Automotive Secrets, what are the productions houses workflows and tricks?

[ali_cgi]

Ok guys, this is a shot in the dark, but would I love to get some insight into what the automotive cgi companies are doing to to get such amazing results, company's like gloss, taylor james, npix, recom etc,
Also form my research all the German studios seem to have a very similar look to their images, from looking extensively at their cgi work it seems they have some kind of cgi bible that know body knows about, unless your in the know, whats happening here!
I'm mainly focusing on print images, not so much animation, but any advice would be fantastic, list of questions below,

How much does this type of work rely on the real cad data of the cars?
How good are the hdri's ?
What do the raw renders look like?
How much post? are the separate elements of the paint shader given to a retoucher . i.e. base, metal, fleck, coat? to be brushed in in photoshop?
Are the hdri domes calibrated or heavily colour corrected?
What methods are used for creating car paint shaders? Vray Blend? Vray car paint? Shellac?
Synthetic lighting, HDR light studio area lights? What's the general lighting workflow?
Reflections? how do you get them looking good, flowing over the cars in the right places? No ugly reflections,
How are motion blurred domes created? Is it virtualrig or are there methods to shoot these on location?
i'm mainly talking about location backplates with matching domes,
Am i missing anything?

I think getting the paintwork right is the key, and a good dome for reflections is also a part of that, but what is done with these elements,

Please share the secrets if there are any? I don't expect anybody to reveal a manual here as i know the whole business is very hush hush, but any little tips would be massivly appreciated,

This thread could become a sticky of automotive trade secrets

Cheers guys hope this is posted in the correct area,

[Dariusz Makowski (Dadal)]

Mostly Cads
HDRS are most of the time shoot by CGI or Photographer usually minimum 9 stops
Raw renders looks like crap
There is around 100-500 render layers in PS
No calibration on HDRS
Car paint shaders are usual car paint scans from custom programmers/companies
Area lights and realistic lights. Full physics no GI - no need for gi.
Reflection - post
Motion blur HDRs are blurred using bleex/photoshop/virtual rig

You need a very good retoucher for this. Renders can be make by amateurs as long as they hold proper physics...

As to germans yea they hold the market. Most of BMW, Audi etc etc are there so they have good market for cars.

[Neilg]

It's all in the retouching - a friend of mine does freelance car work and I was shocked to see the raw renders. they're properly bad, but the final images are incredible.
his psds have hundreds of masks for individual panels, separate curves layers for each with gradient masks. if you look at most car renders they're just complex layered gradients across the surfaces.

[ali_cgi]

Wow, thats a shock, thanks so much for the reply, is this coming from experience?

What do you mean by 'Car paint shaders are usual car paint scans from custom programmers/companies ' sorry if thats a stupid question,

I work for a traditional automotive retouching company, so our main work is normal photo shoots, whats the difference?

Any idea on the render passes the retoucher usually uses, are brackets used like on a traditional retouch job? Would love to get some specifics ,

Your website has some great work! Thanks so much

[ali_cgi]

Thanks, as a cgi guy i find it very difficult to know what quality I should give my retouchers, I have never worked for a big cgi company so I feel blind,
This info is very reasuring! Do retouchers required lots of different renders, we tried a setup, of rendering the dome at 15 degree increments to give the retoucher more to work with, is this sort of thing done? Cheers

It's all in the retouching - a friend of mine does freelance car work and I was shocked to see the raw renders. they're properly bad, but the final images are incredible.
his psds have hundreds of masks for individual panels, separate curves layers for each with gradient masks. if you look at most car renders they're just complex layered gradients across the surfaces.

[Dariusz Makowski (Dadal)]

Many things are done. Different dome rotations as well as plane with gradients on it for reflections and car lines. Lots of light passes and more. It really comes down to retoucher...

Here is one of my breakdowns.

https://vimeo.com/103902959

Scanned car paints I mean we get sample from manufacturer of car paint and send it to "special" people they have crazy scanning machines that can produce that paint in 3d. That paint then is very limited usually all you can do is change strenght of reflections and sometimes fake change the color. Usually its just locked down.

But to be honest Vray car paint is very good as well so u can get away with a lot using it as well.

