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starbase1
11-29-2007, 05:15 AM
This ought to be about the simplest thing possible but...

Anyone got any suggestions for a convincing matt grey painted metal?

I did a simple colour, added a slight specular sheen, a bit of "colour highlights". It's not that it's bad, it's just way too uniform, and particularly when used for larger areas, is not really convincing. No sense of any detail.

I'm after something that is basically similar to a painted plane wing, (it's for a rocket), fairly freshly painted so I can't add rust or dirt to give character. In theory it's also rather smooth, which suggests that bump is the wrong approach, but that doesn't leave a lot to play with!

Nodal or layered, anyone got any suggestions?
Nick

StereoMike
11-29-2007, 01:35 PM
I would give it a slight small bump. The same kind of bump you see in thick painted industry machines. Maybe not that bumpy, only that bit that would be slightly seen in refelctions and specular (very little).

mike

starbase1
11-29-2007, 03:20 PM
I see what you mean, and perhaps a little noise in the specular channel would help too...

I think I need to knock up a simple scene to test this.

One of my reservations is that it will be used on a very large object, which I don't plan on seeing this close up...

Thanks,
Nick

jameswillmott
11-29-2007, 04:24 PM
This ought to be about the simplest thing possible but...

Anyone got any suggestions for a convincing matt grey painted metal?

I did a simple colour, added a slight specular sheen, a bit of "colour highlights". It's not that it's bad, it's just way too uniform, and particularly when used for larger areas, is not really convincing. No sense of any detail.

I'm after something that is basically similar to a painted plane wing, (it's for a rocket), fairly freshly painted so I can't add rust or dirt to give character. In theory it's also rather smooth, which suggests that bump is the wrong approach, but that doesn't leave a lot to play with!

Nodal or layered, anyone got any suggestions?
Nick

A light dose of soft reflections works wonders for metal. :)

Hopper
11-29-2007, 06:50 PM
Just out of curiosity Mike, what exactly is that sticker telling you not to do? "Don't high-five while sitting on the shredder" ?? "Do not operate the 'Boss-Launcher 2000 Pro' without management supervision"?

Yamba
11-29-2007, 11:12 PM
For what its worth I think the sign is telling one: not to pat King Cobra whilst Sitting on Box, but then again I could be wrong.

StereoMike
11-30-2007, 02:09 AM
lmao!
I guess it says: "Don't sneak up on the trash bin and try to steal a broken hockey stick!"

No, really, it says you shouldn't ride electric hand pallet trucks. What a pity. It's such fun. The pic is from my reference folder. I have to deal with these rather frequently (for doing LW, not storing pallets...).

mike

starbase1
12-01-2007, 01:58 AM
Ok, I set up a test scene with a big cube (about 4m). A mix of soft spotlight and radiosity for lighting, and a human figure with the camera at his eye level so that any implied scale errors will show up.

I'll share the surfaces when I am finished.

Anyway, here are some images including a 'limestone' sort of texture I bumped into on my way to it!

The main thing I did was a low level of fine scale bump, with lots of levels, and a spec texture at a somewhat different level to the main setting, again lots of levels.

I think it maybe looks a bit too metal, but I think it is getting there. I've stared at it too long, so I'd really appreciate some constructive feedback!

Nick

StereoMike
12-01-2007, 03:14 AM
For my taste it's way too err...messy (I don't know another word for it right now). The pattern draws too much attention. If it's so big (and you don't need close ups) you should consider dropping the spec/bump pattern alltogether and just apply a blurred reflection map (or blur raytraced reflections), just as jameswilmott said. After all it's matt - but bumps are better to see on shiny surfaces, so dropping them for the matt paint should work, I guess.

mike

starbase1
12-01-2007, 04:16 AM
I see what you mean, I have the effects way too strong, I'll tone things down a lot.

I'm not so sure about the other suggestions though... I think reflections from matt paint would be negligible, though looking at real world stuff a soft broad specular highlight to some degree is there, particularly when there is a strong point like light source.

Thanks for the suggestions, plenty of food for thought there.

