How can I tell if a body is being drawn in Flight?

[MOARdV]

For instance, when I orbit Kerbin, I see Kerbin, Mun, and Minmus. What do I look at to figure out that those bodies are being rendered in flight (I don't care about Map View, for instance)?

[*Aqua*]

Camera.current.WorldToScreenPoint(Vector3 position)

If I understand the documentation right, this method will return the 2D screen position of a 3D coordinate. If you use that on the 3D position of a celestial you should be able to calculate if the center of that celestial is visible on the screen.

Is this what you are looking for? Or do you want to find out if any part of a celestial is visible on the screen?

[sarbian]

You could also try body.gameObject.renderer.isVisible but I m not sure how it will do with multiple cam.

[MOARdV]

@*Aqua* - no, that's not quite what I was looking for. I want to ask KSP "Are you rendering the model for this body?". For instance, over Kerbin, you can look around and see the sun, Kerbin, Mun, and Minmus, but none of the other worlds are visible. If you fly out to Duna, you can't see any worlds once you've moved away from Kerbin, and then one day as you approach, Duna appears. I want to find out which planets KSP wants to draw while in flight.

The specific problem I'm trying to solve is this: I'm currently maintaining the Distant Object Enhancement plugin. It draws impostors ("flares") to represent each planet, so you can see them in space, even when you're not near them. The original plugin developer used an algorithm to determine whether or not to draw the flare based on the angular size of the world. However, the algorithm isn't perfect, so the impostor for Minmus is drawn over / near the model of Minmus that is rendered in orbit. I want to ask KSP if it's already drawing the model for a world, so I know I don't need to draw the impostor.

@sarbian - renderer is null for all worlds. gameObject.activeSelf == true for all worlds. I've already look at PQS (as a wild guess), but that can't be it, since Jool's is null. I think I looked at body.scaledBody, as well, and that wasn't it, either. I guess I'll keep peeking at values.

[xEvilReeperx]

I want to ask KSP if it's already drawing the model for a world, so I know I don't need to draw the impostor.

This snippet might help you, then. You should be able to adapt it to your needs:

[KSPAddon(KSPAddon.Startup.Flight, false)]
public class RenderedPlanetLocations : MonoBehaviour
{
    private List<Transform> _scaledTransforms = new List<Transform>();
    private Texture2D _redTexture;

    private void Start()
    {
        _scaledTransforms =
            ScaledSpace.Instance.scaledSpaceTransforms
            .Where(ss => ss.GetComponent<ScaledSpaceFader>() != null)
            .ToList();

        // create red box texture
        _redTexture = new Texture2D(32, 32, TextureFormat.ARGB32, false);

        _redTexture.SetPixels(Enumerable.Repeat(Color.clear, _redTexture.width*_redTexture.height).ToArray());

        for (int y = 0; y < _redTexture.height; ++y)
            for (int x = 0; x < _redTexture.width; ++x)
                if (x% (_redTexture.width - 1) == 0 || y% (_redTexture.height - 1)== 0)
                    _redTexture.SetPixel(x, y, new Color(1f, 0f, 0f, 0.33f));

        _redTexture.Apply();

    }


    private void OnGUI()
    {
        var ssCamera = ScaledCamera.Instance.camera;

        foreach (var t in _scaledTransforms)
        {
            if (!t.renderer.enabled) // game isn't rendering it at all
                continue;

            if (!t.renderer.isVisible) // might be valid target for rendering, but is offscreen
                continue;

            var screenPos = ssCamera.WorldToScreenPoint(t.transform.position);

            if (screenPos.z < 0f) // behind the camera
                continue;

            if (screenPos.x >= 0 && screenPos.y < ssCamera.pixelWidth)
                if (screenPos.y >= 0 && screenPos.y < ssCamera.pixelHeight)
                {
                    screenPos.y = Screen.height - screenPos.y;

                    if (Event.current.type == EventType.Repaint)
                        Graphics.DrawTexture(new Rect(screenPos.x - _redTexture.width * 0.5f, screenPos.y - _redTexture.height * 0.5f, _redTexture.width, _redTexture.height), _redTexture);

                    GUI.Label(new Rect(screenPos.x - GUI.skin.label.CalcSize(new GUIContent(t.name)).x * 0.5f, screenPos.y - _redTexture.height * 0.7f, 100f, 28f), t.name);
                }
        }
    }
}

Edited February 14, 2015 by xEvilReeperx

[stupid_chris]

Problem is I think theyre technically always rendered. If you could zoom in enough, you could see Jool from the surface of Kerbin. I believe a past telescope mod could show this. Theyre jut so small theyre not really visible.

[MOARdV]

This snippet might help you, then. You should be able to adapt it to your needs:

Yeah, that shows boxes around the worlds I'm near, but nothing for the other worlds, so that's the key I need.

Thank you.