As the title says. I am developing an app for IOS 18, which involves adding a building relatively far away from the user's place (around 10-20m.), and I need to building to show contact shadows with the floor for added realism. Now, I know that RealityKit has automatic contact shadows using GroundingShadowComponent, but this only works if the object is placed in a plane that has been detected by ARKit... and ARKIt doesn't detect floors so far away, so I need to add my own shadows: add an invisible plane acting as a floor below my building, and have it receive shadows and show only the shadows. The problem is that, from what I see, RealityKit has no materials that can do this: UnlitMaterial ignores all lighting, including shadows. SimpleMaterial does display the shadows, but the floor is displayed too. I can make the material almost transparent (setting the opacity to 0.01 or something), but the floor is still visible. OcclusionMaterial with receiveDynamicLighting is a solution, but it doesn't work either. If I declare it using OcclusionMaterial(receivesDynamicLighting: true), all I get is an invisible plane with no contact shadows in it. What do other people do for this? Do people just bake in the contact shadows in the 3D model?

Hi all: Novice iOS programmer here. I am developing an iPhone app (target: iOS 18) where I need to place a large building a bit far away from the user: around 10-20 meters away. Now, the problem I am having is that ARKit's floor detection usually doesn't reach that far. I solved it by using "existingPlaneInfinite" in the raycast: let raycastResults = arView.session.raycast( ARRaycastQuery(origin: rayOrigin, direction: rayDirection, allowing: .existingPlaneInfinite, alignment: .horizontal) But the problem is that the building appears... but without grounding shadows. I tried enabling GroundingShadowComponent, but without success. After some more testing, I found out that if I place an object in a plane that ARKit is actually detecting, then it will have grounding shadows... but if I place it further away, in the part of the floor that ARKit doesn't detect, then it won't add shadows. It will still place the building at the right height (because it extends the detected plane to the infinite), but it won't add contact shadows with the floor. I can solve this problem using the usual tricks (adding an invisible plane as a shadow catcher, etc.), but I just wanted some confirmation that this is indeed the correct behaviour. Also, are there any changes in this regard in IOS 26?