Slava wrote: ↑Tue Dec 17, 2024 11:59 am
Is there any way to check how much the party object or tile underneath it is lit?
i.e. is it in the shade or in the sun?
I understand that there are dynamic shadows under the open sky during the day and it is difficult to implement. But i want to neglect this. Just having day and night. I want to find a way (maybe someone already has it) how to determine the degree of light in the dungeon? Let's say there is a monster. I can getSight its component brain then depending on getAllAroundSight() check if it is looking towards the party. And this functionality I want to extend. We can always check seesParty, so I want to reduce the Sight of all monsters in the level depending on the lighting of the party.
What I'm envisioning. I need to get all the light components in the level, and then depending on getType() check getDirection(), getRange() and maybe getSpotAngle(), getSpotSharpness(). I have no idea what the last two do.
But I hope that all this is needed and can be done in a simpler way. After all, the game somehow understands what part of the texture is illuminated.
This is not a simple question. It is probably the most complicated question that has ever been asked in Grimrock modding. But I guess I might as well answer it here anyway.
You basically have two real options here, both of which are completely horrible. One is to use a umod (or equivalent) to execute native code that does additional render passes to get the lighting information you need (see
here for an example of such an approach). Adding native code is necessary because there's nothing in Grimrock's Lua functions to copy the contents of render buffers or textures into main memory, nor to receive information from shaders. You will need to write 6 slightly different versions of a lot of this code (one each for D3D9 notebook renderer, D3D9 normal renderer, Windows OpenGL notebook, Windows OpenGL, Mac OpenGL notebook, Mac OpenGL).
The other option, which is worse in every way except portability, is to use the CPU to calculate how much light the party would theoretically receive. While this is easy in the notebook renderer, it's almost hopeless in normal rendering modes since those have shadows
and you can't even access the shadow maps. You'll basically need to go through every shadow-casting model in your dungeon that's of significant size and choose a shape that approximates it and can be checked for collision with a ray very cheaply. Then, on any frame where you need this lighting information, cast a ray to the party from every light within range, checking for collision with all of those shapes in range. Oh, and you'll need to apply node transforms to the shapes for any animated models - you seem to want to include monsters in your dungeon, which are usually large, shadow-casting, and animated.
Other options that people may propose, which I do not consider real options:
3. designing your dungeon's levels, spells, monsters, etc. in such a way that whenever this lighting value would matter, it's just trivial to determine and can be baked into the tiles or whatever.
4. have your code just guess how much lighting the party is in and regularly get it completely wrong
I don't think these are real options because the only reason you'd consider adding this mechanic in the first place is that you want to actually do something with it, with moving light sources and shadows (rules out 3.) and the lighting value actually mattering to the player (rules out 4.)
