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View Full Version : I need advice/tips for modelling the back of a (volkswagen beetle)car.



bluemars
04-06-2007, 11:44 PM
Hi , can you guys please give me some advice or pointers on how to model the back bumper of a car? i have spent an insane amount of time on it but still couldn't get it to look right, and is really stressing me out,

I'm finding the slight bump of the curve on the surface is really difficult,i have tried alot of methods but still doesn't work, what i'm finding hard to model is the tip of the curve, i took a snap shot to show you of what i meant, please have a look ( http://img365.imageshack.us/my.php?image=bumperhb2.jpg )

please help me out! thanks in advance!

SplineGod
04-07-2007, 12:26 AM
I would go with splines.Its fairly easy to layout a cage that has the proper form and flow. Once you patch the cage you can multishift in the correct areas.

bluemars
04-07-2007, 12:57 AM
i dave tried darw spline, but it's not working for me! any other ways?

bluemars
04-07-2007, 01:43 AM
srry for the spelling error, but i have tried spline draw, but it's not working for me,

SplineGod
04-07-2007, 05:14 AM
Heres a quick example of what I mean. This is created with a simple spline cage. I didnt use spline draw.

bluemars
04-07-2007, 08:03 AM
OMG, splinegod that look so good, that's what i'm trying to achieve, thanks so much, but i have a question, the centre line have 5 ppoints connecting to it and yet u can sub-patch it? in my previous attempts when i got a polygon with more than 5 points it won't convert to subpatch for some reason, how come it works for your one?

Andyjaggy
04-07-2007, 08:55 AM
I love splines. So yummy.

SplineGod
04-07-2007, 12:42 PM
Once I patch the splines I merge the geometry (point merge) then turn on SubDs. From there I multishift in the panels and cut in more edges using bandsaw. Then you can use spinquads to tweak the flow around some problem areas. I also do some tweaking on a few points to remove an dents or divots in the surface of the mesh. Every patch on my spline cage is 4 sided so I only get quad polys. :)

bluemars
04-07-2007, 10:43 PM
Hey splinegod, i tried your method but the spline cage is so diffcult to control, no matter how hard i try i an't seem to get it into that shape, does anyone know any other easier method cause spline cage seems too advance for me to grasp, thanks!

Surrealist.
04-08-2007, 02:23 AM
Spline patching does take a little getting used to. It is pretty simple though. One thing is that it matters which order you select the splines as to how it is patched.

But in general regardless of how you do it, it is a good idea to understand the polyflow of what you need.

If you look at the shape, a very simple polyflow is required. I just put this together by had with the add edges tool to illustrate the concept. You have two arches inside of one arch. The outer edge loop - blue - defines the shape. The inner two edge loops - green- will give you the control on that specific relief on the hood. From here you can simply mold it into shape and add more sparpness control with bandsaw where needed. I try and keep the 5 poly point away from my edited edge. I try an lay that out on a part of the model that is going to be relatively flat and or not require much editing. Sometimes I try and keep a buffer of one loop between the 5 point poly and your edited edge. That being the edge or edges that define the relief.

To mold it I started out with the spline guide tool to create the bend and then using the drag net tool - you can adjust the size of the influence with a right click to get the blue circle - to simply pull the sides down and flush out the overall shape.

The thing about spline patching is that it gives you great control over the precise position of your panels. Great for car modeling. But as soon as you need to add relief or other detail you should understand your poly flow. You can then simply draw it with the add edges tool and merge polys and so on until you have your flow. Or you can use spinquad as mentioned or both.

Surrealist.
04-08-2007, 10:57 PM
Some Alternate geometry. I moved the 5 poly point and added a line took one away to solve the problem of that 5 poly point causing a bump.

Note that I am not even trying to make it look like a bug hood yet. I am just exploring the geometry to give you ideas.

Concept is simple.

Wherever there is an edge loop it either has to connect to another loop or a grid mesh. In this location there will be a 5 poly point. However, you can control where that falls by adding lines and rearranging things. The goal is to get the pesky 5 poly pointer away from a part of the mesh where it is causing problems. Don't waste your time pushing and pulling it. Just move it.

The more geometry you add the more options you have and this is the main difference between a low and high poly mesh. You have to weigh out control over density and come up with a balance that gives you the smoothness you need that is not too dense.

Note also, if you study it closely, I did not just drag the 5 poly point I actually rearranged where it falls on the mesh. And if you refer to that other post where I talked about subpach these ideas will make good sense.

Surrealist.
04-08-2007, 11:02 PM
And finally, I keep forgetting to plug Larry's site. He has lots of great stuff and a lot of it is free. Some very good videos where you will learn much about modeling. I know I did. :)