# World coordinate problem

I have some world coordinates (~11000 points)like:
(x,y,z)=(533900.0,6178625.0,65.9)
(x,y,z)=(533925.0,6178625.0,74.9)
(x,y,z)=(533950.0,6178625.0,83.9)
All coordinates fall with in a box with dimensions 2km x 3km x 100m. I am used to work in the area around (0,0,0) and can not get the points visible on screen. Keep getting a black screen. Any source or pseudocode to guide me om this problem is very welcome Did you make your viewport big enough?

Passing large values to GL is bad, because GL often works internally in floating-point precision, and thus suffers horrible truncation problems with large values in the transform matrices.

Pick a center. Say, 533900.0,6178625.0,65.9 (or just calculate the average of all the vertices). Then subtract this value from each of your double-precision vertices on load, and store them in single precision floats in your vertex array.

The subtraction and some scaleing really did clear the problem with the coordinate size, thanx 