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Guest Milton

Aircraft and FPS

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Here is a question for all you aircraft and panel designers from someone who knows virtually nothing about how this is done.For that reason I would really appreciate an answer in simple understandable terms if this is at all possible.My question is --- Why is it that some aircraft are more frame rate friendly than others- notwithstanding any scenery settings?I have found that I have various addon aircraft that will ,in exactly the same circumstances ,give widely differing frame rates.The strange thing is ,that often ,the better looking models(more detail) seem to be less damaging in terms of fps.Being more or less ignorant of how this all works I would have expected that the more detail the bigger the FPS hit.Much the same seems to apply to panels- some are much heavier on fps than other even tho they may not look that much different.Any explanations would be much appreciated .Dave

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Hi Dave,Great question that we all have struggled with. The fact is there are many variables in the mix. This is just my observation:Aircraft contributions to FPS hits (spot view): model complexity (high number of polys to be rendered), number of textures, size of textures, format of textures, number of and complexity of animations, all of the aforementioned on animated objects, lights, other visual features like reflectivity, specular lighting, transparency, etc.Your Computer constraints: cpu speed, amount of ram, video card speed and on-board memory (or shared), speed of ram, bus speeds, sound card (or lack of), lack of contiguous hard drive space, hard drive speed (access and fetch times), FS settings, video card settings, aperture setting, etc.The appearance of the model may have little to do with the FPS hit. A great looking paint scheme with lots of detail can hide a fairly basic model. A simple basic paint scheme may have a very complicated model beneath it. It does not matter what is on the texture, what matters is the size of the textures and the number of them. Do they cause your video memory to be exceeded.Your computer configuration may suit one model better than another because of the above listed attributes. Sometimes, video memory will be the largest constraint, sometimes video card speed will be.Sometimes you will find that the resolution you run is not best suited for your video card. Sometimes a higher resolution or color depth works better. What happens if you run 16 bit color and fly a model that has 32 bit textures?Unfortunately, no magic bullet here. Designers must find the best balance of the aircraft model package attributes to suit the masses they target. Getting the best we can out of every aspect of the package while trying hard to constrain our enthusiasm for the sake of FPS is a never ending challenge.We try to keep our eyes on FPS in every phase of the project. All decisions are made with FPS in mind whether it is about textures, panel design, gauges, poly's, VC detail, or sounds. Three weeks ago, I had 90 MB of textures in the current project. I am now down to 12MB and still finding ways to further reduce that. The end result has been a significant improvement in load times and FPS, but a loss of detail, most of which is acceptable to me. I invested 3 weeks in additional model optimizing and 2 weeks in textures so far. There is always more that can be done.Regarding panels, there are many contributors to FPS sluggishness as well. Here are some: resolution, number of gauges, complexity of gauge programming, refresh rates on complex gauges, shape of the 2D panel, number of windows and size and shape of 2D cockpit views textures, conflict with a VC gauge or a duplicate gauge on the copilot side, moving/animated windows (like GPS maps), certain XML functions/events, size of window behind the main panel, low zoom factor, virtual cockpit model detail, texture sizes and quantity, etc.Once again, no quick answer. It takes a lot of time and experience to optimise it all. Sometimes, it seems easier to just throw hardware at it. :-)Hope this helps.Milton

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Thanks MiltonThat is a really full and understandable explanation.I guess the underlaying fact is that ,in this case at least ( the aircraft)what you see isn't neccessarily what you get when looked at in terms of perfomance within FS.As a "user" rather than designer I sort of assumed that the "prettier" the aircraft, the more complex it would be - obviously I was making wrong assumptions to some extent .I can see also how there is a connection between the(visual) complexity of a panel and fps but I didn't realise there were so many other factors to consider in the equation.One other thing to say .You mentioned reducing the "package" size of the aircraft and your efforts to trim it to a reasonable size- it seems to me after 4 years of downloading and trying out aircraft in FS98/2000/2k2/2k4 that in a lot of cases,designers are not perhaps bothering about this so much.Aircraft of 20+ MB are becoming more and more frequent now.I wonder if this is because some designers feel,that as everyone has big HDDs now that they needn't bother to cut the size.However,given what you say,this attitude won't help overall performance.That said - all software seems to be getting bigger anyway.Thanks again for a very interesting postDave

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I think most experienced designers work really hard at this and, in fact, probably are slow to take on more detail, larger textures, complex panels and VC's etc. because of size. Old habits are hard to give up when you had to design within constraints so long.If you contrast FS98 packages to FS9's, they are ions apart in every measureable way. We all want more realism, better detail, improved models, panels, gauges, and systems management functions. The price we pay comes in buying what was not available 4-5 years ago in cpu/ram/video cards and HDD sizes and speed.There were heavy packages in FS98 as well... same performance hits. I loved that old C-133 in FS98.When I go back to fly FS98 and see the 6 and 8 sided blocks used for tires (that did not rotate) ... it's almost laughable but there were severe limits to size then, unlike today.New designers want it all, 48 sided engines and fuselages, all the features, and bump the limits well into the project. Then, it is tough to go cull out the excess later in the project. Eventually the technology will catch up and be capable of handling the more intense aircraft we are starting to see now.Until then, we must cull out what our systems will not handle. :-)

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