ERP Archiver Not Asking for MIPMaps: Understanding the Issue with Bloom Effect

In the world of computer graphics, the bloom effect is a crucial visual enhancement that adds depth and realism to an image. However, achieving this effect can be challenging, especially when dealing with large textures and complex rendering pipelines. In this article, we'll dive into the issue of ERP Archiver not asking for MIPMaps and explore possible solutions to get your bloom effect working correctly.

The Problem: MIPMap Generation

When creating a texture, one of the crucial steps is generating MIPMaps. MIPMaps are smaller versions of the original texture, used to reduce aliasing and improve rendering performance. In our case, we're using the `GlTextureStorage2D` function to create a 2D texture with internal format and width/height parameters. However, when we generate MIPMaps for this texture, the ERP Archiver fails to ask for them.

The Code: An Overview

To understand the issue better, let's take a look at some code snippets. We have an `OpenGLTexture` struct that generates MIPMaps every frame using the following pseudocode:

```c

UpsampledgImage = Create(bloomW, bloomH)

PrefilteredImage = Create(bloomW, bloomH)

ownsampledStagingImage = Create(bloomW, bloomH)

ownsampledStagingImage.GenerateMipmaps()

ownsampledImage = Create(bloomW, bloomH)

```

This code creates several textures and generates MIPMaps for the `ownsampledStagingImage`. However, when we use this approach, the bloom effect fails to work.

The Solution: Generating MIPMaps in a Loop

After further investigation, we found that generating MIPMaps in a loop where the bloom is calculated solves the issue. This means that instead of generating MIPMaps once when creating the texture, we generate them every frame before calculating the bloom effect.

The Role of ImageLayout and Image Blitting

Another crucial aspect of this process is image layout and blitting. We use the `VkCmdBlitImage` function to transfer data from one image to another while changing its layout. In our case, we're using a compute shader to implement the bloom effect, which requires us to blit images in a specific way.

Understanding Offsets

When generating MIPMaps dynamically, it's essential to understand how to set the `VkImageBlit.dstOffsets` and `VkImageBlit.srcOffsets`. These offsets determine the region of the image being blitted, and incorrect values can lead to rendering issues. By carefully setting these offsets, we can ensure that our MIPMap generation works correctly.

In conclusion, generating MIPMaps for textures is a crucial step in achieving the bloom effect. While it may seem like a straightforward process, there are many potential pitfalls and gotchas along the way. By understanding the importance of image layout and blitting, as well as carefully setting offsets, we can ensure that our ERP Archiver asks for MIPMaps correctly and our bloom effect works as intended.

Erp archiver not asking for mipmaps