Thu Sep 01, 2011 1:18 am
Fix displacement range on a per-cylinder basis
Background
And it happened again, it is like groundhogs day, the ever reappearing question here on the forums is:
"How large/small will I be able to make an engine of type X?"
The worst thing with it: it's a perfectly valid question. Until now I have not seen a clear concept for what
displacement an engine of type X can have and why. So I'd like to make a suggestion that will save these
forums from further questions of the above stated form (that's wishful thinking really), and probably
save the developers quite a bit of work:
Fix the displacement range on a per-cylinder basis, regardless of engine type.
My suggestion: 100ccm to 1200ccm per cylinder. (Makes a 9.6L V8 and a 1.2L V12)
Current Situation
The Inline-4 engines we currently design have a minimum displacement approximately 400 ccm, and a
maximum displacement of around 3100 ccm. This is a really good and sensible range for Inline-4 engines.
How?
The current displacement range of 100ccm to about 770ccm is not enough for the big V8 engines that have
been built, while the lower limit even in a general perspective makes sense (with my limited knowledge).
Displacement is a function of stroke and bore, and thus in order to fix the displacement range, both the
stroke and the bore range have to be fixed, i.e. made the same for all engine types (further simplification
that does not hurt).
Why?
This is the crux of the whole thing, and the repetitive forum questions are definitely a minor point here
Advantages:
- Modeling of components: Currently we have three engine block sizes for the Inline-4 engines: small,
medium, and large. Modeling parts may not necessarily be very difficult to do for Daffy, but it takes a LOT
of time. With this simple change sizes stay constant, which means existing models are easier to reuse and
thus, potentially saves a lot of time.
- Modeling of physics: What has to be modeled for large V8s is equally applicable on I4s... at least on the
inside of the cylinders. As all of them behave more or less the same way, modeling them individually would
be a lot of time wasted that could be spent on improving other areas of the game.
- More freedom: Fixing this range automatically means more freedom of choice on all engine types as the
minimum and maximum have to fit the lowest and highest displacement engines respectively.
- Emergent behavior: Why not build a I3 with 3.6 L!? Well, because it probably would suck (be very rough)!
Car nuts will try out stuff like this with joy.
Disadvantages:
- Emergent behavior: There is a downside here for the exact same reason: it may frustrate people less versed
in the art of engine building... but fear not:
- Solution: Each engine type can have a "suggested" displacement range:
Engine displacement shown in white: within suggested range
Engine displacement shown in yellow: slightly outside of suggested range
Engine displacement shown in red: quite a bit outside of suggested range
This in combination with a mention in the description text will work wonders.
Conclusion:
Everyone wins, the developers save time on modeling 3D-art as well as physics, and the user has some more
freedom designing his/her engines.
/Robert
And it happened again, it is like groundhogs day, the ever reappearing question here on the forums is:
"How large/small will I be able to make an engine of type X?"
The worst thing with it: it's a perfectly valid question. Until now I have not seen a clear concept for what
displacement an engine of type X can have and why. So I'd like to make a suggestion that will save these
forums from further questions of the above stated form (that's wishful thinking really), and probably
save the developers quite a bit of work:
Fix the displacement range on a per-cylinder basis, regardless of engine type.
My suggestion: 100ccm to 1200ccm per cylinder. (Makes a 9.6L V8 and a 1.2L V12)
Current Situation
The Inline-4 engines we currently design have a minimum displacement approximately 400 ccm, and a
maximum displacement of around 3100 ccm. This is a really good and sensible range for Inline-4 engines.
How?
The current displacement range of 100ccm to about 770ccm is not enough for the big V8 engines that have
been built, while the lower limit even in a general perspective makes sense (with my limited knowledge).
Displacement is a function of stroke and bore, and thus in order to fix the displacement range, both the
stroke and the bore range have to be fixed, i.e. made the same for all engine types (further simplification
that does not hurt).
Why?
This is the crux of the whole thing, and the repetitive forum questions are definitely a minor point here
Advantages:
- Modeling of components: Currently we have three engine block sizes for the Inline-4 engines: small,
medium, and large. Modeling parts may not necessarily be very difficult to do for Daffy, but it takes a LOT
of time. With this simple change sizes stay constant, which means existing models are easier to reuse and
thus, potentially saves a lot of time.
- Modeling of physics: What has to be modeled for large V8s is equally applicable on I4s... at least on the
inside of the cylinders. As all of them behave more or less the same way, modeling them individually would
be a lot of time wasted that could be spent on improving other areas of the game.
- More freedom: Fixing this range automatically means more freedom of choice on all engine types as the
minimum and maximum have to fit the lowest and highest displacement engines respectively.
- Emergent behavior: Why not build a I3 with 3.6 L!? Well, because it probably would suck (be very rough)!
Car nuts will try out stuff like this with joy.
Disadvantages:
- Emergent behavior: There is a downside here for the exact same reason: it may frustrate people less versed
in the art of engine building... but fear not:
- Solution: Each engine type can have a "suggested" displacement range:
Engine displacement shown in white: within suggested range
Engine displacement shown in yellow: slightly outside of suggested range
Engine displacement shown in red: quite a bit outside of suggested range
This in combination with a mention in the description text will work wonders.
Conclusion:
Everyone wins, the developers save time on modeling 3D-art as well as physics, and the user has some more
freedom designing his/her engines.
/Robert
