Crazy Design Question: Should Fireballs have shadows?

[WILL]

Ok you may love or hate this question, but I just finished adding a nice little shadow texture to my upcoming title, Garland's Quest and I'm sort of looking at what gets a shadow. Looking through all my objects in game I came up to the fireballs (spit from out the mouths of my cute little Red Drakes) and I had to think a moment. Should I give them a shadow when I draw them?

How many games have you seen fireballs in them? Did they have a shadow or some kind of ominous glow around them? I'm leaning towards glow after thinking about it more for obvious reasons, but it does raise an interesting topic of what gets a shadow and how to use them in your 2D games. What do you fellow developers say on this topic?

[SilverWarior]

Since the fireball is source of light it is logical that there should be no shadow from it.

But if we take a look from scientific point of wiew the fireball can actually create the shadow. How? To create a fireball you actually need some flamable material which you can tos. And it is likely that this material isn't compleetly transparent so it blocks the light coming through.
But wait just before I sad that firebal is actually a light source. So how could it posibly create the shadow? Well the fire itself does emits the light but the amount of light is limited. So if you would tos a firebal during the day in high sunlight you would actualy see vague shadow beneath the firebal since the amount of light that fire emits is much lower than the amount of light that it comes from the sun.

Anywhay generally there should be no shadow beneath the fireball.
I don't think I can remember any game with shadow benath the firebals.

[pstudio]

Well, as mentioned a fire ball is a light source, so it would make sense to add a glow to it.

However in the end it is just a game, and personally I wouldn't care if the games graphics adhere to physical lighting. Espically not in a game like Garland's Quest. I would say, that you just try out the different possibilities and go with whatever looks the best/coolest.

[Ñuño Martínez]

I used to play Diablo, but lately I changed it by Minecraft. IIRC fireballs in Diablo doesn't has shadow, but they increase the ligting.

Instead of a shadow you can draw a light point.

[WILL]

Yeah that makes sense. Now if it were a 2D game? I'm thinking of having a texture that has a white glow texture that I can subtly ADD to the tiles and objects underneath, but a bit larger of an area than just the fire ball's shape so that in "Night Mode" (drawn to a bias of RGB 0.25, 0.25, 0.5) it'll stand out even more.

[phibermon]

Yeah that makes sense. Now if it were a 2D game? I'm thinking of having a texture that has a white glow texture that I can subtly ADD to the tiles and objects underneath, but a bit larger of an area than just the fire ball's shape so that in "Night Mode" (drawn to a bias of RGB 0.25, 0.25, 0.5) it'll stand out even more.

This would analogous to old software methods of adding light into existing Lightmap + texture combos, back then you'd work out which faces recieved the dynamic light and then for each face, project the light into the texture matrix for the face giving you the spatial data on what parts of the lightmap textures you need to update.

However in a more or less 2D projection with OpenGL, just a blended quad with your glow could be rendered on top of your tiles, then render the fireball on top of that.

Alternatively you could use a light source with a high quadratic attenuation (it'd have to be per-pixel in a shader to look it's best) that modulates the fragments as you render each frame. Standard lighting equation, gives an effect like the glow from rockets in GL Quake.

You could also add glow as a post process (if you've got a deferred pipeline setup), this is cool because when a fireball is visible, you can easily lower the lighting slightly for everything else and then raise it for the fireball. This is what actually happens with your eyes in reality when your iris contracts as a result of bright light, surroundings not illuminated by that light would appear darker. Same thing for mechanical eyes, think of those programs where you've got an anonymous person spilling beans on some scandle, sitting in on a chair with a bright light behind them, obscuring their faces not in shadow, but with the relative contrast.