topic Re: Control Loft params from MXS. in 3ds Max Programming Forum

Control Loft params from MXS.

dmitriy.shpilevoy — Fri, 29 May 2026 17:16:34 GMT

Hello, fellas.

I want to control Loft's Surface and Skin parameters.

Showproperties only dumps couple of useless things in my case.
Documentation is not much of a help either, unless I want to deal with SDK. And I don't because I can't.
Found a way to set checkboxes, not sure how clean or stable it is, but it works.

Spinners defeated me though.
Setting text to Edit field works, but doesn't stick. If I deselect Loft object and select it again, Length/Width Repeat values are reset.
Best I got is listed below. Idea was to set "fake" text and then "make it real" by clicking the SpinnerControl.
Value I set is treated as purely visual and is being overwritten by some internal value + increment from spinner click.

1.0 becomes 1.01 and not 10.01.

max2024

( commandPanelHwnd = windows.getChildHWND #max "Command Panel" local allControls = windows.getChildrenHWND commandPanelHwnd[1] local WM_LBUTTONDOWN = 0x0201 local WM_LBUTTONUP = 0x0202 for ctrl in allControls do ( -- ctrl[1] HWND, ctrl[4] class, ctrl[5] text if ctrl[5] == "Length Repeat:" then ( local parentHwnd = UIAccessor.GetParentWindow ctrl[1] spinnerControls = (windows.getChildrenHWND parentHwnd) for sctrl in spinnerControls do ( if sctrl[4] == "Edit" then ( UIAccessor.SetWindowText sctrl[1] "10" ) if sctrl[4] == "SpinnerControl" then ( --format "%\t%\t%\n" sctrl[1] sctrl[4] sctrl[5] windows.sendMessage sctrl[1] WM_LBUTTONDOWN 0 0 windows.sendMessage sctrl[1] WM_LBUTTONUP 0 0 ) ) ) ) )

Re: Control Loft params from MXS.

dmitriy.shpilevoy — Sat, 30 May 2026 09:53:52 GMT

Okay, it's definitely not clean or stable. Nor does it work 😃
Command Panel behaves in a weird way - can't find it by name until I undock and dock it again. And since I can't find a way to script this redocking process, this is my code now for searching Command Panel (I have Mirror button always present in Modify panel):

for c in windows.getChildrenHWND #max do ( if c[5] == "Mirror" do ( thisParent = UIAccessor.GetParentWindow c[1] format "%\t|%|\n" thisParent (UIAccessor.GetWindowText thisParent) thisParent2 = UIAccessor.GetParentWindow thisParent commandPanelHwnd = UIAccessor.GetParentWindow thisParent2 ) )

This is bad enough as it is, but on top of that both versions can't find Command Panel while it's undocked/floating.
Is it still a child of main max window in this state? If so, I can't find it.

Re: Control Loft params from MXS.

denisT.MaxDoctor — Sat, 30 May 2026 23:44:00 GMT

Let's break down your questions:

fn editSpinner hwnd val = ( WM_CHAR = 0x0102 VK_RETURN = 0x000D uiaccessor.setwindowtext hwnd (val as string) windows.sendMessage hwnd WM_CHAR VK_RETURN 0 -- press ENTER key )

it's how I do it.

Re: Control Loft params from MXS.

denisT.MaxDoctor — Sun, 31 May 2026 00:39:55 GMT

How is it about:

iGlobal = (dotNetClass "Autodesk.Max.GlobalInterface").Instance iGlobal.CoreInterface.CommandPanelRollup.Hwnd

Re: Control Loft params from MXS.

dmitriy.shpilevoy — Sun, 31 May 2026 07:59:19 GMT

Hi, Denis! Am I glad to see you, man. Max was bullying me again.

Spinner function works. Values are being set and persist.
I was ready to try sending RMB + click, N LMB clicks, N Alt + LMB clicks to hack it.

And the dotnet way to get Command Panel's hwnd works also. But there is a nuance...
If I redock and get it as windows.getChildHWND #max "Command Panel" and then dump children, it shows everything in every tab - 241 item. For example, even stuff from Utilities tab is getting listed.
It's not like I need inactive tab's controls, but listing children of dotnet-accessed panel seems to only show controls from first column - 24 items (if Command Panel was manually resized to get more info on the screen by increasing its width). By going 2 levels up from dotnet result I can get reliable, docking-state independent access and same "everything you wanted and more" amount of children.

This is what I ended up with:

( fn editSpinner hwnd val = ( WM_CHAR = 0x0102 VK_RETURN = 0x000D uiaccessor.setwindowtext hwnd (val as string) windows.sendMessage hwnd WM_CHAR VK_RETURN 0 -- press ENTER key ) iGlobal = (dotNetClass "Autodesk.Max.GlobalInterface").Instance cmdPanel_a = iGlobal.CoreInterface.CommandPanelRollup.Hwnd cmdPanel_b = UIAccessor.GetParentWindow cmdPanel_a cmdPanel = UIAccessor.GetParentWindow cmdPanel_b allControls = windows.getChildrenHWND cmdPanel for ctrl in allControls do ( -- format "%\n" ctrl -- ctrl[1] HWND, ctrl[4] class, ctrl[5] text if ctrl[5] == "Length Repeat:" then ( spnrParentHwnd = UIAccessor.GetParentWindow ctrl[1] loftSurfParams = (windows.getChildrenHWND spnrParentHwnd) for lspCtrl in loftSurfParams do ( if lspCtrl[4] == "Edit" then ( editSpinner lspCtrl[1] "10" ) ) ) ) )

Thank you!

Re: Control Loft params from MXS.

denisT.MaxDoctor — Sun, 31 May 2026 15:43:52 GMT

You found the right solution.

CommandPanelRollup

is a page. You need its grand-grand parent which is … let’s call it “COMMAND TASK PANEL” 🙂