Axis Display in Irrlicht

Mr_Ridd · Post by **Mr_Ridd** » Tue Oct 05, 2004 11:38 am

Hey

I'm writing a 3D level editor and I need to display the axis in the bottom left hand corner of the screen. Like the way Maya and 3DS Max do it. The problem is that I can't just draw lines because if I move my camera then they will disappear.

What other way could I do this?

Thanks

bal · Post by **bal** » Tue Oct 05, 2004 5:21 pm

If I understand you well, use an image?

Mr_Ridd · Post by **Mr_Ridd** » Wed Oct 06, 2004 5:16 am

Thats not gonna work because I need the image/line/whatever to rotate according to the camera. If you look at Maya or 3Ds Max you will see what I mean. Not the big grid in the middle of the screen, the little axis lines at the bottom left.

bal · Post by **bal** » Wed Oct 06, 2004 2:30 pm

If it has to face the camera (always), then you could use an image as a billboard and place it at the right position (srry, no Maya nor 3DS here

) ?

Mr_Ridd · Post by **Mr_Ridd** » Mon Oct 11, 2004 7:28 am

The problem is that it's not just a flat image. What I basically need to know is what axis the camera is looking down?

bal · Post by **bal** » Mon Oct 11, 2004 5:18 pm

Hmm, draw3DLine() then (http://irrlicht.sourceforge.net/docu/cl ... r.html#a22) ?

Mr_Ridd · Post by **Mr_Ridd** » Tue Oct 12, 2004 5:12 am

Yeah, thats what I was originally going to do but I need the lines/axis to stay in the same place on screen regardless of how I move the camera. I think what I will have to do is attach the lines to the camera via co-ordinates. I can't use attachChild() because then they won't move.

bal · Post by **bal** » Tue Oct 12, 2004 4:49 pm

Then they will move, they'll change their position according to the camera's position. Or is this what you want?

turboferret · Post by **turboferret** » Tue Oct 12, 2004 5:19 pm

couldn't you use

Code: Select all

core::line3d<f32> getRayFromScreenCoordinates(
00084                         core::position2d<s32> pos, ICameraSceneNode* camera = 0)

in some way?

if you use that and just make it a little shorter you get one of the lines you need (Z). then just rotate it in the correct angles and you have your axis'.

Tyn · Post by **Tyn** » Tue Oct 12, 2004 6:10 pm

Is there some reason you can't use the axis dependant billboards that are in NX for this purpose?

Mr_Ridd · Post by **Mr_Ridd** » Wed Oct 13, 2004 5:24 am

couldn't you use

code: core::line3d<f32> getRayFromScreenCoordinates(
00084 core::position2d<s32> pos, ICameraSceneNode* camera = 0)

in some way?

Not really. That won't give me a fixed position.

Is there some reason you can't use the axis dependant billboards that are in NX for this purpose?

Perhaps I don't understand billboards.
Would you have a screenshot that I could see what you mean?

bal · Post by **bal** » Wed Oct 13, 2004 3:46 pm

A billboard is a 2D image which always faces the camera (rotates, but does not change position..[/b]

Tyn · Post by **Tyn** » Wed Oct 13, 2004 4:23 pm

...and an axil dependant billboard doesn't rotate to face the camera in one direction, so if you disabled the Z axis one then it wouldn't rotate on the Z axis but would rotate to face on the other two, therefore always aligned with the Z axis. This isn't implemented in Irrlicht but is in NX, although I've not used it yet. It should be exactly what you need for this.

Mr_Ridd · Post by **Mr_Ridd** » Thu Oct 14, 2004 5:19 am

It's sounds like it will work. I can't get IrrlichtNX though because I can't connect to the server.

calimero · Post by **calimero** » Thu Oct 14, 2004 10:50 am

hello, I'm the author of the axial billboard stuff (with some help of people around here

)
the version put in irrlichtnx is a little buggy but I think you can try it to see if it suits your needs. The new version is in the new patch section of the irrlicht forum but unfortunatly not put in the standard release of NX