I ought to begin by clarifying that after I say “Isometric” I’m speaking extra broadly about top-down video games that use a “cheat” to show issues on a z-axis, somewhat than being restricted to video games on this model with a locked 3/4 angle like Sonic 3D Blast, Q**Bert* or Fallout (thus, I’ve not used the “isometric” tag on this query). This being the case, my goal contains most 2D JRPGs and the 2D Zelda titles however doesn’t tackle video games which are really top-down like Grand Theft Auto and Robotron 2084, nor these with true 3D like–well, most video games these days.
However sufficient housekeeping. I’ve made an isometric JRPG system for a university venture (utilizing pygame, for full context), and have had points with rendering order from day one. IIRC most isometric video games simply kind gameobjects by their y-value, however this appears to cease working when objects can stand on prime of eachother. Since all my terrain is objects…there are issues.
I discovered a cheat that allowed me to depth-sort cubes by factoring within the z-position, however the cracks on this system present ever extra clearly because the venture progresses. Angled containers present some glitches that would in all probability be overcome, however conical terrain appears to interrupt it fully. The system will be limped alongside for the needs of the venture, however desirous about the longer term (and a correct re-build of the system) leaves me uncertain of what to take action that depth sorting works correctly.
My first thought was to do depth mapping akin to 3D rendering. In concept would work thus: earlier than a form is rendered, attempt drawing the depths of every pixel to a depth map. Solely pixels nearer to the digicam than the pixel they’re making an attempt to overwrite will probably be drawn. Any pixels that could not be drawn on the depth map should not be drawn on the display screen.
This could resolve my issues, nevertheless it additionally sound a bit costly. Certainly appropriate for contemporary {hardware}, however not one thing any of the outdated isometric video games would have done–at least, not in actual time. So my query is that this: did outdated video games have a extra environment friendly technique for isometric rendering, or did they only pre-compute depth values?
Additionally, simply to make clear: sure, many aged video games certainly solved this downside by dishonest (i.e. place a set off underneath the bridge that renders it above the participant when colliding) or avoidance (i.e. no bridges in any respect). It is a legitimate strategy, however I would somewhat not.
EDIT: As per DMGregory’s suggestion, listed here are some visible aides.
Listed below are the kinds of issues I am capturing for:
It is a conventional “Isometric” game–not explicitly what I would like, however not counter to it both:
Against this, this is what I am not doing:
