Quote: "When I try the model disappears when it gets closer on the Z axis."
Take a look at the Set Camera Range command. It sets the start and end range of the camera's view and if you don't set any value, it defaults to 1 and 3000.
This means that anything closer than 1 3D unit will 'disappear' - as will anything further away than 3000 units.
To get around this, you might have to 'scale up' your world (bigger matrix for example) and 3D models a bit with the Scale Object command.
This takes 4 parameters:
Scale Object ObNum,XScale,YScale,ZScale
ObNum - The object number to scale
XScale - The amount of scaling along the object's X axis (width). This is a percentage value where 100(%) is no change, 200(%) is double the size and so on. Values less than 100 scale down, so 50(%) would be half the size. A value of 1(%) would be 100th of the original size.
YScale - As XScale, but for the Y axis (height) of the object.
ZScale - As XScale, but for the Z axis (depth) of the object.
TDK_Man