From Bugzilla Helper: User-Agent: Mozilla/4.0 (compatible; MSIE 5.01; Windows NT) Description of problem: When I use light sources with look_like statement in internal animation loop (the light source positions depend on time), they disappear (or just don't illuminate anything, or no_shadow stops working) in all frames except the first. When I use external animation loop and specify the same times explicite, the light sources are rendered correctly. How reproducible: Always Steps to Reproduce: 1. unpack the attached archive disappearing-light.tar.bz2 2. cd into the created directory disappearing-light 3. run $ povray internal.ini 4. run $ povray external.ini Actual Results: Two images are created by step 3 (disappearing- light1.ppm, disappearing-light2.ppm) and one by step 4 (disappearing- light.ppm), all showing a dark scene with a big red letter G and two shiny white balls (the only light sources in the scene) whose positions depend on clock value. disappearing-light1.ppm is rendered with clock = 0 as first frame in internal animation loop, the two balls illimunate the G. disappearing-light2.ppm is rendered with clock = 0.4 as second frame in internal animation loop, the balls are in different position, otherwise looking the same, but the letter G is NOT iluminated. disappearing-light.ppm (this is a reference image) is rendered with explicitely specified clock = 0.4 showing two balls illimunating the G. Expected Results: Everything as in actual results, except: The images disappearing-light2.ppm and disappearing-light.ppm should be identical, both looking like disappearing-light.ppm. Additional info:
Created attachment 24927 [details] scene and initialization files
Small correction: the images are rendered at clock = 0.25, not clock = 0.4. New observation: povray prints Scene contains 3 frame level objects; 0 infinite. when rendering disappearing-light2.ppm (the bad one), while it prints Scene contains 15 frame level objects; 0 infinite. when rendering the other (good) images. So the lights seem to `phsically' disappear.
Since powertools has been discontinued, there's no future release to fix this in.