i guess your code is a bit..unfine

u should make it in a while(1)
so it dont stop( in opposite to your code) and can check it every frame new...btw:it is not good to trace: if there are 2 objects ore morejust one object will be transparent

I have done such a Code before with A5 and I only can say it's very slow to build a complete Level with map entities blocks.
My code was done with two traces. One from the player to the cam and one from the cam to the player. With this code it was possible to make two blocks between player and cam transparent. It's really not the best method, but I don't know any better method thats fast enough with 3DGS.

You could try to use vec_diff on each block to the cam and once more to the player and if booth are not more than the distance from player to the cam it must be transparent. I never tried it but it should work and could be fast.

This is an old thread, I doubt you'll get much accomplished here...