I'm using 3ds Max 2014 and Mental Ray Arch Design shaders. When applying a normal map I'm using the Standard Normal Bump shader (using Normal Map slot) and plugging my map into that, then the Normal Bump shader gets plugged into the Arch Design Bump channel.
I created a bump map by using a mid grey (127) background and drawing very dark lines onto that and then converting to a normal map with nDo.
In the viewport everything looks great but when I render it the image gets really bad faceting. When I unplug the Normal Map the render looks great.
So how/where am I going wrong in my normal map creation and shader useage??
Thanks!
Replies
Someone suggested that this might be due to the normal maps and sure enough if I remove the normal maps the render comes out perfectly.
So I am trying to understand how I can use normal maps inside of max without this faceting.
Remember, you can use Imgur.com or another free image host, to get bigger less-compressed images.
I'll take a look at this kind of setup in Max later today, but I'm pretty sure I've used normal maps in Arch & Design before.
To be clear, you're using the mental ray renderer, right?
Can you post a closeup crop of a part of the normal map that's causing the error? Also a closeup render of the model would help.
Around the rivets in your normal map, the JPG format has added a bunch of noise. This is the fault of JPG compression.
Another problem is the rivets are not strong enough in your normal map. Your original depth on the left, and on the right is what it should look more like:
I don't have 2014 installed here though, so I couldn't check your setup in Max. But if you fix those two issues, you should be better off.
OK, here it goes.
I'm using 3dsmax 2013 to render out a Normal map but for some reason I keep getting these annoying pixel artifacts appearing. They look like ray misses but there always 1x1 pixel in size whether rendering at 512x512 or 8192x8192 and change position when the output resolution is changed. Turning of ray miss check just changes them to dark coloured spots. This ONLY happens with the Scanline renderer. I would use mental ray but it keeps offsetting the image output so it doesn't align with the UV properly.
The top image shows the red dots with no supersampling.
The middle shows in with Hammersley but you can see the red dots just get scattered with the sampling filter and look like faint freckles. They're difficult to see but there.
The bottom is xNormal using the same cage with no visible artifacts.
I'm checked everything that I can think of that may cause this such as dithering, anti-aliasing filters and overlapping meshes. I know I could just ignore it but it's so annoying that it happens and is completely random.
Also tried altering UVs on the high poly as I know that can sometimes causes pixel artifacts but so far nothing has worked.
EDIT: Merged the meshes into a completely new scene all with default settings just to make sure it wasn't anything I've done and it still does it.
I have found a work around by rendering out multiple maps so the bad pixels change and then using Photoshop remove the red pixels and fill the holes with the maps that don't have a red pixel in that position. Not practical if I need to render again but it works. I can only hope this is an isolated problem with this model.