Using Lighting With Normal Maps

[duggz]

I have set up basic objects as testers to try to resolve this problem but it gets a tad tricky. I basically set up the NormalBumpMap shader group and colour texture map in hypershader. Now it looks a little dark when rendered. I guess it is because it is rendering from a default light source so I'm trying to add another light source that I can generally move around and that can react well with the Normal mapped object. I think I almost got it to work with Connection Editor when I managed to connect a lightsource to the basic Blinn shader. But now I can't really remember what I had originally done to get there.

If anyone can help me out that would be amazing, otherwise I will have to go through all the nodes in every part of the hypershader graph, in combination. Which means coffee and very late nights.

[joojaa]

the data must be normalized, maya asumes it is so if your normal is half the length it was it would affect the resulting brightness too.

[casey33]

QUOTE(Joojaa @ 09/30/06, 08:47 AM) [snapback]248912[/snapback]
the data must be normalized, maya asumes it is so if your normal is half the length it was it would affect the resulting brightness too.

joojaa,

could you please explain how or what we need to do to normalize something?

i've been having problems with this for a while now, i would be very appreciative!

casey

[joojaa]

Well, usualy the datas normalized somehow howere maya will require you to push it in in the right way.

So say you had it in a texture, because the data itself is normalized to the imahggeformats range its only scaled worng. Normalization means that the length of each vector is set to 1.

Now unless this is a hdr image of some WIERD caliber, you USUALY must put the color gain to 2 and offset to -1 thuis would push the data in right range. IF you dont do gain of 2 you will get half as bright images, and without the negative offset your normals would be totaly slantted bonkers (maost image formats are limitted to positive numbers, vecor fields offcourse having definitively negative interpretations or youd loose 1/2 of space). However ther emigt be some slack in the normalmaop so you might need to push ita bit higher.

You could calc the length and always normalize it with nodes but thats superfluous.

However without seing your map i cant give you more accurate info since i would noot know how its packed ito the image.

[duggz]

how about adding a colour map texture...I've tried it varous ways, with a light source the normal map isn't visible, just the surface shape and texture.

How should I add the texture map to a normal mapped object?

Keeping in mind I have tried adding a texture map file to the shader's Colour Node.

Please help me...my PC can't take much more verbal abuse from me...lol.

[joojaa]

ok sounds like you ahvent connected the normalmap at all then

posta snapshot of the node network you have going and then tell me what renderer you expect to use.

AND NO the normalmap does not connect to the color slot.

[duggz]

The problem with my normal map was that it needed to be inversed. I originally created the map when I was learning Zbrush. Now that is inversed the normal map is perfectly visible.

I have even connected the texture map.

Now the problem is that when I apply a light source to the scene it only shows the texture map and not the normal map. My guess is that the light only reacts with the actual surface and colour of the object. So I will probably need to either play around with the connection of the light to the graph or tweak the lights settings, either way....I haven't got a clue.

But thanks so far, the has been very helpful.