Noise grain in my Max Normal Bake
polycounter lvl 12
It's been a while since I baked a normal map in Max, so I'm not sure what's going on here. I'm baking just a normal map from a highpoly and my output file looks like it has a noise filter applied. Anyone know how to get rid of that? It also shows up in my diffuse base. I'm only going off of memory for the settings in projection and renderer setups
Replies
You might want to straighten out those edges...
The edges are there most likely because of triangle distortion on the uvs, straightening the image content would be counter productive. So no, don't straighten those lines, as it will break the look on the model.
Relax the uvs maybe.
It's easier to maintain a straight line of pixels than it is an aliased diagonal line. The line on the left side and the top could be straightened with very little effect to the final result.
Typically if you're baking a little UV distortion on your low is fine because the distortion is compensated for when the material is baked. Again I would need to know more about the model to say for certain if this is a good course of action, but typically when baking it can be better to favor a straight line rather than an angled aliased line, especially when your sheet is 4x too big.
On second thought, the speckle might be the format that he's saving it as, maybe its a compressed format? He should try outputting TGA's or some other lossless format and see if it still shows up.
But that wasn't really my point, the point I was making is that you should not go around straightening up edges because they look weird in the normal map, the edges there are exactly how they should be to match the mesh/uvs. Even if that isn't what you were suggesting, it could easily have been read as such, and there is enough bad type "oh just paint it out in photoshop" advice floating around polycount already.
Any idiot who's tried painting straight lines on a distorted map knows painting a distortion free image on a distorted image is next to pointless when trying to counteract distortion.
Which is why I brought up the whole if you straighten the UV's, the stretching gets compensated for (to some degree) by the bake, which is what the person painting the straight line can't do without a high degree of difficulty..
I'll use the example of a belt around a fat organic character the belt mesh isn't straight and if you relax it and leave it all loosey goosey it will baked aliased lines all over the place (like above), but if you square off the UV's you get crisp lines. Of course introducing too much stretching on the wrong kinds of shapes can thwart the positive effects of straightening a few lines but that's where experience, trail and error come into play.
My main problem is that there is color noise in both diffuse and normal re-bake in 3DS Max. I pulled half of my hairs already. Deadline is in 5 hours for me.
In general I would say try to stick to TGA it is an uncompressed format while working.
Using a compressed format like jpeg will lead to a loss of quality because it is being compressed. I'm not sure a jpeg would cause noise (without looking at it and possibly running some tests myself) but in general most engines compress whatever you feed them so you really don't want to feed a compressed image to an engine that is going to compress it again. Which is why a lot of pipelines rely on TGA's.
They might be large, slightly annoying to work with and might even slow down some slower video cards, but they offer the best chance of getting your work through the process as unmolested as possible.
A. Noise or "dithering" which is what Max does by default
B. Stepping, which is what Maya does by default.
I personally prefer Max's dithering, but in practical use neither will really show up once your mesh is fully textured.
Not sure if the noise people are getting in max is from dithering, or if its a file format specific thing. I've always used TGA in Max, Maya and most game engines use TGA as well, I've never noticed an excessive amount of noise from TGAs.
Color noise in your diffuse bakes seems like there may be a deeper problem though. You could try saving out your maps as 16bit per channel(tiff?), which should negate any bit depth issues.
To address texture formats, I personally using TIFF/PSD whenever I can cause I got thumbs and it can store layers. As for source files that I obtained in loosy formats, these weren't mine product so I must go with them. (Need to educate our 3D graphics a bit tho
Thank you again dear polycounters! Great community.
OH MY DAYS, I've had this issue for YEARS and just left it as I couldn't fix it.
Tried again today and came across this thread. THANK YOU!
Saved it as a png and all the noise went away, you notice it more if you start overlaying normals over themselves.
16bit TGA refers to 16 BPP (bits per pixel) which means you only get 65,536 colors. This can cause banding, noise, etc. because there aren't enough colors to represent fine gradations, like in a normal map.
24 bpp means you get 16 million colors, so it's better at avoiding banding, but still not quite the best. Normal maps have fine gradations of color, and rely on each pixel storing an exact value, so the map can recreate vectors for precise lighting.
Programs like nDo, dDo, Handplane, etc. prefer working in 16 BPC (bits per channel) which means you get 281.5 trillion colors. No noise, no banding!
For the best results, and as long as you're going out to tools that support 16 bpc color (dDo, nDo, Photoshop, Handplane, etc.), I'd suggest saving in TIF format. The save dialog offers "8-bit Color" which means 8 bits per channel (bpc) which also means 24 bits per pixel (bpp) or 16 million colors. I'd choose "16-bit Color" which is your 16 bpc, 281 trillion colors.
3ds Max's TGA plugin only supports 16 or 24 bpp. When it says 32 bpp, that just means you can save an alpha channel too. But it's still just 16 million colors.
Hope that makes sense.
If you are saving from Photoshop, use TIFF instead of PSD; TIFF can hold everything that PSD can, and I do mean everything, even things like "smart objects" which seem like a PSD-specific feature. It compresses losslessly to about half the size. In addition to that, when you use TIFF, you can finally set the texture "Alpha Source" to "Image Alpha".
When saving TIFF in Photoshop, use these settings for max compression that 3ds Max can still read.
Make sure to also include layers.
And of course, if there is any transparency in your image, the savebox will un-grey as well.