FS2004 GMax Aircraft Creation document

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Microsoft Flight Simulator 2004 gmax Aircraft Creation doc

Microsoft

Flight Simulator 2004:

A Century of Flight

Software Development Kit

Discreet and gmax are trademarks of Discreet Logic Inc./Autodesk, Inc., in the U.S.A. and/or

other countries.

gmax Aircraft Creation document

November 2003

Microsoft Flight Simulator 2004 gmax Aircraft Creation doc

Contents

........................................................................................................................................................2

Introduction....................................................................................................................................3

Getting Started................................................................................................................................4

Setting Units of Measurement ..................................................................................................4

3View Drawings.........................................................................................................................4

LODs...........................................................................................................................................5

Heirarchy....................................................................................................................................6

The Exterior Model........................................................................................................................6

Polygon Counts..........................................................................................................................6

Textures .....................................................................................................................................6

Special Material Names.............................................................................................................9

Animating Textures...................................................................................................................9

Tires and Props........................................................................................................................10

Animations................................................................................................................................11

Pilots..........................................................................................................................................12

The Interior Model.......................................................................................................................12

Polygon Counts........................................................................................................................12

Textures and Virtual Texture Sheets.....................................................................................12

Animating Textures.................................................................................................................17

Animations................................................................................................................................19

Special Material Names...........................................................................................................19

Eyepoints...................................................................................................................................19

Exporting the Model.....................................................................................................................20

Exporting the Model................................................................................................................20

Converting Textures................................................................................................................20

Microsoft Flight Simulator 2004 gmax Aircraft Creation doc

Introduction

Microsoft

Flight Simulator 2004 A Century of Flight Edition supports models created in gmax,

a 3-D modeling tool from discreet. By using gmax, you can create a model of an aircraft, apply

textures and animations to that model, and then export the model to the MakeMDL program,

which creates the format for use in the product.

The Aircraft Creation document is NOT a tutorial on how to use gmax to create an aircraft.

Rather, it provides a set of best practices to follow when using gmax to build aircraft for use in

Flight Simulator. This document focuses on the following four areas:

• Getting Started: a brief summary of what needs to be in place before modeling.

• The Exterior Model: everything you need to create an exterior model.

• The Interior Model: everything you need to create an interior model.

• Exporting the Model: you export the model to the MakeMDL program, and then place

the model in the appropriate aircraft container within Flight Simulator.

Files Required:

• MSXML4 available on www.microsoft.com

• Curtiss Jenny.gmax in \gamepack\FS2004\scenes

• _Panel_Jenny_1.tga in \gamepack\FS2004\texture

• _Panel_Jenny_2.tga in \gamepack\FS2004\texture

• Curtiss_Jenny_C_1.tga in \gamepack\FS2004\texture

• Curtiss_Jenny_C_2.tga in \gamepack\FS2004\texture

• Curtiss_Jenny_T.tga in \gamepack\FS2004\texture

• Decal_nnumber.bmp in \gamepack\FS2004\texture

• Decals.tga in \gamepack\FS2004\texture

• Prop_Jenny.tga in \gamepack\FS2004\texture

• VCRainMoving0000.tga in \gamepack\FS2004\texture

• VCRainStopped0000.tga in \gamepack\FS2004\texture

• Aircraft.cfg in \gamepack\FS2004\extras

• Imagetool in \gamepack\FS2004\tools

Microsoft Flight Simulator 2004 gmax Aircraft Creation doc

Getting Started

In this section, we will cover general information that pertains to gmax and modeling procedures.

Topic Explanation

Setting Units of

Measurement

In Flight Simulator

2004, all dimensions

are measured in

meters, so you must

set the units that gmax

uses to meters.

On the Customize menu, click Units Setup.

In the Units Setup dialog box, click Metric, select Meters from the

Metric box, and then click OK.

On the Customize menu, click Preferences. On the General tab

under System Unit Scale, verify that it reads 1 Unit = 1.0 Meters,

and then click OK.

3View Drawings

It is good practice to work through 3View drawings. These should be

separated into front top and side images and loaded into the

corresponding view ports through Views>Viewport

Background>Files… Button

Microsoft Flight Simulator 2004 gmax Aircraft Creation doc

Topic Explanation

Select Match Bitmap and turn off Lock Zoom/Pan

Create a geometrical plane with the dimensions of the aircraft

corresponding to the view chosen.

