TY - GEN
T1 - Reducing resolution loss in Two-Pass rendering by optimal view directions and Display-Surface partitioning
AU - Steele, R. Matt
AU - Jaynes, Christopher
AU - Yang, Ruigang
PY - 2008
Y1 - 2008
N2 - We describe a method for reducing the amount of aliasing or resolution loss in two-pass rendering for distortion and alignment correction of a projector-based display. Resolution loss is caused by the fact that the second rendering pass must resample the result of the first rendering pass, and the two procedures in general have sampling rates that vary differently. We show that for a flat display surface, it is possible to choose a viewing direction for the first-pass render so that its sampling-rate variations cancel with variations of the second-pass sampling rate. This means that the first-pass effectively S mples the projector frame-buffer evenly, so an appropriate resolution for the first-pass render will provide uniformly low aliasin over the entire framebuffer. We also show that, for flat display surfaces, this choice of view direction can be combined with a appropriate first-pass intrinsics matrix to eliminate the need for a second pass. The resulting single-pass rendering algorithm is very similar to existing single-pass techniques, but has a few advantages that we discuss. For a non-flat display surface, relative sampling cannot be made perfectly uniform, but the optimal view direction for a best-fit plane provides an approximate solution when the display surface is almost flat. Although the approximation is poor when the display surface differs radically from a plane, we d scribe a technique for those cases, which automatically subdivide s the display surface into partitions that are approximately planar. In common displaysurface configurations, great improvements in rendering quality are obtained by using two or three partitions, which causes only modest rendering overhead.
AB - We describe a method for reducing the amount of aliasing or resolution loss in two-pass rendering for distortion and alignment correction of a projector-based display. Resolution loss is caused by the fact that the second rendering pass must resample the result of the first rendering pass, and the two procedures in general have sampling rates that vary differently. We show that for a flat display surface, it is possible to choose a viewing direction for the first-pass render so that its sampling-rate variations cancel with variations of the second-pass sampling rate. This means that the first-pass effectively S mples the projector frame-buffer evenly, so an appropriate resolution for the first-pass render will provide uniformly low aliasin over the entire framebuffer. We also show that, for flat display surfaces, this choice of view direction can be combined with a appropriate first-pass intrinsics matrix to eliminate the need for a second pass. The resulting single-pass rendering algorithm is very similar to existing single-pass techniques, but has a few advantages that we discuss. For a non-flat display surface, relative sampling cannot be made perfectly uniform, but the optimal view direction for a best-fit plane provides an approximate solution when the display surface is almost flat. Although the approximation is poor when the display surface differs radically from a plane, we d scribe a technique for those cases, which automatically subdivide s the display surface into partitions that are approximately planar. In common displaysurface configurations, great improvements in rendering quality are obtained by using two or three partitions, which causes only modest rendering overhead.
KW - Projector calibration
KW - Projector-camera systems
KW - Shadow map
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U2 - 10.1145/1394622.1394642
DO - 10.1145/1394622.1394642
M3 - Conference contribution
AN - SCOPUS:78650761027
SN - 9781605582726
T3 - PROCAMS 2008 - ACM/IEEE 5th International Workshop on Projector Camera Systems
BT - PROCAMS 2008 - ACM/IEEE 5th International Workshop on Projector Camera Systems
T2 - ACM/IEEE 5th International Workshop on Projector Camera Systems, PROCAMS 2008
Y2 - 10 August 2008 through 10 August 2008
ER -