Xfrog Library Checklist
Timm Dapper (td@td-grafik.de)
last change: (05/28/2003)
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Names
Do only use aplhanumerical characters and underscores in Component Names. No Special
Characters (e.g. '.', ';', ':', '-', '/') and Spaces in Copmonent Names. Also ensure that
Component Names do not have more than 15 characters.
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Filenames
Make sure texture filenames also fit the above rule and additionally only use the old DOS convention
for filenames (never more than 8 characters name, 3 characters extension).
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Keyframes
Ensure the last keyframe (which is always automatically generated at the end of the animation)
is identical to the first. Otherwise some strange animation might occur within the
PlugIns if the user doesn't explicitly disable animation (e.g. the whole model transforming
to the Hierachy with default parameters applied everywhere).
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Ranges
Ensure no Parameter Value is outside the Range specified in the GUI. Parameter Values
outside the specified range may cause models to act strange. For animations also take care
that values don't fall out of the range in the course of the animation. This is a
bug/strange behaviour in Xfrog, but library models shouldn't do this anyway since it's
bad style.
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Tree Component Scale
I've encountered numerous models in the libraries which for some reason use tree components
with their scale set to zero for the last third of the tree. This habit should be abandoned
and models containing that should be changed on the long run! It produces an unnecessary
amount of geometry (since the geometry of the last third is still created, it's just too thin
to contribute to the image). This has siginificant negative impact on Level of Detail as well.
There are additional side effects, the models are strange to handle (they don't behave like
expected), bounding volumes are far bigger than necessary (which makes handling the model less
efficient & will make usage of other Components like the HyperPatch unintuitive). This is
especially a problem when people try to modify those models or try to learn from them.
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Keep your Hands off the Growth Scale
The Growth Scale should only be touched very carefully. Growth Scale should not be used for
modeling because it will greatly limit the user he wants to use the parameter for growth
animation later on. The Problem is basically that every point on the growth scale spline
should be lower than all the points on its left, otherwise you'll get funny effects. Walli
had this problem with a cupressus tree a few weeks ago, perhaps he can let us know again
which model this was so you (orio) can just play around with the Trunk Scale and see what
happens, this is probably better than trying to describe the problem over several pages.
I don't want to forbid anybody to use this parameter, I'd just advise only to use it as a
last resort when nothing else will do the job.
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Texture Size
Use Power of 2 sizes (256x256, 512x512, 1024x1024, etc.) and only uncompressed tiff for
textures. This will make sure that each and every application can read and get the best out
of all textures.
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Texture Names
Make texture names as unique as possible (even across different libraries), as
they may all be in texture searchpaths
together and when they have identical names (such as "leaf.tif", "bark.tif") the host
application can get confused.
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Texture Alpha
Use Premultiplied Alpha Textures (see here for more info).
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Color Settings
Do not use the Emission and Alpha Settings at all. Trees don't emit light and using this setting
to make trees look nice in Xfrog will cause major trouble when importing into other Applications.
Try to choose values that make good sense for diffuse. Keep in mind that the Texture Color is
getting multiplied with the diffuse Color. This is good for giving a texture a certain tint, but it
may also darken textures when not set to white. Also be aware that Lighting in Xfrog is usually slightly
brighter than it will be in many major applications.
Don't use Ambient Color too much, especially not for coloring as this does not translate very well to
many applications.
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