   Hierarchical Occlusion Maps - Projection test
  Hi !I'm in the process of implementing hierarchical occlusion maps.I have my Z-hierarchi and I now need to test wether an object is occluded or not.This should be done by projecting the objects bounding box into the Z-hierarchi, but from here it gets a little blurry.Should I:Check each pixel in the projected area and then skip the object if none of the tests is true and continue down the Z-hierarchi if some of the pixel-tests is true?It seems to me that's a lot of pixel-processing >:)Best summer-regards,Roquqkie   
  Basically yes, this is what should be done, the process is pixel intensive butyou may also use a scaled version for your rasterizer and smd instructions for inner loop like checking z value in a single row for 2floats at time or 4 if you use different packing.   ;  HOM's are quite processor intensive. The recursion on a per-pixel level is way more expensive then it needs to be.I researched most of this and found a middle alternative which implimented most of the same software tests on the image map, but without the hierachy.http://www.badheat.com/sinewave/workbench/downloads/McanlisRastOccl.pdf~Main   