Vulkan，多个对象使用相同的统一缓冲区吗？

Question

I'm learning the Vulkan API, and I came across a little "problem":

Currently my program is able to draw, using the Projection-View-Model matrix transformation, a cube at the axis origin:

I'm using 3 images/imageViews/framebuffers, so for each transformation matrix I have a vector of size 3 that holds them, and everything work perfectly (no errors from the validation layers etc)... the problem is:

I now want to draw another object near my cube, so I thought I just had to update the model matrix twice every frame, the first time to position the cube, the second time for the other object, but this cannot work because the cube isn't drawn immediately when registering the command buffer, but when submitting it, so in the end the command buffer would simply use the second update of the model matrix for both the cube and the other object:

How to handle this situation?

Thanks.

Answer 1

Make the uniform buffer bigger put the second matrix after the first and point the second draw to the correct offset in the uniform buffer.

You can use either separate descriptors or dynamic offsets.