grasshopper

Arriving at this thread a bit late … but, yes, Houdini was used extensively on Spider-Man 3. The majority of the Sandman and Goblin effects were carried out in Houdini (sand, mud, glider thrusters, etc). Spider-Man's webs are Houdini. The Symbiote/Venom goo was mostly Maya (although Houdini was used here too).

Have you thought about making a displacement shader? Perhaps you could adapt this old vex snakeskin shader here:

http://odforce.net/codex/?page=4&sec=all&catlimit=&sorty=&limit=5 [odforce.net]

For question, two you could use a trail SOP with the trail length set to 2 (default) and the trail increment set to the frame offset you want to query. So for two seconds you would set this to 48 assuming 24 frames per second. Then append a delete SOP and using “Delete by Range” set the start/end to 0 and ($N/2)-1 respectively. Also set Select _ of _ to 1 and 1. That will leave you with the object as it was 48 frames ago and you can now query the points in a point SOP with point expressions:

point(“../delete1”, $PT, “P”, 0)
point(“../delete1”, $PT, “P”, 1)
point(“../delete1”, $PT, “P”, 2)

An alternative way is to write the geometry you want to reference to disk and then read back in with an expression that gets the earlier frames you want to query.