Mechanical Curves

[yardie]

Hi. I don't have problem with making faces or other object. When it came to making a car model I thought that would be dead easy as I have all my rotoscopes matching evenly. But when I get to Extruding Splines ( example the car wind screen) I find I cant get the splines that make up the part to spread or curve evenly.

I cant post a WIP as I keep deleting and starting all over. Some were they has to be an example of a curved object made from a Rotoscope showing what to do as one extrudes from on edge to another. Most of the WIP on car modeling have models that are complete.

I am sure that I am missing out something very subtle. After all I figured out how to get all the Rotoscopes for a blue print to the same scale.

I tried changing some of the CP's bais but that made the part more of a mess

[luckbat]

Could you post a screenshot of the problem? That might help us diagnose it...

[yardie]

Could you post a screenshot of the problem? That might help us diagnose it...

 

Here are the screenshots. I hope there are self explanatory.

 

 

 

 

 

 

 

 

 

 

 

 

 

As you can see trying to make the splines fit only causing distortion

audi_tt.zip

[digithor]

Perhaps you can model the windshield separately from the rest of the car. Model only the nessary amount of splines to ensure the smoothest possible curve for any given shape, then subdivide (stitch) additional splines as needed for more control or just play with the bias magitude for each spline to get the curve you want.

 

Technically, the windows and various portions of the car bodywork are not one molded piece. Work from that point of view and the curves should be easier to keep very smooth.

[robcat2075]

My first impression is that you don't need nearly that many splines running up and down to define the shape of that windshield. A broad curve like that needs only a few.

 

 

Very quick example, based on your rotoscope. With adjustment it could be made perfect and the black parts deleted.

 

The windshield doesn't need to have rounded corners since the roof and side pillars will overlap its edges

windshield.zip

[Stuart Rogers]

But when I get to Extruding Splines ( example the car wind screen) I find I cant get the splines that make up the part to spread or curve evenly.

I wouldn't use extrusion for the windscreen...

 

I would lay down a spline that outlines the windscreen, concentrating along the top and bottom edges (as the greater curvature is across the windscreen). You shouldn't need many CPs. Make sure it lines up with the rotoscopes from all sides. Then add splines running from the top spline to the bottom spline. Add a CP halfway down each of these new 'vertical' splines, and connect them with a new 'horizontal' spline. Now adjust the CPs along this last spline to get the curvature you need - the magnet tool might be useful here. If necessary, add an extra 'horizontal' spline, but I don't think you'll need it.

 

In this situation it might be best to try doing it with as few CPs as you can, adding CPs only when you really can't get the curvature you need, so some trial-and-error is inevitable. Don't expect to get your curves to ever exactly match the rotoscopes.

 

For the windscreen, I suspect bias tweaking is unnecessary, except perhaps in the corners.

[yardie]

Thanks Robcat and Stuart for the quick replys. I will give both your methods a try

 

Oh dear looks like your on Am V13. sorry but your model wount open in my Am V12

[robcat2075]

 

Oh dear looks like your on Am V13.

yeah, sorry.

 

pic

 

[attachmentid=20952]

 

the fewer splines you use, the smoother it will be.

[John Bigboote]

You could also try 'distortion mode' instead of the traditional methods.