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:

1. 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
2. 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.
3. 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.

Hi Folks. Minimal notes this week as we spent the session working with the sculpting tools in Blender; something you really just need to try for yourself.

To start a new sculpting session, just choose File > New > Sculpting to be presented with a  high-resolution quad sphere and an array of sculpting tools.

Of these tools there are three I find most useful:

1. Draw: Normally pulls out the mesh, but will create depressions when CTRL is held
2. Crease: Makes fine creases in the mesh. Great for adding detail
3. Smooth: Great for when the mesh has become a little rough or uneven

You should experiment with the others to see which you like best!

Finally, here’s a little rough and unflattering 10min self-portrait I knocked up at the end of the session, just for laughs:

When sculpting, it a good idea to remesh from time-to-time where you’ve significantly deformed the mesh. Remeshing evens the mesh spacing automatically, avoiding places where individual polygons are overstretched, but it’s only available in Blender 2.81. Some people had this version already installed, while others installed it during the session. If you haven’t got it yet and would like to install it you can get it here.

Finally, here’s little personal project you might like to see. I sculpted and painted my cat Noodle’s head. I used a couple of reference photos and a technique called stencil painting to generate the texture: