Making the Trees
These tree DFXs are created in Onyx TreePro 4.0. They have all been saved as grouped objects so that the different parts may be textured separately in Bryce. None of these files are too large to be imported into Bryce3 (or 2.1 for that matter)
While I don't want to get into a detailed tutorial on TreePro4.0 there a few points are worth mentioning because every tree in this group had to have its polygon count reduced to make them small enough to use in Bryce. Creating and exporting the DXFs from TreePro is a balancing act. The majority of the polygons are in the leaves. Reducing the number of leaves reduces the polygon count significantly but if you reduce the leaves too much you have a sickly looking tree.
This attractive willow tree has a good full leaf cover but it weighed in at a whopping 24 mbs.
You will note that 94 percent of the size is in the leaves and leaf stems.
To cure this problem I eliminated the stems which would not show except in the very closest camera view and reset the spacing on the main boughs and the primary branches from 50 cm to 60 cm. This left the leaves thick of the branches but reduced the over all number of branches. Look at the the aftertree.jpg. This is still a good natural looking tree.
Yet the file size has been reduced to only 5.6 mbs. Notice that I've increased the number of sides on the trunks and main branches, this will give a smoother polygon mesh and a more realistic look in Bryce
Importing the trees
On some of the largest files, it may seem like they are not importing. The computer needs to parse the file when you first import it, this can take 5 or 10 minutes before the gas gauge ever starts to show any activity. With Bryce's RAM allotment set to 100 mbs and no extensions on, the Douglas fir took 26 minutes to import. So don't cancel the import too quickly, be patient and go make a pot of fresh coffee.
As soon as the tree comes in
SAVE!!
Editing and texturing
Select Tree and go to the solo mode with it.
Ungroup the tree, being very careful all through the next stages to not move anything. If by mischance the tree does get moved, you can revert to saved which will keep you from having to reimport.
Now go to edit and smooth the groups. This may take a while for large polygon counts. Save as soon as the smoothing is finished.
When the trees are smoothed begin tabbing through the objects that make up the tree. As you get to each one, name it and give it a color family. I usually just do trunk, twigs and leaves unless I plan to do an autumn scene and need the leaf groups to be different colors. But name as many separate groups as you need to for the type of tree it is and for the use you plan to put it to. I like to use shades of green and brown for my family groupings just because it gives you a small preview of your rendered tree.
When you get the groups named, SAVE again. Then start choosing the like groups and giving them a material texture or a pict texture. There are several textures in the presets that work as bark and I have included a custom one I cooked up here in the file. Avoid textures that have a strong linear orientation. These patterns will look jarringly different when mapped on vertical trunks and horizontal branches.
When all the families are textured, select all, group them and you guessed it! Save everything again. Sounds like a lot of saving but importing and texturing trees is very time consuming and you don't want to have to do it any more than necessary.
One time saving trick I've found useful is that the trees will look quite different when viewed from different angles. You can duplicate your tree after it has been edited and textured, then move the new tree to another location and rotate it 90-120 degrees. You can use each tree you import several times without it becoming obvious that it is the same tree.
Also for distant woods where the lack of three dimensionalness won't be noticed, you can use the jpegs that accompany the dxfs. Save the Jpegs as picts with your favorite photo program then bring them into Bryce as two dimentional textures mapped on squares in the Material Editor.
Enjoy-Linda Ewing