Render to texture without vkCmdBlitImage.

Vulkan
1

I done render to texture. But now i use vkCmdBlitImage.
Now i have two textures. FrameRenderToTexture and ShaderTexture.
I render to FrameRenderToTexture then vkCmdBlitImage to ShaderTexture. Then render 3d model with ShaderTexture. And I see what was in FrameRenderToTexture.
How direct render to ShaderTexture and not use vkCmdBlitImage ?

2

What’s stopping you from doing the obvious and rendering to “ShaderTexture”?

I mean, at some point, you had to create a render pass instance. And when you did so, you had to put this “FrameRenderToTexture” into that render pass instance.

So what is preventing you from just putting “ShaderTexture” there instead?

3

If i use ShaderTexture, i not get result !
I get result with FrameRenderToTexture.
For this reason ask.

4

For ShaderTexture image.usage = VK_IMAGE_USAGE_SAMPLED_BIT
For FrameRenderToTexture image.usage = VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT + VK_IMAGE_USAGE_TRANSFER_SRC_BIT

5

OK, that’s my fault for assuming that you knew that you would have to tell Vulkan that you intended to use it as a color attachment. And you need to make sure that it uses the appropriate layout for the operation. And you need a memory dependency between the writing operation and the reading operation. And probably two separate render passes, unless you’re willing to use it as an input attachment (which requires a subpass).

Yes, you cannot just slap the texture in there. You have to do what Vulkan tells you that you have to do to use an image as a render target as well as all of the things Vulkan tells you that you have to do to use an image as a sampled image.