Color differences after uploading a model to cesium

Cesium ion
1

I receive a few models created in Blender, the model itself looks great in Blender.
Vivid colors and correct texture.
After uploading the file in OBJ or GLBF format the colors look completely different.
I saw that the topic was raised here in the forum and did not receive a response.

You can check the these assets
3253788
3249307
3215110
3214059

all 4 have the same problem, I have searched for answers online and in forums and there is no solution to the problem.

2

It is likely that the differences come from lighting. Below are some examples of your model with different lighting

From 3dviewer.net

image
image1231×826 51.8 KB

Default preview in ion

image
image1226×714 116 KB

Flashlight in CesiumJS with intensity 2

image
image801×453 67 KB

Flashlight in Cesium JS with intensity 5

image
image1068×658 51.3 KB

Here is some additiona information about lighting in CesiumJS

If you are still having trouble, can you let us know:

  • What settings are you using in your editor application?
  • What settings are you using in CesiumJS (can you provide a sandcastle example)
3

Is there a solution that doesn’t require coding?
The problem recurs on all the models I have. Isn’t there something I can do once and it will affect them all?

4

i don’t think the problem is lightning
see here

image
image973×710 38.4 KB

image
image837×579 81.5 KB

i have download the model from my assets and view it on 3Dviewer
you can see there’s something wrong with the color and lighting presentation in Cesium. And I can’t solve it with the tools you gave me.

6

Can you provide some more context about how you plan to use the models that you uploaded to Cesium ion? Many of our users are developer so we would like to better understand how you are using our service to make it better for non coding users.

Can you clarify why you think the issue in the two images you provided is not lighting? As far as I can tell the geometry appears the same and the second image just appears dimmer. Here are some examples of the same model with different lighting conditions to give you an idea of how much lighting can affect the display.

Image with white flashlight at intensity 2

image
image977×544 60.3 KB

Image with white flashlight at intensity 20

image
image1098×585 84.4 KB

Image with purple flashlight

image
image1142×610 116 KB

7

hi
The general idea is to model a large number of buildings in 3D and eventually upload them as part of a photorealistic map into Cesium. I don’t think the problem with the file is just the lighting.
There is a darkness in the tones that is not only affected by the direction of the lighting and its intensity.
The examples you presented do not fix the problem

8

Hi all,

Chiming in here from a CesiumJS perspective:

  • If the goal is to have the model entirely unaffected by lighting within CesiumJS (or even other runtimes) there is a glTF KHR_materials_unlit extension that can be encoded in the model itself.
  • It’s possible to change the lighting style in CesiumJS to mimic the unlit material, though this does involve a few lines of code. It could make sense to expose this at a higher level in the CesiumJS API. Likewise, it could possibly be supported in the Cesium ion UI.
  • Lastly, it is possible to create a specific lighting setup using image-based lighting. There are many options here, but this workflow currently requires more coding and knowledge of lighting and materials. We’d certainly be open to chatting about workflows or presets which would make this more accessible to users.