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View Full Version : how to get a physical-real bump-caustic in XSI?


JoshuaChang
10-11-2006, 10:49 AM
hi everyone here~
is it possible to make the bumpmap affect the caustic?

i've tried many photon node,only mentalray's original "mib_photon_basic" could be affected by bumpmap......but~it couldn't generate a physical-real caustic......the photonmap is different than any other photon node(xsi's sib_illum_photon_v2;dielectric_material_photon;etc......)

any way to use bump-causitc in XSI?......i don't want to use displacement:sad:

JoshuaChang
10-17-2006, 03:55 PM
eh......no one knows?

Saturn
10-17-2006, 07:14 PM
why don't you want use displacement ? It s faster than bump actually.

and no as far as I know you can't use bump since it's normal perturbation of the surface to generate caustics.

JoshuaChang
10-23-2006, 12:16 PM
why don't you want use displacement ? It s faster than bump actually.

and no as far as I know you can't use bump since it's normal perturbation of the surface to generate caustics.

i don't think so...a fine displacement surface need more cpu time than bump......

and in xsi, the simple photon node can be affected by bumpmap when i plug the bumpmap into its specular parameter~but--as i said before, the photon basic node is not physical-real based...

Saturn
10-23-2006, 12:53 PM
That because Bump doesn't affect the geometry. bump mapping just change normal in the surface.

I disagree about displacement. If you use fine method in view dependant you get an ultra fast displacement. What's are your setting to get something slow ?

I barely use bump map theses day because the bump is slow compared to displacement.

francescaluce
10-23-2006, 01:33 PM
the photon basic node is not physical-real based.
the bump is slow compared to displacement.
guys, can you prove the sentences above ? :)


ciao
francesca

JoshuaChang
10-27-2006, 10:49 AM
guys, can you prove the sentences above ? :)


ciao
francesca

well~when i compare photon_basic with other photon node,like dielectric_material_photon,xsi's sib_illum_photon_v2,max's native raytrace,etc,etc...

all those photon's result were similar to each other and different to photon_basic......

Tekano
10-31-2006, 03:14 PM
JoshuaChang, I would try this with a bitmap and the bumpmap generator and plugging into the bump node of the material rather than the phong. dunno, havnt tried it so cant prove if it would work like this, just a suggestion... :)

JoshuaChang
11-03-2006, 01:45 PM
JoshuaChang, I would try this with a bitmap and the bumpmap generator and plugging into the bump node of the material rather than the phong. dunno, havnt tried it so cant prove if it would work like this, just a suggestion... :)

yes,i've tested with bump node,didn't work,either :-(

anyway,thank you all the same~

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