Animation performance becomes slower in scenes which are having big size textures


I am having 3d scenes, developed using Blender. And also, i am having a Human model who does walk animation in an another blender file. When i execute the scenes and human model, in web app or iPhone app thru program, I am facing an issue. Some scenes are having huge size textures (for ex: 4 mb grass ground) placed and some scenes are having just material color, not textures used. The human walk becomes slow performance in the scenes where i have added big size textures, and the same human walk is faster enough in the scenes where i have only material colors.
So, i would like to ask, why the walk animation performance becomes slower in the scenes where i have big size textures (for ex: 4 mb grass ground or home interior design textures) when i execute it in my apps?

Please advise!


If an animation needs to be processing 4 meg image every 24 frame per second, that is serous number crunching it needs to do. Iphone screen size is only 640 x 300 pixels. Loading big image is an over kill. It can’t even display all that data on the screen.