Panoz AIV Roadster Rendering Help

[Tahl'eN]

Looks nice. Wires would be good to see, too.
Even for showroom shine, it's a bit too reflective. The chrome's hard to look at because it's so blown out. The inside of the car should have more than one material on it, and it should be significantly less reflective. Keep in mind that leather usually has an almost scaley bump to it that seriously breaks up any kind of specularity.
To make the inside of the car brighter, I would suggest you cheat a little and place a low-intensity light inside the footwells. Also, the drink holders seem a little too small, and not nearly round enough.
The window glass is also too reflective, and needs to refract the inside of the car. Without it, it looks like a sheet of celophane across the frame of the windshield.
Finally, I'm uncertain what the black material on the front of the rear wheelwells is. If it's similar to the metal/fiberglass of the car body, it needs to match specularity with the body of the car. If it's something else, make that more clear, too.

[katon]

Thanks Tahl'eN for the feedback.
I am going to go back a look at the shaders agin that you mentioned and add some new ones as well. I agree that the car is still to shiny so i will tone that down. Also the wheels chrome is way to bright, i will check that out too. I am going to add a light in the foot wells and hopefully that will help.
As for the rear wheelwells in my refernce they are not reflective hardly at all, It is for sure not fiberglass or anything like the car and the shinyness on it is nothing like the car. i will have to work on it more, maybe i can post of a pic of the actual car so people knwo what it looks like. Thanks for all the sugestions, i have alot to work on and will post some updates here later today. Also i will get some wires up.
My problem is though i am not sure what settings to change in the shader to make it look how i want, so i have alot of experimenting ahead of me. Thanks alot, and I will be back soon. Peace

Katon

[Tahl'eN]

I was curious about the black part, so I dug up some pics of this car. Looks like that part is rubber, which means you should add some blue to the spec color and a little red/purple to the main color.

I think the reason the chrome is so blown out is that the color is too white. Reflective materials get most of their color from what they're reflecting.

[katon]

Sweet, thanks for the input on the rubber parts. I willl have to try it out. I am right now trying to get a decent seat material along with the rest of the inside. So would leathers spec be any certain type fo color, if any at all. Thanks alot

Katon

I will update with some shots here soon

[Tahl'eN]

Depends on the leather, honestly. Study the pic you're working from. And if you can't figure it out, post it and I'll give it a look.

[katon]

OK I tried fixing some things and making them better. Some of the metal is still a little to reflective. I put an ambiant light inside the car to try and light the dark areas some, but now it looks to flat, i dont know why but it does. I also tried a diferent color for the interior. Do you think the balc would look better or no. Also i was thinking it might be harder to see all the stuff on the inside if it is black, so that is another reason i am trying a new color. I am liking the reer wheelcovers better now the rubber part that is. The blacks on the indies of the car seem so flat, and i tried changing some things but i seemed to not be able to figure it quit out yet. Well what do you think now.

All crit is more than welcome, please help. Thanks

Katon

[Tahl'eN]

With the car blue, I rather like the cream and brown interior.
Never, ever use ambient light. It will always flatten the image out. Use a low-intensity point light instead.
Make the chrome's color black. It'll help.
Make the rubber darker. Or at least the dark areas of the rubber.
Never compress your jpegs below 70%. It's too hard to see details with all that artifacting.

[katon]

Alright here is a small update. The interior render i acidentaly forgot to smooth it prior to rendering it out. O well. I am having problems getting the buttons and swithes and stuff on the inside to have any depth to them, I have tried some setting changes and i seem to not be able to get it looking right. I am begining to be more happy with the chrome, i like how it is starting to look. The rear wheel well is now to dark, so i lightened it up a bit and tried changeinm the eccentricity and specular fall off, and i am not getting the look i want yet. but i do think the point light helped out alot more than the area light, thanks for the tip. Anyways, any sugestions.

Katon

[kweechy]

Download Horvatths blurred reflection utility from Highend 3D. That's the only way to render leather, I'm telling you. Once you have it downloaded and setup and everything, just make a glossy black phong shader and blur the reflections to around 40 - 50 degrees, you'll have picture perfect leather. I don't have examples of leather in particular, but, check out this bar of soap that I did for a magazine advertisement, it's a purely FG lit scene from Maya 5 using MR. The soap is blurred to around 70 degrees, so a little less would give it a blue leather kind of feel, esp if I set the diffuse value to be lower. The metal soap dish also has blurry reflections from Horvatth's utility, this thing is a must have for any Maya user, it's truly awesome to use for realistic scenes with FG lighting. Anyway, here's the soap, check it out:

http://www.pulpandfiber.com/lorne/Fresh%20Inside%20Final.jpg

Here's an example where I use the blurred reflections to get a great metal material for the wheels of my Westley Panther retro car design, all of the metal surfaces in this render has slightly blurred reflections for true realism.

http://www.pulpandfiber.com/lorne/Sample%20work/Panther_Red_3.jpg

Anyway, so go download that utility from www.highend3D.com and try it out, it's really really great.

