Cubemaps / Getting scale to match a scene


#1

Hi Everyone
I am finding that my cubemaps look 2 X the size they ought to be in a room that was used to make the cubemaps
I render a 360 Pan at 2048 X 1024 using 3DS Max and Corona (Corona has a camera modifier that makes these really easy to setup

This cubemap was rendered from the same room essentially.

I use the box projection and then adjust the settins to line things up, but the scale is way off, any pro tips for getting a better match?
Attached are an example and my settings

cubmap scale settings


#2

Are those the default values for the half extents?


[SOLVED] HDRI cubemaps (PBR)
#3

No, those are modified, I make that number larger until the cubemaps stops disorting.
Then offset until it lines up visually

Rooms aren’t at 0,0,0 world space in a lot of cases so those offsets are to move the cubemap projection over until it lines up.

Curious, is there a document that explains the proper workflow?
I find I need to type values in until it sort of works, except the scale of course :slight_smile:


#4

Bumping,

Does anyone know where we can find documentation that is in depth for Play Canvas Cubemaps, both for an artist and for a coder?

We are running into more issues. We are doing a custom loader to grab models from our amazon server and load them into play canvas, everything is working except the cubemaps, filtered and unfiltered are either or, not both and they look a lot darker than the Play Canvas editor versions I set up to compare for our coders

There was talk of reflection probes like those in Unity and Unreal, any updates on that?
That would be the easiest solution :slight_smile:

From an straight engine perspective Cubemaps are scaled double size as shown above, user error for sure, I hope :), but without documents or Play Canvas team feedback I have pretty much tried everything.

The same lack of documentation is hitting us with our custom loader.

Any pointers would be super appreciated.


#5

To use box project cubemaps, you need to make sure you have rendered the cubemap at the same scale as the model in PlayCanvas. Set the half extents to be half the size of the room you have. It looks like you either have your half-extents incorrect or you have rendered at the wrong scale?

Reflection probes are on hold at the moment.


#6

Thanks Dave
How do i know what scale to render at?

Is there a document I can refer to the find that out?
The extents only fix distortion so I need to know how to render at scale it looks like.


#7

You should render it so that it matches the scale that is in PlayCanvas. So your half-extents in PlayCanvas should be the same number of units has half the width/height/depth of the model when you rendered the cubemap.


#8

Sorry to be thick. The scale is the same play canvas and in the cubemap 3ds max file, they are the same file

I set up my extents based on those units, still double the scale.

I am rendering to a spherical HDRI map using Corona at 2048 x 1024 and then using cmft studio I convert to HDR faces for the cubemap.

I haven’t heard of rendering to scale before so I am a little clueless

I’ll try halving the scale and re rendering my cubemaps first, but if there is another step I might be missing please let me know.


#9

I doubt you’re being dumb :slight_smile:

I don’t know anything about Corona, are you sure when you render at 2048x1024 it that isn’t double width?


#10

That’s what I am wondering myself, but the cubemap looks good, it just looks too big :slight_smile:

rendering the half size one so fingers crossed

I’ll do a 1024 x 1024 next

Could you mention the tools / work flow you guys create cubemaps out of Vray with?
We have Vray tool and at least I can fake it using Vray if the scale works :slight_smile:


#11

Could you guys let me know how you make your cubemaps, render engine and scripts or features to get scale to look correct, I can switch back to Vray if needed, we have both engines.


#12

Haven you found a nice workflow to work with those cubemaps? Thanks!