Howdy. I have an enormous, semi-transparent, hollowed-out cube that I use to tint the sky a particular color. This works well, but I notice that it appears in front of other transparent objects (presumably due to depth sorting -- the cube follows the player around as he moves, so the center is right at the camera's coordinates). Is there an easy way to force the object to be drawn first, so that everything else appears over it?

Note: There are, of course, a number of other ways to handle this tinting; I'll eventually just paint over the skycube to tint it. But I thought I'd ask re: the depth sorting, since I'm just prototyping things.

Thanks!

I assume you have this cube placed at the camera position..

Then this sorting problem is natural, because transparent polygons are sorted by entitity position, not the Z-buffer. So think about this, if its x,y,z position is at the camera position, its always closest to the camera, and will generally be drawn on top of other transparent entities, not behind as you want.

Setting aside the fact that it's not the best idea to use a transparent cube in this way, as I'm sure you know, there is no easy way to solve this sorting problem . To do so you would need to render it in a DLL, using the 'render_sky' event. This way you could ensure that it's drawn before all other entities..(of course then I think it would be drawn before the skybox too, so you have another, worse problem).

So basically, this isnt going to work. if you want to tint your sky box, there is a much better to way.. do it with a very simple pixel shader. That way you could change it's tint at runtime to simulate changing time of day, weather, etc.

Aha! Ultimately, I was going to just modify the skycube's bitmap at runtime, but shaders would probably be even better, thanks.

Maybe would work if you set its "layer" lower than other entities.

In the manual...

Elements with higher layer value will be placed over elements with lower layer value. Elements with the same layer value are sorted due to the z buffer

entity shotgun_onscreen
{
type = <shotgun.mdl>;
layer = 2; // display above view entities with layer 1
flags = visible;// visible on screen from the start
view = CAMERA; // same camera parameters as the default view
albedo = 50; // gouraud shading from sun position
x = 100; // place 100 quants ahead of the view
y = -50; // 50 to the right
z = 0; // and center vertically
}


Another you could try would just be a flat transparent sprite infront of camera and use layers. Goodluck

No that wont work as he is not using a view entity, but a real entity.

Just an idea (haven't tested it), but instead of making the center of the cube the center point of the model, put the center point on one of its edges (i.e. a cube with sides of 200 units would be centered at 100,0,0).

This is hard to explain in words, but a picture would be easy.

This might not work, but its worth a try.

Yeah that would probably work, except if you have transparent ents further away than that.

Or, a variation of Doug's idea(?), move the origin of the cube to the center of
the far side that will be in front of the camera in MED. Then assuming the cube
is say 20000 per side, the cube should be kept 10000 quants in front of the
camera so the camera is still in the center of the cube and the cubes origin is
always 10000 quants in front of the camera. (like this;)

Code:

---

action tint_cube
{
 while(me)
   {
     vec_set(temp, vector(10000,0,0)); // create offset with temp
     vec_rotate (temp, camera.pan); //pan temp same as cameras pan
     vec_add (temp, camera.x); // add cameras position to offset
     vec_set (my.x, temp.x); // put me there
     wait(1);
   }
}

---

tint the sky

try using a totaly semi transparent solid color ( like white set to 50%)
for your skybox texture ( be sure its flagged SKY when you apply it to the skybox)
now set your background colors (bg_color. ) to set a sky color tint ( remeber to adjust sunlight color also to help properly reflect the overall level lighitng color)

Edited: any sky texture you use over the background ( like domes ) you then want transparent or overlay areas in the image to allow the BG_color to com through

some shots I did of just the above thing. forground Im using a model with the same 50% white transparent image as the box model skin. a skybox set with the same 50% white texture flagged with sky applied to the walls and cieling of this holow cube ( floor of cube is the floor textured block you see)



for the sort issue I've found it you just don't combine a semi-transparent and full opaque in the same skin image then things seem to work ok then.

I did anotehr example test for the semi transparent sort stuff.

with the new changes in MED. group parts of the model that will have OPAQUE skin. group triangles of the model that need an transparent skin. then apply differnt skin texture to each group


I duplicated the cube in the model itself, deleted teh faces where the 2 cubes meet. set each cube as a differnt group. one gave the 50% transparent white skin, other half gave is some bad wood texture I had ( differnt image formats btw. 32 bit tga and 24 bit bmp)

ill play around with anotehr example If I can find a nice car model, give its windows seperate grouing and apply a transpeent image