Tuesday 5 November 2013

Tuesday Tweakipoos

Performance Gives Way

A strange mixed bag of a day, with some phone calls, email chasing, an interview and quite a few non-performance tweaks in the latest build. I also had a few static entity bridges lying around that I added to the library too.


Not my best shot in the world, but not bad for only a few minutes of messing about while working on the physics stuff.  The latest build now fixes the strange physics issue with dynamic objects sinking into the floor due to an error in how the physical rotations where applied to the visual objects for rendering. I also changed the way Reloaded understands the 'collisionmode' flag in the FPE to increase the change that legacy artwork can load into the editor with full polygon collision in tact (so you can go into buildings designed to do that).

The downside to activating polygon collision on static entities is that they are insanely hungry for performance. We are not yet at the stage where we can happily throw thousands of polygons at the player and expect him to jump. For a single core CPU solution we still need to watch what polygons we move close to the player and dynamic objects, and if possible, to use rotated boxes. I intend to write a simple 'physics editor' which can produce a composite of boxes to represent an entity and then use that in place of a complex polygon soup which is not only bad for speed but also confusing for a physics system which has to solve it 60 frames per second.  I can turn a bridge piece which contains over 200 collision polygons and produce a shape with three sized boxes, making the collision on the bridge smooth and super fast. Naturally this needs to be done with EVERY object, but the payoff in amazing.  Another one for my list, but when you start seeing slow-down when entering polygon soups, you will be requesting this new physics approach daily!

The Fisheye Problem

I have been getting letters!  Apparently the render on Reloaded looks a little 'fisheye'. I keep stating that it's just the product of FOV and ASPECT, and entirely the result of a simple left handed perspective projection, but no-one quite believes me.  If anyone is getting 'fisheye', turn your FOV down to 60 and then let me know if you still suffer from it.

Here is a typical scene from Rick:


And here it is when you glance upwards:


Is this normal, or common for a wide FOV game rendering. It would be good to see actual AAA games in similar situations, and whether nearby buildings scew when you look upwards (at high FOV).

Signing Off

Had a great interview over Google Talk today regarding Reloaded, so I will announce that when it comes out.  Most of it you might already know, but I am sure I have released a few pearls during my prolonged wittering so probably worth checking, just in case :)  An hour left, so I will wrap up an internal version send it to the internal team for testing, then some food.

9 comments:

  1. Hey Lee dont worry about the people complaining about "fisheye issue". As soon as I got my hands on Reloaded the very first thing I went for was the FOV settings and I was able to make my view perfect. No need to make any changes people just arnt playing around enough with these settings.

    Here's what a scene looks like without settings:

    http://imageshack.com/i/mslbkyj

    And with FOV settings modified with the sliders:

    http://imageshack.com/i/0ta8roj


    Everyone that is still complaining about the fisheye stuff should really check out the two links about...

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  3. Tyrone, if you compare settings you should really try to use the same picture.

    I play around with settings, and the problem is when you lower the FOV you also seem to lower the speed of the charatcter moves. That IS an issue.

    I also wonder what the FOV zoom settings are all about as it doesn´t seem to do anything? In fact, a lot of the camera settings seems not to work, I can not spot any difference when using most of them. Only the FOV and Ratio setting seems to do anything. But even these seems to "freeze" once in a while.
    I got a brand new GTX 760 card so I think it would handle it.

    As I got a brand new Windows 7 installation I have no AAA game installed yet so I cant really compare at the moment, but I will :)

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    1. "Tyrone, if you compare settings you should really try to use the same picture."

      YES! How can we be expected to compare to different images? Set the FOV to default, take a screenshot, then without moving the screen or player AT ALL, set the FOV to your custom setting and take another screenshot.

      "I play around with settings, and the problem is when you lower the FOV you also seem to lower the speed of the charatcter moves. That IS an issue."

      Actually it doesn't. Really. It _seems_ like it slows down the character, but trust me, it's moving at the same speed. And this is why:

      With a wider FOV, you can see more to the sides (including stuff that's closer to the camera), which means it appears to moving faster than when you lower the FOV, at which point you can see less stuff to the sides (and therefore, unless you look down, less stuff that's close to the camera and "moving" fast).

      "In fact, a lot of the camera settings seems not to work, I can not spot any difference when using most of them. Only the FOV and Ratio setting seems to do anything. But even these seems to "freeze" once in a while."

      I suspect those settings are placeholders that don't do anything yet. I can guarantee it's nothing to do with your graphics card :)

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    2. You can't notice the difference of the extreme angles? Didn't expect everyone to be that picky lol I understand its more helpful if its the exact same scene. But cant you see the difference in the angles? In any case Rick has his example above to better illustrate. with the wall to the right. I can't help you guys much its too much effort lol

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    3. The problem is not that we can't see the difference. You'd have to be blind to not see it. The problem is that we can't compare the difference based purely on changes to the FOV, because the camera also moves.

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  4. Hello Lee,
    i'm interested in making some buildings/props or objects in general for FPSC:R but i can't find any informations or guidelines.. i asked in forum but without any replies :( i also noticed that simple x object cast shadow buto do not receive any shadow from other objects. i think is because they need a normal map or shadow map but i'm not 100% sure.. any clues/help/tutorial to help me and other users that want to create media for FPSC:R?

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  5. Hi Lee, I coincidentally happened to notice the same slightly "fish eye" view when playing the dayz mod of ARMA2 some days ago and I started thinking that I might have seen this in more games in the past. I think it's perfectly normal to have a distortion like you mentioned in your article. Keep up the work, can't wait for the next release!

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  6. It is true to say that all lenses I guess at least have some distortion. Real life cameras and game engines, 3D software with cameras and so on depending upon aperture settings and the lens and so on and screens/lenses have more marked distortion towards the boundaries.

    Thus its not to be expected that Reloaded have none - its just it seems to me that it is a little extreme. In most game play scenarios no one really notices slight differences as we see it all the time in these things, however as we are looking at and scrutinizing Reloaded here as Beta testers if you like, often not in the actual heat of game play and also with mostly few other world objects to mask our entities in an otherwise mostly bare world the eye is easily drawn to the extremities.

    In a heavily populated entity scene say a forest with trees, grass, bushes, fences, buildings and so on in game play you just don't really look or worry about it, wheres a single of few trees or single building in a bare landscape can and is the focus of criticism. It can bee seen in the photos above that the distortion (leaning) I have to admit does seem rather extreme compared to other software I use and looked at here including other engines and is hard to miss and so obvious as we are looking for it. The lines of the buildings sides being so acute and hard against the background that its hard for us to see it as correct visually. You would not want to have your house built like that would you and don't expect to see them so leaning as the human eye does not distort to the same extent.

    I don't know exactly why the effect seems so marked here but as is I don't see anything Lee can do much to help from this end. I think you may just have to accept and live with it and do the best you can when building your game and with available settings to mask it somewhat.

    :-)

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