In Parashara, planets are the agents of aspect: Mars aspects by 4 and 8 houses, Jupiter by 5 and 9, etc. In Jaimini, the sign itself is the agent. If a planet sits in Aries, then Aries aspects certain other signs based on its modality.
Rashi Drishti rules:
Moveable signs (Aries, Cancer, Libra, Capricorn): Aspect all fixed signs except the one adjacent (e.g., Aries aspects Leo, Scorpio, Aquarius—not Taurus or Pisces).
Fixed signs (Taurus, Leo, Scorpio, Aquarius): Aspect all moveable signs except the one adjacent.
Dual signs (Gemini, Virgo, Sagittarius, Pisces): Aspect all other dual signs.
This is NOT a full 360° aspect like planetary drishti; it is a binary: sign A either aspects sign B, or it does not. No partial aspects, no orbs.
Key implication: A planet in sign A will dominate any planet in a sign that A aspects, regardless of distance or nakshatra. This is used to resolve yoga strength and to predict outcomes when two karakas aspect each other.
The engine computes which signs a given sign aspects. You will use this to resolve Arudha Lagna placement and to check karaka-to-karaka interactions.
The principle. In Jaimini, signs aspect signs. A planet participates in an aspect because of the sign it occupies, not because of anything it does itself. This is a genuine departure from graha drishti, where planets aspect according to their own nature.
The rules by modality. Moveable signs aspect the fixed signs other than the one adjacent to them. Fixed signs aspect the moveable signs other than the adjacent one. Dual signs aspect the other dual signs. Because the pattern follows modality, rashi drishti is symmetrical in a way graha drishti is not: if Aries aspects Scorpio, Scorpio aspects Aries.
Why it changes readings. Two planets that have no relationship under graha drishti may sit in mutually aspecting signs and therefore interact strongly in Jaimini. When a Jaimini reading and a Parashara reading disagree about whether two planets are connected, the aspect system is usually the reason.
A learning exercise. Draw the twelve signs and mark the rashi drishti lines. Doing this once by hand makes the modality pattern obvious and saves repeated table lookups later. Then take a chart you know well and note which planetary relationships appear that classical reading did not show.