[ali_cgi]

Thats fascinating, what would those scanning machines give you to work with in vray?

Would you be able to recreate a shader that these scanners give you?

I do feel like i can't get past amateur with my renders and its hugely frustrating, only so many sliders you can tweak in vray,

would using a plane with gradients be similar to using hdri light studio without the hassle of using that program?

Would a retoucher usually act as creative director and request certain elements from the cgi artist?

Thanks again

Many things are done. Different dome rotations as well as plane with gradients on it for reflections and car lines. Lots of light passes and more. It really comes down to retoucher...

Here is one of my breakdowns.

https://vimeo.com/103902959

Scanned car paints I mean we get sample from manufacturer of car paint and send it to "special" people they have crazy scanning machines that can produce that paint in 3d. That paint then is very limited usually all you can do is change strenght of reflections and sometimes fake change the color. Usually its just locked down.

But to be honest Vray car paint is very good as well so u can get away with a lot using it as well.

[ali_cgi]

Was the wraith done with real cad data? Really nice!

[Dariusz Makowski (Dadal)]

Thats fascinating, what would those scanning machines give you to work with in vray?

Would you be able to recreate a shader that these scanners give you?

I do feel like i can't get past amateur with my renders and its hugely frustrating, only so many sliders you can tweak in vray,

would using a plane with gradients be similar to using hdri light studio without the hassle of using that program?

Would a retoucher usually act as creative director and request certain elements from the cgi artist?

Thanks again

It is a shader that you get back. You simply load it up in vray and bum it renders.

Dont tweak stuff to look nice. Just make it physically accurate.

Either gradients on planes or hdr studio. Which ever is easier for you to position.

Yea retoucher can come back and ask for different passes and layers.

It depends how you render stuff. Some people render all in 1 go other render light by light etc etc.

[ali_cgi]

Would the lighting be hdri or cgi lights? as you say rendering light by light , then the dome used purely for reflection? or would this depend on the artist? Thanks again

[Dariusz Makowski (Dadal)]

Well you render ur IBL just like any other IBL. Then you add extra lights to fill the blanks or tweak HDR if u can in hdr studio. I more often tend to do the 1st option using extra lights rather than adjusting IBL. On IBL maybe I just do a tweak on sun power but I usually leave it natural now.

I've send you private message btw.

[Wilyman]

Hi Alistair,

I thought I'd chip in with some answers to your original questions.
I know Dariusz has worked at Recom, who are one of the best around, so he knows what he's talking about, but I've got to say that my experience differs in lot of ways to the answers he's given, so I thought I'd give another perspective...

How much does this type of work rely on the real cad data of the cars?

Almost entirely. Some companies will provide the nurbs production data as catia, step, alias, etc. whereas some will only send out polies, but it will all originate with the engineering data.
There might be rare cases where CAD isn't available, in which case you could get a car laser scanned and then rebuild over the top, but it's a huge job to do properly.
I have had a couple of ad agencies wanting to work with Turbosquid files in the past, but you just have to politely advise them against it, because they're never going to be up to scratch for an ad.

How good are the hdri's ?

That depends. Ideally you'd be out on a closed road so you can take your time and get as big a range as possible, with lighting as similar as possible to the backplate, but it's often not the case for a variety of reasons.
In my experience, half the time you end up using a different HDRI altogether.

What do the raw renders look like?

This is where I'd really disagree with some of the previous comments in this thread.
As far as I'm concerned, you'll only get out what you put in, so the better the render, the better the final result.
I'll reply to your post in my Porsche Cayenne thread as soon as I get a chance, with a couple of examples of raw renders from that job.

How much post? are the separate elements of the paint shader given to a retoucher . i.e. base, metal, fleck, coat? to be brushed in in photoshop?

Loads of post! But my philosophy is to get the car looking as realistic as possible, so the retoucher's job is no different to a traditional car shoot, with the added bonus of all the masks, separate layers, etc that CG can offer.
So in a perfect world, the vast majority of the post would be creative rather than cleaning up the 3D artist's mess!

Personally I don't separate the layers of the paint shader into Photoshop layers for the retoucher, but I'm sure some do.

Are the hdri domes calibrated or heavily colour corrected?

