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arno

BGL Compat

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Devs,we are considering snipping BGL so that it is only a container system, no rendering behavior.what beside the category system and seasonal variation is currently in use by 3PDs?thanks!

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Hello Phil,Thanks very much for keeping us informed; this is definitely a first!Could you please elaborate on what you mean. To what do you refer when you mention rendering, and what precisely is the category system, a term with which I am not familiar, in any case.Many thanks.Best regards.Luis

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The category system is the thing that does layered drawing (e.g. decals). We are looking at ripping out all rendering behavior defined in BGL. Thus BGL becomes "container only".So anything else in use by the dev community? No BGL streams?

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Hi Phil,I would say the following features are currently missing in the MDL format that are important:- decals / zbias (as you mentioned)- conditional display of parts of the object or the total object, for example let something only appear at a certain time of day or when a certain frequency is tuned. This kind of functionality is really important to be able to make interactive scenery that is interesting to the end user.- conditional display of textures, this could be for seasonal textures, but also to switch textures on other conditions. This is for example very useful for making a functioning docking system as well.The fact that all this kind of functionality is currently missing, making it almost impossible to make realistic dynamic objects, like a docking system or even an Christmas tree that only appears in December. For all those things designers have to stay at the FS2004 MDL format for now. I would really like to see that improved in the future, as else we would loose a lot of functionality that is needed in addons.

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Phil, just read your post on the FSDeveloper forum and as it is in the terrain section there, are you talking about the terrain BGL files here? In that case I misunderstood your question.

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Arno,thanks for a nice list of what is missing from MDL.are all of those part of BGL today? that is what I am really after, what else is BGL being used for in terms of rendering?thanksPhil

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Hi Arno,I guess the MDL would not be the best place for rendering logic as you may want the same MDL to be drawn at different locations under different conditions. So it should go to where the MDL is invoked from.Siggy

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Hi Siggy,>I guess the MDL would not be the best place for rendering>logic as you may want the same MDL to be drawn at different>locations under different conditions. So it should go to where>the MDL is invoked from.That depends on the kind of logic. If you are making a docking system, which is a sort of animation (but then driven by distance not by time), I think it should be in the MDL file. It makes no sense to drive that from the placement, you just want to place the object that contains this logic at a certain location.The same is true for most seasonal textures or other kind of conditions. But for making an object only visible in a certain month or so I agree that would be nicer from the placement XML. But if I want a condition on a part of the object it should be in the MDL again I think.

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Hi Phil,>thanks for a nice list of what is missing from MDL.>>are all of those part of BGL today? that is what I am really>after, what else is BGL being used for in terms of rendering?I am not sure what you would call part of BGL today. We can create that kind of things with the FS2004 MDL format, which uses the BGL opcodes for them similar to the FS2002 BGL format (the BGL files made with BGLC).But a lot of other BGL files exist of course in FS, for example terrain BGL files made with resample or shp2vec or airport BGL files made from XML with BGLComp. In those last formats that kind of tweaks are not there.

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Hi Phil.The conditional rendering can be snipped from models, as long as there is a provision to allow conditional rendering of those models elsewhere in the sim.For example, 3 wildebeast models: walking, swimming, and thrashing about.The sim should allow conditional display controlled to force swimming model when in water, and thrashing about model when in water, and touching a crocodile. This isn't too far from what is already in the mission system.These models could be contained without the need for conditional display.The same would be true for a cottage. It could have 3 models: dry, wet, and snow-covered. The conditional display of these models could be controlled by another means, outside the BGL structure. ( Perhaps MDL structure is what we are actually writing about ).This would simplify model-making.As far as aircraft, this could allow dirt, damage, or ice on the aircraft, as separate models. Any conditional logic to display those models would have to be separate from the models themselves.As long as there are ample provisions in the sim for conditional logic, keeping models separate is not a bad idea at all, and designers will welcome the change... as there art few conditional provisions in FSX.Dick

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>The category system is the thing that does layered drawing>(e.g. decals). >>We are looking at ripping out all rendering behavior defined>in BGL. >>Thus BGL becomes "container only".>>So anything else in use by the dev community? No BGL streams?A container system,hmm. If it can allow for higher-perf, sounds good.I am not "quite" sure what you are driving at, but I can tell you what things, in bgl, that I *have* used:1) time zone bgl2) seasonal bgl3) landclass/waterclass bgl4) apx (airport) bgl5) obx (object/gmax/3dsmax) bgl6) cvx (vector data) bgl7) dem terrain mesh bgl8) AI traffic bgl---------Regarding MDL format, in addition to what Arno said, the MDL format needs the capability to allow custom ground polys--at present FS2002 SDK methods must be used, along with hacks to the .MDL to get this working.----------I also have neat ideas about "smooth-ens" instead of "flattens" for airports, to give sloping runways. But then, I know the complexity of doing that as it relates to AI.----------I'm typing too much :DRhettAMD 3700+ (@2585 mhz), eVGA 7800GT 256 (Guru3D 93.71), ASUS A8N-E, PC Power 510 SLI, 2gb Corsair XMS 3-3-3-8 (1T), WD 150 gig 10000rpm Raptor, WD 250gig 7200rpm SATA2, Seagate 120gb 5400 rpm external HD, CoolerMaster Praetorian

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>Regarding MDL format, in addition to what Arno said, the MDL>format needs the capability to allow custom ground polys--at>present FS2002 SDK methods must be used, along with hacks to>the .MDL to get this working.I would prefer that to be put into the XML format, so that the BGLComp Apron like commands can be used with different textures and texture mappings. But we might be going off-topic for this thread now :).

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