Wavy glass - like olde window panes - HELP PLZ.

[SamSed]

a raytrace map , and tweak between the transparency and the index of refraction.

[j_p]

try a noise as a bump map if you already got refraction going....

[midk]

A low-intensity noise bump-map will work the best. Try setting the noise map type to fractal - it would probably look best. Then adjust the Size parameter to adjust the amount of waviness applied.

[michaeljr]

did anyone say "where" to stick the noise map?

put the noise map in the Index of Refraction map. tweak the map so that there is less grey and more of a soft / hard edge between the globs of glass if you want a chunky glass, or leave it filled if you want a smooth, bubbly glass.

if you use Mental Ray you can have it cast caustic light through it pretty easily.

also try the Cellular map. I have seen old glass windows that look like chunks of glass where just dropped into a mold.

[midk]

Both of us said where. "A low-intensity noise bump-map".

I'm not familiar with your way, involving IOR, so there's another method.

[j_p]

putting it to IOR should give a nice effect too that satisfies your wishes

though i would believe that using the bump map would come closer to what is causing old windows to refract non uniformly in reality....

glass is not really solid, it flows like salt (ok, great example, salt caves have to be cut free on a regular basis because the walls flow). so a noise as a bump would not reflect the way the window will be deformed exactly. i guess it will be thicker the further down you get, since it gives in to gravity....and maybe its own tensions
a mix map with a noise and a gradient might reflect that, but i dont think anyone would notice the difference...

the IOR would change only if the material changed too, and then you should try having the map reflect the way these alterations happen....guess one could do a dissertation on that subject :-) "the chemical dehomogenisation of glass over time" *g*

but as long as you dont want a noble price, i guess both ways work well

[michaeljr]

I did a test scene just for fun. Very interesting results.

on the left I modified the actual object with a noise mod. Not good and that is a 1700 poly object. it started looking smooth when I up the count to 10k polys. while the others are just plain 1 sided boxes.

in the middle is the IOR channel and on the right is the same noise map in the Bump slot

now what I found instresting is how much the camera angle changed the IOR and Bump map method. maybe the IOR is more closely linked to mimicing the object interior?? maybe the bump only effects the surface?? guessing here.

but fun to play with

[zibits]

WOW thank you thank you thank you!

By far the most comprehensive and helpful response I have ever gotten to a technical question here at CGTalk. Even thumbnails, I am impressed.

Andy :)

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