Skybox issues...

[arras]

Well correct me if I am wrong, but if you display 512x512 texture on screen which is say 800x600 pixels large than without something like antialiasing or filtering result must look pixelated. And problem is even worst here since you do not draw whole 512x512 pixels at the time but much smaller area. If you would use same fixed functionality of OpenGL as Irrlicht do to render textures then result must be the same ...I guess.
Dorth is right, what I see from screenshots is that you draw much larger part of skybox texture in Irrlicht than in you project. That might well make the difference. That or some filtering.

[twilight17]

well heres my guess... Either OpenGL is scaling it up by a huge amount.. or shrinking it. I'm a newb.

[Kojack]

If you take the source 512x512 skybox and scale it up by around 320% it matches the size in the first bad skybox pic. It's also very similar quality, I just did it in photoshop and the results are nearly identical (blurred). If in your irrlicht test you moved the camera closer to the panel showing the texture until less than half of it was visible, it should look similar to your engine's shot.


Your screenshot:

Scaling the source sky texture by 3.2 times in photoshop and cropping to 800x450:

[dlangdev]

Hmm, it could probably be the UV coords not set properly, eh?

[JP]

Ahh yes, fov/aspect ratio... i'll try and fiddle with those. you're right that irrlicht shows so much more of the skybox, i.e. you can see almost an entire face in the window, whereas you can't in my engine.. I tried scaling the size of skybox up but strangely this had no effect...

Thanks for the comments on the water, i put soooo much hard work and time into it to actually get it working and i'm pretty happy with the results, kinda drags down the framerate quite a lot though so it needs optimising me thinks. I should be able to post a video of my game soon so you'll be able to see the low-cost ripples i've done, you can't see them in screenshots even remotely

EDIT: whoops, just noticed the second page

Nice one on the photoshop experiments! Makes sense i suppose. I'll beat it around until it displays like the irrlicht one. It's not UV coordinates because the skybox is seamless and displays properly, it's just blown up apparently!

[agi_shi]

Your cube is too small - you're closer to the sky box in your OGL engine than in Irrlicht. The further away something is, the harder it is to notice pixelation.

[Kojack]

Your cube is too small - you're closer to the sky box in your OGL engine than in Irrlicht. The further away something is, the harder it is to notice pixelation.

The size of a proper skybox cube will have no effect on how it looks, because it's always centered on the camera. Make it 1m or 1km across, same result. A small face close to you and a big face far away will be the same, both are showing the same 512x512 texture stretched across them.

[Dorth]

"proper" being the right keyword here. Obviously, one of the 2 implementation doesn't follow that rule.

[dlangdev]

Here's a skybox I made using 10x10x10...

[dlangdev]

Here's another 100x100x100, camera close to the edge...

[JP]

Shame the edges don't meet up properly but it's a nice shot!

Did you have the terragen's camera zoom set to something other than 1?

[dlangdev]

Cube dimension set too high, resulting to clipping anomaly.

cube dimension equal to far clipping plane.

[dlangdev]

Shame the edges don't meet up properly but it's a nice shot!

They do line up, it's just the camera is too close to the edge.

It's part of this thing called minification and magnification artifacts.

Set the size of the cube to a right size and you'll be able to achieve the seamless effect.

[dlangdev]

Here's another view.

Perpective at 60.

[dlangdev]

Now, this is the sweet spot for me.

But... I will keep it a secret for now.

Figure it out, and let me know your solution later.

Let's compare notes. I don't want to be stuck with my own solution.

I wanna see your solution to this problem.