Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] I need help! => Topic started by: John.McWaters on 2025-04-07, 17:32:11

Title: Issues with Step amount in Mapping Randomizer
Post by: John.McWaters on 2025-04-07, 17:32:11
I use the Mapping Randomizer component to randomize a wood texture across several boards. My wood texture contains 20 boards, so I set the step amount in the Mapping Randomizer to .05 (1.0/20). However, it seems that it's not actually stepping it by 1/20th.

I've attached an example 3dsMax file and couple images. In the first image, there is no randomization as you can see each board has the same texture. The next image has the randomizer set to X value offset at 0 to 1, with a step of 0.5. I would expect to see different numbers on each board, but it appears the step amount isn't offset the texture correctly.

I have attached the texture I'm using as well. It's a simple guide to figure out if my 20-board texture is aligning correctly.

Title: Re: Issues with Step amount in Mapping Randomizer
Post by: John.McWaters on 2025-04-07, 18:02:39
After playing around with it a little, it seems that the Mapping Randomizer works if my texture is square. I was trying to use a real-world size that was slightly rectangular. If I se the texture to be 12' x 12', the step size works as expected.
Title: Re: Issues with Step amount in Mapping Randomizer
Post by: romullus on 2025-04-08, 15:46:57
Can you save the max file to an older version please? It seems to me that mapping randomizer step size works correctly even with your non-square texture.
Title: Re: Issues with Step amount in Mapping Randomizer
Post by: maru on 2025-04-08, 17:04:00
It looks like when you are using the real world size option, the mapping randomizer operates on scene units. Here is what I did:
- changed scene units to generic 3ds Max units
- this gave me the bitmap height of 110
- I set "to" offset to 110 (full "one texture tile" offset)
- I set step to 5.5 (110/20)
This seems to be working. Don't think that I "knew" how to do it! I just tried lots of random combinations until I accidentally found this. :D
Title: Re: Issues with Step amount in Mapping Randomizer
Post by: John.McWaters on 2025-04-09, 14:21:10
It looks like when you are using the real world size option, the mapping randomizer operates on scene units. Here is what I did:
- changed scene units to generic 3ds Max units
- this gave me the bitmap height of 110
- I set "to" offset to 110 (full "one texture tile" offset)
- I set step to 5.5 (110/20)
This seems to be working. Don't think that I "knew" how to do it! I just tried lots of random combinations until I accidentally found this. :D

Thank you Maru. I also confirmed it works without changing the scene units.
Title: Re: Issues with Step amount in Mapping Randomizer
Post by: maru on 2025-04-09, 16:23:13
Yes, but first you need to know what the texture size is in generic units. :)
Title: Re: Issues with Step amount in Mapping Randomizer
Post by: John.McWaters on 2025-04-09, 17:34:11
Yes, but first you need to know what the texture size is in generic units. :)

Right, but in this case, it looks like inches=generic units as that dimension of the texture is 110" long and I needed 5.5" steps (to correspond to a 1x6 board).
Title: Re: Issues with Step amount in Mapping Randomizer
Post by: maru on 2025-04-10, 11:33:27
Oh, ok, so it sounds like there is conversion between units.