Hi Ed:
Yep, I elaborated on use of custom land class with Annotator because IIUC, custom AGN files can
only be used with custom land class BGLs and textures.
As I think you realize, if one were to use Annotator to edit the AGN files associated with default land class quad tiles, since those files are re-used throughout the FS world, one would bring about "chaos".
However, as you may know, a frequent motivation for using autogen objects is to allow display of any inherently designed seasonal change in vegetation along with other objects via somewhat more efficiently rendered 3D MDLs which most often also have more efficiently rendered textures.
In the case of AGN files, these "placement instructions" are read and sent to the appropriate optimized part of the FS rendering engine to be processed and displayed after subjected to extra parameters and variables associated with the terrain mesh and other BGL instructions.
But I believe one can
still use a fair number of such autogen and autogen-like objects in a smaller scenery area like an airport project by simply placing them with XML methods via Instant Scenery or other XML object placement utilities.
The trade-off would be that one might NOT be able to display any inherently designed seasonal change in vegetation.
And I don't think one gets as effective of a rendering optimization as one would if XML-placed autogen objects had been placed via the AGN file "batched autogen draw call" part of the FS rendering engine.
But at least one would be able to ensure that selected autogen objects show up at an assigned location and scenery density slider setting.
More specifically to the objective of your quest and query here then:
One must bear in mind also that some of the objects (including some types of polygons and poly-lines) we place at or around airports and other scenery areas EXCLUDE the underlying instructions that would have otherwise resulted in display of autogen even if there was an AGN file for the scenery project area that was intended to put autogen there.
So, IIUC, in those cases one must use manually "XML-placed" autogen objects intermixed with one's other airport and generic buildings to fill back in what had been "excluded" by our other customized work in the area.
However, there are ways to
minimize the impact and extent of some incidental excludes which I have seen discussed at FSDeveloper that may reduce the amount of work required to "fill back in" what got excluded by one's other customized work in the area.
Usually this is achieved by careful use of airport flattens with exclude attributes that are
segmented; rather than the quick-and-dirty huge "single" flatten polygon (that immediately obliterates all autogen beneath it), one uses a
number of flatten polygon types.
FYI: By default, most scenery utilities automatically use the "
Flatten + MaskClassMap + ExcludeAutogen" GUID when making a flatten.
What I am describing here is judicious use of the "Flatten Only" GUID attribute in parts of one's airport where display of autogen is
desired:naturesm:.
You may recall the alternative choices described in the FSX SDK "
Terrain and Scenery.html" document:
"Vector Data - Airport Boundaries
Example - FLX7824
Notes - Although this area is titled Airport Boundaries, these are used for a number of purposes, including flattening a surface and excluding certain types of data, in addition to defining airport boundaries.
The .dbf file contains two columns, UUID and GUID. Enter the following GUIDs in the GUID column to achieve flattening, or autogen or land class exclusions. Airport boundaries are one example of the use of Flatten + MaskClassMap + ExcludeAutogen.
{6c0c6528-5cf1-483a-a586-2c905cf2757e} ExcludeAutogen
{47d48287-3ade-4fc5-8bec-b6b36901e612} Flatten
{5a7f944c-3d79-4e0c-82f5-04844e5dc653} Flatten + MaskClassMap
{1f2baab1-4132-416e-8f6f-28abe79cd60b} MaskClassMap
{46bfb3bd-ce68-418e-8112-feba17428ace} Flatten + MaskClassMap + ExcludeAutogen
{18580a63-fc8f-4a02-a622-8a1e073e627b} Flatten + ExcludeAutogen
{594e70c8-06a5-4e3f-be6e-4dbf50b49d11} MaskClassMap + ExcludeAutogen"
© 2007 Microsoft Corporation. All rights reserved.
One might have better granularity of area control (and thus save the work you might be now considering) by using a number of "flatten-with-autogen-exclude" polygons interspersed with "flatten-only" polygons when flattening the airport (all with matching elevations), and using segmented airport backgrounds to minimize un-desired exclusion of autogen.
Then one can overlay the segmented "flatten-only" polygons using polygons "textured" with land class that has associated "autogen" to reduce the need for individual XML-placed autogen objects. :iidea:
Besides, it might be nice for a change, to
purposely take advantage of having those darn persistent autogen trees pop up through a part of the airport that we
actually want them to, right ? :d
Jim Vile (aka jvile of ADE and 9 Dragons Kai Tak Scenery renown) has used this approach:
http://www.fsdeveloper.com/forum/showthread.php?t=16694&highlight=autogen+exclude
Note that in this scenario, we are are creating "holes" to allow nesting of land within land polys, rather than the more commonly seen nesting of islands within water polys.
But it seems that for
total control, the sequence that Jim Vile uses is to:
"
exclude everything then add back the basic Airport landclass, flatten /exclude autogen"; then "add many different types of LC with autogen so the polys use the default FSX blending."
Hope these ideas help !
GaryGB
