Sprite issues

[kdrnic]

The current THREE.Sprite implementation has a number of issues.

• Sprites can't have their texture translated, that is you can't change UVs, so you can't use them for explosions or other effects
• You can't translate the image of a sprite, that is, the center of the texture is aligned with the origin of the object and you can't move it horizontally or vertically
• Sprites can't be rotated independently, as rotation is set in their material. If you want to rotate sprites independently you must assign each one a different material, even if they share the same texture. I see no reason the rotation attribute couldn't and shouldn't be stored on the Sprite structure instead of the SpriteMaterial structure.
• The BufferGeometry in the sprite is make-believe and actually ignored, which is not only inefficient as it is also confusing as it implies you can rotate, translate and animate the sprite by changing it, but you can't

The last one is actually quite interesting.
See https://github.com/mrdoob/three.js/blob/master/src/objects/Sprite.js#L12
and https://github.com/mrdoob/three.js/blob/master/src/renderers/webgl/plugins/SpritePlugin.js#L24
I even tested this by commenting out the BufferGeometry creation in THREE.Sprite, and sprites continued working.

Meanwhile I imagine the workaround is to use a Mesh with a PlaneGeometry and a .lookAt(camera.position) in every loop in place of Sprites if one needs the features mentioned above.

Fixing this issue I imagine is not terribly difficult.

Here is my suggested plan:

• Move rotation from SpriteMaterial to Sprite (and take rotation from Sprite instead of SpriteMaterial in SpritePlugin)
• Either add an UV array and a translation array to Sprite, and use that in SpritePlugin, or actually use the BufferGeometry already in Sprite
• Depending on the above, remove the BufferGeometry from Sprite

[kdrnic]

Also, I am aware that the issue title is bad, please change it to something more adequate, I could not think of a sufficiently descriptive name myself

[karimbeyrouti]

Couple more to add:

• Ray casting on a sprite does not return a UV co-ordinate.
• and feature request for grouping sprites: Feature Request - Grouping sprites to share the same transform point #7941

[WestLangley]

Sprites can't have their texture translated

What about the sprite sheet example in http://threejs.org/examples/misc_ubiquity_test2.html?

In any event, there is room for improvement.

In fact, in the above example, type webglRenderer.info into the console to see that in the sprite sheet example, there are many textures pushed to the GPU.

[karimbeyrouti]

I was looking at your lovely prototype with translate, scale, rotation and centre properties for Materials ( on this feature: #5876 ) when I was implementing sprite sheets.

However nice that material update would be, repeat and offset to worked nicely with translation / scaling of texture.

[kdrnic]

One has to have a different THREE.Texture for each sprite as long as one wants them to be individually animated. Though, as I understand that example uses .clone() to make the texture copies, which is not a deep copy thus resulting in no texture repetition in the video RAM, so it is not an issue.

Is webglRenderer.info counting each THREE.Texture existent, or somehow accounts for the clones?

I agree that .repeat and .offset should be moved to THREE.Material.

Also I was not aware that .repeat was for scaling, the name is a little inadequate IMHO.

[karimbeyrouti]

Could be wrong - but I think you can hack it not to re-upload the cloned to the GPU texture by setting the cloned uuid to the same as the source texture, i.e.:

clonedTexture.uuid = sourceTexture.uuid;

[WestLangley]

Confirmed. In the sprite sheet example, using the hack

var tex = texture1.clone();
tex.uuid = texture1.uuid;

prevents the texture from being uploaded to the GPU repeatedly.

[kdrnic]

If so, couldn't/shouldn't THREE.Texture.clone be patched to include setting the uuid perhaps? Or is there something I am missing

[karimbeyrouti]

Note the GPU texture hack:

var tex = texture1.clone();
tex.uuid = texture1.uuid;

caused a huge performance drop in my render time ( sub 1ms to 35 ms + ).

[kdrnic]

Are you sure this uuid hack affects texture being uploaded to the GPU instead of just affecting webglRenderer.info counting of textures?

[karimbeyrouti]

I am going with whatever WestLangley says on this one :-) - however the huge performance drops are caused by Image Decode events in chrome: http://imgur.com/dcUliZc

These go away when I disable 'tex.uuid = texture1.uuid;'

[bhouston]

I have just submitted a PR that allows for per-map/per-material UV offset/repeat that should address this issue: #8278

[augusttty]

I have a solution to make spriteMaterial objects to rotate with scene.
mesh.material.rotation = - controller.constraint.getAzimuthalAngle()
add this dynamicly when scene updates,or controller rotates.
: )