Hello Alex! (And everyone)
The artist in me did not get out, but I used an existing scan from @miekeroth to experiment with glowing effects - some of which you might find helpful - in case I ever find time to participate in the challenge (needless to say I’ll also need to find a pumpkin ).
So here are my 2 cents:
Basically, I carved the original model by using blender’s boolean operator on meshes generated in python from images of Banksy work, and used some emissive materials inside the object (I had to create an interior surface) and on the cuts edges. This makes for a grand total of 3 different materials on this object.
I also added a strong point light in the middle of the pumpkin.
And the glowing effect is just the “bloom” post-processing filter pushed to the max, with a low threshold, and max radius and intensity.
Depending on your carving skills, I could suggest to try and add an orange-yellow-white (depending on the depth) colored emission map to the main material which, if tweaked correctly, could probably reflect the effect of a shallow surface carving allowing some light to pass through… You can see what I tried to do with the covers of marvel comics on this model.
Also, I guess that playing with translucency materials could also help you get that desired effect.
Finally, a trick I’ve been thinking to try and that might give you fun results would be to animate a sphere-shaped model with holes around a spot light casting moving shadows inside and outside the pumpkin (imagine this lamp rotating on its axis).
I think that if I enter this challenge, I’ll try to scan a pumpkin and the inside surface (by cutting the pumpkin in 2 or 3 pieces and merging the textures), and progammatically mimic the carving from images and python (everyone can’t be a real-life artist ): that would be kind of cheating, but could give fun results IMHO.
I’m eager to see what nice effects you (and others) manage to create! Have fun!