SVG Rotation in 3D

Question

I need to rotate the paths in my SVG document around an arbitrary point in 3D. It appears that there are multiple ways to do this by either using a 4x4 transformation matrix or the rotateX or rotateY transforms. I've tried both of these methods, and neither seem to work. Are these supported anywhere?

For my application, a bitmap is going to be the final output, so I'm not worried about browser support. I am open to any tool--I can run a specific browser through selenium, or use a standalone SVG rasterizer.

This is what I've tried so far (using Google Chrome 31):

I would expect this to be a black rectangle, rotated about the X axis, and appearing like a trapezoid.

<svg version="1.1" 
     xmlns="http://www.w3.org/2000/svg" 
     xmlns:xlink="http://www.w3.org/1999/xlink" width="640px" height="480px">

    <rect x="100" y="100" width="440" height="280" fill="#000000" 
          transform="rotateX(30 580 100)"></rect>
</svg>

(omitting cy and cz from rotateX gives the same result).

I've also tried with a 4x4 matrix. I don't see any difference from above. I also doubt my math is correct in finding the right matrix elements.

<svg version="1.1" 
     xmlns="http://www.w3.org/2000/svg" 
     xmlns:xlink="http://www.w3.org/1999/xlink" width="640px" height="480px">

    <rect x="100" y="100" width="440" height="280" fill="#000000" 
          transform="matrix(102400 0 0 0 0 88681.00134752653 -159.99999999999997 1387899.8652473476 0 159.99999999999997 88681.00134752653 -15986.602540378442)"></rect>
</svg>

Answer 1

I found that there really isn't a way in SVG to do a 3D rotation that is supported in any modern browser (to the best of my knowledge). However, CSS3 does have a similar "transform" property.

The following works for me:

<svg version="1.1" 
     xmlns="http://www.w3.org/2000/svg" 
     xmlns:xlink="http://www.w3.org/1999/xlink" width="640px" height="480px">

    <rect x="100" y="100" width="440" height="280" fill="#000000" style="-webkit-transform: rotateX(30); -webkit-transform-origin-y: 580px; -webkit-transform-origin-z: 100"></rect>
</svg>

This, obviously, isn't a good cross-browser solution (as it uses prefixed properties), but that isn't something I need in my application.

Answer 2

3d rotations are tricky and i've only just started using them. transform: rotateX() and rotateY() will apply the transformations for you, but to get that perspective of a trapezoid, you'll need to use perspective in the css of the parent element.

Here's a codepen.

The relevant bits are

#parent {
  perspective: 4rem;
}

#child {
  transform: rotateX(45deg);
}

Think of perspective as the distance the object is from the back of your screen. The lower the value, the more intense the distortion of the perspective will be.