Problem with multiple WebGL views on the same website

[CRiess]

I am currently building a webapplication, that needs several 3D view windows. In total I need five different 3D views on the website. So I created a test to show a simple test scene with a cube and loaded it five times using an iframe.
The problem is, that memory usage raises rapidly, and eventually I get the message “The browser could not allocate enough memory for the WebGL content. If you are the developer of this content, try allocating less memory to your WebGL build in the WebGL player settings.” I then tried to do exactly that. I set the memory usage of each player to the minimum of 16 MB. But the error message still pops up.
It seems that the complete asm.js and Unity Engine is loaded in each iframe (which makes sense because of the iframe). Is there any way to load those files only once?

[Marco-Trivellato]

@CRiess

I am currently building a webapplication, that needs several 3D view windows. In total I need five different 3D views on the website. So I created a test to show a simple test scene with a cube and loaded it five times using an iframe.
The problem is, that memory usage raises rapidly, and eventually I get the message “The browser could not allocate enough memory for the WebGL content. If you are the developer of this content, try allocating less memory to your WebGL build in the WebGL player settings.” I then tried to do exactly that. I set the memory usage of each player to the minimum of 16 MB. But the error message still pops up.

I guess now you are running into a different out-of-memory: I think your Unity Heap is too small for your content to run. You need to find the sweet spot, which is basically the least amount of memory required for a single instance of your content to run.

It seems that the complete asm.js and Unity Engine is loaded in each iframe (which makes sense because of the iframe). Is there any way to load those files only once?

Each instance needs its own heap, which is allocated at instantiation-time. Do all 5 instances need to be “alive” at the same time?

[CRiess]

@Marco-Trivellato

I guess now you are running into a different out-of-memory: I think your Unity Heap is too small for your content to run. You need to find the sweet spot, which is basically the least amount of memory required for a single instance of your content to run.

That would be curious. I tried to load simple scenes with nothing more than a primitive geometry object (cube, sphere etc) with two simple scripts. Could that really already eat up 16 MB? I also tried to approach it in steps, halving the amount each time. So I already tried 32 MB, 64 MB and 128 MB. The maximum number of Instances I could get to load in any configuration (the 16 MB one), was four. The last one, or the last two one in most cases, never even began to load after the memory error message was displayed…

Each instance needs its own heap, which is allocated at instantiation-time. Do all 5 instances need to be “alive” at the same time?

Only two instances are required to be “alive” at the same time. I already played around with a two-instance setup combined with loading new scenes. I am currently aiming for a single-view approach, which seems to be to most stable variant.

One thing I found out while fiddling around: MonoBehaviour.Start is not fired, if the parent html object (in this case the iframe) is hidden by CSS styles. This should be documented somewhere.