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Mustang 69 GT

Posted: 06 Oct 2011, 06:10
by Numb69
Hey everynone
Im trying to re-render my mustang. This is the new test render. Only applied an AO, the rest is an HDRI with a point light for some light and shadows.I am going to tweak the materials (add some flakes to the car body maybe?!),the lighting and the background..Meanwhile if u can give me ur opinions and critcis, that will be great help ;)

Re: Mustang 69 GT

Posted: 06 Oct 2011, 09:39
by Zafar Iqbal
Nice ride, one of my favorites.

Setups looks great to start with. Tyre rubber is off though. Looks too hard and there's a lot grain/noise.

I think you should stay away from fancy (metallic paint) stuff and instead keep the car original. It's easy to get some horrible and tasteless.. like this:
http://www.mustang-parts.org/news/wp-content/uploads/2009/12/eleanor-mustang-gt500.jpg

Oh, the horror

Re: Mustang 69 GT

Posted: 06 Oct 2011, 19:46
by Hirazi Blue
I know absolutely nothing about cars (I'm a "radical" pedestrian myself :D )
For that reason, I can't say much about the car model, but I must say I really like the monochrome render.
This gives it a nice subdued and vintage look. So keep it in monochrome!!!
;)

Re: Mustang 69 GT

Posted: 06 Oct 2011, 19:52
by Zafar Iqbal
Oh wow - I first saw it when I was at work (no, I wasn't slacking, I promise :P ) and we have some crap monitors there, but I seem to keep forgetting just how severe the gamma shift (or whatever) on them is. The side was much brighter and the "noise" on the tires was really popping out. Looks much much better here on my trusty and calibrated home monitor.

Re: Mustang 69 GT

Posted: 07 Oct 2011, 03:54
by Numb69
Hey guys thx for critics ;)

Me too I have color issues somites, I have a wide gamut monitor, so i only trust PS, since its color managed :D
Anyways Zafar, I am goign to tweak stuff like that noise for instance, I just wanted to make sure when u say original color, do u mean the Silver/black stripes or u actually mean the material itsealf, make more rough (like the older cars)

Re: Mustang 69 GT

Posted: 08 Oct 2011, 07:11
by shadow_ex_
this looks really really good,well done :)

Re: Mustang 69 GT

Posted: 10 Oct 2011, 23:00
by Numb69
Thx dude! ;)

Re: Mustang 69 GT

Posted: 10 Oct 2011, 23:19
by Zafar Iqbal
Numb69 wrote:I just wanted to make sure when u say original color, do u mean the Silver/black stripes or u actually mean the material itsealf, make more rough (like the older cars)
Basically pretty much whatever paintjobs it came with back in the days. Metallic paint would be too modern for this - but thats just my 2 cents.

Re: Mustang 69 GT

Posted: 15 Oct 2011, 03:13
by Numb69
Thx Zafar, ill look into that

Meanwhile I could use some help from experienced ppl.
Below I am trying to composite my mustang with a background plate. What happens is that the HDRI doest seem to produce good results (or probably im setting it wrong)
I got a set from Hdri4free, basically a backplate in the environment background and the HDR in the environment's environment. It does work a bit, but its way too dark, I cant really see any good reflection in the rims and the rest of chrome materials,the side of the car is dark and theres no blue tint from the HDR.
If anyone could point me in the right direction, much appreciated :)


P.S. dont bother with the camera mapping and the shadows, I kno its not perfect, its only for testing purpose

Re: Mustang 69 GT

Posted: 16 Oct 2011, 01:26
by Zafar Iqbal
Hm.. could be number of things. Would be easier to have a look at the scene. You could remove or replace the car with a sphere if you understandably don't want to share it.

But for now I'd say make sure you check visibility for all "helper" geometry and make sure they don't conflict with your hdri setup. It could be the reason for the sky reflection/blue tint now showing up.

Re: Mustang 69 GT

Posted: 16 Oct 2011, 07:16
by Numb69
Well the problem is that the HDR is not mapped to a sphere, its directly plugged in the pass shader as environement..
I tried looking around and for now I stopped on the Linear Workflow and gamma thing, Im doing some test but its either black like now or way too washed, Im gonna read up more on the LWF for now
Meanwhile you can get my scene here ;)
http://hotfile.com/dl/132445836/6b44348 ... 1.scn.html

Re: Mustang 69 GT

Posted: 16 Oct 2011, 09:43
by Zafar Iqbal
Thanks - so much easier to see whats going on now.

First the LWF.

Locate Preferences->Display->Color Management
Make sure everything is enabled with the tickmark.
Set Profile Source to Gamma Values, and set the Gamma Values to 2.2

Now Locate Preferences->Rendering->Images
Set color Profile to Automatic.
Set Gamma to 2.2

That's it for all your future needs. XSI makes it very easy to work with LWF.

