I''m using VB6 to Compile a 3d model editor kinda like Milkshape 3d but I''m having 2 problems with it. The first is that when I render wireframe, lines disappear when both vertices leave the screen even if I should still see the line, the second problem is the error I get, when a vertex moves behind the viewpoint. I only get the problem on my Celeron 533 with a Voodoo 3 2000. Any other computer I have tried this on runs correctly. Any help or information you can give would be great thanks.

If you''re using frustum culling, your code is deleting the line because both verticies cannot be seen (since they are behind different planes). try checking to see if both points are behind _one_ plane at a time (ie check against all viewport planes before dismissing the line from being drawn)

That makes sense but I''m just rendering normaly, and the odd part is that it only will prematurely remove lines on certain computers. The same also goes for the "Expression too complex" error... maybe I just shouldn''t buy HP''s anymore...

are you doing the rendering yourself? cause opengl/d3d support in voodoo3s is kinda lacking in windowed mode. also is this when you run it on a system with the SAME vb runtimes installed compiled as exe? could be that the other pc has a later version. also consider breaking up equations that give you "expression too complex errors". as for disappearing things, the other error probally makes the result invalid thus goodbye vertices. this could be a simple round error or an under/over flow. make sure you run the EXACT same test on all the machines. ie the exact rotations/translations. this should be done in code and not for the user to do. since the code handles the movements, you will knw for sure the same thing is being done on all machines (this could be a problem on all machines but you are doing things different with the movement when testing, since many ppl dont move the mouse exactly the same everytime). also do yourself a favor and rocerd the position (viewport/model/looat, etc) and model loaded. and then hardcode this is a preset to test on all the machines to see if its reproducable.

Thanks!

I compiled a little test program like you suggested you suggested, and tried in three computers with the same runtime libraries, one comp with a PIII 450 and a ATI Rage, the second A Celeron 533 with a Voodoo 3 2000, And the third a PIII 550 with a Voodoo 3 2000. On the first no error occured and no lines where ever removed, the second errors and lines are removed, and on the third no errors occur but lines are removed. So best I can tell is that the Voodoo 3 is removing the lines, and the Celeron on the second is having rounding trouble or something cause objects to move to the origin or give me that Error 16. So, I''m stumped. My next choice would be to create a dll in C++ a call it from vb, does anyone know how to convert my opengl app in C++ to a dll?

Thanks again...