CompuServe Messages

Rotation format in .COB

    26-May-95 16:48:12
Sb: Rotation format in .COB
Fm: Ken Tabor 75703,2504
To: Caligari
Hello, I am an application developed working on "VR" apps and have been using TS as my object modeler. I am now trying to improve my development cycle by writing a tool to convert objects in .COB binary format to .RWX for my RenderWare real-time 3D API to use. I am succesful converting object geometry, scaling, translation, polygon textures including UV coords and colors, but am lacking a correct interpretation of the .COB encoding of object rotation. What is the trick? Is all I need to know about an object's rotation stored in the values of the "Current Position" block of a Polygon Chunk? Or do I need to somehow apply the numbers in the "Local Axis" block of the Polygon Chunk? Furthermore would you please tell me what in what order the values are in the "Current Position" block are? For example the scaleX is in position 2 of row1, etc. The matrix notation I must adapt to for RenderWare script files gives a generalized transformation matrix which looks like this: ScaleX Something Something 0 something ScaleY something 0 something something ScaleZ 0 TransX TransY TransZ 1 As I say I have Scaling and Translating down, the "Something" fields are how I mix in the rotation business, although I have a tech support question in with them on the exact nature of their matrix as well. It's confusing that your file spec says the fourth row is always [0,0,0,1], but yet RenderWare thinks that is a column. New file formats always confuse me! Please respond ASAP if possible as I am working on this tool now. thanks Ken Tabor Micro Focus