I changed all the 16k textures from 16bit png to 8bit png and now it works, and doesn’t crash UE on import
going to test the udims in a bit
yah, originally the udims were exported out of substance painter
with changing the names to the BaseName.####.[Support Image Format] suggested in the docs
all files were png, some files were 8bit some were 16bit
a few of the 8bit ones I re-exported out of photoshop with png with the highest comression since that seemed to work well for the 16k textures
in the end UE still imports the udims in the wrong slots,
so for me, merging the udims seems to be the safest route
but is quite a few more steps in the pipeline I’d rather avoid if I can get the udims working
I came to this thread looking for a solution to the issue of tiles being shuffled around as well, but I was able to figure it out myself.
Here’s how my virtual texture looks when imported in the standard UDIM format of tile 1001 in the bottom left, 1002 to its right, 1011 above it, etc (the black is padding to get it to a power of two). Should be pretty apparent that the rows are out of order.
So naturally, here it is with the UDIM V axis inverted, looking correct. So that’s 1001 in the TOP left, 1002 to its right and 1011 below it, etc.
Am I misunderstanding something about how virtual texturing works or is this a bug?
so the udims are reversed and flipped?
looks like it is kinda flipped
and it’s moved up a tile
so i guess if i flip the udim numbers around and move the tile down in UV space the udims will be in the right spots
I also had to save the images as png 8bit, as they were originally 16bit and unreal would have a memory crash trying to load it
the mesh in the middle picture is actually a 7x7 udim mesh so it repeats after the 4th udim UV space
noticed a UX bug where if you ‘open source location’ a UDIM virtual texture it opens the source folder a few times
I’ve had it open 2 and 3 at different times
so I’ve attached a simple virtual texture shader (character udim 4x4- some 4k some 128px textures from substance painter to unreal) to 2 skeletal meshes same one to both
one shows dark green while the other shows red
are there any gotchas for keeping things relatively lower on that shader scale?
is it polycount? or something else?
Trying to use it with any type of particle system crashes the engine 
Ignore my msg above
it was 2 stacked meshes i didn’t notice
Can anyone explain what the two first digits in the UDIM-code represents (the 10 in name.10xx.png) ?
I tried messing around changing the two numbers but the results are strange. I can’t figure it out!
(Google didn’t help me)
The starting UDIM number of 1001 is basically arbitrary. The last digit is the U (x) coordinate, which ranges from 1-9. So 1001, 1002, … 1009. The remainder of the digits are the V (y) coordinate. These are allowed to go above 9…once they do, they will ‘spill’ over into the first 2 digits. So 1001, 1011, 1021, … 1091, 1101, 1111, 1121, etc. If you needed a V coordinate above 99, then it would cause the initial 1 to become a 2. So 2001 would represent U=0, V=100.
Hi Everyone! I have 1px border in the each tile on my Udim texture. Could you please help me fix this?
UDP: Problem solved. Tiling Method - Clamp
Hi guys,
I’m trying to map a material to a simple DAZZ character using the UDIM setup with virtual texturing enabled.
Importing the 7 textures results in one virtual texture with al 7 images included (see image). So I guess that’s ok:)
The mesh has UV’s layed out for the UDIM setup. So I created a material for testing and attached the virtual texture to the basecolor input.
The result (see image) is not what it should be.
I’ve tried several things. Adding a texture coordinate, playing with settings sampler source and const coordinate. NOthing seems to work or fix the problem.
Hope somebody can help me out! 
Cheers,
Marcus
Try adding an empty 8th texture to your layout. 4.23 has a bug where non-power-2 UDIM layouts don’t work correctly (should be fixed in 4.23.1)
Hello, I haven’t seen any info about Tessellation in the whole topic:
Given the objective is to use Virtual Textures on landscapes, will it ever/(when will it) be possible to get Virtual Textured Tessellation as well? Currently the shaders error out if you plug a virtual texture into the tessellation pin.
To bypass that you end up with more texture samples in use, so it’s not exactly a performance gain.
I’ve been playing with virtual texturing in landscape materials and have been getting a lot of crashing doing tests
I have 2 questions - are there caveats to using virtual textures inside material functions for landscapes?
is using VT with lots of layering with UV tricks not a good idea?
I seemed to crash a lot when i tried to layer a few endless textures
Sorry if someone already asked this (I didn’t have time yet to read all previous pages here), but:
- Is it possible to use virtual texturing for a landscape that uses a material that automatically textures slopes/cliffs, using world aligned textures etc?
I didn’t try it yet, but I was wondering here how this would be stored in a 2D texture, as it has texturing in 3 dimensions, in a sense…
Mostly just leaving some feedback.
Enabling VT cuts framerate/ms by around 20fps on kitedemo. This seems to be because of the increased number of draw calls.
Likewise, implementing VT with 8k textures on a 2km landscape provided only a loss of performance. And quality obviously, since there is no virtual texture tessellation yet.
As a result, I dont think it’s a generally good idea to implement any of this in a working project just yet. Maybe once the links get worked out, and If the performance stops dropping on the final scenes.
It would have to really just be the same performance or better then not using it, and a frame loss of 20fps to draw calls is pretty prohibitive.
https://www.youtube.com/watch?v=DPGu8PWEevk
you can do that with tri planar mapping already with world coodinates
i think i saw somewhere there’s a node with that built into the engine as well,
i’ve only tested tri planar on objects
is that using the virtual texture volume? or just virtual textures?