger than your water surface), and paint it with the same transparent material you used for the water. Create several copies of the new, larger surface below the original water surface to create the illusion of depth. By doing this, your reflections will appear to fade away.


    Hint #1: Play with the distance and number of copies of the water surface to get more or less of this effect and adjust the opacity of your materials as well. Below, you can see the effect of simulating water depth in the image on the right.


    Hint #2: Remember that if your ground plane is sloping, you may need to mirror it as well. You can see in the example below that I mirrored the entire hill and trees to get good reflections. Turning on fog resulted in a pretty nice scene.


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    15 comments :

    joem said...

    So, the SketchUp team clearly knows that SU is missing this functionality... Does that mean that it'll be be built into the next version, or is this "hack" going to permanently be the official way to do reflections in SU?

    joem said...

    Don't get me wrong, though. I don't want to sound ungrateful for the post. I hadn't thought of that, and I just assumed that was something I wouldn't be able to do at all in SU. Thanks.

    Anonymous said...

    Erm, my contribution is somewhat non related, but I am looking for advice: Can anybody explain me, why are there white lines in my models? They are seen just on edges and in specific angles. And how to remove them? I enclose .JPG for demonstration:

    http://i204.photobucket.com/albums/bb28/stinky82x/begging4advice.jpg

    thank you very much...

    Unknown said...

    good technic
    maybe a little heavy?

    what about mirror reflection?

    where there is no depth to copy/paste objects to reflect?

    keep up the good work.

    best regards

    Pablo Oneto said...

    im sure this is a BIG patch, but youll get better results combining Sketchup with Kerkythea (a really great free 3d ray tracing tool)

    Anonymous said...

    just a thought....go buy Sketchup Podium, it's cheap, has some cool features, and provides an easy way to create "reflections" within the Sketchup program.

    Anonymous said...

    Hey, Dominique82...

    I think that your white lines are due to your background color in the style being set to white. Try going to window > Styles > Edit and change your BG color to something like gray or black.

    Anonymous said...

    If only Podium was available for mac........

    Anonymous said...

    I've seen this workaround before on go-2-school.com and I always thought the objects you wish to be reflected ought to be combined in a component before creating the "mirror image".

    This way you can add anything to your objects on top, and there's no need to do the work all over again for every new object you add.

    "work smart, not hard"

    Allister Godfrey RIBA said...

    Blimey Aiden, you are a little late with this one ... ;o)

    I described this technique on the old SU forum some years ago, and more recently here ... http://www.formfonts.com/blog/?p=10

    Allister

    affyx.com said...

    Here's the original I posted a couple years ago... http://video.google.com/videoplay?docid=-8033212466112425583&hl=en

    Anonymous said...

    Hello Scot,
    thanx for your advice. I´ve set it up and it works good... :)

    Arinthros said...

    Hey Dominique,

    I've also had this problem due to interior surfaces showing through at edges and angles. My fix is to either remove the interior surfaces or to paint them black.

    Anonymous said...

    i have a quesion
    if u download items
    how do you, after using, delete them

    Anonymous said...

    Podium is available for Mac-users the program is really nifty and user friendly.....I am combining SU with Podium along with PS