Which MipMap filtering method is used during the Encode function in the PVRTexTool

PowerVR Insider
1

I am using the PVRTexTool (v4.1.5 - 64-bit Windows) to encode a 1024x1024 textures for 3D models. I choose “Generate MIPMaps” but I don’t see anywhere to choose the MIPMap filter function. In the Toolbox “Create MIP Map Chain” dialog there is a choice for the filter function (nearest, linear, cubic). Does this setting only work when running this separately from the Toolbox or does it also apply to the “Encode the Current Texture” from the icon bar? On the Encode dialog is “PVRTC Encodiing Mode”, does this affect the MIP Map filtering function? I want to be sure bilinear" filtering is performed.



Thanks,

Chuck

2

Hi Chuck,



You’re right. The filtering function that is selectable from the toolbox only affects the mipmapping done there. However, the mipmapping performed from the encode dialog is always bilinear, which seems to be what you’re looking for.



Thanks,

Lawrence

3

Lawrence,

Sorry, made a mistake there, I want cubic mipmap filtering. Do I have to have to use the toolbox and if so, how does that over-ride the Encode functionality? Why can;t you set the mipmap filter function in the Encode dialog?



Thanks,

Chuck

4

Lawrence,

I want cubic mipmap filtering. Do I have to have to use the toolbox and if so, how does that over-ride the Encode functionality? Why can’t you set the mipmap filter function in the Encode dialog?



What are the steps for creating and saving a pvr encoded texture with cubic filtered mipmaps?



Thanks,

Chuck

5

Hi Chuck,



To generate a cubic mipmapped texture in the GUI, first you need to generate the mipmaps using the toolbox to select cubic filtering, then you need to encode the texture using your chosen format (e.g. PVRTC 2bpp RGB). When you do this last step, make sure you don’t tick “Generate MIPMaps” as this will re-generate the mipmap chain using bilinear filtering.



I agree that it would be useful to be able to select the mipmap filtering method in the Encode Texture dialog. I’ll submit this as feature request.



Thanks,

Lawrence