Making Karts: Shadow Files

Last update july 8th 2011

This short tutorial explains how to make a perfect shaped kart shadow, using the kart model in Blender and a graphics editing software as The GIMP. See the Kart resources index for more information about karts.

The following manipulations will have to be done every time you'll change the kart model a way that impacts its top view look (eg. up-scale and down-scale transformations). So you may want to finalize the model before making the shadow.

Taking screenshot

Shadow tutorial 1.jpg

Jump to top-view (numpad 7) fullscreen (Ctrl + up) orthogonal mode (numpad 5 to switch persp/ortho) in Blender, making sure you will be able later to locate the (-1, -1) (1, -1) (1, 1) (-1, 1) square on the (X, Y) plane even without seeing its edges. Here, the screen's side and the View>"Background Image" Blender property window will enable to locate the square.

Shadow tutorial 2.jpg

Add a colored background in Blender. It creates a high contrast with the model in shaded view mode. Don't forget to increase the background's size in the property window if you use a small image.

Cropping screenshot

Shadow tutorial 3.jpg

Then, open your screenshot image with your favorite graphics editing program. Simply crop your image following the square we made easy to identify earlier. Thanks to this, the shadow will have the right scale on the shadow image.

Getting shadow shape

Shadow tutorial 4.jpg

With the fuzzy select tool (aka magical wand), select the colored background (don't forget to click in every closed area), then invert the selection so it corresponds to the kart's shape

Shadow tutorial 5.jpg

Feather the selection by roughly 10px (this value may need to be adjusted following your screen resolution), then eventually grow it by 2 or 3px, to smooth the shadow.

Filling shadow

Shadow tutorial 6.jpg

Create a transparent layer, and fill your selection with black opacity 50% using the bucket tool.


Shadow tutorial 7.jpg

Then, resize your image to 256x256 (or even 128x128 if it does not contain a lot of details), hide or delete your green layer, and save the image as a PNG file, with transparency.

Shadow tutorial end.png

Here is your final shadow. To polish it, you can also add some darker areas as in Puffy's one :

Puffy shadow.png

If you have remarks or feedback about this tutorial, don't hesitate to post them on the forum, and if you see any mistakes please tell, or even correct them !