Tuesday, September 2, 2008

How to fix/avoid the "point of view too far" (Scale) issue in FSX planes

I think the major defect of my Goshawk is that, in "free flight" selection screen and -much more important- in the spot views, the camera is very far away.

This is an issue related to the XtoMdl software (the one that processes the .X file and makes the .mdl), which, in certain conditions makes an incorrect estimation of the plane size and moves the camera away assuming your plane is much bigger than it is. This is caused by animated meshes that have a Uniform Scale applied to object level (e.g. small gear details that you may have drawn in much bigger scale and then you shrunk to right size)

At the moment, there is no workaround for the .mdl (hexediting will not work) - but something can be done in the source file. Most important, there are good practices to avoid it in future projects.

If you have done a model which has that issue, in 3D studio or gmax, you need to:
1) Open the source file and select the parts that may have been rescaled and apply the Reset Scale command (better do this in keyframe 0). You may need to selectively and temporarily delete part of the aircraft and compile them separately to see where the issue is. Important: if the model is not animated the issue will not appear.
2) You may end with deformed meshes or incorrect animations. In some cases it is easier to remake them rather than try to fix them
3) Compile the .mdl and see what happens. If you still see the camera is far away, there are other "guilty" parts. Go back to (1). If the camera position is OK (or close enough) then you're done.

If you are making a new model, in gmax or 3Ds you need to:
1) NEVER apply a scale command to an object as a whole. Always apply a "Edit mesh" modifier an manipulate vertex from there.
2) As soon as you have an animation in you model, export, compile and try what happens. If the model is not animated the issue will not appear.
3) See point (1)
4) Export often
5) Always remember point (1) when you model!!!!!

If you are an end user and have an aircraft with that issue, there is nothing you can do.
Yesterday I've tried to fix the Goshawk. The problem was found to be the front landing gear. The camera is much closer now, even if still slightly far. Maybe I've not found all the defective parts. The whole fixing process took no less than 5 hours :-(

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