Thanks for your reply SteveMacc, most of the surfaces will marry up, but the naked edges are not what the problem is, or I assume not - All of the surfaces need to have a fillet or blend applied first, and then they would be joined up after that process. If I join tem up now, the fillet wont work as the surfaces are joined - pop them apart again and it will work. If there was an Isocurv extraction facility then it would be as easy as trimming and then either blending or doing a 3 point arc and a twin rail sweep.
Hi Martin, you can fillet 2 separate unjoined surfaces but when you do that it performs a surface-surface fillet operation which is a little bit different than an edge-based fillet which is more usually used and which requires things to be joined.
Surface-surface fillets can indeed construct fillet surfaces in some kinds of difficult situations where the edge based one can fail, but one reason why is that unlike the edge-based one it does not try to construct corner patches where multiple fillets are coming together. So if you do surface-surface filleting you will usually have to do a lot of more low level trimming and manual construction of juncture areas.
re: Isoparm extraction, that is on my list of stuff to add, for the time being if you need isoparm extraction you would need to use Rhino in combination with MoI to do that particular operation though.
Here's another problem if you try to blend with G2 continuity, which you need for cars:
This is a problem related to the other thread discussing patches with continuity. In order to get curvature continuity at the edge, the actual surface created is wobbly. In order to avoid this you need the edges to be exactly aligned, then cut back by some distance on each side. If one edge is on or above the virtual intersection of the surfaces, you will get a wobble.
I have built a car model in direct Solidworks (although most of the ones I have done have been done using sub-D poygon methods). The approach used was to build a spline cage covering the whole side of the car, then creating one large surface. Details like the wheel arches, etc, were cut out afterwards. You can break down a car in to 4 or 5 main surfaces, that are then detailed afterwards.
Here are some renders of the Camaro I did in Solidworks:
There were some really tricky surfacing issues involved in the detail, which I don't think MoI could handle with the current toolset. This model took far longer to produce in Nurbs than it would have done in Sub-D. As it is a conceptual exercise and not engineering detail, nothing was gained by doing it in SW.
Yeah, MoI could do that, but these particular curves would have to be re-worked a bit. Here is a video that shows what Steve was talking about with regard to the joined surfaces. Fixing those, would allow a fillet in alot of those areas. In the last part of the video, i also show where, when you have an edge/angle that disappears or creates an issue for the filleter, you can trim the surfaces back and use the blend tool to fill in the gap. If you needed to do this, then this would need to be a "pre-thought" modeling method, because it would require you to have your surfaces extended "past the boundries" where you have defined the junctures, then trim them back. It wont work going to "Just the boundry", like you see in the video. This is Michaels explanation that the surfaces need to be created "larger", then trimmed.
If you need an example of what that looks like, i can present one here. You excluded the surfaces that had the more complex junctions from this model..
Michael - Thanks for the advice, it certainly explains why i was having problems doing the fillets and blends, will have to wait and see how it goes with this one. All of the patch's down the left side now marry up, that was fun killing curves and stealing edges - but at least it now forms on big mass. One thing for sure though Michael, after reverting back to Rhino to try some things, your interface was sorely missed and i soon became miffed with Rhino, MoI's surface construction is much cleaner too!
SteveMacc - Nice work with solid works, I tried it on a 30 day download but it was way to cumbersome for my delicate grey matter. However i have followed your advice and made all patch's unite. The enclosed 3DM now has the image guides embedded so feel free to have a play at smoothing the seams provided or creating your own from the prints.
Same applies to anyone, just be kind and show me how you would do it in MoI.
Hi BurrMan - Dude you went to some trouble to explain the process there. Sadly I was replying to Michael & SteveMacc and missed the video post, but i have watched it and it explains really well, I especially like the trick with the edge stealing and the offsetting - Lesson learnt and taken on board!
Well this third incarnation is definitely going better than the other two, but i need some help again ...
As can be seen from the first screen grab, this model is coming along,
But is there a more efficient way of creating this kind of grill, the two of those add 15mb to the file, that seems rather heavy. I have already exported them out as there are another eight of the blighters to do which will push the model over 70mb at this rate, they are a networked surface but are simple planes, so any pointers would be good.
Hi Martin, usually it is much more efficient to use texture mapping inside of your rendering program to do small repetitive patterned detail like that, rather than actually modeling it directly.
Thanks Michael, i know materials can save a huge amount of modelling, especially bumps and displacements and of course grid like items with holes. I just queried it as the those two grills alone are 15mb where as as a medium high resolution OBJ file (Angle 5, Divide 10 as planes) is 2mb in size, which is much more acceptable.
Hi Martin, yeah NURBS models have a higher overhead for things like edge structures, basically for every edge in a NURBS model there is a lot of various pieces of data including both a UV-space version of the edge as well as a 3D edge curve.
So when you get to a situation where you've got something similar to a polygon structure with just a lot of little planar faces and lots and lots of little edge curves, that is not very efficient data-size wise in a NURBS model as compared to a polygon model structure.
NURBS are more efficient in other kinds of ways, especially when your model has large sections of it made of curved surfaces, since a big curved thing can be exactly represented as one NURBS spline surface while with polygons you have to use a whole lot of little polygons to represent it.
For a case like you've got there, you'll probably be fine with those heavy pieces if you just break them out into a separate file (select them and use File > Export to put them in their own separate file and then delete them from your main working model) so that you won't bog things down so much with a huge file for your main working model.
A little more progress, the lower porting of the back-end of this Lamborghini is a lot more tricky than i first thought, also it's the first time modelling this area, no excuse i know, but sometimes i need a few goes to get things looking right! But i am happy with my artistic licence result ... What say you ?
Some more updates, this is getting more tricky and I am finding myself having to try and work from photos. If you are reading this Michael, any chance of some proper camera matching in v3 ?
@ Burrman - Glad you like it, and as you asked so nicely, and because we all like to sho off from time to time, here are two more screen grabs ...
> If you are reading this Michael, any chance of some proper camera matching in v3 ?
Usually camera matching is more associated with animation type functions, so it's not really on my radar for implementing in v3.
Are you trying to use a perspective angled reference image? Usually that type of image reference is problematic to use as a reference, you need to find things like top/front/side blueprint like reference images instead if you're trying to trace over stuff, since it's primarily intended for reference images in MoI to go on the Top/Front/Right views.
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