Hi all

So there are a number of threads to do with cube mapping mainly dealing with DX9, so I just wanted to get the heads-up on the correct process for cube maps and PBR.

1) Should we put an alpha channel in the _color map?
2) Should we save that out as dxt5, dxt3, or just dtx1 1 bit alpha?

Thanks for any input

Reliquia....

I didn't think we needed to use cube maps now that we are using PBR, surely that is taken care of with the new system. Not great I know since that it only reflects the outside plane even when indoors, but hopefully will get better.

You can use your own cube map with PBR assets.

The color map will not need alpha in this to work unless you want opacity like in a window.
What ever is white in your metalness texture and black in your gloss texture will show the _cube map you made.

color map - dxt1 if no windows or transparency needed. dxt5 if transparency is needed
gloss map - dxt1
metalness map - dxt1
AO map - dxt1
Normal map - no compression with A8R8G8B8 setting

Just be aware when making your cube maps, if you are using gimp it can be a bit funny about exporting cube and mip maps, make sure you have the right settings in the dds export box (i forget what settings it is right now, theres tick boxes for cubemaps iirc), took me ages to get it to work.

Here are the settings in GIMP.

That's the kiddy, thanks Myke.

My pleasure.

Hi all

Thanks for all the feedback - yes non problem making the cube map, just wasn't sure about the alpha in the color map. So thanks for the clarification Myke.

@Tasman: I have been working on an interior sci-fi space station, and skybox\ground reflections look terrible indoors Actually finding it much more work to make interiors with shiny stuff work, but cube maps look pretty cool.

Thanks all for your input.

Reliquia....

color map should need no alpha/separate shader in PBR to emit cubemaps, i think cubemap emission is controlled by roughness if im not mistaken...

anyways @tazman you should DEFINITELY make your own cubemaps as gameguru chooses to reflect the sky and ground only. there is no env probes or automatic generation based on object position, however sometimes when using non-pbr textured objects in PBR, they will reflect their illuminationmaps.

Yeah I did notice that, but wasn't sure if the alpha should be there, since it was required before PBR was in the engine.

I just wanted to be sure I was heading the right way before I got carried away with my little project, as I really want to do all the textures myself in Photoshop so I can get a feel for how PBR works, rather than just letting Substance or Quixel create the maps - just a little learning curve thingy

I was also not sure because I tried one part of my sci-fi interior using Normalizator to compare the outputs and every texture it puts out for PBR (color\metalness\gloss\height\ao\normal) has an alpha channel added, and I think they might be using A8R8G8B8 setting for the .dds.


Yes, came across that a few times already In my experience animated objects like doors for example will do that when they also have an _I map.

Reliquia....

there can be an alpha channel, I just dont know if it controls any shadermaps emission. probably just actual opacity, although I know most PBR material renderers require an opacity map for alpha.