Zoom in the plane to match the 3 view drawing. Once the size of the

plane and drawing match, check the Lock Zoom/Pan box. This

locks the drawing with the aspect of the plane and allows you to

zoom in and out of both. Do this for all of the three views.

Now you have a template to work from for creating the exterior of

the aircraft and the drawings should have the same aspect ratio.

LODs

For Flight Simulator 2004, we expanded the LOD value range from

000-200 to 000-400. This allows the LODs to switch earlier than

before. This was particularly useful with higher polygonal models.

Our models include 6 LODs in our new exterior aircraft (LOD 400,

150, 75, 35, 15, 5). For this document, we only included the LOD

400 and the LOD 5 models. Our virtual cockpit models do not use an

LOD scheme.

When creating LODs of the aircraft, make sure that every name is

unique. Makemodel does not recognize duplicate parts and can

respond by not exporting one of the duplicate objects.

The per part LOD system will not be supported due to performance

issues. Please see the Makemdl SDK for more information.

Microsoft Flight Simulator 2004 gmax Aircraft Creation doc

Heirarchy

In order to combine the exterior model with the virtual cockpit

model, two top nodes need to be in place. The exterior top node is

named Exterior and the virtual cockpit top node is named Interior.

These nodes need to have an XYZ center of 0,0,0 and be free of any

transform or scaling.

The Exterior Model

In this section, we will cover features of the exterior model.

Topic Explanation

Polygon Counts

The LOD 400 model of the Curtiss Jenny has a triangle count of

nearly 15000 including the pilot. This was an increase of almost

100% from the previous models. We decided to model with more

fidelity because most of the newly featured aircraft are not

included in the AI traffic. Nearly all of the aircraft on the AI plane

list are around 6000 triangles at the top LOD.

Textures

No matter what the texture extension is in the .x file, the

output file (.mdl or .bgl) references a texture with a .bmp

extension. If you model with .tga files, the output file

references a .bmp file.

Microsoft Flight Simulator 2004 gmax Aircraft Creation doc

We still use the same system for differentiating between non-

damaged and damaged textures. Any texture with an _T

suffix is used as the undamaged exterior texture sheet. Any

texture with an _D suffix is used as the damaged exterior

texture sheet.

The reflection map texture is the alpha channel in the _T

texture sheet. Load the _T in the specular color channel of the

material to get reflection information. The strength of the

reflection map is determined through the colors of the map in

the alpha channel. Black represents full reflection and white

represents no reflection.

Lightmaps are placed in the self-illumination channel and are

used for night lighting on aircraft such as the airliners.

Microsoft Flight Simulator 2004 gmax Aircraft Creation doc

All decals used on an aircraft model should Decal_ at the

prefix of its name. If the texture name starts with

“DECAL_” a z-bias is added automatically to all polygons

drawn with this texture.

DECAL_NNUMBER is a generated texture used for generating

the NNumber of the aircraft. The actual texture does not

appear on the mapped geometry. In its place is dev text of the

number generated through the dialog box.

The target amount of texture space that we use on an exterior

model still remains at 1 1024x1024 which includes an 4 bit

alpha channel for the reflection map. In some cases, we gave

additional texture space to larger aircraft or if decals were

Microsoft Flight Simulator 2004 gmax Aircraft Creation doc

used as in this case.

Special Material

Names

LINE_ = Lines are drawn instead of triangles.

ZBIAS_ = A default z-bias is added to the polygons.

ZBIAS_## = A z-bias of ## is added to the polygons.

DS_ = Polygons are drawn double sided.

BRIGHT_ = The material is bright (emits light).

LIGHT_BEACON = A beacon point light is drawn and the

diffuse color is the light color.

LIGHT_STROBE = A strobe point light is drawn and the

diffuse color is the light color.

LIGHT_RECO = A recognition point light is drawn and the

diffuse color is the light color.

LIGHT_WING = A wing point light is drawn and the diffuse

color is the light color.

LIGHT_LOGO = A logo point light is drawn and the diffuse

color is the light color.

LIGHT_NAV = A navigation point light is drawn and the

diffuse color is the light color.

