diff -r d960df03359f -r a5d25b4668ac man/man1/pmdblur.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/man/man1/pmdblur.1 Sun Jun 26 16:57:40 2011 +0100 @@ -0,0 +1,133 @@ +.\" RCSid "$Id: pmdblur.1,v 1.4 2008/11/10 19:08:17 greg Exp $" +.TH PMDBLUR 1 1/17/05 RADIANCE +.SH NAME +pmdblur - generate views for combined camera motion and depth blurring +.SH SYNOPSIS +.B pmdblur +.B speed +.B aperture +.B nsamp +.B v0file +.B v1file +.SH DESCRIPTION +.I Pmdblur +takes two viewfiles and generates +.I nsamp +views starting from +.I v0file +and moving towards +.I v1file, +simulating an aperture of diameter +.I aperture +in world coordinate units. +When rendered and averaged together, these views will result in +a picture with motion and depth-of-field +blur due to a camera changing from v0 to v1 +in a relative time unit of 1, whose shutter is open starting at v0 for +.I speed +of these time units. +Either +.I pinterp(1) +or +.I rpict(1) +may be called to do the actual work. +(The given +.I v0file +must also be passed on the command line to the chosen renderer, since +.I pmdblur +provides supplemental view specifications only.)\0 +.PP +For +.I pinterp, +feed the output of +.I pmdblur +to the standard input of +.I pinterp +and apply the +.I \-B +option to blur views together. +In most cases, two pictures with z-buffers at v0 and v1 will +get a satisfactory result, though the perfectionist may wish to +apply the +.I \-ff +option together with the +.I \-fr +option of +.I pinterp. +.PP +To use +.I pmdblur +with +.I rpict, +apply the +.I \-S +option to indicate a rendering sequence, and set the +.I \-o +option with a formatted file name to save multiple output +pictures. +When all the renderings are finished, combine them with the +.I pcomb(1) +program, using appropriate scalefactors to achieve an average. +Note that using +.I rpict +is MUCH more expensive than using +.I pinterp, +and it is only recommended if the scene and application +absolutely demand it (e.g. there is prominent refraction that +must be modeled accurately). +.PP +For both +.I pinterp +and +.I rpict, +the computation time will be proportional to the number of views from +.I pmdblur. +We have found a +.I nsamp +setting somewhere between 7 and 15 to be adequate for most images. +Relatively larger values are appropriate for faster camera motion. +.PP +The +.I \-pm +and/or +.I \-pd +options of +.I rpict +may be used instead or in combination to blur animated frames, with +the added advantage of blurring reflections and refractions according +to their proper motion. +However, this option will result in more noise and expense than using +.I pmdblur +with +.I pinterp +as a post-process. +If both blurring methods are used, a smaller value should be given to the +.I rpict +.I \-pm +option equal to the shutter speed divided by the number of samples, and the +.I \-pd +option equal to the aperture divided by the number of samples. +This will be just enough to blur the boundaries of the ghosts +which may appear using +.I pmdblur +with a small number of time samples. +.PP +To simulate a particular camera's aperture, divide the focal length of +the lens by the f-number, then convert to the corresponding +world coordinate units. +For example, if you wish to simulate a 50mm lens at f/2.0 in +a scene modeled in meters, then you divide 50mm by 2.0 to get 25mm, +which corresponds to an effective aperture of 0.025 meters. +.SH EXAMPLES +To use +.I pinterp +to simulate motion blur between two frames of a walk-through +animation, where the camera shutter is open for 1/4 of the +interframe distance with an aperture of 0.1 world units: +.IP "" .2i +pmdblur .25 .1 8 fr1023.hdr fr1024.hdr | pinterp \-B \-vf fr1023.hdr \-x 640 \-y 480 +fr1023.hdr fr1023.zbf fr1024.hdr fr1024.zbf > fr1023b.hdr +.SH AUTHOR +Greg Ward +.SH "SEE ALSO" +pcomb(1), pdfblur(1), pinterp(1), pmblur(1), rcalc(1), rpict(1), vwright(1)