It is best to UV map the model in some external application before importing into Bryce if possible. If an object was already UV mapped before it arrived in Bryce the UV mapping will be retained upon export from Bryce…but there is a bug where the texture gets flipped vertically so keep a close eye to see if the texture flips. I use UV Mapper pro to fix the issue or I just export the mesh twice with also fixes the issue.
Models constructed in Bryce made of booleans need to be carefully considered. For one thing, it may be essential to export pieces of the model for individual uv mapping. Bryce will “try” to create textures that it will send out with the new meshes, but they are not strictly uv mapped. It’s more like a sample of your texture gets exported in a way that you can then tile it in your other application, but it isnt a real solution in the way texture baking would be.
A few issues to keep in mind:
1. Think about your material zones carefully. I usually revert my materials back to default gray before I export to avoid the long wait while the exporter tries to generate maps for all the various channels.
2. Sometimes the boolean collapse function causes the resulting mesh to have inverted normals. This can cause TA rendering to fail on such objects. If ever you do collapse a mesh best to export it and then re-import it to fix the normals.
3. Sometimes boolean objects that are exported will not re-import back into Bryce at all. I’ve had situations where I’ve selected my recently exported mesh from the list of obj’s only to find that Bryce begins to load the model but then stops with no explanation. This is why I keep the free UV Mapper around, as these same meshes load fine into uv mapper, which somehow fixes whatever was broken, allowing Bryce to re-import the model as expected.
4. OBJ models usually are already smoothed when they are imported, which can save a lot of time. I dont know why the smoothing function in Bryce is so slow on complex meshes.
5. When working with true primitives, remember that the export polygonal resolution of the model is determined by the Static mesh detail setting for the Wireframe view.
There is a clever trick to share with you at this point. UV Mapper is a MUST HAVE tool in my opinion. Bryce’s Boolean Collapse function is good, but it is risky because it handles the process very crudely. When joining meshes, it adds additional vertices as well as deletes others, it can screw up normals and all of that. If only there was a safer way to connect two objects into a single one. Well, UV Mapper can do exactly that by means of material zones. So if for instance you have a boolean object comprised on three spheres. In this case the three spheres have not been boolean collapsed, they are merely grouped together, and all of them are “positive.” Bryce should allow you to export this group (even if it isnt collapsed I think) as an obj. Import the object into UV mapper. The magic happens during the export from UV Mapper. Make sure you tell UV mapper NOT to export materials, save the mesh. Now open Bryce and import the mesh. Notice that Bryce gives 3 different options for importing. You want to select the top one called Material, and allow the import. This tells Bryce to import the model as a single mesh object sharing all the same material…essentially a boolean addition sequence, but without the hiccups.