ciappo Posted August 15, 2006 Share Posted August 15, 2006 Hi everybody, maybe another Cg car is less needed than a teapot, but I did this one to get used to the Houdini interface,(I'm another Ray's fellows in Vancouver), and trying to understand the basics way of thinking of it, and I had a real great time. Now I'm at the shading /lighting part, and I'm trying to build my own materials for it. I'm having a great time with Vex too, even though sometimes things just happen, and I understand them some hours later. Some wires, an occlusion test, and a test of integration in the last picture. I really need some hints, I'm not using global illumination, my material has the possibility to have the occlusion .. so far I'm using some hdr from Debevec website as environment maps. Thanks to everybody. Quote Link to comment Share on other sites More sharing options...
stu Posted August 15, 2006 Share Posted August 15, 2006 ...maybe another Cg car is less needed than a teapot... Looks great - any chance of seeing it in a colour other than grey (red? yellow?) so that we can more clearly make out the behaviour of the shader? Nice work! stu Quote Link to comment Share on other sites More sharing options...
Overload Posted August 15, 2006 Share Posted August 15, 2006 Yea that looks great so far... Ray really seems to be doing a great job for you guys up in Vancouver. Some other colors would be great as stu said... maybe even a few close up renders. Great work!! Anthony Quote Link to comment Share on other sites More sharing options...
Val Posted August 15, 2006 Share Posted August 15, 2006 looks good . just glass needs litle more work --- Val Quote Link to comment Share on other sites More sharing options...
ciappo Posted August 15, 2006 Author Share Posted August 15, 2006 Hey guys, thanks for the feedback, here is the car with a red color, so as Stu suggest you can judge better the shader. Unfortunately tomorrow is the last day that i can work on it I will start working on that again in one week... Val, you're absolutely right about the glass, i'm going to model some interior so i can have them more transparent, that maybe is going to help a little.. Here's the image. See you. Quote Link to comment Share on other sites More sharing options...
zoki Posted August 16, 2006 Share Posted August 16, 2006 looks awesome ! How is your light setup or are you currently busy just with shading? Usualy for cars is good to add huge white lighting cards above and on sides to get those nice polished car magazine renders this ofcourse doesnt apply if you want ot composite it into live scene! check this guy out if you dont know him already he is professional car modeler: http://www.suurland.com/ regards Zoran Quote Link to comment Share on other sites More sharing options...
LEO-oo- Posted August 16, 2006 Share Posted August 16, 2006 Good job! Some interior is a good idea. I hope to see more! Quote Link to comment Share on other sites More sharing options...
Jason Posted August 16, 2006 Share Posted August 16, 2006 Hey pietro; I think this biggest thing we're missing here are reference pictures of exactly what type of paint you are trying to match. Car paints do vary in look quite a bit and it'd invaluable to be able to see what exactly you're aiming. Take advantage of the fact that you are not materialling a fantasy object: there are a ton of images out there of cars in the a similar lighting environment. Pick one car, hopefully with a few pictures at differing distances and angles. From your images it's actually pretty hard to tell if you're attempting a matte or a metallic paint. If you read about how metallic or matte paints are made, there are some hints on how to create a shader for them. There are also sketches and papers out there to help. For instance, a metallic paint will often have two speculars; one for the metal flakes in the paint and one for the clear laquer over the substrate. Depending on the range to the care, you might have to emulate the speckles of the flecks of the metallic paint suspended in the substrate. I find that it's useful to roll off the base metal color based on viewing angle too (i.e. a ColorMix VOP with an Edge FallOff as the driver) and make the colour darker at the horizon to give it a kind of retro-reflective feel. Quote Link to comment Share on other sites More sharing options...
ciappo Posted August 16, 2006 Author Share Posted August 16, 2006 Hey guys, thanks all for your suggestions... Were I want to put this car is a big deal.. in the beginning I was thinking about comp in live footage, using the defaults materials of Houdini, but then I started using the Vex and now I'm trying to reach a nice look whit my material. Actually now I'm thinking more about the shader than the car.. Because I'm trying to build a "general material" were you can have lot of solutions in the same shader..maybe is not so useful but I'm doing it mostly to improve my Vex understanding So I'm improving my shader step by step, as I see the lack in the render or in the controls. For that reason, Jason, I would be very happy if you have some links about metallic shader creation. Here is an other image created with my shader, that allow the user also to control the opacity of the object by the lights in the scene and to mix that whit the normal opacity or not. I used the L variable for that. here is also my shader so far, so maybe you can have a look at that if you want to..now i want to start adding the two specular as Jason suggested. Hey Zoran, thanks very much for the hint on lighting and the website, I want to do also a render like magazine cover too!! pietro_shader.tar.gz Quote Link to comment Share on other sites More sharing options...
