How to increase UV scale precision in Image Editor?

Support Materials and Textures
1

Hello, for now it seems that UV scaling precision is about 0,01 (1 percent) at the top. How could I get more precise scaling like 0,00000001? If it cannot be set, who should be contacted in Blender Development to increase it? Thanks

2

thats just obsurd-- IIRC blenders precision is 5 decimal places

3

Test it please. Unwrap a mesh, scale it down to like 0,33333… GUI will say = 0,33

4

Vertex coordinates in UV layout have two digits of precision and they are in actual pixel values. Why do you need precision that is higher than 1/100th of pixel width?

And by the way, internally the coordinate values are stored as floats because when you scale something down to say 0.3333333 and set the active image in UV Editor to be very big (10000 x 10000 pixels for example), the coords will be 3333.33 in pixel coords. This means that when you need to use a very big texture, the precision is there.

5

Thanks, i need sometimes huge textures (16K).
I made a quick test to check the precision and it seems just the GUI is bad with converting values (so that should be fixed).
Precision is correct (0,333333 and 0,3333333 have different results).

Thanks again. Who should be contacted to fix the GUI (I mean I was clearly misled with its conversion).

6

internaly as I know of Bl is limied to 7 digits
like 9999.999

so I doubt that UV could go higher then 7 digits
not certain about how UV handle number of digits !

what size would be a 16 K image and how much memory it uses ?

thanks
happy bl

7

Scaling the same uv island resulted non-overlapping results with the example I wrote, but 7 digit is fine.
I was mislead by the GUI what converted numbers like 0,333333 to 0,33 all the time.

A 16 or 32 K image typically is a texture atlas.

8

if I remember well numbers in the GUI are done with OS like win 10
but does not equal what the value really is inside blender!

so be careful when you read value in N panel !

but not even certain you can use 16 K image in blender
this represent like 256 Megapixels in size
it Is huge what file size it is this not certain ?

not certain if it can be use in blender !

happy bl

9

I use Win7 and it is not the N panel, it is the UV Layout window wherer I get the 0,33333=0,33 info. 16K textures are available in Blender; I use this size for creating atlases, not for rendering.

10

how do you render that
I mean max pixels is like 10K anyway
so have to render in parts !
there was a script I think that might help to go to 20 K
at least in 2.49 but have not tested it lately

happy bl

11

I don’t render. I create atlases only. For rendering I use reduced resolution, but for UV work the bigger resolution is better.

12

only thing I can think is that you might get more precision if you change the scale
like making it smaller to get like 1 BU = 100 cm or 1 cm
then you might get more precision on the small values

instead of being limited to 0.001 you could get smaller value
but you would loose on the other end !

now it won’t change values or precision in UV map cause it is limited in range from -1 to 1
but the mapping could be better

don’t know if this can help

happy bl

13

As I wrote, it is fine and only the GUI has a malfunction. Thanks anyway.

14

I think the best way to test UV precision would be using a script to check the real values
that way you would know what the min is
but again python use 16 digits so it would not show values from bl after the 7 digits

but you can always ask in python forum how to check that

happy bl