Hi, On 24. Jan 2012, at 2:24, cpapado [via Software] wrote:
> My application requires the per-segment FoV when rendering the contents of a > segment (I am doing some LoD related stuff that require this). > > Is there some way to get to this info from inside eq::Channel::frameDraw() > (or at least get access to the current Wall and Segment geometries so i can > calculate it manually for a given viewer position)? You can't, by design, get to the wall/segment stuff from the render clients. When you need the FOV there is often a deeper underlying problem: Getting the FOV of a segment is not enough, since the same image might be generated by multiple segments or a big, single display. Getting the FOV of a canvas does not work for non-planar surfaces. The FOV might change through the view's wall description. Tracking is another variable. What you often want for LOD is the screen-space coverage of your geometry in pixels or centimeters as an input parameter. This you can compute without having access to the segment/canvas. That said, I strongly advise to look at your LOD code. If you really want to go the FOV route, '1 / vp.w * pixel.w' should give you the theoretical fraction of the destination canvas covered by your channel, the frustum gives you the sub-FOV. HTH, Stefan. -- View this message in context: http://software.1713.n2.nabble.com/Getting-the-Field-of-view-for-a-particular-segment-when-rendering-tp7218596p7220538.html Sent from the Equalizer - Parallel Rendering mailing list archive at Nabble.com. _______________________________________________ eq-dev mailing list [email protected] http://www.equalizergraphics.com/cgi-bin/mailman/listinfo/eq-dev http://www.equalizergraphics.com
