I changed a bit surface of the arches for better fit, but we will see it in the process if it managed to be reasonable.
two sections on board, area on top of back arch.
Also added some curves here, just for orienting. So they are, lots of spans, not clean, but allow better understanding.
In fact this car is very difficult. Even I don’t always understand what is what here. This is why all comes clear in the process
Well, we have four curves. This is how CV distribution looks like. And using them we will build this part of the board.
Pick Square tool, which builds a surface using four curves. A nice and clean surface is obtained. We can check the zebra.
I don’t know how does its curvature fit on original Lexus, but along construction, we will compare using highlights.
If we want to obtain a clean surface, we need those two splines to have almost identical curvature, and to be parallel to each other more or less.
Using curvature combs we can see that they have almost same degree. Those splines should accordingly be almost identical.
Althrough it can be the other way. Actually we can align them a little. This is not so important. Surface went clean enough.
Well, now let’s try to build this area, quite complicated. The area of back arch. Blending between side surface and back arch.
It is done in the same way it is on the new Nissan GTR. I have this photo, lots of references.
And you can see how the highlight moves along. It’s an excellent collection. A way of understanding of what happens with this surface.
Lots of different references. Actually the more we study this issue, the better quality result we get. Here we can see it well too.
It is not a difficult zone, we just should build it accurately. Here is nothing supernatural. Let’s start with a blend.
Here is the surface of the arch, and we can try to approach it circularly. Use G3. Start – Default. And now see what we got, something like this.
This row falls quite strong… It tells us that the curvature here is a bit too strong. Doesn’t help. Then this is the way it is.
Well, let’s check zebra. Well, looks smooth enough. If we look closer, we observe that this arch has its specific character.
It is concave - inflated, surface close to the edge is inflated a bit. Let me find a good photo. Well, we see that it curbs here
Here, a good angle, we see that it is clearly not a flat surface, it is concave in the beginning and then is inflated closer to the edge.
For this we take and copy this curves that we obtained and delete the surface. And change curve degree from four to five.
Now we will try to obtain something from this. Something nice. We create a square again, connect the curve, it is clean now.
We get such a thing, and if we turn explicit control ON we can achieve a curvature, even on degree five
we see that curvature matches, but at the edge we lose position. But actually it is not so bad.
Well, we get a nice thing now. Now let’s see what we have when we check curvature comb.
Use cross section control, Z axis. Related to class-A, when we need to create something smooth, we need to check this kind of things.
We see that it behaves strangely. Now we take it here and pick change history instrument, and adjust.
Well, something like this, anyway not that important. It is possible that all this we’ll have to rebuild.
Now delete all this lines. And yes, we had to inflate these a little. Superb, everything looks smooth.
And now we need to pull off a little these control points. We can set it to degree six to be able to manipulate just with those two points.
This first dot is responsible for tangency, second one is for G2, and third is for G3.
So if we want to leave continuity, we don’t touch them, just increase curve degree and manipulate them. Now we’ll try to do something
Take the point, pull first, second one too. Try to obtain some sort of practicability. And on the bottom just something smooth.
Well, much better now. Actually it’s not bad this way, let’s see what will happen here, and based on this we will adjust our further steps.
Well, delete this thing. And now, sort of, looking nice. Moving forward. Hitch up the edge of surface.
And again, everything that is related to quadrangles is done with Square tool. Here is a mismatch, I modified the arch, so the point is misplaced now.
Nothing to worry, anyway I do it with approximation. Again, hitch up the edge of the surface, curve, curve, and one more curve.
Here it says that position failed, but that’s not scary. Degree six here, Check curvature.
But curvature matched. And here is unclear why position departed somehow. I think it is because of some dots on the top here
Yes, well, a little, nothing to worry. We see now, nothing good here… let’s try to align with the help of those manipulators.
Doesn’t work… Well, then we need to understand why it happens… Most probably it is because of the dots that we moved.
Now let’s try to adjust something again. We can even move the point which is related to G3, nothing bad would not happen
even if we lose a part of smoothing. This one, pull out, this one pull out too.
Well, now we have an acceptable result. Yep, better. And this one looks nice.
But from some angles it doesn’t look that good. Well, now the last chance. First of all check curvature.
Yes we see that something totally strange happens here. This way we accurately adjust here.
By all means let’s make something nice out of this curve. Ok, leave it this way, look well now.
And now the super tool for verifying all the errors. Check curvature analysis, pick Gaussian and watch.
Well, now we see where the problem is. Here the blend is very tight. But overall it is not bad. Now let’s repair it.
Most probably it can be solved quite simple. Let’s take this square and adjust a little. Yep, much better now.
Good enough I think. It is even possible that the original is done the same. Well, looks nice.
But here again something ugly happens. Actually this is the way it is done in such places. Comes out not so well…
Actually this is the way it is done in such places. Comes out not so well…
Now it is good, and this is how it is done. It is a classic method for such a blend.
Same way is on Nissan GTR. Back is absolutely the same. One to one. Save now. And move forward.