Note:This is for moderate level Rhino users... Its imperative that you know most of Rhino tools, and basic knowledge on curve/surface continuity.
Before we start, I want to Thanks SWIPS and Snecx for everything related to Rhino. Without them, I won't be writing this mini-tutorial.
I Also want to tell you, this is not going to be very precise model since I don't have Blueprint uploaded. I am just giving you technique overview on modeling wheel arches with NURBS
O.K. Let get started.....
Step One:
At the front viewpoint... Draw a curve and turn on edit point to shape up the curve. I use Interpolate Point Curve, you can use control point curve if you like, they both will work the same way.
Step Two:
Draw another curve as shown image above, and turn on Edit Point (EP) to shape up the curves.
Note: You might need to rebuild both curve to get it aligned up right.
Step Three:
Now build a surface with Sweep 2 Rail tool. Network surface is not recommended
Step Four:
At the front viewpoint... Create a circular curve then use EP to extend curve along to make a shape of wheel Arch. See image above. Then, after chaging curve with point, use rebuild tool. (Best recommendation: Always rebuild curve after changing curves around)
Step Five:
At front viewport, trim the surface.
Step SIx:
Now important steps for you...Not so many of rhino user may know this.... (This step Reflects from TRK's tutorial)
Before we went ahead, I want to vertify if there's spilted edge on trimmed surface. So to vertify this we would need to turn on Anaylsis Tool. (Anaylize --> Edge Tool --> Show Edges) and see if there's one or more points on the trimmed edges (disregard on the both ends). See attached images above... I have confirmed that there was two spilted edges. So for me to solve it I need to merge them together. (Right mouse click on spilt button or at the menu click Anaylize --> Edge Toiol --> Merge Edge) and merge it together...
For those who didnt see any points between both ends, disregard this step and move onto next.
If we don't merge them, then making two surfaces continuity is impossible. If you cannot merge spilted edge, then you would need to delete that surface and redo surface. Remember, rebuild the curves before you apply surface.
Step Seven:
Offset Curve from Trimmed surface... (offset distance: Use your judgement or deterime one following your BP reference)
Step Eight:
Don't be alerted about ugly offset curve... Move the offset curve outward from the surface... and REBUILD the curve. set the point count between 10 -13 and degree to 3
Step Nne:
Turn on EP, and move around points til it suit to you, just like mine from attached image above.
Step Ten:
Enable the OSNAP. make sure "NEAR" is checkmarked. Now create curve like the image above....
Then this
Turn on Edit point to shape up little... It doesn't require you follow exact shape as mine since there are variety type of wheel arc shapes. (Dont forget to rebuild them)
Step Eleven:
Almost done... Select network surface from menu or button cotrol , then select those curves/edge like the image *1. Now, make sure the edge you select nearby to surface (Either A,B,C or D, mine's "A") has curvature bullet in. See Image*2 above (This is what make continuinty between two surfaces)
Ta-da! Now we just created wheel arc...
To vertify surface continuity.. open zebra anaylisis and see if the striipped color actually blend very well between two surfaces.
Yes it does...
If you have any questions, problems, or need some help don't hesitate to ask post one here in this thread topic or at Nurb Modedling Feedback Thread. Good Luck!
Based on the above, note that surface area near edge B and D appears a bit funny. That is because the curve B and D only have positional continuity and the surface are forced to have curvature continuity. To prevent such problems, the B and D edge matching should be set at "loose" at the prompt below:
Btw, I kinda forgot a lot of the steps in modelling! Merge edge, split edge, ah.. I'm getting rusty.
@TpwUK - I am glad you learned something about merge edges
@cheasie- You got what you wanted didn't ya... don't ya worry there's more tutorial coming
@Snecx - I didn't notice the B and D looks until now... you are right maybe I should set it to loose but unfortunately, I didn't save that work. Hopefully someone will come in sense.
@Sotman - I am glad it helped you... I suppose you use rhino too?
@Snecx - I didn't notice the B and D looks until now... you are right maybe I should set it to loose but unfortunately, I didn't save that work. Hopefully someone will come in sense.
Snecx and Equinox....you can also align the end of curve B and D in curvature with the bottom edge of the big surface, before building the blend. Then a position condition on B and D is possible. Note that in this case this is not really usefull....but remember that if you want curvature between two surfaces, the curves around will be better if their are built to respect this curvature...
jwilyman- I would normally do that.. but that would make it terrible on wheel arch... I would do it if I was going to get one surface blend to another surface but not the wheel arch. Unless you show me how to do it.
jwilyman- Look at TRK's comment... it says align curve at B and D section.... what you are doing is getting curve continuity, that's not the point here.
Isn't it?
Just instead of matching 2 curves like I did, you would just match the curve (B or D) to the bottom edge of the surface it's touching. That's exactly how I read what TRK said.
Isn't it?
Just instead of matching 2 curves like I did, you would just match the curve (B or D) to the bottom edge of the surface it's touching. That's exactly how I read what TRK said.
You are right, but it would bend the sharp corner at the other end "corner that is away from the body" if you know what I mean?
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Originally Posted by EquiNOX
