PDA

View Full Version : Xray with altered normals


alexx
02-11-2005, 09:35 AM
hi,

since i am using maya default renderer usually and i dont have the option to do micro-displacement this shader is really cool:
http://smorigin.scm.cityu.edu.hk/intranet/easn/docs/HowTos/eMicroscope/index.html

it changes the normals, so that the object gets its (kind of facing ratio) shading way better than if i would just use facing ratio and bump mapping seperated.

but what i try to puzzle now is: is there a way to use any other 3d textures besides crater (which is the only one that provides "outNormal")?
i tried using an other 3d texture, conect it to a bump3D and get my outNormal from there.. but that exactely no result, which i dont really understand.

can anyone bring me some light? i think i miss something really stupid.

cheers

alexx

playmesumch00ns
02-11-2005, 09:59 AM
Are you sure it looks different from doing facing ratio and bump mapping seperately? Have you tried taking the luminance of the crater's colour and using that to do bump mapping to see if you can get them to match?

The outNormal attribute on the crater node could be doing 1 of two things:

1) Taking the crater colour and adding it to the NormalCamera attribute to get a "bent" normal, then normalizing the result and outputting it to the outNormal attribute

2) Internally doing a bump from the luminance of the and then outputting that

If the results are different, then it's most likely to be method 1. You could get the same result with another 3d texture by taking a NormalCamera from samplerInfo, then adding the 3d colour texture onto the normal, normalizing, then using the result to drive your facing ratio. Your 3d texture will need to have a similar colour seperation to the crater texture to see a good result.

alexx
02-11-2005, 10:02 AM
yes it looked different until now.

it looks about the same in the well lit areas.
but especially in non lit areas you can see that the bump map is done after the facing ratio calculation - it simply looks flat in those areas.

i have to check the normal camera attrib from the sampler info.. havent tried that so far.

thanx a lot

alexx

CGTalk Moderation
02-11-2006, 11:00 AM
This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.