Oh yay!!! Spymac didn't delete my gallery, here's an actual example of me using the shader to make a leather sofa. You can see how much potential the results could have. http://www.spymac.com/gallery/show_photo.php?picid=52356&size=big

[katon]

Hey kweechy,
thanks for the info, I have installed and tryign to figure otu that utility. I read the usage faq on it and i am not seeing any diference yet. I have hooked it up to the reflection channel fo my shader and set the blur to like 45, and rendered it with and with out it and it looks the same. I dont know what I am doing. Also i did set the reflective value to 0 in raytrace options. Anyways i will cont working on that. Also would oyu mid helping me get that nice chrome look you have, i cant seem to figure it out. And what HDR image are you using it loks very nice. Anyways talk to you later
Katon

[kweechy]

Oh okay, well you don't want to be setting the reflective value to zero, you want to set the reflection rays to 0 in the raytrace option on the shaders, maybe that's wat you meant and I jsut missed it or something. The HDRI image is from the very very fine cd sold by www.hdrimaps.com I mean, wow, if you have 60 bucks lying around, do it, seriously, pure gold. Try out the two demo images on their site, I guarantee you'll be impresses, I should also say I'm not affiliated with them haha, just very happy with my 55 images. If by the chrome look you are refferring to the soap dish in the top image, I did my lighting with big polygon planes (which I convert to Sub-D for smooth corners) so that's what gives the soap image a nice studio lit look and makes it easy to carry brand identity throughout all the ads I'll do for them in future.

Yeah, so, maybe I'll just run through how I use the utility to make sure you get all the steps. Okay, I'll make a phong or something, attach the utility to the reflected color attribute of the shader, then I set the utility options to whatever I need. Another CRUCIAL CRUCIAL thing for making ANY material, is the use of sampler info nodes connected the the V coordinates of ramps which you attach to certain attributes. Let me elaborate cause that was a mouth full. Basically, make your shader, whether or not you use the utility doesnt matter. On an opaque shader, you'll want a ramp connected to the diffuse, and the reflectivity attributes. so go ahead and connect a ramp to each one of them, just make a nice smooth 2 color ramp. then, in hypershader, graph the network of this new shader, go to create, general, sampler info and connect the "Facing Ratio" attribute of the sampler info to the V coordinate of each ramp. Basically, this means that as the surface curves away from the camera, it becomes more reflective and then use diffuse to add more depth to the effect as well by making it darker as it veers away. In your ramps that you use for this, go from dark at the top, to light at the bottom, not vice versa or the effect will be backwards. I have the ramp and sampler infos attached to every single material in the car scene and the soap scene and it really pays off. On a transperant shader, you want to not only map the ramp and facing ratio to diffuse and reflectivity, but also transperancy so it becomes more opaque around the edges.

Anyway, holy jesus I made a long post here, I'll cut off now. I'm not sure if you knew the facing raiton thing or not, but just for anyone checking out the thread, it's a good FYI for achieving photo real renders.

[katon]

Holy crap man, that is alot to take in.

Thank you for being specific though this will relay help out alot. I will have ot run through all that later tomorow, so I will get back to you with an update and what not. Thanks alot for the help and I will start testing this stuff as soon as i can. Thanks

Katon

Edit:Thanks for the link, those hdri images look very cool, i might just have to pick that up.

[kweechy]

Gimme a minute, I'll post up a comparision between two spheres, one with facing rations attached, the other without, you'll be amazed at how simple it is to do and how important it is for true realism.

[kweechy]

Okay, I think this is a great demonstration. The effect is GREATLY exaggerated in this sample, used a ramp going from 0 to 100% reflectivity when normally I'd use like 30 to 80 or something, same with diffuse, goes from white to black, but it's great to see the difference and how much more real the facing ratio makes renders.

http://www.pulpandfiber.com/lorne/Sample%20work/Facing%20Ratio.jpg

Note, these are the exact same shader, just the one on the left has ramps attached to the two attributes, the shader on the left has jsut a solid color instead.

[kweechy]

Actually, with my massively exaggerated ramps, it almost exhibits sub surface scattering qualities, I kind of like it :) If you want me to send you the quickie shader for the red material just let me know.

