Hi, I just wonder do you have any idea how was Diablo or similar games made? When the player replaces an item - shield, sword, helm it is displayed physically on the screen or the weapon. And the new items look and move perfectly with the player avatar. I doubt they've drawn all kinds of combination. How did they do that kind of sprites?

They drew all kinds of combinations.

Well, they prerendered all kinds of combinations, people didn't actually draw the stuff in diablo 2. They rendered it in 3d, and then rendered animation frames onto sprite sheets. But yes, somewhere in the d2 files, there's a personless mace, dagger, short sword, etc... in every animation position.

So basically they have a naked person with all kinds of stuff prerendered in the proper position in each and every frame and then they render the person and the stuff onto him.

Hmm... I'll try that. That's a lots of work.

In Diablo 2 (I cant remember Diablo 1 well), they don't render every combination, instead they would use layers of sprites. They would draw the base person first, then if he was wearing a shield, they would draw the shield sprite over it. Then if he was wearing a sword.. etc.

You have to draw every item in every position, but you do not have to draw every combination of every item in every position.

If that makes sense =).

Edit: I should also add that their sprites are renders of 3D models so they arent actually drawing each item again and again.

Right, but they did draw every item in every position, which is what I was calling 'every combination'. Honestly though, they likely never even had a naked player model as a starting point because each armor config completely changed the player model. So they had an armor, a weapon, a shield, and a helmet, with 'no armor' being a form of armor as a base. It is actually a pretty simple strategy, and isn't terribly complicated. You can quite easily convert a 3D model with proper animation slides into all the sprites. It does however sit on a hefty chunk of memory if you don't pack the sprites well.

Quote: Right, but they did draw every item in every position, which is what I was calling 'every combination'.

Yes, we're making the same point. Either I read your post badly to begin with or you edited it to make it more clear, but I was just clarifying, not disagreeing.

How does this work? I can't imagine that it's a manual process. They must have a program that links the item to some wireframe-type model and systematically produces positional renders for each possible angle, and then saves them as a single, handy file that contains image and layer data. How hard would something like that be to write? Once it's in place, you could just model the item and then punch in the "grip spot", the angle and the color, and then hit "Go" and it'll zip through the algorithm and generate a fully realized file that can be dropped into the engine and used.

You can do it in 3ds max for instance, you create the models, rig them. Create the animations, then save the frames for the animations to create the desired sprite sheet.

One thing I don't understand is how they deal with the drawing order. Example: if the character is facing away from the camera, its face should be drawn before the helmet. This order is not fixed: it depends on the orientation of the character and the specific shape of the gear. Or do they store some kind of z-buffer in the spritesheet? Or do they fix rules on how the artists have to model everything, so that it fits in the drawing order they've set up?

It just depends on how many views you need created for the spites from the 3d model. You can setup the cameras for the specific views and render those into a 2 file you can then setup as a sprite. I'm sure it would depend on the type of game engine from there whether you'd create the complete views, or overlay the clothing with the correct animations.