Artifacts in normal map...

pillowsama

I've generated my normal map in maya using the transfer map for both the head and the body... but after rendering, artifacts show up for the body (quite clearly too..) but not for the head, does anyone know why this is?? the image below shows the artifacts that i talked about..

Shot at 2007-07-28

Any help would be appreciated, thnx guys!!

Chai

I'm not sure which artifacts you're reffering to ... do you mean the smoothing errors ? (the black spots around the sharp lowpoly areas)

MoP

Almost looks like image compression to me ... what format is that normal map saved as?
Unfortunately I have no experience with Maya's normal mapping so I can't help further.

Asthane

What MoP said, also-- what are the maps' respective resolutions? (Or if they're on the same map, equative UV space)

fritz

yeah. to me it looks as tho you may have given lots more space for the head as opposed to the body.

Joshua Stubbles

[ QUOTE ]
yeah. to me it looks as tho you may have given lots more space for the head as opposed to the body.

[/ QUOTE ]

Ditto.
The body's texel area looks to be about 1/2 of what you gave the head. Can you show us the UV map for this? Or is it different textures? Did you use 1 512x512 for the head, and 1 512x512 for the body? That would be why it looks so bad. You need to keep the texel density even.

Mongrelman

Make sure you've merged uvs on your low poly before baking, I've forgotten to do that before and got some artifacting which was fixed when I merged and rebaked.

pillowsama

ahhh i see, thnx guys! well, I used a 1024 map for the head, and 1024 map for the body, these are just for testing though, first time running it through maya for normal map..

I will try to keep them even, and this is saved as jpeg, that's wut i was thinking about too, checked on some forum regarding the issue and it mentioned file compression...

what formats are generaly recommended for normal maps? I wanna try and avoid the artifacts because I am doing this for my portfolio, and it needs to look as good as possible haha thnx guys!

fritz

use targas. if you have an alpha channel in any of your maps that you are using for transparency....save as 32 bit. actually, i just save everything as 32 bit.

pillowsama

To Fritz:I tried it out, and it works perfectly! thnx a lot!

To Chai: yah the weird shadings turned out to be the normals facing the wrong way and i fixed that too, thnx for pointing that out man

Thnx for the help guys, I'll post some updates later on for you guys so maybe i could get some critiques, thnx a lot!

MoP

Yeah, JPEG is a compressed format, it will create artifacts like that no matter how you save it.
TGA is uncompressed and definitely what you should be using here.

Ryan Clark

If you want a format that's pixel-perfect and web-compatible, use PNG. Most web browsers know how to show PNGs, but not TGAs.

Also, I usually find PNGs are smaller than TGAs.

Asthane

[ QUOTE ]
If you want a format that's pixel-perfect and web-compatible, use PNG. Most web browsers know how to show PNGs, but not TGAs.

Also, I usually find PNGs are smaller than TGAs.

[/ QUOTE ]

We're talking about what to save the normal map as, not the screenshot

Ryan Clark

Yeah, png's a better format for that too. It makes smaller files than tga and supports higher bit-depths.

Web-compatibility is just icing on the cake, because it lets png work as a lossless replacement for jpeg across the board.

I guess smaller files aren't that big a deal, and most people aren't using high bit depths... but it's nice to have one file format that works for everything.

Eric Chadwick

Yeah, PNG's a great format for web or storage, but I think it should be mentioned that ultimately a compressed lossless PNG will be uncompressed at render time, potentially wasting valuable video memory. Probably more than the OP wants to know, but good to know about anyhow. There are a few lossless and lossy formats you can use specifically for normalmaps... ST3C, 8.8 DDS, DXT5nm, etc.