P3D v4 Ground Poly


I've looked at many tutorials and videos on how one should create ground polies for FSX and P3D. Now since I'm using Sketchup in stead of Gmax or 3ds Max as in those videos. I'm a bit unsure of how to translate some of those seeminly unique Autodesk features to the sketchup realm.

Most of all i'm wondering about the layering of textures. Does this imply they simply assing multiple textures to a single surface or do they layer several duplicate polygons over one another and assign textures to each of those?

The other thing is for taxiway lines. There appears to be a tool in the gmax product that makes it easy to assign a texture to what looks to be a " flat line". What's the best way to do this in sketchup?

I created a test surface with my interpretation of layering as you can see in the attached screenshot.
It includes duplicates of a flat rectangular polygon, at about 1cm appart, the bottom one has a tiled asphalt texture, the one above that has a single texture that contains all the line markings and the one above that adds some dirt over the other layers.
Is this the way i should continue or are there better ways?


Hi Johan:

FSX and AFAIK P3D assign multiple textures to a single surface for concurrent display only on aircraft; for scenery objects, one must layer "several duplicate < flat 3D object surfaces > over one another and assign textures to each of those".

BTW: Since your target FS platform for this thread apparently is P3Dv4, you may wish to distinguish the use of a 'flat' 3D MDL file with Z-Bias Material Properties for P3Dv4 ...from the otherwise required use of legacy SCASM / ASM coded 'flat' 3D non-MDL based methods for FSX G-Poly creation.

While P3D currently supports both types of G-Polys when created properly, the future plan of P3D is to NOT support the legacy methods of making G-Polys. :alert:

To distinguish the different G-Poly methods:

* For a 'flat' 3D MDL file with Z-Bias Material Properties in P3Dv4, one adjusts the object Z-drawing order via the Z-Bias to assign the effective "position" for an object layer from the user aircraft camera location.

* For a 'flat' 3D non-MDL file with a VTP layer number in FS2002 / FS2004 / FSX, one adjusts the object Z-drawing order via the VTP layer number above ex: layer 16 in alternating increments of 4 interposed skipped VTP layer numbers to assign the effective "position" for an object layer from the user aircraft camera location that also displays aircraft shadows.

FYI: Sketchup's Ruby plugin scripting language distinguishes object Faces as thin as 1/200th of an Inch (0.005 Inches) aka 5 Millimeters aka 0.0127 cm ...when such plugin scripts are used to help simplify the work-flow for such a project.

Regarding optimal Sketchup work-flow for 3D Face layers, you might find it easier to compose the multiple 3D model object layers in precise alignment with another as you have shown in your screenshot above, if you place each such "layer object" on its own "Layer" in Sketchup.

However, each such textured 'flat' 3D layer object must be exported as a Geo-located KMZ file (which contains a Collada *.DAE file) for import and processing by ex: Arno's ModelConverterX (aka "MCX") as individual objects (...which are subsequently assembled by MCX into a composited G-Poly from those individual 3D objects).


: Arno's MCX and Don Grovestine's GP Editor Tool in ADE each have useful features to assist with the work-flow to create aerial imagery G-Polys and/or other ground marking objects for both FS2Kx and P3D.


Hope this helps with exploring G-Poly creation options. :)

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