How do I use a Shading Rate Image to call multiple invocations per pixel

Hello,
For my master thesis I need to use Variable Rate Shading. I’m also new to Vulkan, so I apologize if I’m missing something obvious.

Part of what I need to do is use a shading rate image to call multiple invocatations per pixel. I based my program on one of Sascha Willems examples (this one to be specific: SaschaWillems/variablerateshading ). In theory I thought that would be very easy. Just change the the values used to create the shading rate image (in prepareShadingRateImage() ) from VK_SHADING_RATE_PALETTE_ENTRY_1_INVOCATION_PER_NXM_PIXELS_NV to VK_SHADING_RATE_PALETTE_ENTRY_N_INVOCATIONS_PER_PIXEL_NV. Unfortunatly this didn’t work. The original program with 1 invocation for multiple pixels works perfectly, but I am not able to call more than one invocation per pixel.

Is there something I’m missing? Do I have to enable it somewhere? It’s really hard to find anything about that topic online. I thankfull for any help.

Greetings
Tim

(PS: the only other change I made is adding a few lines of code to the fragment shader to display the amount of invocations per pixel)

So I have figured it out in the meantime. You have to enable multisampling. Which I tried before posting, but apparently I missed something and it wasn’t working correct.