Warping with Gmax for version 4.1 & v4.5

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Warping with Gmax for version 4.1 & v4.5

Postby Jan Huewel » Thu Dec 17, 2009 7:59 am


Pandoras Box Media Playback Systems provide the ability to use shapes and objects for any display output to be rendered to. This tutorial is intended to show the basic steps for correcting curved screens.

As Gmax is a extensive and powerfull 3D modelling tool we will only scratch the surface of 3D modelling in this tutorial.
Geometric correction has to be setup onsite with the projector hooked up to your system and running Gmax in Fullscreen.

In order to get started make sure Gmax is installed properly on your system. If you need to work from a distance use a remote desktop viewer like Real VNC to mirror the output of the projectors on your laptop or PC.

To gain a maximum warping area make sure that the Windows taskbar is not set to be "on top of other windows" by right clicking on the windows taskbar and choosing its properties dialog.


Start Gmax.
If you need to setup two outputs simlutaneously start Gmax in Desktop extended mode once for each screen so that you can edit two warping grid at the same time.

Once Gmax is started it is recommend to adjust the follwing settings for a better workflow during the screen shaping process.

First of all we want to make sure that the background is all black and the all lines that we will edit turn to primary green. This makes it much easier to see the grid in most lighting conditions.

To do this click on Customize Userinterface in the Main menu. follow these steps:



1.Select Viewports from the Elements pulldown menu
2.Choose Viewport Background
3.Change the colour in the colour dialog to black


1.Select Geometry from the Elements pulldown menu
2.Choose Selection
3.Change the colour in the colour dialog to primary green
4.Apply the new settings
5.Save these settings for the future in File dialog by overwriting the
default colour file.


Last make sure to hide the track bar from the main UI by unchecking "Show Track Bar"

Now you are ready to start warping! Please always make sure your Gmax is setup this way, these settings are important for working in Expert mode with Gmax in order to use the full desktop.

In this next section we will look at the basic deformation of a flat planar object, to start with please download the PB_Native_4to3_Scale.gmax file and open it in gmax.
Gmax template for Pandoras Box Version 4.1

Please Note:
From version 4.5 on a 4:3 fullscreen object corresponds to the size of 16 units wide and 12 units high.
Depending on your output aspect ratio the fullscreen object always have a width of 16 and the corresponding height. The exporter described in this tutorial is for Pandoras Box version 4.1 scaling. For version 4.5 please use the new files and the new export script.

Gmax template for Pandoras Box Version 4.5

Gmax export script for Pandoras Box Version 4.5

To use the Pandoras Box native .x file export script, please copy the .ms file to Gmax_rootdir/Scripts/startup.

Restart Gmax and the export features will be available in the "Tools" tab under "Max Script" in the "Utilites" dropdown menu.

To export .x files from Gmax create an object and make sure UV Mapping coordinates are applied.

Once the x file data is generated run the separate PB GMAX X File Exporter.exe to save the generated data to disc.

With PB version 4.5 the unitsystem has been adjusted.
For 4:3 Output the fullscreen object size is 16:12.
For 16:9 Output the fullscreen object size is 16:9.
For 16:10 Output the fullscreen object size is 16:10.


The PB native 4to3 Scale File contains two items:
- a flat Planar Object and
- a Camera

If you would export the Planar object as is to an .x File and load it into Pandoras Box, the shape of a layer would not change since this plane is a reference file to match the full screen scaling of a layer object.

The camera helps us with a fixed view to ee the boundaries of our output and allowing us to create shaes that cross the boundaries.

Please make sure to alway work in within the camera view when shaping the grid. You may use the front view to work outside of the screen boundaries, but the camera view is a static reference for Pandoras Box.

The most comon task for Screen shaping is a curved screen. To achieve this task the planar object must be modified. The grid points have to be re-aranged in a way that the grid unwraps itself on the curved surface of your screen.

To do this, all you need to do is to aplie a tool that will allow you to bend and shape the planar objects.

In order to apply a new tool or so called "modifier" in Gmax first select the planar obj by clicking on it, once its selected it should turn primary green.


To apply a new modifier to the selected object you will need to switch to the modify mode by clicking on the "Modify" tab.
Here you will see a hirachy list of the history of the objects modifiers.
In order to apply a new one select FFD 3x3x3 from the pull down menu.

Image Image

Then open the FFD 3x3x3 modifier in the stck and click on the Control Point level. Now you should see a 9 point orange control point grid surrounding the planar object.


Since gmax and all objects are alway treated as 3D objects the modifier works also in the 3rd dimens there for underneath each of the 9 points there are 2 more control points. But since the object we need to modify is totally flat we need to make sure when selecting the control point to always catch all three of them by draging a selection window over the control points.

Now feel free to select and move the controlpoints arround to get a feeling of the dynamic behaviour of the underlying planar grid according to the control points positions.


Please Note: Always make sure that none of your points move towards the z axis, all control points must stay at the same distance from the camera at all times. To control this check your control points positions in the top and left view.
You might wonder how you can actually draw and shape this plane according to your screen, the answer is only a few clicks away.

In order to control the FFD´s Control point you are in the Controlpoint level of the selected objects modifier stack. Once you are in this mode you can right click in the camera few and press CTRL+X to toggle to the expert fullscreen mode of Gmax, by pressing "W" on the keyboard you may toggle to the maximzed camera view.

Now start modeling your planar object according to the screens physical shape.

If you need to toggle to the Front view while in Expert mode, you may use the "F" key for front view, "L" for left view and "C" for the camera view.


Please make sure that you make all adjustments to match your screens only accordin to the camera view, as this is your reference view for Pandoras Box output.

Once your done with shaping the screen you only have to export the selected object form the file menu and load the object into the output camera.

In any case you need to get more detailed control over every grid point you might want to explore the "edit mesh" modifier and add this one to the stack and choose the Vertex level for in depth control of ever segment of the shape.


This modifier will do a great job when you do Softedge setups with over-laying grids. The Edit Mesh modifier will allow you to get the overlapping vertices accurately on top of each other for a perfect shaped softedge blend.


For this 180 degree Screen two Gmax application edited at the same time. In the overlaping zone all vertices were touched up to match exactly the screens deformation.

GMAX hotkeys:
F3 - Toggle textured view
F4 - Toggle grid on Textured view

F - Front View
C - Camera View
L - Left View
R - Right View
T - Top View
P - Perspective View
G - Toggle Background Grid

Ctrl+X - Toggle Fullscreen Mode
X - Toggle XYZ Axis Control

Object Export for version 4.1:

First of all make sure that the plugin Files are in the Plugin Folder in the Gmax executable root Gmax_plugin_files.zip

Or use the Gmax_installer.zip instead this installer will copy all files into the gmax root directory.

If the files are not there, please save your work first close Gmax copy the plugin Files and then start Gmax again to get the export options. To export the object, make sure its selected by clicking on it and then choose from the file menu export selected Export selected as "Flightsim Aircraft Object (*.MDL)"

Since the Flightsimulator uses different units a messagebox will pop up, simply click "OK" to continue.
In the next dialog that opens go to option and check "xfile" and "no compile" and click on "GO"


You might save the options so that you don´t have to check this at every export by clicking "Save as Default".
The object is now properly exported as .x file and can be loaded into Pandoras Box.
Jan Huewel
Posts: 260
Joined: Fri Jul 11, 2008 11:49 am
Location: earth

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