回复： 回复：[cesium-dev] Re: gltf bufferview

CesiumJS
1

yes , in threejs it’s lighter,and i can set exposure .

how can i enhance ambient light in cesium

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It’s actually not possible to adjust the ambient light right now. I opened an issue with some of these ideas: https://github.com/AnalyticalGraphicsInc/cesium/issues/6412

3

Oh，I find that’s my data bug, I have fixed , it’s bright enough now? I think you dont need do anything.

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Oh ok, good that you fixed your model!

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my data have 4 layers , layer1’s geometricError=1000, layer2’s geometricError=100, layer3’s geometricError=10, layer4’s geometricError=1;

layer3.content is empty

all layers have no requestVolume, but have boudingVolume

I found layer3 will not show boundingFame,while I use debugShowBoundingVolume.

and layer2 and layer3 will show ,when camera is far. and many tiles were loaded even debugShowBoundingVolume were not show.

can you explain what geometricError,maximumScreenSpaceError,boudingVolume,requestVolume?

6

I found that some problems

  1. if camera look down from the sky vertically, all the tiles will be loaded despite geometricError. If camera look at ground at 45 degree, tiles will be loaded as LOD according geometricError.

  2. If I have many empty tiles (only json,no b3dm), cesium also distirbute big RAM for them

  3. 3Dtiles api unloaded tile ,but browser’s RAM will not be destroyed when I watch in windows task manager

7

I found layer3 will not show boundingFame,while I use debugShowBoundingVolume.

The bounding volumes of empty tiles are not shown due to a bug that will be fixed when https://github.com/AnalyticalGraphicsInc/cesium/pull/6390 is merged. It’s possible the other debug bounding volume issue you described will be fixed in that pull request as well.

  1. if camera look down from the sky vertically, all the tiles will be loaded despite geometricError. If camera look at ground at 45 degree, tiles will be loaded as LOD according geometricError.

When you are looking down from the sky and then zoom backwards do lower LOD tiles get rendered? When using the 3D Tiles Inspector what geometric errors do you see? They can be turned on with Tile Debug Labels → Geometric Error.

  1. If I have many empty tiles (only json,no b3dm), cesium also distirbute big RAM for them

How many tiles is in your tileset? I think this is the same issue: High memory consumption if tiles.json is big · Issue #3453 · CesiumGS/cesium · GitHub. Even empty tiles take up probably too much memory - that’s something we want to fix.

  1. 3Dtiles api unloaded tile ,but browser’s RAM will not be destroyed when I watch in windows task manager

GPU memory is freed but CPU memory is not. Basically once a tile is created it is never destroyed, only its contents are destroyed. Likely this will be something we will address when we fix the issue above.

can you explain what geometricError,maximumScreenSpaceError,boudingVolume,requestVolume?

I think the best resource for explaining these is the spec itself. Check out this section which has an overview of all these parts: https://github.com/AnalyticalGraphicsInc/3d-tiles/tree/1.0/specification#tiles

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thanks for ur detail reply ,i have found my data error.now everything ok ,except empty tiles boundingvolume not show and RAM not release when tiles unload

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is bug of model dark fixed?

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the sample data Cesium_Air(gltf 1.0) brightness is not affected by postion of sun

my data(gltf 2.0) is affected by sun

and my data looks dark at night.

I check the spec ,gltf 1.0 have shader ,gltf 2.0 don’t .is that the factor ?

can you tell me where code of light is,and can i modify code to let my data bright?

or should i write shader like gltf1.0 in gltf2.0

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To light the model without using the sun direction, set optimizeForCesium to false in Model.js: https://github.com/AnalyticalGraphicsInc/cesium/blob/master/Source/Scene/Model.js#L4247