This is the proper 3d cam for studio... This setup is 200 units above ground looking north (-y). drop the cam in the bottom of the room
execute code:
depth = 1000000
z = -200;
vecFacing = d3d_transform_vertex(0,-1,0);
vecUp = d3d_transform_vertex(0,0,-1);
Draw Event:
execute code:
//set the proper 3d
d3d_start();
d3d_set_culling(1);
draw_set_alpha_test(1);
draw_set_alpha_test_ref_value(128);
d3d_set_hidden(true);
aspect = view_wport/view_hport;
d3d_set_projection_ext(x,y,z,x+vecFacing[0],y+vecFacing[1],z+vecFacing[2],vecUp[0],vecUp[1],vecUp[2],59,-aspect,1,32000);
admittedly I think you are right, in studio they inverted something because note the -aspect. and I think you may need to flip the models inside out with add_scaling(1,1,-1) but I'm basing this with memory fragments of like 4 projects