Question of performances
polycounter lvl 11
hello everyone,
I don't really know if it's an already-asked question or just a stupid question, but since I'm pretty new to UDK, I was wondering, performance-wise, if it was better to have a big texture or numerous little textures, i.e: a house with only one 2048x2048 texture or the same house with two 1024x1024.
Thanks in advance.
I don't really know if it's an already-asked question or just a stupid question, but since I'm pretty new to UDK, I was wondering, performance-wise, if it was better to have a big texture or numerous little textures, i.e: a house with only one 2048x2048 texture or the same house with two 1024x1024.
Thanks in advance.
Replies
On mobile for example, depending on the device, you can do about 60-120 draw calls per frame (in simple terms), so if you have a model with two textures, the two parts will need to be rendered separately. It may be much more efficient to have it as one texture, so the model can be rendered as one batch.
Yeah.. I really shouldn't comment at 5 in the morning anymore..
Nevertheless, if you don't change the texture resolution and use the 2k texture only to hold 2x1k textures, then you are actually using an atlas. The real size of a texture doesnt really matter that much, it is more important what region of the texture is sampled (which will be most likely cached on the GPU). Therefor the 2k version will most likely better perform then the 1k version due to avoiding texture switches...
But the engine could support texture atlasing, in this case it would automatically try to pack these images on a single larger atlas texture, or using texture arrays, bindless textures etc. to avoid texture switches, but it depends on the used engine (sry, I dont know how ue handles it internally).