abstract: An easy approach to make sculpted plants. The tutorial also discusses Alpha sorting and shows a nice trick how to solve one frequently occuring issue


Hello and welcome!
With the new Primstar-2 Star shape it is very easy to make a simple framework
for trees and plants. It is possible to make entire plants with trunk and leaves
from just one single sculptie. But in this tutorial-i want to concentrate on the leaves,
and show you one nice trick how you can avoid the alpha sorting problems,
which typically show up in this sort of sculpties.

Let us start with making a simple frame containing 2 crossed planes.
Add a new star shape by navigating to:

Add -> Mesh -> UV-shape -> Star.

In the Operator panel set:

  • depth = 1.0
  • taper = 0.0

You also should give your object a reasonable name. That will help you later
to keep-track of what you are doing. If you like then you can remove the
dark shades at the outer ends of the planes by disabling smooth-shading.

Now bake the sculpt-map. Do this by navigating to:

Object -> Bake Sculpt Maps

and then let the baker do the rest for you. Well, you still have to import
the generated sculpt-map-image to OpenSim (or your preferred online world):

  • In the image editor select the sculpt-map-image. This image is named
    similar to the name of the sculpty, as it was named during its creation.
    In our case it will be named “plant-frame”.
  • if you like you can change that to something more convenient here.
  • Now navigate to: image, save as image,
  • then store the image on file,
  • and import it to your online world.

Assure that you have checked loss-less compression, otherwise your sculpty
may suffer from distortions. Please also assure, that the stitching type of your
object is set to: “plane”.

Now you only need an appropriate Alpha-texture for your object.
Since it is a plane surface you can use a simple side view of your
plant for this purpose. The special construction of the sculptie makes
it possible to tyle our texture. In our case we want to tile it 4 times.

Now let us inspect the result. While moving the camera, we now see
unexpected distortions. These distortions-are due to a problem in the
graphics-engine. Sometimes it is impossible for the engine, to find out
if one texture is in front-of or behind another texture.

This is the alpha-sorting problem.

But fortunately there is a solution to this issue for our special case.
We have to rotatE the sculpty’s UV-map and then rebake the sculpty
in blender.

  • go to edit-mode
  • and assure that all vertices are selected.
  • Now go to the image-editor
  • and again select all vertices.
  • Now rotate the map by 90 degrees by typing: ‘r’, 90
  • Now bake again,
  • and transport the result to your online world.

And because the sculpt-map has been rotaightad by 90 degrees, we also
need to rotate the texture back by the same value!

If you now examine the sculptie in detail,  you will see that the alpha texture
problem-is gone and the final result-does no longer
show any distortions, as you can see here.

I am now at the end of this tutorial.

  • I have guided you through the construction of a simple frame for plants.
  • We have seen that this simple approach shows alpha-sorting problems.
  • And we have learned that you can get much better results when you add
    a rotation of 90 degrees to the UV-map.

By now you should be able to build all sorts of trees and plants for your virtual

Thank you for watching,
Have a nice day!