Hi whats differences between BC5 format texture and DXT5 texture ?
"The 3Dc format 10] is specifically designed for tangent-space normal map compression and produces much better quality than DXT1 or DXT5 normal map compression. The 3Dc format stores only two channels and, as such, cannot be used for object-space normal maps. The format basically consists of two DXT5 alpha blocks for each 4x4 block of normals. In other words for each 4x4 block there are 8 samples for the X components and also 8 independent samples for the Y components. The Z components have to be derived in a fragment program.
The 3Dc format is also known as BC5 in DirectX 10 5]. The same format can be loaded in OpenGL as LATC or RGTC. Using the LATC format the luminance is replicated in all three RGB channels. This can be particularly convenient, because this way the same swizzle (and fragment program code) can be used for both LATC and _Y_X DXT5 (DXT5nm) compressed normal maps. In other words the same fragment program can be used on hardware that does, and does not support 3Dc. The following fragment program shows how the Z is derived from the X and Y components when the normal map is stored in RGTC format."
Source from nvidia :Using ASTC Texture Compression for Game Assets | NVIDIA Developer
So,İf i use BC5 format, it will decrease my framerate per second but looks better than others, or DXT5 for better performance,(i still cannot undestand )
It dont think it will have any impact on the framerate. Unreal uses dxt1/5 for color/grayscale and dxt5 for normalmaps.
Why do you ask? If you are having any issue I cant help more without more info.
There’s not much of a reason to change the default texture formats, they were already selected to best balance memory usage and quality.
Memory usage doesn’t really affect performance until you are out of memory, so there isn’t an immediate or direct impact on framerate when switching between BC5 and DXT5.