Jason Posted August 16, 2006 Share Posted August 16, 2006 There are plenty of resources out there you can find with a simple Google search, including: http://www.bhsunshine.com/shaders/interfere.html Quote Link to comment Share on other sites More sharing options...
ciappo Posted August 16, 2006 Author Share Posted August 16, 2006 There are plenty of resources out there you can find with a simple Google search, including: http://www.bhsunshine.com/shaders/interfere.html Thank you very much Jason. I asked just because I'm totally new to this kind of stuff, and I thought you knew something specific regarding Houdini. Quote Link to comment Share on other sites More sharing options...
Jason Posted August 16, 2006 Share Posted August 16, 2006 Thank you very much Jason.I asked just because I'm totally new to this kind of stuff, and I thought you knew something specific regarding Houdini. Oh, I don't have any Houdini-specific tricks for this:) This is all general shading theory which, very fortunately, Mantra does conform to very closely. Quote Link to comment Share on other sites More sharing options...
ciappo Posted August 16, 2006 Author Share Posted August 16, 2006 Ok, don't worry I know that I have to put myself on those generic stuff to understand better what is happening in the VOPs... And I will !! Actually as you said looking for "Shader Writing" on Google gave me more than I can handle Quote Link to comment Share on other sites More sharing options...
peterr Posted August 16, 2006 Share Posted August 16, 2006 It's lovely and I would concur with the lighting, particularly using large cards to spread the light some. If you compare with the car in the background you'll notice the highlights aren't as sharp. The one new thing I'm might suggest starts with a quetion. What are your camera settings. Your car doesn't quite sit in the scene and I'm thinking the camera could be tweaked some to shape the car better to match the camera that took the original picture. You don't happen to have the camera settings for that do you? Hi everybody,maybe another Cg car is less needed than a teapot, but I did this one to get used to the Houdini interface,(I'm another Ray's fellows in Vancouver), and trying to understand the basics way of thinking of it, and I had a real great time. Now I'm at the shading /lighting part, and I'm trying to build my own materials for it. I'm having a great time with Vex too, even though sometimes things just happen, and I understand them some hours later. Some wires, an occlusion test, and a test of integration in the last picture. I really need some hints, I'm not using global illumination, my material has the possibility to have the occlusion .. so far I'm using some hdr from Debevec website as environment maps. Thanks to everybody. Quote Link to comment Share on other sites More sharing options...
ciappo Posted August 17, 2006 Author Share Posted August 17, 2006 The one new thing I'm might suggest starts with a quetion. What are your camera settings. Your car doesn't quite sit in the scene and I'm thinking the camera could be tweaked some to shape the car better to match the camera that took the original picture. You don't happen to have the camera settings for that do you? Hey Man, you're right!!!! I was thinking so much about all the other stuff...I'm dumb. Okay, I can get the parameters from Photoshop, but if I use the same focal lenght, my car is very squeezed. the focal lenght is 24 from the camera (nikon N70) but maybe there is a conversion to do ? ? Quote Link to comment Share on other sites More sharing options...
Rafal123 Posted August 18, 2006 Share Posted August 18, 2006 hey pietro, nice renders, I like it but... I think it's a little bit too dark Quote Link to comment Share on other sites More sharing options...
peterr Posted August 18, 2006 Share Posted August 18, 2006 Ah, don't sweat using the specific lens settings. They could be useful as a reference, but really your just after getting it to look right, so cheat It might be impossible to sort out the exact conversion. The N70 is a nice camera but it's not really a professional camera so there are going to be all sorts of little inconsistencies that will factor into the image distortion. -The lens may not be sitting quite right on the camera body. - What lens are you using? Is it a nikor or 3rd party? Are the lens glass or plastic? All of them? - What year was the lens made? Where? The same model of lens, even of the same year, could be made in several different factories. - What f stop? These are just a few of the factors you need to consider when dealing with a professional film camera. Hey Man, you're right!!!!I was thinking so much about all the other stuff...I'm dumb. Okay, I can get the parameters from Photoshop, but if I use the same focal lenght, my car is very squeezed. the focal lenght is 24 from the camera (nikon N70) but maybe there is a conversion to do ? ? Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.