LIGHT_TAXI = A taxi spotlight is drawn and the diffuse color

is the light color.

LIGHT_LAND = A landing spotlight is drawn and the diffuse

color is the light color.

Animate_ChainSegment_16_100_ = The physical geometry

under the engine0_turning node needs a material name of

Animate_ChainSegment_16_100_ and must mapped to texture

ChainSegment0000.bmp. See “Animating Textures” below.

Animating Textures

The only animated texture for the exterior model is the chain

for the Wright Flyer model. Two nodes are needed to drive the

animated chains. One node needs to be named

Engine0_Stopped. Any parts below this node are shown when

Microsoft Flight Simulator 2004 gmax Aircraft Creation doc

the engine is off. The physical geometry needs no special

material or texture. The second node is named

Engine0_Turning and all geometry below this node needs a

material name of Animate_ChainSegment_16_100_. This

material must be mapped to ChainSegment0000.bmp. There

are 16 chain textures that cycle through to create the

animation.

Tires and Props

Tires retain the same naming conventions from previous

versions of Flight Simulator to show the different states of

rotation. The geometry is physically switched out through the

part name.

c_tire_still = Visible and rotating when the center tire’s

rotational speed (in rpm) is very slow.

c_tire_blurred = Visible and rotating when the center tire’s

rotational speed (in revolutions per minute (rpm)) is fast.

The same is done with l_tire_still, l_tire_blurred, r_tire_still

and r_tire_blurred.

Props use a naming convention similar to tires, except there

Microsoft Flight Simulator 2004 gmax Aircraft Creation doc

are three speeds. The names have not changed. The number

following prop reflects the engine number (0-3) The prop

texture uses an 8 bit alpha channel to show transparency in the

rotating blades. Transparency is also set within the opacity

settings of the basic parameters section in order for Make

Model to process it with the correct drawing order.

prop0_still = Visible when prop 0 is very slow.

prop0_slow = Visible when prop 0 is slow.

prop0_blurred = Visible when prop 0 is fast.

Animations

A complete list of animation part names is available in the

Makemodel sdk.

Makemodel does not recognize animation on helper objects in

gmax. During the export process, the animation information

on helper objects such as a dummies or points is lost. An

object must have geometry in order for the animation to be

exported. An object with geometry can be animated and then

have its geometry deleted, leaving only a pivot. (This is

recognized through Makemodel, however, this is not

recommended.)

In order for an animation to be exported out of gmax, the

parameters of the animation must be set to linear. Set the

position, rotation and scale to linear for best practices. This

can be set through Motion Tab>under Parameters Tab.

Microsoft Flight Simulator 2004 gmax Aircraft Creation doc

Pilots

The pilots of the new exterior models animate according to

user input. The head and legs are driven by rudder movement

and the arms are driven by the stick\yoke and throttle lever.

The geometry consists of a segmented pilot with key framed

animations.

The Interior Model

In this section, we will cover features of the interior model.

Topic Explanation

Polygon Counts

The new interior models are in the range of 9000 triangles. The

models had an increased poly count due to the scope of

animation work and because only part of the model is visible

at any one time. For best practices, we suggest staying in this

range for performance.

Textures and Virtual

Texture Sheets

The base texture name suffix (_C) has no special properties.

Microsoft Flight Simulator 2004 gmax Aircraft Creation doc

We use this naming convention for organization and because

there is no damage associated with our interior model.

If a texture name starts with “$” or “_panel_” then the texture

is assumed to be a virtual cockpit (VC) gauge texture. This

texture serves as a specific coordinate reference on a virtual

texture sheet which maps the 2D bitmap panel gauges on the

sheet in real time. The reference to the 2D panel bitmaps is

done through the panel.cfg of the aircraft. A texture sheet

with “$” or “_panel_” is not needed once the model is exported

out of gmax.

Here is a simple step by step to show how the referencing is

done.

1. Create the geometry for the gauges.

2. Create a texture sheet that shows the edges of the gauges for

precise mapping. Be sure that it has a _Panel_ prefix. FYI:

Some programs won’t let you export a $ in the name.

3. Map the texture onto the geometry as you normally would

using UVW Map and the UVW Unwrap in the UV

Coordinate Modifier stack.

