Smoke - flat leading edge

[Drughi]

Hi!

sometimes when simulating fast moving smoke there emerges a flat surface on top of the leading edge of the smoke. I've tried to increase the upper padding of the gas resize dynamic, but it seems not to help. Can someone tell me how to avoid this effect?

 

 

[Andrea]

Hi! Can you post the hipfile? The volume looks low resolution but shouldn't be that visible the flat edge

[Feather]

Without seeing your hip file I can only take a guess. That plateau looks like you've multiplied up the density of what would have otherwise been a very thin or empty voxel.

If this is the case you're sending density values greater than 1 into your shader which is often going to make your shading experience a bad one. 

The image below from left to right is.

1. The original simulation, with a density of 1 and a shader render density of 1. This is the sim's natural look.

2. This has a post multiplication of 10 before and a shader render density of 1. This is what I believe you've done and why you see the plateau.

3. This is the same volume, with a density of 1 and a shader render density of 50. This is the correct way to make a thin simulation render more dense without lifting the empty voxels.

Either you need to lift the density emitted in your sim to begin with or make sure that you're working with the shader to change the look of the sim, not the actual density values

Edit: This sim has an upward velocity of about 20-30. The leading edge is curved but when rendered incorrectly will look flat because the curve is very subtle. Cranking the density values before it gets to the shader erases the variance responsible for the curve.  

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Edited October 23, 2019 by Feather

[Drughi]

thanks for your replies. I guess its just a viewport / too lowres problem.