This week we looked at colour and generating textures.
White light contains all other colours; we can see this when a prism splits it into a rainbow. A green object appears green because it absorbs other colors and bounces the green light back and into our eyes.
When we render an object in Blender, or any other 3D software, we want the renderer to generate the highlights (specular reflections) and shadow on the object. Any texture we use should be as free of highlights and shadow as possible.
To generate a relatively highlight and shadow-free texture of an apple, we used a pop-up portable photo studio. The interior of this box is white and reflective and lights the object relatively evenly on all sides.
We photographed the object, an apple in this case, at four angles around the circumference and once again for the top and bottom of the apple respectively. This left us with six shots of the apple from all sides.
I then opened each shot in Gimp (the image editing software), and removed as much of the rest of the image, everything that wasn’t apple, as possible. To do this I:
- Used the Rectangle Selection Tool to select a box close in around the apple and then used Image | Crop to Selection to remove the rest of the image
- Used the Fuzzy Selection Tool (aka. Magic Wand tool) to select white areas. I adjusted the Threshold value in the Tool Options panel as high as possible so that no parts of the apple were being selected when I clicked. I then used Edit | Cut to remove those portions.
- Finally, there were portions of the supporting bowl that were still remaining. I used the Free Select Tool (aka. Lasso Tool) to select these and remove them.
Once I had each photo of the apple cleaned up, I created a new image, and pasted all the individual images into it, scaling them so that they were close to the same size. The result is here:
We also built a simple apple model by shaping a UV sphere. Next week we are going to stencil paint the apple model with this texture.
The apple model can be found here.