I don't know why the drawn triangle has flaws

[capp-adocia]

Question

When I was learning how to draw a triangle at the link https://docs.vulkan.org/tutorial/latest/03_Drawing_a_triangle/03_Drawing/02_Rendering_and_presentation.html, I noticed that the triangle I drew had obvious flaws compared to the image shown in the tutorial. I really don't know why such a problem occurred.

This is the image displayed on my machine:

Tutorial images:

Reoccurrence of the problem

Download the 15_hello_triangle.cpp file and the slang file from the tutorial website, and compile the slang file. The file structure is as follows:

├── 15_hello_triangle.cpp
└── shaders
    ├── shader.slang
    └── slang.spv

Then run the following command:

clang++ -std=gnu++20 -DVULKAN_HPP_NO_STRUCT_CONSTRUCTORS \
"15_hello_triangle.cpp" -lglfw -lvulkan -o triangle

./triangle

Machine Environment:

• Operating System: Kubuntu 26.04 LTS
• Qt Version: 6.10.2
• Kernel Version: 7.0.0-22-generic (64-bit)
• Graphics Platform: Wayland
• Processor: 16 × AMD Ryzen 7 5700X 8-Core Processor
• Graphics Processor: NVIDIA GeForce RTX 3060
• Graphics Card Driver Version: 595.71.05
• Clang version: 19.1.7

[SaschaWillems]

Can you elaborate? The difference between the screenshots is virtually invisible.

Also note that graphics API like Vulkan give drivers some liberties in terms of the final rendering output. So things might look (very) slightly different depending on what GPU, driver and/or OS you use.

[capp-adocia]

Can you elaborate? The difference between the screenshots is virtually invisible.

Also note that graphics API like Vulkan give drivers some liberties in terms of the final rendering output. So things might look (very) slightly different depending on what GPU, driver and/or OS you use.

Thank you for your reply. I observed on my phone and indeed the two pictures were almost identical without any flaws. However, on my monitor, I could clearly see a very distinct color transition that resembled a ridge at the place indicated by the arrow in Picture 1. This picture was obtained using a screenshot tool.

Currently, the computer is not with me, so I will upload a picture taken with my phone later.

[capp-adocia]

I took the photo with my mobile phone, but it seems that I couldn't clearly distinguish the color transition like a mountain ridge. However, I could still vaguely see that the effect was a bit weaker than what was shown on the display. I also specifically went to the internet cafe to check the pictures before, and there were other strange displays as well? This seems to be related to the monitor. I guess it might be a problem with the monitor?

[capp-adocia]

I've figured out the problem. It's indeed a display issue. Because I enabled the HDR mode, it caused problems with the color transition as I perceived it. The solution is quite simple - just turn off the HDR mode.