Hello!

I'm trying to figure out how to create a sky dome in Houdini so I have a 360 Degree sky the camera can view. I don't want to composite right now, I just want this in the scene. How do you go about doing this? Is there a tutorial on this somewhere?

Thanx

Made a Example.

I just changed the camera setup:
Camera -> View -> Projection: Polar

Hello Mandrake0!

Thanks for the file! Camera Projection: Polar I see is set, and I plug a HDRI sky image into the background? When I move the camera, it switches to perspective on it's own. I guess I"m not doing this right… Do I need to create a giant sphere and project the image inside the sphere?

You can't just put your texture on an environment light?

I tried that, but it only acts as a background. As soon as I pan the camera it still looks the same when I want it to pan the sky… sorta like a skydome in Maya or 3dsmax … you see this all the time in Houdini ocean scenes with an iso offset for the fog to give it a nice falloff in the horizon.

Think of a camera inside a dome… you pan the camera around and it see's an entire HDRI Sky that's wrapped inside

mestela
You can't just put your texture on an environment light?

What happens when I use environment light is that yes, you can rotate the camera around, and view a spherical sky … that's fine… but translate the camera left or right, the sky stays still and the foreground moves …

Does anyone know of a way to make this all work? Do I have to somehow connect the image map to the translation of the camera to move with it?

Have you used another 3d app that lets you cheat this somehow without creating geometry? I'd be interested to see how that's handled.

The environment light behaves as a latlong HDRI is traditionally used; in a lighting context it's behaves as an infinite sphere, so translating the camera wouldn't generate parallax.

If you're trying to simulate objects near the camera thats visible in your hdri, that normally means you have to generate simple versions of those objects in your scene, then project your hdri onto those objects, and if you move too far around those objects, deal with painting in detail that needs to be there, combining projections etc… that's all possible in houdini, but normally that'd be handled in external app like mari.

If you're just after some simple faked parallax, you could do the method you hinted at earlier; create a large (just not infinitely large!) sphere, and blend a small amount of the camera translation onto the sphere. A blend node lets you do this.

Take your camera and a stationary null, attach both to a blend node. Set the toggles so that its only working for translation, and use the sliders so that its inheriting, say, 0.9 from the camera, and 1.0 from the null.

You can then make the sphere a child of the blend, that'll make the sphere move not quite as fast as the camera, giving you (sort of) parallax.

If you were keen on a more render-time method, you could probably hack up your own environment shader that did a similar effect, but that sounds like work.

Attached a little proof of concept.

mestela
Have you used another 3d app that lets you cheat this somehow without creating geometry? I'd be interested to see how that's handled.

The environment light behaves as a latlong HDRI is traditionally used; in a lighting context it's behaves as an infinite sphere, so translating the camera wouldn't generate parallax.

If you're trying to simulate objects near the camera thats visible in your hdri, that normally means you have to generate simple versions of those objects in your scene, then project your hdri onto those objects, and if you move too far around those objects, deal with painting in detail that needs to be there, combining projections etc… that's all possible in houdini, but normally that'd be handled in external app like mari.

If you're just after some simple faked parallax, you could do the method you hinted at earlier; create a large (just not infinitely large!) sphere, and blend a small amount of the camera translation onto the sphere. A blend node lets you do this.

Take your camera and a stationary null, attach both to a blend node. Set the toggles so that its only working for translation, and use the sliders so that its inheriting, say, 0.9 from the camera, and 1.0 from the null.

You can then make the sphere a child of the blend, that'll make the sphere move not quite as fast as the camera, giving you (sort of) parallax.

If you were keen on a more render-time method, you could probably hack up your own environment shader that did a similar effect, but that sounds like work.

Attached a little proof of concept.

Mestela that's it! Perfect! Saved me a lot of time! Thank you so much for your generosity!