[Goku]

That Genset Foamer, on 06 October 2015 - 09:44 PM, said:

Also, could curve radius be constrained by the user (selecting a design speed or manual input), meaning that only arc and thus arc length need to be computed by the sim?

Here you can see example use: https://www.youtube....h?v=BH6pUjOMqdA
(I did only one curve solution that only sometimes works).

You know only position and rotation of two endpoints.

Instead of calculating R1, R2, A it will be fine to calculate P3 and something about vector V. Maybe that will be easier.
With P3 and vector V i can split two curve solution into two separate one curve solutions.

http://i.imgur.com/qKM5IQO.png

[That Genset Foamer]

Update--Found that the bearing for the tangent can be related to the bearing from the two angles. This new point where the opposing points of tangency intersect (Here, the PT of Curve 1 and the PC of Curve #2).


The first constraining equation is the one fixing the bearing of point "I", this intersection, to the known bearings.

I = C + A
I = 90 - A + D

C + A = 90 - A + D ---> 2A + C = 90 + D -----> 2A = 90 + D - C

Therefore A = (90 + D - C) / 2 is one constraining identity.

The second constraint is that the tangents must be identical between one bearing of the curve and

T₁ = R₁tan(A/2)
T₂ = R₂tan((90-A+D)/2)

The length between the PI of curve 1 and the PI of curve 2 are the sum of both tangents, plus any added tangent the user inserts.

Attached File(s)

•  CurveProblemWithTangents.jpg (19.16K)
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[Goku]

I think 90 - A + D on my image could be wrong.
Look here:

http://i.imgur.com/niDSfs8.png

[Goku]

Another question. Is any open source ACE compression software awailable? Something like aceit? Or I need to write all by myself?
Now I have only uncompressed rgb. No dxt and no mipmaps.

[James Ross]

Goku, on 07 October 2015 - 11:53 AM, said:

Another question. Is any open source ACE compression software awailable? Something like aceit? Or I need to write all by myself?
Now I have only uncompressed rgb. No dxt and no mipmaps.

My personal project has an ACE writer which includes compressing with DXT1 (lossy) and RGB with ZLIB/DEFLATE (lossless) in C#. License is BSD 2-clause so you should be able to do whatever you like with it (whether that's translating the code to C++ or just seeing how the formats are implemented). :)

[disc]

Goku, on 07 October 2015 - 11:53 AM, said:

Another question. Is any open source ACE compression software awailable? Something like aceit? Or I need to write all by myself?
Now I have only uncompressed rgb. No dxt and no mipmaps.

What do you save in ACE? is it connected to route editor?

[Goku]

disc, on 07 October 2015 - 12:42 PM, said:

What do you save in ACE? is it connected to route editor?

Yes. Terrain painting uses this feature. It will be also possible to put png/bmp textures on terrain tiles with auto convert.



Also I will make ui for texture conversion like tgatool/aceit.

[disc]

Goku, on 07 October 2015 - 01:12 PM, said:

Yes. Terrain painting uses this feature. It will be also possible to put png/bmp textures on terrain tiles with auto convert.



Also I will make ui for texture conversion like tgatool/aceit.

Will be DDS support too? Maybe ACE is needed for MSTS, but for OR DDS is better.

[eugenR]

Goku, on 06 October 2015 - 10:34 PM, said:

I think 90 - A + D on my image could be wrong.
Look here:

http://i.imgur.com/niDSfs8.png

I Think it is: C + A = D + X or X = C + A - D
If you think first the Tangentialline thru the Point P3 now rotate it along the circle to the Point P1 (Angle A)
now you rotate the Tangentialine in the Point P1 to the vertical (Angle C).
And now the same on the other side.

both sum of Angles (A +C) and (D + X) are equal:
They start on the same Angle in Point P3 and end in the vertical.

[conductorchris]

When thinking about curves, don't forget that most don't go straight from tangent into curve but have a "spiral" section that eases into the curve.
Christopher