Cleaning Hell, One Vertex at a Time

In this post, we're diving into some of the technical challenges and solutions behind the scenes of our game, Infernal Cleaner. Here's a look my approach to runtime vertex painting, materials and additional VFX. We will be breaking down each core element.

					// Paint-vert: result = Sphere Overlap Check on a raycast. 
					// This is within a coroutine.
					foreach (var col in result)
					{
						if (!col)
							continue;
						col.TryGetComponent(out Cleanable cleanable);
						if (cleanable)
						{
							Vector3 returnColor = Global.I.PaintVert(
								col.GetComponent<MeshRenderer>(),
								hit.point,
								// Paint strength depending on number of objs being painted
								paintStrengthNormal * result.Length,
								paintRadius,
								// 
								cleanable.KdTree);
						}
						// Paint 1 mesh per frame
						yield return null;
					}
				

					// the KDTree was generated during Init()
					KDQuery query = new KDQuery();
					query.Radius(tree, originLocal, radius, results);
			
					float redAmountDelta = 0f;
					float greenAmountDelta = 0f;
					float blueAmountDelta = 0f;
			
					foreach (int i in results)
					{
						Vector3 vertex = vertices[i];
						
						float distanceSqr = (originLocal - vertex).sqrMagnitude;
						if (distanceSqr < radiusSqr)
						{
							float proximity = 1.0f - Mathf.Sqrt(distanceSqr) / radius;
			
							float originalRed = colors[i].r;
							float originalGreen = colors[i].g;
							float originalBlue = colors[i].b;
							float redChange = channelStrength.x * proximity * Time.deltaTime;
							float greenChange = channelStrength.y * proximity * Time.deltaTime;
							float blueChange = channelStrength.z * proximity * Time.deltaTime;
							
							float newRed = Mathf.Clamp01(originalRed - redChange);
							float newGreen = Mathf.Clamp01(originalGreen- greenChange);
							float newBlue = Mathf.Clamp01(originalBlue- blueChange);
							
							redAmountDelta += originalRed - newRed;
							greenAmountDelta += originalGreen - newGreen;
							blueAmountDelta += originalBlue - newBlue;
			
							// Update vertex color array
							colors[i].r = newRed;
							colors[i].g = newGreen;
							colors[i].b = newBlue;
						}
					}
					...