Virtual Texturing Feedback

[motorsep]

@beningram

> does this work at all on mobile?
Not in 4.23. It’s technically possible to make it work, so it should be supported in some future UE4 release.

So, no UDIMs for mobile either until further notice ?

[anonymous_user_2681644d]

Yeah, UDIM textures require VT to be enabled/supported.

[YuuJin]

thanks beningram!

I also noticed the virtual texturing material domain, what’s that for?
I found looking around for something that i thought i read once where it said that when virtual texturing came out there would be something where you could have multiple shading models in one model?

[Tim_Hobson]

@YuuJin

I also noticed the virtual texturing material domain, what’s that for?

That’s used for Runtime Virtual Texturing specifically, there is some material setup along with asset and actor setup in the level to use it. We’ll have docs that break down both Streaming and Runtime VT at release.

I found looking around for something that i thought i read once where it said that when virtual texturing came out there would be something where you could have multiple shading models in one model?

For this one, you’re referring to the “From Material Expression” blend mode that can be used in a Material to have multiple shading models. When you enable this blend mode and use the Shading Model expression in the graph you can assign a shading model to parts of your graph. We’ll have a doc page for that as well at release.

[NilsonLima]

@Tim_Hobson

For this one, you’re referring to the “From Material Expression” blend mode that can be used in a Material to have multiple shading models. When you enable this blend mode and use the Shading Model expression in the graph you can assign a shading model to parts of your graph. We’ll have a doc page for that as well at release.

This looks like some serious Voodoo! Can’t wait to see this working!

[brisck1]

Hi ,

I have a question about virtual texturing in regards to optimising draw calls:

From my understanding, virtual textures are all atlased up into one giant texture, from which only the relevant parts are streamed at runtime. Is this correct?

If true, let’s say I have a bunch of material instances coming one Parent material, the only difference between them being the base color textures. Would changing those textures to virtual textures mean that these material instances get batched into one draw call? (since they’re essentially coming from the same giant atlas)

[anonymous_user_2681644d]

In principle using VT could improve batching. In practice this optimization hasn’t been implanted yet, but it could be transparently applied at some point in the future.

[YuuJin]

this gonna be soo awesome!!! when;s the official release?
do you know off the top if all of those shading models are raytrace friendly? or maybe there’s up to date raytrace material documentation that I don’t know about hidden somewhere?

[YuuJin]

Real-Time Ray Tracing

nevermind stumbled across it myself, still have issues with trying to get the digital humans to not look weird with the raytraced translucency issues though

[YuuJin]

is it possible to mix virtual textures with non virtual textures in a shader in raytraced mode?

I seem to be getting a lot of crashing trying to convert an originally textured head from vray to unreal.
I’m copying shaders from the meet mike digital humans package. and slowing inserting virtual textures in the material constantly causes crashing, I was wondering if there’s some gotchas I don’t know about when mixing shaders for virtual textures

[anonymous_user_2681644d]

It should work fine to mix virtual/non-virtual textures in the same material. Virtual textures are not currently supported in ray-traced shaders however.

[YuuJin]

there are ray trace specific shaders? are those new?
on my opaque,default lit stuff is still looking fine with raytracing and virtual textures, same somewhat on the skin shaders in the digital human projects

raytracing just seems to have problems on the translucent objects
haven’t tried virtual texturing on translucent things though

[Frenetic_Pony]

@YuuJin

there are ray trace specific shaders? are those new?
on my opaque,default lit stuff is still looking fine with raytracing and virtual textures, same somewhat on the skin shaders in the digital human projects

raytracing just seems to have problems on the translucent objects
haven’t tried virtual texturing on translucent things though

I’d assume the problems are on raytraced reflections and GI

[anonymous_user_ab3cb83a1 (anonymous_user_ab3cb83a)]

Hi, I am having issues with Unreal crashing when I import 1 of 24 UDIM images to use as Virtual Textures, I have updated to the latest 4.23 version, and restarted both the engine and my computer several times.
When I first got the 4.23 release, the Virtual Textures imported just fine, but then this problem started happening and I have not found a solution since then.

This is the message I get after the crash occurs:

Unhandled exception

VCRUNTIME140
UE4Editor_Engine
UE4Editor_UnrealEd
UE4Editor_UnrealEd
UE4Editor_UnrealEd
UE4Editor_UnrealEd
UE4Editor_UnrealEd
UE4Editor_AssetTools
UE4Editor_AssetTools
UE4Editor_UnrealEd
UE4Editor_UnrealEd
UE4Editor_Engine
UE4Editor_Engine
UE4Editor_UnrealEd
UE4Editor_UnrealEd
UE4Editor
UE4Editor
UE4Editor
UE4Editor
UE4Editor
kernel32
ntdll

Any idea what is going wrong?

edit:

I missed this in the crash message: Assertion failed: [File:D:/Build/++UE4/Sync/Engine/Source/Runtime/Core/Private/GenericPlatform/GenericPlatformMemory.cpp] [Line: 186] Ran out of memory allocating 18446744073441116160 bytes with alignment 0

So its a memory issue, as previously reported by other users on here.

[anonymous_user_ab3cb83a1 (anonymous_user_ab3cb83a)]

I am struggling some more now, after I imported my 24 4k udim textures and created the VT, I apply it to my model (with the proper udim layout), but the textures just plaster themselves seemingly at random all over the model, just a small porting of the model gets the proper texture, while the rest looks like a piñata exploded over the whole scene…What am I missing?

[anonymous_user_ab3cb83a1 (anonymous_user_ab3cb83a)]

Nobody is feeling like throwing a bone my way?

[YuuJin]

I don’t know how you got 24 4k textures in one UDIM import, if you read the older posts, you can see that I was only able to get smaller sizes in
and beningram said that at the moment only 16,384 x 16384 texture is stable. I could be wrong though.

but building my own giant textures in photoshop with max 4x4 tiles at 4k seems to work completely fine

[anonymous_user_ab3cb83a1 (anonymous_user_ab3cb83a)]

ok, yes, I see that there is some confusion, probably mostly on my part, but here is what I do.

-I have a folder with 24 4k textures.
-I drag 1/24 textures in to UE.
-UE then shows me one texture file in my content browser, and when I double click that texture, it shows me this:

Which led me to believe that I now had a VT texture with all my 24 textures in it(40,960x12,288), that I can apply to my model (which has 24 udim slots)

But by looking at the image, it is clear that, the image at least, only contains the texture from that 1 image that I dragged and dropped in to UE, and applying it to my model just creates a mess.

[anonymous_user_2681644d]

@Limkork You need to enable Virtual Texture Streaming in your project settings. You can see the texture method is ‘Streamed’ rather than ‘Virtual Streamed’. Also, the size is only 4k by 4k, which represents only the first UDIM tile. With VT enabled, UDIM texture size should represent the entire UDIM space.

[YuuJin]

test a subset to isolate your issue,
take a few meshes with textures only within a 4x4 grid (assumed safe area VT size of 16k x 16k) (1001-1004 , 1031-1034)

import only a folder with those texture tiles in it
and throw it onto a that mesh