New Project - Porsche Carerra GT: New renders added

[Cris]

Realy cool man! Keep it up! 8o

[dilbert1]

Parked it by the harbor. I love HDRI's, but they can be a real pain to work with. First off, it's hard to find a good HDRI that isn't too over the top, and then once you've found one you like it's an even bigger pain to find the camera angle that looks best. The same HDRI can range from looking absolutely terrible to great in the course of a few degrees of camera movement. Any suggestions on getting good HDRI results would be welcome.

[XSImatrix]

Looks really grainy, but I think you only did that to speed up render times, btw what render are you using, vray handles hdri perfectly and I got a nice tut bookmarked.

[dilbert1]

Yeah, you're right about the graininess. I rendered at 640x480 and it just isn't high res enough to pic up the silver flake in the paint clearly enough, so it turns out looking grainy. Plus the conversion from a Maya iff image to a JPEG always sucks.

I'm using Mental Ray, and I'm just not experienced enough with it yet. I've seen some amazing renders with Maya and Mental Ray, so it's just my lack of skills. I'd love to see that tutorial though. I'm sure I could translate it to Mental Ray without too much trouble. They just came out with Renderman for Maya, which is boasted to be able to render to the quality of movies such as The Incredibles, but unfortunately its a little under $1000 so I won't be picking it up any time soon.

[XSImatrix]

vray>mental ray, i doubt you will be able too... cause vray uses its own hdri material/map.
And also maya sets up their environment diff.

Heres a Mental Ray Material and rendering Turorial for MAYA. (Thanks to SeiYuusha)

http://www.3dfuturebits.org/forum/viewtopic.php?t=134

Its really informative, and comes out with a good result. (No hdri, but its still good, for white plane reflections.)

Ill try to find a HDRI mental ray>MAYA tut later.

[dilbert1]

Thanks! I think Mental Ray has the same sort of function through it's HDRI light probe node, but I haven't messed with it yet. You basically plug a HDRI image into the node, and it sets up the environment automatically. Saves the applying an image to a sphere workflow. It has a whole bunch of parameters within that node to mess with, but I wouldn't even begin to know how to use them all.

That brings up a side point. I don't know if it's just Maya, but do you guys find that it's really hard to find a comprehensive user manual for your software? I mean, these 3d software programs are HUGE, and it seems like every day I find a new parameter, slider, or gizmo that can be adjusted. I love the internet for information, but sometimes I find it so much easier to actually have some written text in front of me. I guess that's how they get you to spend millions on additional learning books.

Anyway, gotta get back to modeling. I want to try to finish up the body today so I can start on the wheels. I found a bunch of nice detailed reference pics and I've already spotted a bunch of mistakes that need fixing* :x. Oh well, there's no time limit on this, so I want to try to be accurate.

By the way, check out www.hdri3d.com . It's the website for a magazine we have here in the U.S.A devoted to HDRI image rendering. I would recommend this magazine to anyone. There's a huge amount of good information, and each issue has a tutorial for each of the major software programs, so it's not software specific.

[jumpman]

pretty HDRI, is it free?

[dilbert1]

Here's a couple more HDRI's using Maya's image based lighting node as apposed to a mapped sphere. I think it works a little better and has more flexibility. The first pic is with a car paint shader, but is too reflective. The next 2 are with geometry updates behind the seats, but I forgot to apply the paint shader* :x, at least the reflectivity is a little better.

Jumpman, yes it's a free HDRI but I can't find the website I got it from. Do a search for free HDRI images, and eventually you'll come across it. It comes in a free batch of 5 or 6 HDRI's with a couple pics from Paris, one of a living room, the harbor, and a couple more. Hope you find it.

[XSImatrix]

I think you need to work on the carpaint shader, so that it looks better in smaller res renders Cause it ruins the image.

[dilbert1]

Agreed XSI, this shader is a little better I think. Almost got the basic shape done. Got to finish the air intakes, engine grill, and headlights, and then finally the wheels. Gonna do the interior on this one also.

[XSImatrix]

looks clean, i ordered a tamiya kit from my local hobby shop, hopefully dey get it in stock soon, its been a week so far. This topic makes me want it more and more.

[dilbert1]

After looking at the same model for hours you need another set of eyes for critiques. I added the air intakes and grill above the engine. Also fixed the spoiler and worked on the headlights a little. I think I'm about ready to start on the wheels, but if there's any major mistakes that you guys see, please let me know now. I know I'm missing the rear round lights, and the indicators at the front, and a couple of small details like the silver knob in front of the headlights, but other than that I think the basic shape is pretty good. Anyway, let me know please.

[XSImatrix]

um nice glass 100% reflective hehe, um well......... I have nothing to crit, but just say GREATJOB.

One question, did you do transparency mask on the engine grill? if not what did you use?

[dilbert1]

Yeah, sorry about the glass, there's always something I forget before rendering. :x

For the grill I did a Mental Ray displacement map (so it actually has some thickness), with the out alpha of the image projection node plugged into the material transparency. That way the displacement map serves as it's own transparency. Whip up a quick black and white grill pattern in photoshop, and voila you have a grill that follows the contours of the glass cover. Usually I prefer to use actual geometry, but I initially tried that and quickly realized that putting together thousands of hexagons that conform perfectly to the shape would be a nightmare. Also, as long as you use high enough settings on the displacement map, the results are just as smooth.

[mpfive]

sweet model.. tell me please, wut do u use to render with? if vray.. can u tell me how u do ur glass material plz??

[dilbert1]

I'm using Mental Ray, so I don't know if it'll translate. In general though, try a black material, turn your diffuse to zero, refractive index to around 1.56, ramp the reflectivity like you would car paint so it is more reflective at oblique angles, and turn the transparency to whatever looks good to you. Also, I make my glass 'thick' i.e. the glass geometry has 2 planes for the light rays to pass through.

Question. You guys prefer to make your tires from a displacement map, or actually make the geometry? I've seen both look good, and both have their downfalls. Displacement maps take ages to render, but seconds to make. Detailed geometry takes up thousands of polys, and causes a huge system slow down (at least with my machine).

[Night Fire]

I think your actual lights inside the headlights are to big (both of them). They look like the right shape, just need to be scaled down a bit.

You seem to have nailed most of the other parts quite well, I also modelled the same car, and as you are well aware, it was a dog to model, so many odd shapes and bits and pieces. Just wait to you have a crack at the interior.. Now that is a mission!

[dilbert1]

A few updates. Added the rear light geometry (it took about 3 hours to weld together all those half spheres, and it's still not finished), and finished the smaller round lights next to the exhaust. Also modeled the side mirrors, but didn't get round to the actual mirror yet.

Agreed Night Fire, the interior's gonna be a long task. Gotta do the wheels before I get to that though.

[dilbert1]

Finished the wheels. Haven't worked on textures for them yet, but I'm happy with the modeling. I'll maybe do a little more chamfering around the little spoke thingies, just to get then a little sharper, but other than that I just need to add the Porsche logo to the center.

[mpfive]

wow, very nice, i got a video i took of a spining carerra gt in the autoshow, if u want, i can send u.. it might help