Convex & concave"problem when export to .dif?

#1 IIRC concave objects are not supported for .dif's. You'll have to cut then into brushes to eliminate the concave components or consider a .dts if possible.

#2 You can achieve concavity by breaking the BSP model into convex pieces before exporting. It might take a bit of experimentation but it can be done. Bathtubs, bowls, domes, even fake curves can be done in Constructor if you just don't give up on your vision. It can be frustrating and tedious but just hang in there.

#3 When creating interiors in 3dsmax, you have to enforce all the CSG rules yourself in order to get the geometry into Constructor and ultimately into Torque. Max2Ctor will do no geometry checks, so you have to make sure your geometry is convex, all faces consist of coplanar vertices, and each face is mapped in a linear fashion from world space to texture space. It may sound difficult, but it's really quite simple if you understand CSG basics. If you want to email me one of your MAX files that you're having problems with, I can send you back a MAX file with the properly modeled geometry, so you can see how to do it.

#4 Hi, Brian, Michael and Ryan, firstly, thank you all...

I found even I included some concave geometry in my model, I still can export it to .dif using Constructor without any error message. But when look this model in the engine, you'll find many faces missing (or not rendering...); So, I'm not sure whether this case is totally due to the concave problem?

To make it more clear, below is a screen shot Link to show you what my model looks like in Max, it really contains many concave geometry... So as you said, if we modify all of them by hand, it is really a frustrated thing for my Artist...
photo.163.com/photo/ta123tu456/?u=ta123tu456#m=2&ai=18696606&pi=744105816&p=1

And below is what it is like after conversion to .dif...Seems so many geometries or maps are missing...
photo.163.com/photo/ta123tu456/?u=ta123tu456#m=2&ai=18696606&pi=744105807&p=1

And Ryan, I really appreciate if you can help me to check the model and help to modify it. I have sent you the email...thanks for your time...

Again, thank you all very much!

#5 That's because all the concave areas are actually invalid geometry. That it compiled at all is somewhat of a miracle.