Curve Angle
Monkey Forums/Monkey Programming/Curve Angle
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| Hi All, I'm new to Monkey but have been using various different engines for a few years now. I'm currently working a car game and have hit a bit of a wall. I need to smoothly rotate from one angle to another, in other engines I would use something like Lerp (3D) or CurveAngle. I cannot seem to find a similar function in Monkey. Say my (top down 2D) car is facing 45 degress and my next waypoint is at 90 degress, how would I smoothly rotate the angle? Thanks in advance. |
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| Sin/Cos/Atan/Atan2 Search for those commands. |
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| it's called "tweening" for 2d. check out monkey/bananas/skn3/tweening or diddy http://monkeycoder.co.nz/Community/posts.php?topic=4589 or http://monkeycoder.co.nz/Community/posts.php?topic=4173 or box2d https://code.google.com/p/monkeybox2d/ |
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| Hi Monotonic, Might have misunderstood.. can't you just have a variable for the angle, increment it in the OnUpdate loop, then use the rotation parameter to DrawImage in your OnRender loop? |
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| Sin/Cos/Atan/Atan2 Search for those commands. Calculating the angle is not a problem, I got my head around basic trigonometry many moons ago. it's called "tweening" for 2d. check out monkey/bananas/skn3/tweening Tweening! That is what I was looking for, I'm used to working in 3D so was searching for things like 2D Lerp and 2D Interpolation which returned nothing useful. Thank you. |
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That's it:Function Lerp:Float(value1:float, value2:float, speed:float) Local dif:Float = value2 - value1 speed = Abs(speed) If Abs(dif) < speed Then Return value2 Return value1 + speed * Sgn(value2 - value1) End You can also use non lienar interpolation for "slowly stopping" interpolation: Function Eerp:Float(value1:float, value2:float, speed:float) Local dif:Float = value2 - value1 Const NARROW_FACTOR:Float = 10.0 'Avoid interpolation to be too quick. value1 += dif * (speed / NARROW_FACTOR) Return value1 End If you multiply the speeed factor by any deltatime factor, you should get smooth tweening if this interpolation is used on animations. Maybe this could be built-in to the Monkey Math module? |
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| @ziggy Interesting, I will try that function out when I get home after work. Thank you for that :) It really should be built into the Monkey framework as this method is used quite frequently in many different languages, I was surprised when I couldn't find it in the docs. Edit: I'm using you IDE btw, great work! Edit 2: Does this forum not send out notification emails when a reply is posted? |
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| I'm using you IDE btw, great work! Thanks! That's very appreciated! Does this forum not send out notification emails when a reply is posted? You have to subscribe to the thread. Notice the small "subscribe" label at the bottom left area of the page.Edit: To use it on a 2D vector, be sure to normalize the vector and multiply speed for X and Y of the normalized vector. The same applies for 3D, etc. |
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| Well, I'm a complete muppet when it comes to this stuff. Anyone got a nice pointer to what tweening is, and how it can help? |
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| In the context of what I'm doing its the process of gradually rotating from one angle to another. For instance cars don't go from one direction to another instantly, they gradually turn until they reach the desired angle. The term also applies to moving from one animation to another in a smooth manner rather than jumping instantly. |
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| Ah, sounds exactly like the kind of stuff I've been wanting to do.. |
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