However, you already worked on a scene with wrong settings, so we need to change few more things:
Normally, accessing the properties for your background image and changing it's Gamma (Adjust tab) to Automatic or sRGB should do the trick. But it's as if the Cameramip node ignores this and instead overrides with its own Gamma setting (bug?!). I can only get the background image to look correct by changing the Gamma in the Cameramap node to 2.2 - make sure you do that for the ground as well.

Do a testrender - your background should look as before, but the car should now be brighter.

Now the HDRI setup:
You are using a Light Surface node. I don't know this node but can tell it wont work for you.
Grab the Environment node and plug the HDRI directly to it's tex port (you also wont need the HDRI's Image node).

You will be needing the HDRI for FG and reflections - this means we need to split them up so they can have different gammas. FG should be fed with a linear gamma, but you do not want "linear reflections" on your car. They will look wrong (washed out).

Duplicate the Enviroment node.
Grab a Ray Type Switch node.
Plug the first Env node to the FG port.
Plug the second on the remaining ports - Eyes port can be ignored since you have already have a background defined.
Access the Ray Switch PPG and change the last pulldown to "Use FG port for final gathering".

Plug the Ray Type Switch nodes Out port to Environment on the mip rayswitch environment.

Thats it.

You can control FG and reflection intensity of the HDRI inside the Environment node:
Background: Controls how bright the image is in your background. Since you already have a background this parameter wont have any effect.
Reflections: how much the image is visible in reflections.
Image: how much the image will affect FG.

0=black, 1=normal, 2=double exposure/intensity etc.

One last thing - I promise:
You need to enable "apply display gamma correction" under Passes. Otherwise you will get a bad surprise as the rendered frame will be in linear space. If you however save as EXR or other formats that truely support linear space, and your workflow after 3d revolves around linear space, then you can ignore this step (but instead apply 2.2 gamma in post).

I didn't have your images so I worked with some random pics I have on my computer.. this was the result :)
Image

Edit: Oh, one last thing. Make sure the HDRI is rotated so it matches with the background image. Do that in both of the Environment nodes).

Re: Mustang 69 GT

Posted: 16 Oct 2011, 19:35
by Numb69
WOW dude ure amazing!, you just filled in the missing gaps that I had and on top of that gave me a walkthrough haha thanx a lot man,really appreciate it!! :D
I followed your steps and now it starting to make sense, I guess I'll have to tweak a lot and do a good compositing

If I can annoy you one last time, I only have one more question:)
Lets say I'd rather add the gamma in PS and not burn it straight from XSI (have more flexibility)
Now last nite(before setting up the environement the way u showed me) I would render in linear,get very dark render and add in PS gamma to correct it,and it would look ok.
What happens now tho is this weird color (banding) happening as soon as I apply a 2.2 gamma in PS

Re: Mustang 69 GT

Posted: 16 Oct 2011, 20:59
by Zafar Iqbal
I felt it could be of more use to write instead of just sending you a corrected scene. I'm glad you found my post helpful.

I tried applying 2.2 gamma to the darker half of the image you just posted. I get different result than you, but it's as if the image is still too dark than how it should be. Did you apply any color correction in XSI?

Anyways, that's a smaller issue for now. I'd suggest you try again, but this time save the render as 16bit exr (half float) or tiff. You'll need to convert it back to 8bit again once you have your final render.

Re: Mustang 69 GT

Posted: 16 Oct 2011, 21:22
by Numb69
Yup, everything is set up for Linear Workflow.
I think the problem is with the colour, cuz since im in LWF,I try to make it look proper black colour (forgetting that It's supposed to be brighter/washed out, since it will be compensated in PS when I apply gamma correction 2.2), but the actual output will be in linear so the image will be even more darker, so when applying gamma it doest really work
That's ok, Im new to all this LWF, so I'll figure this out once Im get used to it :)

Re: Mustang 69 GT

Posted: 16 Oct 2011, 21:45
by Zafar Iqbal
True, can take some time to get adjusted to. I had been doing things the old way for more than a decade so it was hard to me to appreciate LWF in the beginning. It just kept looking wrong to me. But I stuck with it and now wouldn't go back at any cost. Unless a project deliberately requires an oldschool style for nostalgic reasons :D

The best thing, and the biggest argument for working with LWF is that everything is much more predictable than before. Once you start to get used to it you will notice lots f tasks such as lighting takes less time. but you will also notice you will be dealing with older color/property values than before because itøs now much easier to obtain details in renders.

Forinstance, I cheched the bodypaint on your car to see if you were having the problem because perhaps it was set to 0,0,0. But it was on 0,05, which is OK. however, I use 0,005 for blacks (not saying you SHOULD - just an example that some thing like this will change).