Sprite Pops - Image Sequence

[pepemaracas]

Hello everyone, I've seen multiple posts and some discussion on regards to sprites, but most of it is from 8 or 10 years ago, so I was wondering if anyone would have some insight on a workflow or an example on H.17 for adding a looping image sequences to sprites. You must be thinking, "sprites? people still use those?", but the style I'm aiming to achieve relies heavily on some 2D animation. I've used some techniques with traced 2D sequences instanced into particles but for the sprites I am a little lost, specially when it comes to rendering the sequences. 

I've created an attribute for it based on the life $HIP/Sprite_v001_`padzero(4,round(fit01($LIFE,1,20)))`.png but not sure where to use it afterwards (shops have changed a lot in recent years). Also tried adding something to the Sprite Map on the popsprite inside dop: $HIP/Sprite_v001_`padzero(4,$F%40+1)`.png but still no success.

Any help would be greatly appreciated. 

[pepemaracas]

No one has any insight on this? 

[StepbyStepVFX]

Can you post a light version of your file so that we can see what's wrong with what you tested and understand better what you want to achieve ?

In last resort, if you're lost with the POP Sprite, you can try to copy stamp or point instance grids on your particles after simulation, and simply put your sequence on the color map of your shader. You'll just need to be sure there is an orient attribute on your particles (use a POP look at node for example), so that it faces the camera.

Edited September 6, 2019 by StepbyStepVFX

[pepemaracas]

On 9/6/2019 at 12:26 PM, StepbyStepVFX said:

Can you post a light version of your file so that we can see what's wrong with what you tested and understand better what you want to achieve ?

In last resort, if you're lost with the POP Sprite, you can try to copy stamp or point instance grids on your particles after simulation, and simply put your sequence on the color map of your shader. You'll just need to be sure there is an orient attribute on your particles (use a POP look at node for example), so that it faces the camera.

Thanks for replying, for the time being I've done something similar to your last resort option, but since I couldn't drive the image sequence frame by the age of the particles I did it with traced geo based of of the initial image sequence, which is great for certain things. But this I feel is over kill for something as simple as sprites, so I really would like to find a way to do it with those. 

I've attached a simplified file of just some sprite fire attempt where I'm creating a string texture attribute to try and drive the material with. I appreciate the help. 

 

Sprite.zip

[StepbyStepVFX]

Hi, I modified a bit your file ad it seems to work.

I just created a string attribute spritemap with a popwrangle (using your fit01(age ...)), and in the spritefog material I used a bind node to feed the base texture map (see in the file).

Just save the file in a place where your sprites are in $HIP/Sprite_v001/***.png (you'll see an error when Mantra tries to load the texture if you did not save it there :-)

Hope this helps

 

SpriteTest.hip

Edited September 9, 2019 by StepbyStepVFX

[pepemaracas]

3 hours ago, StepbyStepVFX said:

Hi, I modified a bit your file ad it seems to work.

I just created a string attribute spritemap with a popwrangle (using your fit01(age ...)), and in the spritefog material I used a bind node to feed the base texture map (see in the file).

Just save the file in a place where your sprites are in $HIP/Sprite_v001/***.png (you'll see an error when Mantra tries to load the texture if you did not save it there :-)

Hope this helps

 

SpriteTest.hip

This does help, thanks!

Very interesting approach, so not really using the pop sprite. I guess for viewport visualization purposes I could link them all to the values on the material. I just thought the pop sprite would be a very straightforward simple node.

 

[GDonkey]

Hi pepemaracas,

Did you figure out a way to visualise this in the viewport ?

I am also trying to drive a 2D animation based effect like this, and only being able to see the result in Mantra is not the way forward. There are so many applications for this using Houdini with 2D based effects but months later and I can't seem to get past this one thing.

[anthonymcgrath]

On 20/08/2020 at 10:40 AM, GDonkey said:

Hi pepemaracas,

Did you figure out a way to visualise this in the viewport ?

I am also trying to drive a 2D animation based effect like this, and only being able to see the result in Mantra is not the way forward. There are so many applications for this using Houdini with 2D based effects but months later and I can't seem to get past this one thing.

+1 for this - i cant seem to render it in Mantra - i've got my own sprite sequence but is there REALLY no way to visualise this in the viewport?

[anthonymcgrath]

found this tutorial on Vimeo by Peter Quint - it literally animtes sprite sheets in houdini's viewport

if you cant see the link just look on vimeo for "mosaic sprites houdini 13" and go near the end to edit the vexpression