Not especially. It's good to give them a quick once over in photoshop, just so they're not casting too much of a tint over the whole scene, and to get rid of traffic cones and lampposts, etc. but they're usually not altered too much.

What methods are used for creating car paint shaders? Vray Blend? Vray car paint? Shellac?

In my experience, the scanned BRDF shaders aren't really worth using. They're great to have as reference, but as Dariusz said, there's so little you can do to adjust them, that you're usually best off recreating them with standard shaders.
VRayCarPaint's great for a metallic paint. VRayBlend's great for a solid paint. Personally I wouldn't touch shellac with a bargepole.

Synthetic lighting, HDR light studio area lights? What's the general lighting workflow?

If we're still talking about location shots here, then generally the HDR from the location, or an appropriate equivalent, will be your main lighting tool.
If you need to add extra lighting, I prefer to use VRay lights rather than HDR Light Studio, because you'll get more realistic falloff from the lights, but again, I'm sure everyone's different.

Reflections? how do you get them looking good, flowing over the cars in the right places? No ugly reflections,

Personally, I'd spin them around a bit in VRayRT so they're flowing nicely over the body, and then if you've got some ugly bumps, take the HDR into photoshop and get rid of them.
You could do it all in post, but I don't think it looks as realistic that way.

How are motion blurred domes created? Is it virtualrig or are there methods to shoot these on location?

Yeah, VirtualRig or Bleex, or something similar. There's no way that I know of doing it on location.

Please share the secrets if there are any? I don't expect anybody to reveal a manual here as i know the whole business is very hush hush, but any little tips would be massivly appreciated,

I don't think it's particularly hush-hush. There's not really anything going on that's different to any other aspect of CGI. It's just a case of getting your materials and lighting as good as possible.

I hope that helps.

Cheers,

John

[ali_cgi]

Well you render ur IBL just like any other IBL. Then you add extra lights to fill the blanks or tweak HDR if u can in hdr studio. I more often tend to do the 1st option using extra lights rather than adjusting IBL. On IBL maybe I just do a tweak on sun power but I usually leave it natural now.

I've send you private message btw.

Thanks Dariusz loads of great advice here! I also feel using cgi lights works better than hdrstudio, hdrstudio maybe for painting shapes on the bodywork but, I feel you can be much more subtle with normal cg lights, Ive replied to your message also,

Cheers

[ali_cgi]

Hi John, Thanks for the reply, thats excellent advice, I didn't expect much comment on this thread but I'm really happy with some of this info.

And yes it would be excellent to see those Porsche shots in raw! Would help hugely!

I think the hardest part is getting the paint right personally, and John the Porsche shoot is some of the best I've ever seen. Would the bodywork, rims glasswork be all separate lighting setups?

I agree real cgi lights look better most of the time, yes still talking about location shoots, HDR studio always felt very harsh to me unless i was using it wrong?

What about falloff curves for paintwork reflections/ glossiness etc how aggressive are the curves or are they quite subtle? Custom curves or ior numbers?


Again this helps a a lot! Thanks John,

Cheers

Alistair

[Wilyman]

I think the hardest part is getting the paint right personally, and John the Porsche shoot is some of the best I've ever seen. Would the bodywork, rims glasswork be all separate lighting setups?

No, not at all. It was almost always rendered in one pass. The only exception being if the sky was a bit too clean, I might do another render to get some cloud on the bonnet and glass, but generally, if you want to keep it looking like it's part of the scene, you don't want all the components of the car being lit differently.
I didn't use any additional lighting at all on the Porsche shoots, other than putting in VRay lights when headlamps or daytime running lights needed turning on. There were no artificial lights lighting any of the bodywork.

I agree real cgi lights look better most of the time, yes still talking about location shoots, HDR studio always felt very harsh to me unless i was using it wrong?

I'd say exactly the same. I've never got good results from it, but then there are plenty of people that have, so perhaps it's worth giving it another bash.

What about falloff curves for paintwork reflections/ glossiness etc how aggressive are the curves or are they quite subtle? Custom curves or ior numbers?

It depends on the paint really. To my eye, black paint seems more reflective head on than most colours, whereas silvers tend to have much more reflective and less glossy basecoats. It's just a case of playing with the shader until it looks right, just like any CG material.

Cheers,

John