This is my first post here, and i dont know if i post it on the correct sub-forum, feel free to re-alocate it
Well, i used Collada exporter for 3D Studio MAX 9 and there was no problems exporting data with tangents and binormals, but now, i changed to 3D Studio MAX 2009 and when i mark the ‘check’ for tangents/binormals’ nothings happen, all models are exported without tan/binorm information.
What i making wrong ? Is there any issue related to this ??
Could you let me know which plug-in that you are using now? Is it from feeling software one or new Net Allied next gen? That will help us a lot for testing the problem. And also could you provide the 3D Max sample file for us to reproduce the error if permitted?
I first downloaded the pluguin taged with ‘NEWCOLLADA’, and as i mention, none of any 3D object i can made in 3D Studio exports with tangent and binormal information, its like the exporter doesnt have this function activated.
Then, i search a little in sourceforge and i downloaded another Collada exporter, this, in 3D Studio, is taged with ‘COLLADA’ ( i think, i dont remember now ), but this exporter can export tangents and binormals, so now im runing with this pluguin instead of other.
Its ‘NEWCOLLADA’ exporter finished ? or there are some features that doesnt are implemented yet ?
The Tangent and the Binormal are not stored within 3ds Max. Typically they have to be calculated by the exporting process. In the lifecycle of a COLLADA document that would be a job for a conditioner: write a Binormal/Tangent generator once, reuse it on any other COLLADA document.
// Computes the bump basis vector for the U texture channel (called the Tangent),
// and the cross product of the surface normal with the Tangent (called the Binormal).
// These along with the surface normal are used as the basis vectors for normal mapping.
void ComputeTangentAndBinormal(const Point3 tv[3], const Point3 v[3], Point3 bvec[2]);
Nevertheless we’ll include an option to enable/disable the automatic generation of those during the export process. It will be included in the upcoming 0.9.0 release.
I would like to say thanks for the information about these changes.
im still using last stable version until new version (that can export tangent and binormal) is released.
btw, i would ask you if do you know about the ‘problem’ exporting tangents and binormals in meshes that have mirroring UV coordenades and if you know any way to fix this.
I will try to explain better: If you make an object and map UV for the half of this object, then you can mirror the mesh and make a simetric mesh, but this makes that UV mappinc coordinates will be mirrored too. With this method, there will be points near middle of the mesh that will have diferent normal-tangent-binormal matrix, so normal mapping appears as a discontinuity.