Microsoft Flight Simulator 2004 gmax Aircraft Creation doc

4. Once this is complete, open the panel.cfg of the aircraft in

which you are modeling. In this case, we will work with the

Curtiss Jenny.

5. Create a section for the virtual cockpit under the last window

reference section.

6. It is very important to follow the exact naming structure.

[VCockpit02]= second texture section for virtual cockpit

Microsoft Flight Simulator 2004 gmax Aircraft Creation doc

Size_mm= size of texture sheet

Pixel_size= size of texture sheet

Texture= name of texture sheet ($ is the equivalent to _panel_)

Background_color= should be 0,0,0 which is transparent.

7. For the list of gauges, each gauge number needs to be unique

per texture section in the config. If the numbers repeat, they

may not draw in the simulation.

Gauge#= obtain exact name of gauge from panel section

The numbers that follow the gauge name are listed in specific

order. To get this information, you will need to open the

texture in the paint program of your choice.

Number = X coordinate of top left pixel in gauge bitmap

Microsoft Flight Simulator 2004 gmax Aircraft Creation doc

Number = Y coordinate of top left pixel in gauge bitmap

Number = width of gauge on texture sheet

Number = height of gauge on texture sheet

Microsoft Flight Simulator 2004 gmax Aircraft Creation doc

When the model is exported for the sim, it will have all of the

information for the texture sheets. No _Panel_ texture sheets

are needed in the texture folder once the aircraft is in the sim.

The physical texture sheets are only for laying out the gauges.

Animating Textures

Animating texture technology was implemented for rain

effects in the virtual cockpit windshields. There is a specific

method to implementing rain in the virtual cockpits. The

hierarchy is as follows:

Microsoft Flight Simulator 2004 gmax Aircraft Creation doc

There are two top nodes ambient_noprecip and ambient rain.

These nodes are dummy objects for hierarchy purposes and

are triggered by name if rain is encountered. Two subnodes,

airspeed_effects_windshield and airspeed_noeffects_windshield,

call different texture sets based on aircraft airspeed. These

objects could be the geometry that switches out. For this

exercise, the objects were hierarchical dummy objects. The

bottom objects are the glass geometry.

The physical geometry under the airspeed_effects_windshield

node needs a material name of

animate_VCRainMoving_16_20_ and must be mapped to

texture VCRainMoving0000.bmp. The material needs to be at

Microsoft Flight Simulator 2004 gmax Aircraft Creation doc

0 percent opacity.

The physical geometry under the

airspeed_noeffects_windshield node needs a material name of

animate_VCRainStopped_16_20_ and must be mapped to

texture VCRainStopped0000.bmp. The material needs to be at

0 percent opacity.

Animations

A complete list of animation part names is available in the

Make Model SDK.

Make model does not recognize animation on helper objects in

gmax. During the export process, the animation information

on helper objects such as a dummies or points is lost. An

object must have geometry in order for the animation to be

exported. An object with geometry can be animated and then

have its geometry deleted leaving only a pivot. (This is

recognized through Makemodel, however, this is not

recommended.)

Special Material

Names

Animate_VCRainMoving_16_20_ = Needs 0 % opacity and

triggers specific moving rain textures.

Animate_VCRainStopped_16_20_ = Needs 0 % opacity and

triggers specific rain textures.

Eyepoints

The eyepoint for the virtual cockpit is set through the aircraft

config under the view section.

The numbers are: (feet) longitudinal, lateral, vertical distance

Microsoft Flight Simulator 2004 gmax Aircraft Creation doc

from reference datum.

Exporting the Model

This section covers exporting models and converting texture sheets.

Explanation Steps

Exporting the Model 1. File>Export>Name the file and select Flightsim Aircraft

Model (.mdl) for the format. Save the file to the Model folder

within the aircraft container

2. This will export the model and launch makemdl.exe.

Converting Textures 3. Convert the necessary textures through Imagetool.exe which is

available in the tools folder within gamepack

4. Open Imagetool.exe and create mipmaps (Image>Create

MipMaps).

5. Convert to specific formats (Image>Format).

6. _T textures are DXT3.

7. _D, _C, and decal textures are DXT1.

8. Prop textures are 32 bit.

9. Save the textures to the Texture folder within the aircraft

container.