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Upgrading Old Models

Models created prior to SpeedTree 8 comprise mostly Spine and Leaf generators. These models will open and look the same in 8 (with a few, minor exceptions), but they do not make use of many of the new features.

Please see the sections below for why you should consider upgrading old models and how to go about it.

Note: Upgraded models will not be an exact replica of the old model. They will, at best, appear to have been randomized, and, at worst, require some editing to restore them to something resembling their previous state.

Why Should I Upgrade Leaf Generators?

Leaf generators have been superseded by two new generators: Batched Leaf and Leaf Mesh. The two new leaf generators are identical in their properties but differ in how they are computed. Batched Leaf generators compute very fast but do not allow node editing of individual leaves. Leaf Mesh generators compute much more slowly but each leaf can be edited as necessary. Batched Leaf generators are preferred and used in the automatic upgrade process.

Here's some of what you gain when you upgrade:

  • Significantly faster leaf computation (up to 1000 times faster than v7 models)
  • Easier leaf orientation
  • Leaf deformation (fold, curl, noise)
  • Resolution control
  • Improved collision (leaf-leaf and leaf-branch)
  • New season system

Why Should I Upgrade Spine Generators?

Three generators now do the job of the Spine generator: Branch, Frond, and Cap. The new approach requires an explicit entry in the Generation Editor for each type of geometry you want to appear. Frond and Cap generators must be the child of a Branch generator in order to work.

Here's some of what you gain when you upgrade:

  • Branch extensions (child branches “continuing” their parent)
  • Spine noise
  • Context sensitive pruning
  • Aspect ratio correct UV mapping
  • Shape control
  • Improved welding
  • Blending between different branch materials
  • New vertex displacement (noise, shape, flares)
  • Resolution control
  • Easier control over caps and fronds

How Do I Upgrade a Model?

Open any old model and look at the tool bar in the Generation Editor. If any generators that can be upgraded are detected, the “Upgrade” button will appear. Select any eligible generator and press “Upgrade.” The selected generator will be swapped out for a new one (or several as appropriate) that has its properties set to a close approximation of the original values.

It is possible to convert the entire model at once; however, it is not recommended. The best approach is to upgrade generators one at a time, making corrections as you go to ensure the final result is an acceptable conversion.