InstancedPointNodeMaterial: depth issue

[Lafeu-p]

Description

In the current InstancedPointNodeMaterial, the vertex offset is applied within the vertexNode, but the depth is calculated based on positionView.z, which is obtained before applying the offset. The depth calculation should use the positionView.z value after the offset is applied. This approach may result in incorrect depth values.


If the positionView is recalculated after applying the vertex offset in the vertexNode, the result will be correct.

//clipPos.xy += offset;
clipPos.addAssign( vec4( offset, 0, 0 ) );

positionView.assign( cameraProjectionMatrixInverse.mul( clipPos ) );

return clipPos;

Reproduction steps

Code

Live example

Screenshots

No response

Version

172

Device

Desktop

Browser

Chrome

OS

MacOS

[Mugen87]

Instead of implementing vertexNode, I wonder if it isn't better to implement positionNode in InstancedPointsNodeMaterial instead and apply the offset in local space. In this way, we can update the existing positionLocal TSL object which means subsequent objects like positionView are automatically correct.

[RenaudRohlinger]

Unlike setupVertex, vertexNode won't assign nodes such as positionView. To fix your issue you could use setupVertex @Lafeu-p:

  material.setupVertex = (builder) => {
    builder.addStack();
    ... your code
     builder.context.vertex = builder.removeStack();
    return clipPos;
  };

To be honest I feel like this is something we should fix directly in vertexNode. /cc @sunag