Nick

starbase1
12-01-2007, 06:12 AM
OK, everything toned down, trying again.

StereoMike
12-01-2007, 07:08 AM
Much better. Maybe up specularity a bit, glossiness seems right (maybe you have to decrease glossiness slightly when you up spec, to avoid it getting to bright on too much of the surface).

refering to the reflections: maybe you can apply an image that would give a very blurred idea of the light conditions/sky ground. Nothing exact, just a blue/brown pic with a big white spot (and much blurred).
I can't promise that this will work, it's just an idea :)

mike

starbase1
12-01-2007, 08:13 AM
Thanks, I'll try the specularity. I think that it will tend to pick pick up local colour from the radiosity - I expect to use this for almost all the renders, and that should give an appropriate hint of colour.

IgnusFast
12-09-2007, 07:41 PM
Ok, I set up a test scene with a big cube (about 4m). A mix of soft spotlight and radiosity for lighting, and a human figure with the camera at his eye level so that any implied scale errors will show up.

I'll share the surfaces when I am finished.

Anyway, here are some images including a 'limestone' sort of texture I bumped into on my way to it!

The main thing I did was a low level of fine scale bump, with lots of levels, and a spec texture at a somewhat different level to the main setting, again lots of levels.

I think it maybe looks a bit too metal, but I think it is getting there. I've stared at it too long, so I'd really appreciate some constructive feedback!

Nick

No insult intended - I swear, the first one looks like a salt lick.... :)

jameswillmott
12-09-2007, 08:26 PM
OK, everything toned down, trying again.

You know what would really convince someone that this is metal is things like seams and rivets. Even if the texture isn't quite right, these extra details would help make up for it...

starbase1
12-10-2007, 12:07 AM
You know what would really convince someone that this is metal is things like seams and rivets. Even if the texture isn't quite right, these extra details would help make up for it...

Good points but...

I have some rivets for the real model, though they only show in close up shots, (which is like the real thing). It was more about making it look like a big piece of metal from a distance, when these details can't be seen. That's what I find tricky.

Twisted_Pixel
12-10-2007, 02:09 PM
Probably having a search for some reference images to pick the look from may help. From what you have said, this image I found through google ("industrial grey") may fit the look. http://www.istockphoto.com/file_closeup/?id=1970813&refnum=506154

Glendalough
12-10-2007, 03:51 PM
This whole area is really intriguing. Very interested to see what you're going to come up with. Think the image map thing a good idea, you could even make your own first (to add even more complications to the problem).

The lighting is going to play a big part in this which does add a lot of complexity to the problem unfortunately. Also, time and again, if you check out what other people have done so far in this area, there doesn't seem to be a clear solution. An awful lot of metal out there is looking just way too much like plastic.

Another thing that could be tried maybe (more work) would be to put a distance gradient (how to do this with nodes??) on the bump/ image maps etc. and see by moving camera and changing strengths of the textures if you can come up with anything, aside from more avenues leading nowhere. This is not an easy problem, but hopefully, as the nodes are pretty amazing, you can discover something.

starbase1
12-11-2007, 03:16 AM
Probably having a search for some reference images to pick the look from may help. From what you have said, this image I found through google ("industrial grey") may fit the look. http://www.istockphoto.com/file_closeup/?id=1970813&refnum=506154

Thanks - those are not really a good match for the look I am after though...

As I said earlier, it's making it look like painted metal at larger scales / more distance that is troubling me...

starbase1
12-11-2007, 03:19 AM
The lighting is going to play a big part in this which does add a lot of complexity to the problem unfortunately. Also, time and again, if you check out what other people have done so far in this area, there doesn't seem to be a clear solution. An awful lot of metal out there is looking just way too much like plastic.


The lighting is going to really complicate things - this is for my big N1 rocket, so the surface will be hit with a wide range of lighting conditions, from an overcast outdoor day, light by fiery exhaist from underneath for a night launch, bright sunlight as it rises above the clouds, (different launch, obviously!), and space lighting as it leaves the atmosphere.