Need help - Painting jet metal?

dj snyder

So! I'm modelling and skinning a Jian-10, for the Source Engine:


I really have no idea how to go about painting the fuselage to look like a convincing jet-fighter-metal. How much should I leave to a shader?

So far I've been procrastinating by doing details, but I'm running out of stuff to put on there:

CheeseOnToast

Get your normal and spec maps done, then bake some ambient occlusion into the diffuse. The shader should do a decent job of the rest, so don't go crazy on faking shadows etc.I'd put the glass on a separate texture so that the alpha will sort properly and so you can apply an envmap to it. The rest is fairly non-reflective, so I'd use the phong shader for it. You can always tweak it later on if it's not looking right. If it's going in as a static prop, the cast shadows it makes should look pretty good.

dj snyder

Is there a way to effectively paint normal maps, or will I need to make a high-poly model? I've never done a normal map before and this mesh in particular looks like it could be TRICKY

TRICKY YOU KNOW

pliang

I'd also lay off a little bit on scratches and bumps if you're thinking of doing that as it might make it look styrofoam.

dj snyder

Not sure what you mean by bumps but I definitely wasn't planning on putting scratches on it

pliang

Just worn and tear in general...but anyways occlusion assigned to a surface shader would fake it pretty well for what you're looking at.

CheeseOnToast

Don't worry about making a high poly model to create your normal maps for this one. The Nvidia photoshop filter or crazybump will do the job. Ben Mathis has a good tutorial explaining the basics of how to use the photoshop plugin. Once you get the normal map looking right in Max/Maya, you'll need to invert the green channel of it to make it look ok in the Source engine. The spec map goes into the alpha channel of the normal map, if you didn't already know.

Slainean

I recommend that you go and extract the textures from the Combine helicopter for a strong example, and pay close attention to the spec map.

You can create a normal map by converting it from a hand painted bump map, but the key is to stick to geometry for details and avoid using too much tough texture.

dj snyder

Thanks guys--I'll try and start with the normal maps after I bake this here shadow map. Running into a problem though:

los

make sure your advance lighting is checked on in you render drop down menu.

dj snyder

Well, i think it is--as shown in the upper image it renders regularly just fine.

HarlequiN

I can never get lighting map or shadow map to work, always do a complete map instead (with a white material applied to the object).

eld

Harlequin, that's not the right way though, lighting maps should look the way they too so that one can use them correctly, multiplied.


did the file output look like anything other than black?
the render window will show what it sees in the viewport, with all the shading and that stuff, but the files output
will be seperated stuff, lightning will be white where there's no occlusion and darker where there is.

if there's no image you've probably de-activated what you need to render any actual lightbaking.

CheeseOnToast

I'd also say don't bake any directional lighting, just ambient occlusion. The game engine will take care of the rest.

Mark Dygert

This looks more complicated then it actually is I'm sure you don't need as quite a step by step but I'll list it out for other people who might visit this thread
- Switch your render to Mental Ray. F10 > common tab > Scroll down to Assign Renderer > switch production to Mental Ray.

- In the material editor, create a new material > under maps > click none next to "reflection" and Pick "Ambient/Reflective Occlusion".
Note: It will only show up if mental ray is set as your renderer, so make sure to do that first

- Set the Samples to 64 > the spread to .5 and apply that material to your model.
Note: setting the samples lower like 16 will speed things up, but can give grainy results, which is great for dirt maps

- Add a sky light with default settings, it doesn't really matter where you place it in your scene.

- Now in the Render To Texture options there will be a new output option that only shows up once you have mental ray set as your default renderer, its called Ambient Occlusion(MR). Pick that instead of Light Map, click render and wait. It could take a while but considering you can't rush pretty.

- You can turn on Final Gather to smooth out the graininess even more and really refine the map. But often that isn't necessary and takes quite a bit longer. Most of the time you end up tweaking the map in PhotoShop anyway.
F10 > indirect Illumination > under basic check "enable final gather".

I've also gotten good results with the default scan line renderer, and a light dome like Harl suggested, but technically if you want an actual Ambient Occlusion map, this is the official way to do it. AO is a cat, skin it whatever way works best for you =P

Xenobond

vig- you don't even need to apply a material to the object when rendering the ambient occlusion map in rtt. all you need is the renderer set to mental ray, and then select ambient occlusion in the type of map you are going to render out.

Mark Dygert

ahh cool! That saves me some time! However you do need the material if you're rendering the entire scene and compositing. Why they haven't added that functionality to the main render settings is a bit mysterious. I would think that it would be really handy to have on the render frame window, kind of like the view alpha button. But I guess the 15% of the Max user base that dictates what goes into Max (architects) haven't asked for it yet... They get paid so much to make such crap. I choose the wrong line of work...

snap.crackle.pop

Man i love those jet planes, i remember playing Falcon3 and 4 a lot when i was a teen. Get more scratches and dirt like pliang said, it just looks like paper right now. This is a nice project, keep at it