# Frag_My_Mind

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1. ## Visible Distances

Exactly right! Thanks for the reply - as I said I wasn't very with it this morning.
2. ## Visible Distances

Hi, I previously started this (very early this morning) in the beginners section, but have been advised to move it here. I'm currently working on a space combat game. To simplify some of my lod calculations, I'm trying to find the distance at which an object becomes invisible (ie: is less than 1 pixel wide or tall). All of my objects have a bounding sphere or radius r_obj. Supposing we have a horizontal field of view fov_x, and similarly a resolution res_x I had reasoned as follows: d_critical = r_obj / tan( fov_x / 2res_x ) where d_critical is the distance at which the object takes up 1 pixel. So far this is all very basic trig. And yet when I tested this method, I find that the critical distances are much larger than this predicts. Any ideas where I've gone wrong?
3. ## Visible Distance

Doh - yeah thanks. As I said in my post it was early in the morning and wasn't very with it. Sorry about that.
4. ## Visible Distance

Hi, yay - my first post! I'm fairly new to D3D, and having followed several tutorials I've started to play around with a few of my own ideas. For my current project, I need to be able calculate the distance at which an object would no longer be visible (based on its bounding radius) as part of my LoD scheme. I've been trying to figure out the required formula based on the distance at which an object displays as only 1 pixel. I had reasoned something along the following lines: critical_distance = bounding_radius/Tan(field_of_view / 2*resolution) but this doesn't seem to work. Does anyone know how to correctly find this distance? Many thanks, Mark PS: It's now 4am, so I hope this post makes sense :S