Mesh edges?

fnolis · Post by **fnolis** » Fri Jul 16, 2004 7:50 am

I have a mesh in the shape of a car, and I need to find out how "big" this mesh is, where its front is so that I can draw a missile infront of it when fired and also put lights infront of the car. How do I do it? How can I find the front of the car? and its size?

thesmileman · Post by **thesmileman** » Fri Jul 16, 2004 12:07 pm

Wahoooo lots of questions there. to find the direction the car is pointed you can use the getRotation funtion when you know this you can find out where you need to put the missile. and the lights. You would want to put the lights on the car at the begining of the scene then make them a child of the car so they would stay with the car and then toggle them on an off as needed.

fnolis · Post by **fnolis** » Fri Jul 16, 2004 12:10 pm

Well.... the rotation I have... I need to find out how big the car is and in that way calculate where the lights should be placed... if I set the light (and the missiles) at the default (0,0,0) then it will be placed in the middle of the carmesh... so... what I'm after are the "box" around the car...

Felipe · Post by **Felipe** » Fri Jul 16, 2004 12:47 pm

I needed to do something similar, but with a gun instead. I don't remember exactly how I did it, but if you take a look in the Newton+Irrlicht tutorial, you'll see how to get vertices out of the mesh. Just save the vertex with the largest X (or Z) value and use that for placing the lights.

Tyn · Post by **Tyn** » Fri Jul 16, 2004 12:51 pm

What I would do is open up your car mesh inside your modeller and find the 3D position that you want the lights to be. Then, create the effect and add it as a child of the car mesh. You will then be able to enter the position you found inside your modeller and it will be correct.

You will also not need to worry about rotation as whatever rotation the car is set to will be translated to the car light or whatever effect you plan to have.

thesmileman · Post by **thesmileman** » Fri Jul 16, 2004 12:58 pm

Just try a few positions for the lights at the start of the scene until they are where you want them on the car then make the lights children of the car and you will not have to worry about them anymore only the car.

EDIT: I see Tyn already beat me to it.

Felipe · Post by **Felipe** » Fri Jul 16, 2004 12:58 pm

but what if he has different car models? He'd have to pre-locate the headlights for every model.

thesmileman · Post by **thesmileman** » Fri Jul 16, 2004 1:01 pm

Felipe wrote:but what if he has different car models? He'd have to pre-locate the headlights for every model.

Well of course, how is Irrlicht supposed to know where the lights on a car should go without the programmers guidence? You could simple have that data stored and then read in when a new model is loaded.

Felipe · Post by **Felipe** » Fri Jul 16, 2004 1:09 pm

well, he could use the method I described above. Having to code the coordinates would not allow players to create there own cars. Players love messing around with game data.

Tyn · Post by **Tyn** » Fri Jul 16, 2004 1:12 pm

If they want to add their own meshes then they will have to define where abouts they want the lights exactly the same as they would have to define where the wheels would go on the car. Unless you wanted to model the car around a set of lights and wheels which not be a very intelligent solution. It doesn't need to be hardcoded but it DOES need to be defined.

Felipe · Post by **Felipe** » Fri Jul 16, 2004 1:55 pm

I guess that's the easiest way to do it. Though, to me it feels like I'm doing something for the code that it could be doing by itself. Sorta like if a math game were to ask you the answer to a problem so it could tell you if your kid's answer was right or not.

thesmileman · Post by **thesmileman** » Fri Jul 16, 2004 4:58 pm

Felipe wrote:I guess that's the easiest way to do it. Though, to me it feels like I'm doing something for the code that it could be doing by itself. Sorta like if a math game were to ask you the answer to a problem so it could tell you if your kid's answer was right or not.

NO its not the easiest way to do it. It is the only way. The location of the lights HAVE to be defined unless they are their own model. To Irrlicht the model is a set of trinagles nothing more nothing less (Well there are some normals and some other stuff but who cares).

thesmileman · Post by **thesmileman** » Fri Jul 16, 2004 5:01 pm

Sorrey for that I am really not feeling well and I haven't slept in two days. Some of you may have noticed I have been on the fourm for two days straight and have moved from 10th to 6th in total number of posts in just three days

I just got back from the doctor and he says that I have really bad asma even though I have never had it before. My chest is hurting and I can barely breath. I am 22 and I get #@@(#(!(!!! asma what the @#$!!!!

Anyway sorry just a little pissed.

Tyn · Post by **Tyn** » Fri Jul 16, 2004 5:42 pm

*off topic*
Quit smoking then

*on topic*

Though, to me it feels like I'm doing something for the code that it could be doing by itself

If you can write some code that can figure out what you were thinking then I think some goverment officials may be interested in it

fnolis · Post by **fnolis** » Sat Jul 17, 2004 10:17 am

some code would be good...
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