My first Normal Mapped Weapon!

BigL

Hey there,

I've just finished my first normal mapped weapon:

424 tris, made in maya. The squares on the end of the cylinders will be alpha mapped.



I'd like some help to produce an occlusion map or whatever it's called, for producing a map with a Global Illumination look to it. I'm not too sure how I do this in maya, although I think mental ray does something like it.

Hope you like it.

el.

Ninjas

What program are you using?

CheapAlert

[ QUOTE ]
424 tris, made in maya.

[/ QUOTE ]

Reading is a very fun ability

Downsizer

he may have meant to ask 'what program are you using to generate the maps'

MoP

Looking good BigL. I can't help you with Maya generating AO or lightmaps, but I believe if you search the 2d/3d forum you'll probably come across a couple of threads about it, I recall seeing some, about Mental Ray in particular. Also I think there was some info in Daz's entry to the Generals contest, you might be able to dig that up.

I'd be tempted to round out some of the edges of the square shapes with small bevels, shouldn't add too many polys but might make it seem slightly more believable and less boxy in silhouette, the normal map will deal with interior detail.

Keep it up!

BigL

aye, thatnks for the comments - but I've run into a problem:

for some reason or another, the normal mapping on a simple box is driving me insane.

as you can see, it seems half of the normal map is being generated the right way up, and half not:



anyone know why this is?

KevinCoyle

Are you using tangent or world space normal maps?

fogmann

If you have mirrored UVs, then the normal map on faces that have flipped UVs will look inverted in Maya, though game engines usually take care of that, but Maya just can't without some tricks, as far as I know. Also, if you're using floating geometry for additional details, check the normals on them - if they are facing the wrong direction, the concave shapes will look convex in normal map and vice versa.

As for AO baking, I'd recommend you to check out xNormal utility, because it's very simple to use and generates AO map from high to low poly meshes and it's fast as well. There are some methods to do it in Maya, and here's a tutorial: http://www.alexmunn.com/html/class_levels_shaders.htm - it is a bit more involved and requires you to bake AO map for high poly, and then transfer it with surface sampler back to low poly. Hope it helps a bit.

Snowfly

I second using xNormal to generate AO, but can't vouch for the quality of the output as I can't tell the difference between a good AO map and a bad one. So how do you gauge the quality of an AO map anyway>?

Good use of normal maps BigL!

fogmann

In the manual for xNoraml it says that value for rays per sample can be increased up to 5000, and 1000 is a film quality AO map, and that the time it takes to calculate the AO map linearly increases with the number of rays per sample... So I'd assume that you could see noticeable quality difference on AO map with low and high number of samples. I can't say much about the quality though, until I directly compare AO map made with xNormal and with mental ray or other means. But when I do that I'll post the results, it's worth checking out.

BigL

hey, thanks for the replies.

So here's the thing: I've tried using world, tangent and object space settings in maya, and also changing the search depth incase it was grabbing from the other side. Still no change Im going to see what happens when I import them into a new scene, then if that fails I'll try with the xNormal.

cheers again, L

BigL

Ok, in studying the normal maps, I have found that It looks like the rays are being cast from the centre of the object, regardless of the settings I use. This is creating the effectyou see above.

I've freezed and reset both object transform nodes, so now they are perfectly alligned, and still - crappy results.


I'm just downloading xNormal now, but what would be different in that to ensure that the normal looks correct?

Also I have tried using mental ray for some AO maps, looking good

L

BigL

sorry fr the triple post, but:



The side faces appear done, and the normal mapping is in tangent space. But now I have a different problem, one which I presume is quite common. As you can see above, there seems to be an edge created in the normal map making black lines appear instead of bevel looking edges when rendered.

Anyone know why this is, and how I can get rid of it?

el.

MoP

Does the lowpoly model have smoothing groups? Often you get problems like that if you're using more than one smoothing group (or i guess in Maya, it means you may have hard edges in your mesh - try making all the edges soft then rendering the normals)
Also it could be a UV map seam, if that's the case you should find that any edges which aren't on a seam look fine. And there's no real way to avoid that I think.

BigL

Ah got it, searching aroud on the net said no 90 deree angles for calculation. So I bevel the box once and am experimenting with hard/soft edges. Atm soft looks the best though it's creating some weird maps atm

as such

Joao Sapiro

well, the way you unwraped the box makes it distort like that ahah

BigL

LOL, i know it distorts,I mean there's a gradient on an otherwise flat face.

KDR_11k

That's because the lowpoly normals describe it as round, which the normalmap has to counteract. Look at it without the normalmap, it's shaded like a round surface.