How do I give a creature sight/smell?

Questions & Answers
1

In my simulation, there are spherical creatures, food, and viruses (which aren’t actual game objects, just a separate part of the same code). The creatures change color if they are infected, and I want them to be able to see and smell food and other creatures. Creatures have a diameter of one, and food has a diameter of 0.5. Creatures are shown in colors between red and green, and if they are infected, then their color gets a certain level of blue added, depending on a specific virus trait. These are the traits:

bool infected = false;
float moveSpeed = 1f;
float turnSpeed = 0.5;
float sightRange = 2f;
float scentRange = 2f;
int otherInfected = 256; //range is 1 - 256. 1 means that the creature can tell if a creature is infected if it has 1 or more blue added to the rgb scale, and 256 means it can't detect it at all, as the rgb scale is 0 - 255.

I won’t include any other code because it is irrelevant to my current question.

2

Seems like what you need is some kind of AI state machine so that the creatures have at least 3 states: patrolling and looking for food, seeing the food and going for it, getting infected and changing color.
AI state machine is fairly easy concept to understand and you should find a lot of tutorials for it on the internet.
Good luck!

3

The Physics.BoxCast method might be of use. It’s like Physics.RayCast except it sends out a block, letting you find anything within a column that extends outward from your creature.

4

you mixed up the phy and coding each other- 1 but i have a solution to your question!