[katon]

Hey kweechy,

You realy can see a diference that is awesome. I would love to see the shader you made, if you dont mind sending it. This way I could see how you set it up, and know i am looking at a good material and learn from it. Thanks for all your help. Hit me up with a pm, or email me. Peace

Katon

[kweechy]

Yeah, here's the red shader used on the left side material. It has a reflection utlity on it as well, I just have reflection rays turned to 1 instead of 0 so it's not active right now. You can just break the connection to it if you want. Anyway, here's the link:

Facing Ratio Shader (http://www.pulpandfiber.com/lorne/Shaders/Red%20Shader.mb)

[katon]

Thanks kweechy for the sahder, i am goign to start messing abotu with it tonight. Talk to you soon. Peace

Katon

[katon]

Kweechy quick question, In the shader you gave me, the ramp you have connected to the difuse is going from light to dark, and the reflectivity is dark to light. You sated that they need to go from dark to light in one of your last post, should the difuse be dark to light or light to dark. Also i was wondering, is the V cord corespoinding to the uv cordinates of your model, so does that mean i have to have clean uvs or not. just curios thats all. but thanks alot for the shader understand now what you are saying it realy helped out alot. Thanks man.

Katon

[kweechy]

Yeah sorry, forgot to say that part, basically, the top of the shader is the value for when the camera is perpendicular to the surface, the color at the bottom is when the camera is parallel, so, for reflectivity, you want it to be more reflective at the glancing angles (which is the brighter colors for the reflectivity value) which diffuse you want to go down at the edges (which is a darker color) just keep in mind how the attribute works when making your ramps, I made a mistake when making this one at first too and had the diffuse reversed, I only realised my mistake when I saw the render. Anyway, try rendering your car with this new technique I showed ya and post up pics, I'm pretty sure you'll already be on the road to more realistic images and renders. Have fun playing!

[katon]

Alight here is an update. Kweechy these shaders realy helped i ended up compile all of them and now i understand you tecnique, thanks so much for the insite and help. but now what do you guys think. I am definently likeing the car shader better, what could be weaked on it. The metal I am still not happy wiht, the weheels just seem not very metal like and kind of flat still. I do like the head lights though, the metal seemed to come out nice on it, and i am asumming it is cause it has more things to reflect. Also the trim around the window, something is nto right about it, it shoulde tbe so reflective, but since it is balck it is hard to get the depth in it i want.I am mainly just having a hard time with the black areas, especialy on the inside, everything just runs together that si black and just looks like it si nothint there. Anyways i hope it is getting better. Thanks guys, and please keep the crit coming.

Katon

[kweechy]

When I make a shader for my wheels, it's basically as reflective as a pure chrome shader would be (like around .8 reflectivity on a close to black shader) then I just blur the reflections to around 20 degrees, that'll give you a nice wheel shader right away, if you map a ramp and facing ratio to the reflectivity it'll look even better.

[katon]

Hey Kweechy,

I have fooling around with my shaders, and i think my problem on my chrome wheels is my hdri maps arent that good, i dont think i am getting the lighting i need. It just seems the lighting get wek as it aproahces the ground and there isnt as much or somehting, and that of course is where my whells are located. I downloaded the free building one off that website you sent me and it is cool, excpet for half of it is realy dark and the other side looks good, and i dont know how to get a more even daylight look. So i think i need to find some better hdri images. Do you know of any website or anything i could get some good ones from cause i think i am goign to buy that cd you recomended but i have to wait for it, so in the meantime i need some better ones. Or maybe i am setting the scenes up wrong. If you have a sec, can you check out the one i am tlkaing about, it is the free one with the sky scrapers on it from that web site. It just doest seem to work to well. Also i have the ones off of paul devebec sites and they work alright.

Also, i looked at your car render, i liek the blur effect you have on the floor in the background, did oyu do that in post or was it rendered like that? peace dude

Katon

[kweechy]

My floor is actually a bowl with a gradient mapped to it, basically, set up the floor plane like usual, just a poly plane with one face, then, i extrude that face, only offset it a bit inwards so that the bowl has a flat floor, then, grab the outer edge of the plane, extrude them upwards and smooth smooth smooth basically. The just give the whole thing a planar mapping and put on a gradient for the color. Make sure the top of the bowl is pure black and make sure to turn off 'primary visibility' on your HDRI sphere too.

About the HDRI map, yes, the one half is actually pretty dark, I try to render from the other side if possible. My car has no post work other than blurring out some shadow aftifacts slightly, even with 6000 FG rays you still get minor spots. For my production art for magazines and thing I like to render with 20,000 - 30,000 FG rays, but these I'd rather just have now and just blur a bit in Photoshop. I don't even do color adjustment, my images are typically just straight from MR.

Some of the other HDR images from the cd are better with more even lighting and less dark spots, I jsut like this one because it's got that city feel and give my car model more realism. If this were a model car I'd go with one of the images taken on a kitchen table or something. That's another great part about the cd, nice range of scale to communicate anything from salt shaker to jet airplane scale, that's a real plus.

Happy rendering!

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