Maya - Normal VS bump map issue

omegalith

Hi, up to this point I have been working with greyscale bumpmaps. They work great in Maya software and mental ray renders. For importing into game engines I have been converting all of my bump maps into normal maps. This is the first time I have spent extensive time messing with Normals. I have tried using CrazyBump as well as the Nvidia Photoshop filter to create normals. It seems like no matter what I try, the normals do not turn out correctly. They do not render as nicely as the bump maps do, also they render differently under software and mental ray, whereas bump maps look the same under each renderer. What am I doing wrong?!?!

Thanks in advance!

Below are images, for clarity sake I have croped the textures so you can see the most important details.

The original Bump map


Rendered in Software, it works perfectly!


Rendered in Mental Ray, the bump map still looks great, the spec map seems to be more subtle, this is still acceptable


The Normal map, created using CrazyBump, very little tweaking in the software



This is the normal map rendered in software. I have the bump node with the exact same settings as before except it is switched to Tangent Space Normals mode.....what happened??


and this is the same normal map rendered in mental ray, for some reason most of the small detail in the normals seems to be lost. The bolts seem to be defined correctly but they do not have the sharpness of the pure bump map.

Cybroxide

Try inverting the green channel

omegalith

thanks for the quick response

here is my normals with green channel inverted




and here is a software render using the newly inverted normals, still not looking right!

Joao Sapiro

well,do you really need a normal map on that ? that asset could be done perefectly with tiling textures and still look good

Gilgamesh

When you create the bump map node on the material, it will flip to the bump2d node of the material. There is a drop down that says 'bump' in it already, if you click and change it to Tangent space normals it will change the look of it.

Basically it wont detect that you have plugged in a normal map and change it accordingly and still use the image for a 'bump' map instead.

At least I think that's your problem.

Firebert

Maya Software handles Tangent Space all funked for some reason, regardless of if you tell it to be tangent space in the bump node. It should render fine in your viewport with high quality set on and lights in the scene. As for your specular blurring in Mental Ray, check your filter type on your file texture node. Really, I wouldn't rely on rendering in Maya. Either use your viewport or a game engine to show your work. If you really want to use Maya to render your models for presentation, then stick with MentalRay, but the results will be extremely different in terms of the final image to the point of it being noticeable that you didnt use an engine or a realtime viewport image. Also, start exploring HLSL and CGFX Shaders. Check out this thread. Having knowledge on using these will help you out in the long run for sure.

throttlekitty

The default Tangent Space attribute for the model *should* be set to auto-detect, but left- and right-handed winding order can be specified, this might fix the problem.

omegalith

Thanks for the advice everyone, but I have yet to figure this issue out. Experimenting with other models, it looks like Maya renders normal maps correctly through high quality mode, but not through software render. It does render normals correctly in hardware mode though. I MUST be doing something wrong, this is a strange issue!


This one is rendered using software render, there are seams and a lot of noise



This one is rendered in the viewport using high quality mode, it looks PERFECT and it has no seams. When I render using maya hardware mode, it looks like this as well.

Gilgamesh

You need to define the map you are using (bump map or tangent/object space normal map)

When you add a normal/bump map you can choose from the dropdown menu which it is, default it is bump map so it 'looks' like you are trying to use the normal map but still is set to a bump map giving you a freaky look.

Also when you 'render' the piece, if you are not using mental ray you wont see a proper normal map render because as far as I know Software render doesn't support it properly.

omegalith

Ok thanks, here is an image of my render network and renders.





I took your advice and rendered in Mental ray, it looks great! I am still disappointed that Normal maps work so poorly in the software render, it makes me want to just work with greyscale bump maps because I know they will render out the same in Mental ray or software.

whipSwitch

simply put, as of maya 2k8, the software renderer just doesn't support normal maps. You aren't doing anything wrong. You can do a google search for JS normalMapper. It's a shader for rendering normal maps in the software renderer that might give you acceptable results. If you have your heart set on using the SW renderer, then it's worth a try...