Rotating 3D object DirectX VB .NET

Question

3.00/5 (2 votes)

See more:

Hi guys I'm a begginer in DirectX and now I'm writing a small 3D demo app where you have an object and the goal is to rotate this object around X and Y axes with the mouse, this is my code:

VB

device.Transform.World = Matrix.RotationY(0 - _
(Control.MousePosition.X / int3DSpeed))'rotate around Y
device.Transform.World = Matrix.RotationX(0 - _
(Control.MousePosition.Y / int3DSpeed))'rotate around X

The problem is that VB is executing only the first assignment:

VB

device.Transform.World = Matrix.RotationY(0 - _
(Control.MousePosition.X / int3DSpeed))'rotate around Y

and the second one:

VB

device.Transform.World = Matrix.RotationX(0 - _
(Control.MousePosition.Y / int3DSpeed))'rotate around X

is always ignored.

What is wrong with my code, how can I rotate the object on X and Y axes simultaneously?

Posted 26-Nov-11 10:49am

O.G.I.

Updated 26-Nov-11 10:51am

v2

Add a Solution

Comments

LanFanNinja 26-Nov-11 19:42pm

Check solution below

2 solutions

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Sergey Alexandrovich Kryukov · Answer 1 · 2011-11-26T14:20:00

Let me explain this obvious thing about what happens: you assign two different values to the same object device.Transform.World, one value in first statement, another value in second statement. In this way, only the second statement has effect, the result of first one is lost.

I have no idea why do you feel that the second statement is ignored. In fact, "ignored" is the first one, more exactly, has no effect. I think you just misinterpreted the result of rotation. Remove first statement and check it up.

Nothing is ignored, which you can easily see by running this code fragment under debugger. Please always run you code in question under debugger before making any statements and asking questions.

As to combined transform, it is obtained via matrix multiplication.

—SA

LanFanNinja · Answer 2 · 2011-11-26T13:42:00

Solution 1

Try this

VB

device.Transform.World = Matrix.Multiply(Matrix.RotationY(0 - (Control.MousePosition.X / int3DSpeed)), Matrix.RotationX(0 - (Control.MousePosition.Y / int3DSpeed)))

Posted 26-Nov-11 13:42pm

LanFanNinja