Most sprites in GoldSrc already automatically rotate on their own, to face the player camera. This is known as
Parallel Orientation. It is one of 5 Orientation types:
- Parallel - Most common default type; image always faces camera
- Parallel Upright - Locked to z-axis so only rotates to face camera (best for things that need to be placed on ground, for example trees or fire effect)
- Oriented - Does not rotate to camera; has a fixed orientation defined in hammer (not for use with env_glow)
- Parallel Oriented - Faces camera just like Parallel but can be rotated in hammer (not for use with env_glow)
- Facing Upright - Lesser used mode that works just like Parallel upright, but rotation aligns with player origin instead of camera. (can be buggy at close distances, would only recommend for a specific effect)
- From The303's GoldSrc Sprite Tutorial
What you might want to use is the
Oriented type. In vanilla HL1 you're not able to set a sprite's Orientation type through mapping, it must be done by editing the sprite file itself. You can use
Half-Life Texture Tools to do this, either when creating a new sprite or when editing an existing one.
After that the sprite will obey the
Entity Attribute: Pitch Yaw Roll (
angles) keyvalue.