Does it exhibit this bug when just one of the interior handles is being adjusted?
Misleading preview:
Resulting surface:
Rhino needs a good tool to handle this kind of loose input geometry:
Bobi, you should be working with the latest version ,even though they may apply to V7. As others have said about you having access to the WIP. At the very least a discounted V8 . Oh well!
That is an ugly arrangement of CV’s on the lower picture .----Mark
If you have in mind my last post with the link to the other thread, I made these samples with Rhino 9 WIP. Even its new “Patch” tool fails miserably, especially with G1 tangency set to two of the edges. The WIP crashed numerous times while I was trying to build these samples. Rhino 7 is much more stable in that regard. I use a nearly stock Rhino 9 WIP, with just 6 of my display modes and latest Nvidia drivers.
If you write about my latest image two post above (the blue extrusions with the white blend surface), the “Blend surface” in Rhino 9 WIP still suffers from exactly the same bug. There is zero improvement in this regard. It’s a sad situation, because the user is forced to NOT adjust the adjustable interior handles, or else the resulting surface will be heavily distorted and very time-consuming to fix manually. The preview may seem good, but it’s highly misleading, because the control points of the actual blend surface get super chaotic.
Hi Bobi -
From your crash reports (thanks for sending those in!), it looks like the crash was related to the tooltips in the toolbars. That problem was fixed in yesterday’s release so you should update the version that you are running.
-wim
Hi @wim , thank you for the suggestion! You were right. After I updated to the latest WIP, I worked for several hours and its seems like the new built is rock solid. Zero crashes and freezing since then. 
The latest WIP crashed over 20 times in less than half a hour. I have sent two crash reports with the included 3dm file to “McNeel”. The crash occurs every single time when I try to switch the next to the last layer named “New version 4-a”. Video sent to PM.
There is one unwanted behaviour of “Blend surface” that really bugs me a lot of times. The “Interior shapes” option ignores the user-set end limits of the blend surface, and instead spreads it along the entire length of either target edge. The user is then forced to pick each of the 12 handles and manually adjust everything for a minute wasted time. This is super annoying.
However, if the user then clicks again on the “Interior shapes” twice (turn it of off and on again), the manually set positions of the 12 handles are lost again, hence he or she is forced to redo the work again.
I propose to make some improvements in this regard and make the “Interior shapes” remember the end limits of the blend surface.
Note: I’m aware that the surface edges could be split to limit the range of the blend surface, but in many cases the target surfaces must remain untouched to avoid various bugs and issues with tolerances related to other surfaces. An, yes, I know that I can copy the target surfaces, isolate them split their edges, then use them to build the blend surface, then delete the target surfaces and unisolate the blend surface. But that takes time.
Plus, most users may have already used the “Isolate” command, so isolating and unisolating again will erase the state of the isolated objects that they had initially. I use a macro to have multiple sub-isolations, but I’m a minority. As I mentioned above, the whole manual process of copying the surfaces, isolating and splitting the edges takes time and multiple mouse clicks.
One more time to remind about the urgent need to implement non-destructive matching to G2 using the normal direction for the 3rd row of control points. This is just one of my old videos that I made 6 years ago, but the request was made much earlier in multiple topics…
Also, please allow use of different continuity settings when using the “Multiple matches” option. For example, such control already exists in the new “Patch” tool where the user could mix G0, G1 and G2 for each target edge.
It’s very limiting to be forced to use only G2 for all sides, for example. In many cases a combination of G1 and G2 is necessary to achieve properly matched surface ends due to the input geometry having G1 in one direction and G2 in the opposite direction.
Is there a way to swap the U and V directions of a surface? If not, here is a request about that:
Make a new SwapUV command to swap U with V.
The _Dir command lets you swap U/V.
Hi @menno , as far as I know, the “Dir” command flips the normal direction. However, my request is about swapping the U with V, and vice version. They basically need to rotate to 90 degrees to swap with each other.
With other words, if I have a long vertical surface whose U direction points to up and the V direction is sideways, I would like to swap them so that the V direction will point to up and the U direction will be sideways. Is that possible with any current command in Rhino?
I tried the latest WIP, but the UV markers remain unchanged after I ran the “Dir” command numerous times.
That would be useful, also to be able to stick persistent G0, G1, and G2 locators on arbitrary surface boundaries. A typical example below - you need G1 to the vertical tangency enforcement strip so you have G2 after mirroring (or a consistent draft angle in other cases), while you need G2 on the opposite boundary. The short sections are degree 4 curves that you first want to match G2 and G1 on opposite ends, while noodling the CPs to get the desired shape, and then build the surfaces.
@Rhino_Bulgaria Check the “single surface options” section.
You are thinking of the Flip command, which only reverses the normal direciton.
I figured out where is the issue (and partially my mistake, as I see the red and green UV isocurves as the same colour since I’m colour-blind). While Rhino 9 WIP changes the tiny arrows, the preview does not change the newly introduced large UV indicators at the corner of the edited surface when the control points are visible. This caused my confusion and made me think that the command does nothing when I click on “SwapUV”.
Also, the name of the RMB command tooltip could be more appropriate. It is called “Analyze direction”, whereas its main purpose and ability is to change the direction (hence my proposal to change it to “Swap direction” or “SwapUV”, because it does exactly that).
Having “Flip direction” for the LMB also adds to the confusion, because the ! _Flip can flip the direction, hence the tooltip of the same name.
However, the ! _Dir command can also flip the direction with a simple LMB click, or use the command line options to swap the UV, but it’s not called “SwapUV”, or “Swap direction” or “Change direction”. The ! _Dir command is not a basic analysis tool. It’s the primary editing tool for change the normal direction and swap the UV coordinates.
Using the same logic, the “Blend surface” tool’s main purpose is to actually build a blend surface rather than just analyzing how the latter could look like. This is why it’s not called “Analyze Blend surface”.
Other confusion that I notice in the latest WIP is that when I activate the ! _ShowDir tool, the buttons on the pop-up panel are inactive (grayed-out). I’m forced to de-select the surface by clicking on a blank area in the viewport, then select it again to make the buttons clickable. Is that a bug?
In Rhino 7 the buttons are clickable even if the surface points are visible. However, when the control points are visible in V7 and I click on “SwapUV”, the buttons become inactive forever.
No, the confusion comes from the fact that upon activating the ! _Dir command a mouse click on the selected surface changes its normal direction (the tiny white arrows). This is the primary function chosen by the developers. Swapping the UV is a secondary option in this command placed on the Command line. It’s very difficult to read the options there, because the letters are grey instead of black.
Another confusion is caused by having two commands with very similar names: “Analyze direction” and “Direction analysis”. This is yet another reason to rename the current “Analyze direction” into “Change direction” or “Swap direction”. Both, ! _Dir and ! _ShowDir have nearly the same capabilities, but the 1st one relies on a pop-up window while the 2nd one relies on the Command line.
I can’t find which is the advanced setting to make the text in the Command line deep black to improve the visibility. The Rhino 7’s Command line options are 1 billion times easier to read in comparison.
It’s even more confusing that the ! _ShowDir command shows some very inappropriate colour (cyan or something like that) for the normal direction, despite that I set “Tracking lines” to be white, whereas the ! _Dir command shows pure white arrows.
I started a new thread reporting this bug and another bug I found.
Bug reported in a new thread: Dir Bug in V9 WIP