Это мой HTML-код, связанный с ng-моделью
<div class="col-xs-4">
<div class="height:100%;">
<input type="file" ng-model="addmaterials.vray_mat_file" name="material_vray_mat" id="material_vray_mat" class="hidden" required="" ng-model-options="{ allowInvalid: true }"/>
<label class="mat_file" for="material_vray_mat" >Upload Mat file</label>
</div>
</div>
<div class="col-xs-4">
<div class="height:100%;">
<input type="file" required="" ng-model="addmaterials.vray_sbsar_file" name="material_vray_sbsar" id="material_vray_sbsar" ng-disabled="!addmaterials.createdWithSubstance" class="hidden" >
<label class="mat_file" for="material_vray_sbsar" >Upload Sbsar</label>
</div>
</div>
<div class="col-xs-4">
<div class="height:100%;">
<input type="file" required="" onchange="angular.element(this).scope().setVrayPrevImg(this)" ng-model="addmaterials.vray_prev_img" name="material_vray_prev" id="material_vray_prev" class="hidden" >
<label class="mat_file" for="material_vray_prev" >Upload Preview</label>
</div>
</div>